Blog

Heart Anatomy

Heart and Aorta, pulmonary Trunk

Heart Anatomy 2

Chambers of Heart,valves

Femur-Osteology-Anatomy

Bones of Lower limb- Femur anatomy-pkk

1. Front of Thigh -Muscles

Thigh- Muscles, Quadriceps, Sartorius-pkk

Lower Limb Muscles of Anterior Comp.

Front of Thigh and Leg Muscles -pkk

3. Femoral Triangle- Boundaries and Contents

Inguinal Triangle - Boundary Contents Relations-pkk

Quadriceps - Front of Thigh-LL

Three Vastii, Rectus Femoris- Quadriceps Femoris- Thigh Muscles-pkk

Hunters Canal

Structures of Adductor Canal-pkk

Adductor Canal

Hunters Canal- Boundaries and Contents-pkk

Contents of Adductor Canal

Structures in Adductor Canal-pkk

Contents of Femoral Triangle

Structures in Femoral Triangle-pkk

Relations in adductor Canal

Relations of Artery ,Vein and Nerve in Adductor Canal-pkk

Adductor Canal and Hiatus

Relations of Adductor Canal and Hiatus -pkk

Hunters Canal Complete

Details of Hunters Canal- Boundary ,Contents, Relations-pkk

Femoral Triangle- Boundaries

Sartorius and Adductor Longus- Boundary of Femoral Triangle-pkk

Hunters Canal Location

Location of Adductor Canal-pkk

Profunda Brachii Artery

Course and Branches of Profunda Brachii artery -pkk

Femoral Nerve

Formation and branches of Femoral nerve-pkk

Femoral Nerve Branches

Branches of Femoral nerve in Thigh and Leg-pkk

Lumbar Plexus

Formation and Branches of Lumbar Plexus-pkk

Front of Thigh and Leg Muscles

Muscles of Thigh and Leg -Anterior compartment-pkk

Femoral Triangle Dissected

Structures after dissection of Femoral Triangle-pkk

Relations of Femoral Triangle

Boundaries and Contents of Femoral Triangle-pkk

Typical Intercostal Space

Structure of Typical Intercostal Space-pkk

Typical Spinal Nerve

Formation of Typical Spinal Nerve-pkk

Intercostal Space Contents

Structures in Typical Intercostal Space-pkk

Branches of Typical Spinal Nerve

Typical Intercostal Nerve Branches and Distribution-pkk

Intercostal Muscles

External ,Internal Intercostal and Innermost-pkk

Rib Cage- Intercostal Space

Formation of Thoracic Cage-pkk

Structures in ICS

ICS Contents-pkk

Intercostal Space Typical- ICN, ICA

Nerve and Arteries in ICS-pkk

Distribution of IC Nerve

Course and Distribution of ICN-pkk

Posterior ICV Drainage

Drainage Pattern of Posterior ICV-pkk

PICV

Posterior ICV Drains-pkk

PICV ,Azygos Veins

Azygos, Hemiazygos, PICV Drains-pkk

Azygos, Hemiazygos, PICV

Azygos System of Veins-pkk

PICV Drainage and Azygos Veins

Arrangements Drainage of PICV and Azygos Veins-pkk

Pleura

Parietal And Visceral Pleura-pkk

Lungs and Pleura

Thorax- Lungs and Pleura-pkk

Parts of Pleura

Parietal Pleura Parts-pkk

Thoracic Cavity

Structures of Thoracic cavity-Pkk

Pleural Recesses

Costodiaphragmatic and Costomediastinal Recesses of Pleura -Pkk

Pleural Cavity and Lungs

Structures in Pleural Cavity-Pkk

Pleura and Lungs

Lungs enclosed in Pleura-pkk

Thoracocentesis And Paracentesis

Procedure and Location-pkk

Parietal Pleura Parts

Four Parts of Parietal Pleura-Pkk

Thoacocentesis Procedure

Position and Process of Aspiration Thorax-Pkk

Pleural Cavity

Contents of Pleural Cavity-Pkk

The Lungs

Lungs Structure with Trachea -Pkk

Lungs Surfaces , Fissures and Lobes

Lungs Surfaces , Fissures and Lobes-Pkk

Lungs and Pleura

Parts of Pleura and Lungs-PKK

Lungs Surfaces Borders , Fissures and Lobes

Ext. Features - Lungs Surfaces ,Borders Fissures and Lobes- PKK

Lungs- Mediastinal Surface

Relations of Mediastinal Surface of Lungs - PKK

Hilum of Lungs

Structures Present at Hilum of Lungs-PKK

Lungs Lobes and BPS

Lobes of Lungs and Bronchopulmonary Segments-PKK

Lungs-BPS

10-10 Segments (Bronchopulmonary )of Right and Left Lungs-PKK

BPS-Lungs

3 Lobes-10 segments in Right Lung, 2Lobes 10 Segments on Left Lung-PKK

BPS-Lungs

BP Segments of Lungs-PKK

Pectoralis Major Muscle

Anatomy Of Pectoralis Major Muscle- Attachments-PKK

Cutaneus Innervation of Pectoral Region

Anterior and Lateral Cutaneous Nerves Supplying Pectoral Region-PKK

Nerves of Pectoral Region- Cutaneous

Anterior and Lateral Cutaneous Nerves Supplying Pectoral Region-PKK T2 of Lateral- Intercostobrachial Nerve

Clavipectoral Facia

Pectoralis Minor and Subclavius Enclosed in Clavipectoral Fascia-PKK

Pectoral Region -Cutaneous Nerves

Anterior (T2 -T6), and Lateral (T3 -T6) Cutaneous Nerves -PKK

Nerve of Skin- Pectoral Region

Anterior and Lateral Cutaneous Nerves-PKK

Pectoralis Major- Attachments

Origin (proximal attachment) Sternocostal head • Has manubrial, sternal, and aponeurotic fibers • Manubrial fibers – from lateral half of anterior surface of manubrium • Sternal fibers –from lateral half of anterior surface of sternum up to 6th costal cartilage • Costal fibers – from 2nd to 6th costal cartilages. • Aponeurotic fibers – from aponeurosis of external oblique muscle of abdomen

Pectoralis Major and Minor

Insertion (distal attachment) • Form U-shaped bilaminar tendon that inserts on the lateral lip of bicipital groove • Bilaminar tendon has two laminae as follows: – Anterior lamina – shorter than posterior lamina, formed by clavicular fibers of the muscle – Posterior lamina –formed by sternocostal fibers

Muscles of Pectoral Region- Pectoralis major

Actions 1. As a whole muscle: Adduction and medial rotation of arm Draws the scapula forward along with serratus anterior 2. Clavicular head: Flexion of arm. 3. Sternocostal head: Extension of flexed arm against resistance.

Clavipectoral Fascia

Structures piercing 1. Lateral pectoral nerve 2. Cephalic vein 3. Thoracoacromial trunk 4. Lymphatic vessels from breast to apical axillary group of lymph nodes

Quadrants of Abdomen

9 Quadrants of Abdomen

Landmarks of Abdomen

Pubic tubercle: Small bony projection can be felt at medial end of fold of groin Pubic crest: Short bony ridge between pubic tubercle and pubic symphysis Pubic symphysis: Lies in median plane at level of tip of coccyx

Arterial Supply of Abdominal Wall

Anterior cutaneous branches of superior and inferior epigastric arteries Lateral cutaneous branches of posterior intercostal arteries Three superficial branches of femoral artery Superficial external pudendal artery Superficial epigastric artery Superficial circumflex iliac artery Deep circumflex iliac artery (branch of external iliac artery)

Nerves of Abdominal Wall

Supplied by lower six thoracic nerves and first lumbar nerves-PKK

Superficial Fascia Of Abdomen

Fascia of Camper (superficial fatty layer) This layer – continuous with subcutaneous fat of adjoining areas In penis – devoid of fat; in scrotum, replaced by involuntary dartos muscle-PKK

Bony Cavity of Abdomen

Bounded as follows Superiorly by xiphoid process and right and left costal margins Inferiorly by iliac crest, fold of groin, pubic tubercle,pubic crest, and pubic symphysis On each side, extends up to midaxillary line and continues with posterior abdominal wall-PKK

Holdens Line- Abdomen

Holden’s line: Extends 8 cm laterally from pubic tubercle in horizontal plane-PKK

Extravasated Urine Flow- Abdomen

Due to attachment of fascia of Scarpa, extravasated urine in ruptured urethra gets accumulated in superficial perineal pouch in thigh up to Holden’s line and in anterior abdominal wall inferior to umbilicus

Cutaneous Nerves-Abdomen

Supplied by lower six thoracic nerves and first lumbar nerves

Superficial Veins- Abdomen

Above umbilicus: These veins run toward axilla and drain into axillary vein and finally to superior vena cava Below umbilicus: Cutaneous veins run toward groin and drain into great saphenous vein and finally to inferior vena cava Small veins (paraumbilical veins) from umbilicus run along ligamentum teres drain into portal vein

Superficial Lymphatics -Abdomen

axillary and superficial inguinal nodes and follow water-shed line at level of umbilicus as follows -- 1. Above umbilicus, lymphatic vessels run upward to drain into the axillary lymph nodes 2. Below umbilicus, lymphatic vessels run downward to drain into superficial inguinal nodes

Dermatomes- Abdomen

Lower six thoracic nerves (T7–T12) Two lateral intercostal nerves are derived from lower two intercostal nerves (T10, T11) pierce external intercostal muscle Divided into anterior and posterior divisions to supply skin on side of abdomen

External Oblique Muscle -Abdomen

Origin-- Originates by eight fleshy slips from outer surfaces of middle of shafts of lower eight ribs Direction of fibers-- Run downward, forward, and medially (similar to direction of fingers when one keeps hand in Trousers’ pocket)

External and Internal Oblique Muscle

External Oblique-- Insertion Posterior most fibers insert on outer lip of anterior 2/3rd of iliac crest Posterior border of muscle extends from 12th rib to iliac crest Forms anterior boundary of lumbar triangle of petit

Internal Oblique Muscle

Origin-- 1. Lateral 2/3rds of upper surface of inguinal ligament 2. Intermediate area of anterior 2/3rd of iliac crest 3. Thoracolumbar fascia

Transversus Abdominis

Origin-- Lateral 1/3rd of upper surface of inguinal ligament Inner lip of anterior 2/3rd of iliac crest Thoracolumbar fascia Inner surfaces of lower six ribs and their costal cartilages

Rectus and Transversus Abdominis muscle

Rectus Abdominis-- Long, flat strap muscle supports anterior abdominal wall (rectus = straight in Latin) Origin Originates by two tendons or heads Medial head originates from anterior surface of pubic symphysis and anterior pubic ligament Lateral head originates from lateral part of pubic crest Insertion Inserts on horizontal line passing laterally from xiphoid process Intersecting 5th, 6th, and 7th costal cartilages Innervation Ventral primary rami of lower six or seven nerves (T7–T12) Actions Maintains anterior abdominal wall tone during standing Flexion of trunk on pelvis Protects abdominal viscera

Pyramidalis Muscle

Origin-- Front pubic crest and anterior pubic ligament Direction of fibers--Run upward and medially Insertion--Inserts into linea alba, midway between umbilicus and pubic symphysis Innervation--Subcostal nerve (T12) Action--Tenses linea alba

Cremaster Muscle

Origin-- Superficial fibers – originate from middle 1/3rd of upper surface of inguinal ligament Deep fibers – originate from pubic crest and conjoint tendon Insertion Superficial fibers extend along spermatic cord and reach scrotum Superficial and deep fibers – connected with each other around spermatic cord and upper part of scrotum In females, few fibers of cremaster muscle accompany round ligament of uterus, Innervation---Genital branch of genitofemoral nerve (L1–L2) Mostly these fibers carry sympathetic innervation Cremaster muscle – not under voluntary control, Actions--- Pulls testis upward toward superficial inguinal ring helps in closing superficial inguinal ring and controlling temperature of testis

Iliohypogastric and Ilioinguinal Nerve

Iliohypogastric Nerve--Branch of 1st lumbar nerve Close to iliac crest, nerve divides into Lateral branch – pierces external and internal oblique muscle, passes posteriorly to supply skin of gluteal region Anterior branch – pierces internal oblique at 2.5 cm medial to anterior superior iliac spine Pierces external oblique about 3 cm above superficial inguinal ring

Fascia Transversalis

Thin layer of areolar membrane lines deeper surface of transverse abdominis muscle Extent-- Superiorly, continuous with ill-defined subdiaphragmatic fascia Inferiorly -- continuous with fascia iliaca (fascia covering iliacus muscle) Extent Attached to iliac crest, inguinal ligament, pecten pubis, and pubic crest Continuous with pelvic fascia

Iliopubic Ligament

Also Called Thompson Ligament-PKK

Abdomen Superficial Structures

Landmarks of Abdomen-PKK

8 Layers of Anterior Abdominal Wall

Consists of eight layers from superficial to deep as follows Skin Superficial fascia External oblique muscle and aponeurosis Internal oblique muscle and aponeurosis Transverse abdominis muscle and aponeurosis Fascia transversalis Extra peritoneal connective tissue Parietal layer of peritoneum

Muscles of Anterior Abdominal Wall

External oblique Internal oblique Transverse abdominis Rectus abdominis Pyramidalis External oblique, internal oblique, and transverse abdominis – large, broad, flat muscles

Scalp Layers

Made up of five layers -- Skin Superficial fascia (subcutaneous connective tissue) Deep fascia (epicranial aponeurosis) Loose areolar tissue Pericranium

Scalp

1st 3 Layers-- Surgical Layer of Scalp-PKK

Arteries of Scalp

Arterial supply Supplied by following five arteries on each side In front of auricle-- Supratrochlear artery Supraorbital artery Superficial temporal artery,, Behind auricle-- Posterior auricular artery Occipital artery

Layers of Scalp

4th Layer- Dangerous Area of Scalp-PKK

Extent of Scalp

Extends -- Anteriorly: Up to supraorbital margins,,, Posteriorly: Up to external occipital protuberance and superior nuchal line,,, On each side: Up to zygomatic arch and external acoustic meatus

Nerves of Scalp and Face

In Front of Auricle -- 1. Supratrochlear – branch of frontal nerve (ophthalmic division of trigeminal nerve) 2. Supraorbital – branch of frontal nerve 3. Zygomatic temporal nerve – branch of zygomatic nerve (maxillary division of trigeminal nerve) 4. Auriculotemporal nerve – branch of mandibular division of trigeminal nerve 5. Temporal branch of facial nerve Behind Auricle--- 1. Posterior division of great auricular nerve (C2, 3) – From the cervical plexus 2. Lesser occipital nerve (C2) – From ventral ramus of 2nd cervical nerve 3. Greater occipital nerve (C2) – From dorsal ramus of C3 nerve 4. Third occipital nerve (C3) – From dorsal ramus of C3 nerve 5. Posterior auricular branch of facial nerve

Nerves and Arteries of Scalp

10 Arteries and 20 Nerves Supply Scalp-PKK

Nerves and Arteries of Scalp

Supplied by following five arteries on each side -- 1. In front of auricle--- Supratrochlear artery Supraorbital artery Superficial temporal artery,, 2. Behind auricle-- Posterior auricular artery Occipital artery

Parts of Human Body

Various Body Parts of Human Body -PKK

Organ System of Body

Different Systems of Body -PKK

Regions of Human Body

Different Regions of Body -PKK

Different Regions and Body Parts

Various Regions and Parts of Body Anatomy- PKK

Body Systems Details

Systems of Body Physiological -Pkk

Male Reproductive System

Organs of Male Reproductive system-PKK

Female Reproductive System

Organs of Female Reproductive System-PKK

Male and Female Urogenital System

Both Urinary and genital Organs of Male and Female-PKK

Reproductive Organs -Lateral View

Male and Female Reproductive organs in Lateral View-PKK

Herophilus -Father of Anatomy

335–280 BC - Father of Anatomy

Andreas Vesalius

Father of Modern Anatomy, founder of modern human anatomy , Andries van Wezel (31 December 1514 – 15 October 1564), wrote De Humani Corporis Fabrica Libri Septem -PKK

Vesalius

Father of Modern Anatomy, founder of modern human anatomy , Andries van Wezel (31 December 1514 – 15 October 1564), wrote De Humani Corporis Fabrica Libri Septem - He was born in Brussels, which was then part of the Habsburg Netherlands. He was a professor at the University of Padua (1537–1542) and later became Imperial physician at the court of Emperor Charles V.--PKK

Hippocrates

Hippocrates of Kos- (460 – c. 370 BC), Greek physician and philosopher, "Father of Medicine" -PKK

Claudius Galen

Aelius Galenus or Claudius Galenus, September 129 – c. 216 AD, Roman and Greek physician, surgeon, and philosopher, -PKK

Claudius Galen

Galen (born 129 ce, Pergamum, Mysia, Anatolia [now Bergama, Turkey]—died c. 216) was a Greek physician, writer, and philosopher who exercised a dominant influence on medical theory.He distinguished seven pairs of cranial nerves, described the valves of the heart, and observed the structural differences between arteries and veins. One of his most important demonstrations was that the arteries carry blood, not air, as had been taught for 400 years. Notable also were his vivisection experiments.-PKK

Anton von Leeuwenhoek

24 October 1632 – 26 August 1723) was a Dutch microbiologist and microscopist . commonly known as "the Father of Microbiology",.He was the first to relatively determine their size. Most of the "animalcules" are now referred to as unicellular organisms, although he observed multicellular organisms in pond water. He was also the first to document microscopic observations of muscle fibers, bacteria, spermatozoa, red blood cells, and crystals in gouty tophi, and was among the first to see blood flow in capillaries.-PKK

Leeuwenhoek Anton Von

Father of Microbiology.-PKK

John Hunter

(13 February 1728 – 16 October 1793) was a Scottish surgeon.The experiment, reported in Hunter's A Treatise on the Venereal Diseases (part 6 section 2, 1786).Hunter helped to improve understanding of human teeth, bone growth and remodelling, inflammation, gunshot wounds, venereal diseases, digestion, the functioning of the lacteals, child development, the separateness of maternal and foetal blood supplies, and the role of the lymphatic system. He carried out the first recorded artificial insemination in 1790 on a linen draper's wife. The adductor canal in the thigh is also known by its eponym "Hunter's canal" after John Hunter.[

Roentgen

(27 March 1845 – 10 February 1923). Roentgen, was a German experimental physicist[4] who produced and detected electromagnetic radiation in a wavelength range known as X-rays. For this discovery, he became the first recipient of the Nobel Prize in Physics in 1901.-PKK

Leonardo d Vinchi

(15 April 1452 – 2 May 1519) was an Italian polymath of the High Renaissance who was active as a painter, draughtsman, engineer, scientist, theorist, sculptor, and architect. master of topographic anatomy, drawing many studies of muscles, tendons and other visible anatomical features. He drew the heart and vascular system, the sex organs and other internal organs, making one of the first scientific drawings of a fetus in utero.-PKK

1. Anatomical Position

The standard anatomical position is a universally accepted body posture where a person stands erect, facing forward, with feet parallel, arms at the sides, and palms facing forward.-PKK

Anatomical and Fundamental Position

The standard anatomical position is a universally accepted body posture where a person stands erect, facing forward, with feet parallel, arms at the sides, and palms facing forward. In Fundamental Position Palm is Facing Medially.

3. Anatomical Position

Everything in Anatomy is Described in Anatomical Position.-PKK

Terminology of Body

Names of Various body parts and regions.-PKK

4. Positions of Body

Anatomical and Fundamental-PKK

Body Planes

The sagittal plane (dividing into right and left halves), the coronal (or frontal) plane (dividing into front and back portions), and the transverse (or horizontal/axial) plane (dividing into upper and lower halves).-PKK

Planes of Body

The median (or midsagittal) plane is a sagittal plane that passes through the exact middle of the body. Coronal Plane (Frontal Plane) . Transverse Plane (Axial/Horizontal Plane)

The Skeleton

206 Bones of Human Body-PKK

Planes of Body

in 3D view-PKK

Basic Terminology

Superior-Inferior, Anterior-Posterior, Medial Lateral -PKK

Anatomical Planes

3 Basic Planes of Body-PKK

Regions of Human Body

Various Regions of Body -PKK

Types of Movements

flexion - extension abduction - adduction circumduction (no opposite) elevation - depression internal/medial rotation - external/lateral rotation dorsiflexion - plantar flexion pronation - supination inversion - eversion protrusion/protraction - retrusion/retraction opposition - reposition

Body Movements

flexion - extension abduction - adduction circumduction (no opposite) elevation - depression internal/medial rotation - external/lateral rotation dorsiflexion - plantar flexion pronation - supination

Flexion-Extension

Flexion and Extension at Elbow joint-PKK

Inversion- Eversion

Foot inversion, turning the sole inward, is primarily caused by the Tibialis anterior and Tibialis posterior muscles, while foot eversion, turning the sole outward, is caused by the Peroneus longus, Peroneus brevis, and Peroneus tertius muscles.-PKK

Pronation- Supination

Pronation is primarily performed by the pronator teres and pronator quadratus muscles, while supination is mainly driven by the biceps brachii and supinator muscles. The brachioradialis muscle can also assist in both pronation and supination. These movements, which turn the palm downwards and upwards, respectively, occur at the radioulnar joints of the forearm.

Finger Movements

flexion (curling the finger towards the palm), extension (straightening the finger away from the palm), abduction (spreading fingers apart), and adduction (moving fingers together)-PKK

Shoulder Movements

It include flexion (forward motion), extension (backward motion), abduction (moving away from the body), adduction (moving toward the body), internal rotation (rotating toward the midline), external rotation (rotating away from the midline), and circumduction (a combination of movements to form a circular motion)-PKK

Thigh Movements

Adduction and Abduction of Thigh-PKK

Thigh Abduction

The main abductor muscles of the thigh--Rresponsible for moving the leg away from the body's midline, are the gluteus medius, gluteus minimus, and tensor fasciae latae. Other muscles that contribute to hip abduction, though secondary, include the piriformis, sartorius, and the superior fibers of the gluteus maximus. -PKK

Thumb Movements

All movements are 90 degree to the Rest 4 fingers-PKK

Abduction of Thigh

Mainly by Gluteus Maximus muscle-PKK

Bones of the Body

Regional Classification of bones-PKK

The Skeleton

206 Bones of Body-PKK

Types of Bones

Structural Classification of Bone-PKK

Bones-Types

According to Structure-PKK

Structure of Long Bone

External and Internal Structure of a Long Bone-PKK

Long Bone Structure

Young Long Bone-PKK

Parts of Young Long Bone

A young long bone includes the diaphysis (shaft), epiphysis (ends), metaphysis (flared zone), and the epiphyseal plate (growth plate) located in the metaphysis, which is a layer of cartilage enabling the bone to grow longer before it eventually fuses to the diaphysis after puberty.-PKK

Sites of Red Bone Marrow

Used for Bone Marrow Aspiration-PKK

Axial Skeleton

80 Bones of Axial Skeleton-PKK

Periosteum -Bone

The periosteum is a thin membrane of blood vessels and nerves that covers the outer surface of most bones, providing nourishment, sensation, and playing a crucial role in bone growth, repair, and regeneration. It is composed of an outer fibrous layer and an inner cambium (or osteogenic) layer containing progenitor cells that differentiate into osteoblasts, essential for increasing bone width and healing fractures.

Compact Bone -T.S.

-Compact bone, or cortical bone, is the dense, hard, and smooth outer layer of bones, forming their external surface and providing structural support, protection, and resistance to mechanical stress. Its key structural unit is the osteon, a cylindrical structure containing concentric layers called lamellae, which surround a central Haversian canal that contains blood vessels and nerves. Compact bone accounts for about 80% of the total weight of the skeletal system.

Compact and Spongy bone-T.S.

Spongy bone, also known as cancellous bone or trabecular bone, is a porous, lattice-like bone tissue found in the ends of long bones and in the vertebrae, skull, and ribs. Its honeycomb structure, made of thin bony plates called trabeculae, helps to reduce bone weight, absorb stress, and provide space for red bone marrow, which produces blood cells.

Osteon- Compact Bone

In Shaft of Long Bones-PKK

T.S. of Compact Bone

An osteon, also known as a Haversian system, is the fundamental structural and functional unit of compact bone. It is a roughly cylindrical arrangement of concentric bone layers (lamellae) surrounding a central Haversian canal, which contains blood vessels, nerves, and lymph vessels. Osteons are responsible for the strength and rigidity of compact bone and are crucial for bone metabolism and repair.

T.S. of Compact Bone

An osteon, also known as a Haversian system, is the fundamental structural and functional unit of compact bone. It is a roughly cylindrical arrangement of concentric bone layers (lamellae) surrounding a central Haversian canal, which contains blood vessels, nerves, and lymph vessels. Osteons are responsible for the strength and rigidity of compact bone and are crucial for bone metabolism and repair.

Long Bone- Arteries

Nutrient artery, Periosteal arteries, and Epiphyseal/metaphyseal arteries- PKK

Periosteum -Remodelling

Active, lifelong process by which the periosteum, the outer membrane of bone, contributes to bone reshaping, repair, and growth by supplying osteoblasts and promoting the formation of new bone tissue.-PKK

The Skeleton

206 Bones of Body-PKK

Bone Marrow -Types

Red and Yellow Bone Marrow-PKK

Spongy Bone

Found in -- The enlarged ends (epiphyses) of long bones. The middle of other bones, such as the vertebrae, pelvis, ribs, and skull. -PKK

Joints Classification 1

Classification of Joints-PKK

Classification of Joints-2

Classification of Joints- Structural - PKK

Structural Classification of Joints-3

Structural Classification of Joints- Fibrous, Cartilagenous and Synovial Joints-PKK

Types of Joints

Structural Classification of Joints- Fibrous, Cartilagenous and Synovial Joints-PKK

Joint Types

Immovable, Slightly Movable and freely Movable Joints- Structural Classification of Joints- Fibrous, Cartilagenous and Synovial Joints-PKK

Types of Joints - Structure

Structural Classification of Joints- Fibrous, Cartilagenous and Synovial Joints-PKK

Fibrous Joint

Sutures, Syndesmosis , Gomphosis- Fibrous Joint. Fibrous joints connect bones with dense collagenous connective tissue, lacking a joint cavity, and are typically immovable or allow very limited motion.-PKK

Fibrous Joint- Types

Sutures: Found exclusively in the skull, between the flat, interlocking bones. Syndesmoses: Found in the forearm (between the radius and ulna) and the lower leg (between the tibia and fibula) Gomphoses: These are the joints that unite the roots of the teeth with the sockets in the jawbones (maxilla and mandible)

Sutures- Fibrous Joint

Serrate (saw-like), Denticulate (finger-like interlock), Squamous (overlapping), Limbous (beveled), Plane (flat), and Wedge and groove (or Schindylesis).Sutures: Found exclusively in the skull, between the flat, interlocking bones.

Types of Sutures

Sutures: Found exclusively in the skull, between the flat, interlocking bones.Serrate (saw-like), Denticulate (finger-like interlock), Squamous (overlapping), Limbous (beveled), Plane (flat), and Wedge and groove (or Schindylesis).

Fibrous Joint - Types

Fibrous joints connect bones with dense collagenous connective tissue, lacking a joint cavity, and are typically immovable or allow very limited motion.

Different Types of Sutures

Sutures: Found exclusively in the skull, between the flat, interlocking bones.Serrate (saw-like), Denticulate (finger-like interlock), Squamous (overlapping), Limbous (beveled), Plane (flat), and Wedge and groove (or Schindylesis)

Fibrous Joints -Types

Sutures, Syndesmosis , Gomphosis-PKK

Syndesmosis

It is a type of slightly movable fibrous joint where two bones are held together by a strong interosseous membrane or a bundle of ligaments, such as the distal tibiofibular syndesmosis in the ankle, which connects the tibia and fibula.

Fibrous joint

Syndesmosis- type of slightly movable fibrous joint where two bones are held together by a strong interosseous membrane or a bundle of ligaments, such as the distal tibiofibular syndesmosis in the ankle, which connects the tibia and fibula.-PKK

Fibrous and Cartilagenous Joint

Sutures and Symphysis-PKK

Primary and Secondary Cartilaginous Joints

A joint where bones are connected by either hyaline cartilage (synchondrosis) or fibrocartilage (symphysis), allowing for slight movement and providing stability to the body.-PKK

Cartilaginous Joint

Intervertebral discs between vertebrae and the pubic symphysis connecting the pelvic bones, as well as temporary synchondroses like the epiphyseal (growth) plate in children's long bones. -PKK

Cartilaginous Joint 2

Egs. Intervertebral discs between vertebrae and the pubic symphysis connecting the pelvic bones, as well as temporary synchondroses like the epiphyseal (growth) plate in children's long bones.

Secondary Cartilaginous Joint

Symphysis, is a permanent, slightly movable (amphiarthrotic) joint where two bones are united by a pad of fibrocartilage. These joints are found in the midline of the skeleton, such as the intervertebral discs between vertebrae and the pubic symphysis. -PKK

Secondary Cartilaginous Joint 2

They allow for limited movement, which can vary in extent depending on the amount and compressibility of the fibrocartilage.- PKK

Types of Synovial Joints

Plane, hinge, pivot, condyloid, saddle, and ball-and-socket joints. These joints, which are the most movable in the body, are classified by the shape of their articulating surfaces and the specific movements they allow. Examples include plane joints (wrist bones), hinge joints (elbow), pivot joints (neck), condyloid joints (wrist and knuckles), saddle joints (thumb), and ball-and-socket joints (shoulder and hip).

Synovial Joint- Types

Diarthrosis- Plane, hinge, pivot, condyloid, saddle, and ball-and-socket joints. These joints, which are the most movable in the body,

Synovial Joint- Types

Ball-and-Socket (e.g., shoulder, hip), Hinge (e.g., elbow, knee), Pivot (e.g., atlantoaxial joint), Gliding (or Plane) (e.g., intercarpal joints), Saddle (e.g., thumb base), and Condyloid (or Ellipsoid) (e.g., radiocarpal joint of the wrist)

Synovial Joints -Location

Ball-and-Socket (e.g., shoulder, hip), Hinge (e.g., elbow, knee), Pivot (e.g., atlantoaxial joint), Gliding (or Plane) (e.g., intercarpal joints), Saddle (e.g., thumb base), and Condyloid (or Ellipsoid) (e.g., radiocarpal joint of the wrist)

Synovial Joint- Types and Location

Movement: Permeates movement in two planes (biaxial), including flexion, extension, abduction, and adduction,Rotation and Circumduction--PKK

Formation of Synovial joint

hinge, pivot, ball-and-socket, plane (or gliding), condyloid, saddle joints and Ellipsoid-PKK

Types of Synovial Joint

Hinge, pivot, ball-and-socket, plane (or gliding), condyloid, Ellipsoid and saddle joints-PKK

Structure of Synovial Joint

Articular cartilage covering bone ends, a joint capsule made of a fibrous outer layer and inner synovial membrane, a synovial cavity filled with lubricating synovial fluid, and reinforcing ligaments.-PKK

Synovial Membrane

The synovial membrane has two main layers: a superficial intima composed of synoviocytes and a deeper, vascular subsynovial layer (subintima) of loose connective tissue

Synovial Membrane and Capsule

The intima contains two types of cells—macrophage-like (Type A) cells that remove debris, and fibroblast-like (Type B) cells that produce synovial fluid components like hyaluronic acid. The subsynovium provides nutrients and support, containing fat cells, blood vessels, nerve fibers, and fibroblast-PKK

Capsule of Synovial Joint

Two-layered enclosure that surrounds a synovial joint, consisting of an outer fibrous layer that provides structural support and an inner synovial membrane that secretes lubricating and nourishing synovial fluid-PKK

Types of Synovial Joints- Plane Gliding Joint

Plane Gliding Synovial Joints- A type of joint where flat or slightly curved bone surfaces slide past one another, allowing for limited gliding movement. These joints, found in places like the wrist, ankle, and between vertebrae, are crucial for stability while still providing a degree of motion. -PKK

Plane Synovial Joint

Carpometacarpal, Intercarpal ,Intermetacarpal , Tarsometatarsal, Intertarsal, Intermetatarsal Joints

Hinge Joint- Synovial Joint

It allows movement in a single plane, like the hinge on a door, for bending and straightening. These joints are found in the body at the elbow, knee, and the interphalangeal joints of the fingers and toes, and are characterized by a convex surface of one bone fitting into the concave surface of another.-PKK

Pivot Synovial Joint

A type of synovial joint that allows for rotational movement around a single axis, where the rounded or cylindrical surface of one bone rotates within a ring-shaped structure made of another bone and/or ligament.-Atlantoaxial joint:, Radioulnar Joint

Pivot Joint

A pivot joint consists of a cylindrical bone that fits into a ring-shaped structure. - Movements like shaking your head "no" and rotating your forearm -pronation and supination-PKK

Condylar Synovial Joint

A type of synovial joint where an oval-shaped bone end fits into a similarly shaped hollow in another bone. They allow for movement in two planes, such as up-and-down and side-to-side, enabling actions like flexion, extension, adduction, abduction, and circumduction, though not full rotation.-PKK

Condylar Synovial -Knee Joint

Knee Joint- Largest and Most complex joint

Ellipsoid Synovial Joint

II consists of an oval-shaped convex condyle of one bone fitting into the elliptical concave cavity of another bone. type of biaxial synovial joint that allows movement in two planes: back and forth (flexion/extension) and side to side (abduction/adduction).-PKK

Ellipsoid Wrist Joint

Allowed motions: Flexion, extension, abduction, and adduction. Wrist joint (radiocarpal joint), Metacarpophalangeal joints (knuckles of the fingers), Metatarsophalangeal joints (knuckles of the toes), and Atlantooccipital joints (where the skull meets the spine

Saddle Synovial Joint

A type of synovial joint where the articulating bones are shaped like a saddle, with each bone having both a concave and convex surface. This structure allows for biaxial movement (flexion, extension, abduction, adduction, and circumduction) and provides a balance between stability and a wide range of motion.-PKK

Saddle Joint

Eg. Joint at the base of the thumb (carpometacarpal joint) and the joint connecting the collarbone to the breastbone (sternoclavicular joint).

Synovial -Saddle Joint

1st Carpometacarpal Joint, and SternoclavicularJoint

Ball and Socket Synovial Joint

It is a type of synovial joint where the rounded end of one bone (the ball) fits into the cup-shaped cavity of another bone (the socket). This structure allows for a wide range of motion in multiple directions, including rotation.

Ball and Socket Joint

The most flexible joints in the human body are the shoulder and hip joints. It permits movement in all directions, such as flexion, extension, abduction, adduction, and rotation- Shoulder , Hip Joint, Incudostapedial Jpint

Ball and Socket Joint

Smallest - Incudostapedial Joint- The joint between the incus (anvil) and stapes (stirrup) is a type of ball-and-socket joint, known as the incudostapedial joint

Muscle -Types

Skeletal muscles are voluntary, attached to bones, and control body movement. Cardiac muscle is involuntary and found only in the heart, responsible for pumping blood. Smooth muscle is also involuntary and found in the walls of internal organs like the digestive tract and blood vessels, controlling functions like digestion and blood flow-PKK

Pennate Muscles

A pennate muscle is a type of skeletal muscle with fibers arranged at an oblique angle to its tendon, resembling a feather. This structure allows for a greater number of muscle fibers to be packed into a given volume, resulting in higher force production and power, though the range of motion is typically smaller compared to other muscle types. Examples of pennate muscles include unipennate, bipennate, and multipennate arrangements-Pkk

Muscle Arrangements

A sphincter, is a muscle with fibers arranged in a circle around a body opening. When the muscle contracts, it decreases the diameter of the opening, closing it off, while when it relaxes, the opening widens. Examples of circular muscles include the orbicularis oris around the mouth and the orbicularis oculi around the eyes.

Types of Muscle Fibers

Fusiform skeletal muscles are spindle-shaped muscles that are thicker in the middle and taper to a point at both ends, with fibers arranged parallel to the muscle's length. Examples include the biceps brachii and sartorius. This arrangement allows for greater range of motion and velocity of movement because the muscle's force is concentrated.

Skeletal Muscle

Skeletal muscle is a type of striated muscle tissue, attached to bones by tendons, that is responsible for voluntary movements like walking and lifting.-PKK

Structure of Skeletal Muscle

Skeletal muscle is made of thousands of muscle fibers, which are long, multinucleated cell. Each muscle fiber is composed of smaller units called myofibrils. Myofibrils are made up of contractile units called sarcomeres, which are the basic units of muscle contraction. Sarcomeres contain thick (myosin) and thin (actin) filaments that slide past each other to cause muscle contraction.

Skeletal Muscle Microscopy

Skeletal muscle consists of muscle fibers (cells) which are multinucleated and packed with cylindrical bundles called myofibrils. These myofibrils are composed of repeating units called sarcomeres, the functional contractile units, formed by the organized arrangement of thick filaments (myosin) and thin filaments (actin). This arrangement creates a striated or striped appearance under the microscope.

Microscopic view of Skeletal muscle

Endomysium, Perimysium, Epimysium.

Muscle Fiber Structure

Multiple myofibrils, which are bundles of protein filaments (actin and myosin) arranged in repeating units called sarcomeres. The fiber is surrounded by a cell membrane called the sarcolemma, and its cytoplasm, or sarcoplasm, contains the myofibrils.

Structure of Tendon

A hierarchical arrangement of collagen fibrils that are grouped into fibers, fascicles, and the overall tendon unit. These bundles of collagen are primarily type I collagen and are densely packed, oriented parallel to the tendon's axis, and have a wavy or "crimp" pattern.

Myotendinous Junction

It is the specialized interface where skeletal muscle fibers connect to a tendon, serving as the primary site for transmitting force to create movement. Its unique, complex structure optimizes this force transmission, but also makes it a common location for strain injuries, especially during high-effort exercise

Myotendinous Junction .

The MTJ has a complex structure where the muscle membrane has many infolds that intertwine with the collagen fibrils of the tendon. This interdigitation increases the contact area between the tissues for better force dispersal and to reduce stress concentrations.

Motor Units

A motor unit is the basic functional unit of skeletal muscle, consisting of a single motor neuron and all the muscle fibers it innervates. When a motor neuron is activated, all of the muscle fibers within its unit contract together in an "all-or-none" fashion. The force of a muscle contraction is controlled by the number of motor units recruited and activated -PKK

Motor Unit of a Muscle

A motor unit is comprised of a single motor neuron (a nerve cell) and all the muscle fibers that the neuron's axon terminals connect to at neuromuscular junctions.

Muscle Motor Unit

Slow-twitch (Type I), Fast-twitch (Type II)

Motor Unit 3

Thigh muscles can have a thousand fibers in each unit, while extraocular muscles might have ten only.-PKK

Motor Unit 4

Henneman's size principle indicates that motor units are recruited from smallest to largest based on the size of the load. For smaller loads requiring less force, slow twitch, low-force, fatigue-resistant muscle fibers are activated prior to the recruitment of the fast twitch, high-force, less fatigue-resistant muscle fibers. Larger motor units are typically composed of faster muscle fibers that generate higher forces.

Motor Unit 5- Motor Neuron

FF — Fast fatigable — high force, fast contraction speed but fatigue in a few seconds. FR — Fast fatigue resistant — intermediate force, fatigue resistant — fast contraction speed and resistant to fatigue. FI — Fast intermediate — intermediate between FF and FR. S or SO — Slow (oxidative) — low force, slower contraction speed, highly fatigue resistant.

Clavipectoral Fascia

It encloses the subclavius and pectoralis minor muscles and forms the suspensory ligament of the axilla, which supports the armpit's floor. The fascia also acts as a barrier, with several structures piercing through it, including the cephalic vein, the thoracoacromial artery, the lateral pectoral nerve, and lymphatic vessels

Pectoralis Major Muscle

In Poland syndrome, the anatomy of the pectoralis major is affected by the unilateral absence or underdevelopment of its sternocostal head

Attachment of Pectoralis Major

Insertion: Both heads converge to form a tendon that inserts onto the lateral lip of the intertubercular groove (or bicipital groove) of the humerus. Its lowest fibers are attached on highest position.-PKK

Fascia- Clavipectoral

Thickened upper portion: The portion from the first rib to the coracoid process is called the costocoracoid ligament-pkk

Pectoralis Minor

A triangular muscle located beneath the pectoralis major, originating from the third to fifth ribs and inserting onto the coracoid process of the scapula

Pectoralis Minor

The muscle originates from the anterior surfaces of the third, fourth, and fifth ribs near their costal cartilages. It inserts on the medial border and superior surface of the coracoid process of the scapula.

Pectoralis Minor 3

Medial and Lateral pectoral nerves (from spinal nerves C8 and T1). It Stabilizes the scapula: Pulls the scapula inferiorly and anteriorly, pressing it against the thoracic wall.

P. Minor

The pectoralis minor muscle creates a passage between the ribs for the transit of the brachial plexus and both the subclavian artery and vein. If the muscle is shortened/tight this abnormal tension: negatively affecting the Scapulohumeral Rhythm; can also cause thoracic outlet syndrome

Clavipectoral Fascia 3

At most superficial part, where it is attached to the coracoid process laterally and blends with the upper two external intercostal membranes medially, it is referred to as the Costocoracoid membrane-PKK

Subclavius Muscle

Origin: The junction of the first rib and its costal cartilage. Insertion: The inferior surface of the middle third of the clavicle.

Subclavius 2

Nerve to subclavius: A branch from Upper trunk of the brachial plexus, specifically from the C5 and C6 nerves. Stabilization: It actively stabilizes the clavicle at the sternoclavicular joint, which is important for movements of the upper limb. Depression: It helps depress the clavicle, moving it downwards and forwards

Subclavius 4

The vessels and nerves running behind the subclavius muscle can sometimes become entrapped between the clavicle and the first rib, inside the costoclavicular space. This is referred to as costoclavicular syndrome and marks one of the three types of thoracic outlet syndromes (TOS)

Mammary Gland Anatomy

Tissue: The breast is primarily composed of glandular (milk-producing) and fatty tissue, the ratio of which can vary with age and hormonal status. Glands: It contains lobes, which are clusters of smaller sacs called lobules that can produce milk. Ducts: Thin tubes called ducts carry milk from the lobules to the nipple.

Breast Location and Bed

Breasts also have nerves, blood vessels, and a system of lymph vessels and lymph nodes, which can be affected by breast cancer. Location: The base of the breast is formed by the pectoralis major muscle, which lies over the ribs.

Structure of Breast

The breast is an apocrine gland. The breasts are about 80 to 90% stromal tissue (fat and connective tissue), while epithelial or glandular tissue only accounts for about 10 to 20% of the volume of the breasts.

Mammary Gland Structure

The nipple of the breast is surrounded by the areola (nipple-areola complex). The areola has many sebaceous glands, and the skin color varies from pink to dark brown. The basic units of the breast are the terminal duct lobular units (TDLUs), which produce the fatty breast milk. breast is also composed of connective tissues (collagen, elastin), white fat, and the suspensory Cooper's ligaments.

Anatomy of Breast

Nipples have hundreds of nerve endings, which makes them extremely sensitive to touch. Each breast has between 15 to 20 lobes, or sections. These lobes surround your nipple like spokes on a wheel.

Male Breast

During puberty, the hormone testosterone usually stops breasts from developing. On the outside, there are nipples and areolae. Internally, they have undeveloped milk ducts and no glandular tissue. Male breast problems can include gynecomastia, a benign condition that causes the breasts to enlarge, and very rarely, breast cancer.

Mammary Bed

The muscles that form the mammary bed (the deep surface upon which the breast rests) are the pectoralis major, the serratus anterior, and the external oblique muscle

Cutaneous Innervation Mammary Gland

supraclavicular nerves (\(C_{3}\) and \(C_{4}\)) from the cervical plexus, anterior and lateral cutaneous branches of the intercostal nerves (T2to (T6. The intercostobrachial nerve (T2 also contributes, supplying the skin of the upper medial arm and the floor of the axilla.

Arterial Supply Breast

Lateral thoracic and thoracoacromial branches. Lateral mammary branches – originate from the posterior intercostal arteries (derived from the aorta). Mammary branch – originates from the anterior intercostal artery.

Arteries of Breast

Axillary artery via several branches: superior thoracic, thoracoacromial, lateral thoracic and subscapular arteries Internal thoracic artery via the medial mammary arteries Perforating branches of second, third and fourth intercostal arteries

Blood Supply of Breast

Venous- Axillary, internal thoracic and second to fourth intercostal veins.

Nerve Supply Breast

Anterior and lateral cutaneous branches of the second to sixth intercostal nerves Fourth intercostal nerve (nipple)

Lymph Nodes of Breast

Subareolar lymphatic plexus -> pectoral lymph nodes -> axillary lymph nodes -> subclavian lymphatic trunks (75%) Subareolar lymphatic plexus -> parasternal lymph nodes -> bronchomediastinal lymphatic trunks (25%)

Breast Lymphatics

There are three groups of lymph nodes that receive lymph from breast tissue – the axillary nodes (75%), parasternal nodes (20%) and posterior intercostal nodes (5%). The skin of the breast also receives lymphatic drainage: Skin – drains to the axillary, inferior deep cervical and infraclavicular nodes. Nipple and areola – drains to the subareolar lymphatic plexus.

Lymphatics of Mammary Gland

The axillary (underarm) nodes, the parasternal (chest) nodes, and the intercostal nodes

L.N. of Breast

75% of drainage. Lymph is collected in the subareolar plexus (Sappey's plexus) and then travels along the inferior border of the pectoralis major muscle to the axillary node

Breast cancer

Common presentations associated with breast cancer are due to blockages of the lymphatic drainage. Excess lymph builds up in the subcutaneous tissue, resulting in clinical features such as nipple deviation and retraction, and prominent skin between small dimpled pores (peau d’orange). Larger dimples are generally caused by cancerous invasions and fibrosis. This causes traction of the suspensory ligaments, causing them to shorten.

Breast Cancer

Metastasis commonly occurs through the lymph nodes. It is most likely to be the axillary lymph nodes that are involved. They become stony hard and fixed. Following this, the cancer can spread to distant places such as the liver, lungs, bones and ovary.

Peau'd Orange- Breast Cancer

Peau d'orange" is a medical term for skin that has a dimpled or pitted, orange-peel-like appearance, which can be a sign of inflammatory breast cancer. It happens when cancer cells block the lymph vessels in the breast, causing fluid buildup and a thickened, leathery skin texture. If you notice this on your breast, it is important to see a doctor right away for an accurate diagnosis.

Anatomy of Breast

Structures and Lymph nodes.

Axilla Boundaries

A Pyramid-shaped space bounded by anterior, posterior, medial, lateral, superior, and inferior walls. The anterior wall is formed by the pectoral muscles, the posterior wall by the subscapularis, teres major, and latissimus dorsi muscles, and the lateral wall by the humerus. The medial wall consists of the serratus anterior and thoracic wall, while the base is the skin and fascia of the armpit. The apex is the open, superior part, defined by the first rib, clavicle, and scapula.

Axilla Boundary and Content

Anterior wall Muscles: Lateral part of the pectoralis major, pectoralis minor, and subclavius Fascia: Clavipectoral fascia Posterior wall Muscles: Subscapularis, teres major, and latissimus dorsi

Axilla Inlet Apex

Axillary apex, is the triangular opening at the top of the armpit (axilla) that connects the neck to the axilla. It is bounded by the lateral border of the first rib, the posterior surface of the clavicle, and the superior border of the scapula, and serves as the passage for major nerves and blood vessels, like the brachial plexus and subclavian vessels, to enter the axilla from the neck.

Walls of Axilla

Posterior wall is made of the subscapularis, latissimus dorsi, and teres major muscles. The medial wall is the serratus anterior muscle and the first four ribs, and the lateral wall is the humerus, coracobrachialis, and short head of the biceps brachii.

Axillary Vein

It begins at the lower border of the teres major muscle where the basilic vein and brachial veins merge and ends at the outer border of the first rib, where it becomes the subclavian vein. It is a clinically significant vessel used for venous access for medical devices like pacemakers and defibrillators

Axillary Lymph Nodes

Divided into groups based on their relationship to the pectoralis minor muscle: Level I (lateral), Level II (deep), and Level III (medial).

Brachial Plexus 1

Formed by nerve roots C5 through T1, it is structured in five parts: roots, trunks, divisions, cords, and branches.

Brachial Plexus 2- Formation

Roots: The network begins with five nerve roots from the spinal cord (C5–T1). Trunks: The roots combine to form three trunks: superior (C5-C6), middle (C7), and inferior (C8-T1

Brachial Plexus 3- Branches

Divisions: Each trunk splits into an anterior and a posterior division. Cords: The divisions then regroup into three cords, named for their position relative to the axillary artery: the lateral, posterior, and medial cords. Branches: Finally, the cords form the terminal branches, which are the major nerves that extend into the shoulder, arm, and hand.

Brachial Plexus 4- Location

The roots of the brachial plexus emerge from the spinal cord and travel between the anterior and middle scalene muscles in the posterior triangle of the neck.

Brachial Plexus 5 - Formation

The ‘roots’ refer the anterior rami of the spinal nerves that comprise the brachial plexus. These are the anterior rami of spinal nerves C5, C6, C7, C8, and T1.

Brachial Plexus- Branches of Root

1. Dorsal scapular nerve C4, C5 rhomboid muscles and levator scapulae - 2. long thoracic nerve C5, C6, C7 serratus anterior - 3. branch to phrenic nerve C3, C4, C5 Diaphragm 4. Branch to Longus Coli and Scalene Muscles

Brachial Plexus 7- Branches From Trunk

Only Upper Trunk Gives Branches- 1. Suprascapular Nerve- Supraspinatus and Infraspinatus 2. Nerve to Subclavius- Subclavius

Brachial Plexus 8- Branches of Lateral Cord

(LML) 1. Lateral Pectoral Neve 2. Musculocutaneous Nerve 3. Lateral Root of Median Nerve

Brachial Plexus 9- Branches From Medial Cord

(M4 U) 1. Medial Pectoral Nerve 2. Medial Root of Median Nerve 3. Medial Cutaneous nerve of Arm 4. Medial Cutaneous nerve of Forearm 5. Ulnar Nerve

Brachial Plexus 10- Branches From Posterior Cord

(ULNAR) 1. Upper Subscapular Nerve 2. Lower Subscapular nerve 3. Nerve to Lattissimus Dorsi (Thoracodorsal neve) ( Middle Subscapular Nerve) 4. Axillary Nerve 5. Radial Nerve

Long Thoracic Nerve of Bell

Roots Long thoracic nerve C5, C6, C7 serratus anterior- Winging of Scapula

Erb's Palsy- Brachial Plexus Injury

Erb’s palsy refers to an injury to the upper roots of the brachial plexus (typically C5-6). It most commonly occurs as a result of a stretching injury during a difficult vaginal delivery. Nerves affected – the peripheral nerves derived from C5-6 roots are most affected. This includes the musculocutaneous, axillary, suprascapular, and nerve to subclavius. Muscles affected – supraspinatus, infraspinatus, subclavius, biceps brachii, brachialis, coracobrachialis, deltoid and teres minor.

Brachial Plexus Injury

Erb’s palsy- Motor functions affected – abduction at shoulder, lateral rotation of arm, supination of forearm, and flexion at shoulder. Sensory functions affected – sensation over the lateral aspect of upper limb (C5-6 dermatomes).

BP Injury

Klumpke’s palsy is an injury of the lower roots of the brachial plexus (C8-T1). It is also most commonly associated with a difficult vaginal delivery but has a much lower incidence than Erb’s palsy. Nerves affected – the peripheral nerves derived from T1 root are most affected; the ulnar and median nerves Muscles affected – the intrinsic hand muscles Sensory functions affected – sensation along medial side of upper limb (C8-T1 dermatomes).

Brachial Plexus Injury 3

Erbs Palsy- ‘waiter’s tip Hand", Policeman Tip hand, Porter Tip Hand-PKK

Axillary Artery - Parts

It is a continuation of the subclavian artery, starting at the lateral border of the first rib and ending at the lower border of the teres major muscle, where it becomes the brachial artery. The pectoralis minor muscle divides the artery into three parts, with one branch arising from the first part, two from the second, and three from the third.

Axillary Artery- Relations

First part (proximal to pectoralis minor) Anterior: Pectoralis major (clavicular part), a nerve loop connecting the medial and lateral pectoral nerves. Posterior: Medial cord of the brachial plexus, the long thoracic nerve, and the first digitations of the serratus anterior muscle. Medial: Axillary vein. Lateral: Lateral and posterior cords of the brachial plexus.

Axillary Artery -Relation 2

Second part (behind the pectoralis minor) Anterior: Pectoralis minor. Posterior: Posterior cord of the brachial plexus and the subscapularis muscle. Medial: Medial cord of the brachial plexus and the axillary vein. Lateral: Lateral cord of the brachial plexus.

Axillary Artery -Relation 3

Third part (distal to pectoralis minor) Anterior: Skin, superficial fascia, and deep fascia. Posterior: Radial nerve, axillary nerve (in the upper part), and the subscapularis, latissimus dorsi, and teres major muscles (tendons). Lateral: Coracobrachialis muscle, musculocutaneous nerve, and the lateral root of the median nerve (in the upper part). Medial: Axillary vein and the medial cutaneous nerve of the arm and forearm.

Axillary Artery - Situation

The axillary artery is located in the armpit (axilla), beginning at the outer border of the first rib and ending at the lower border of the teres major muscle. It serves as the main artery for the upper limb, with its path divided into three parts by the pectoralis minor muscle

Axillary Artery - Branches

First part Superior thoracic artery: Supplies blood to the pectoralis minor and major muscles. Second part Thoracoacromial artery: Divides into several branches, including the acromial, pectoral, clavicular, and deltoid arteries. Lateral thoracic artery: Supplies the pectoral muscles, serratus anterior, and the mammary gland.

Axillary artery - Branches 2

Third part Subscapular artery: The largest branch, which gives off the circumflex scapular and thoracodorsal arteries. Anterior circumflex humeral artery: Wraps around the surgical neck of the humerus. Posterior circumflex humeral artery: Also wraps around the surgical neck of the humerus, supplying blood to the shoulder joint and surrounding muscles.

1. Classification of Nervous System

The nervous system is classified into the Central Nervous System (CNS) (brain and spinal cord) and the Peripheral Nervous System (PNS) (nerves outside the CNS). Functionally, the PNS further divides into the Somatic Nervous System (voluntary control of muscles) and the Autonomic Nervous System (ANS), which regulates involuntary functions and splits into the Sympathetic (fight-or-flight) and Parasympathetic (rest-and-digest) systems.

2. Autonomic Nervous System

It Controls involuntary bodily functions like heart rate, breathing, digestion, and blood pressure, operating automatically without conscious thought to maintain homeostasis (internal balance). It's part of the peripheral nervous system, divided into the sympathetic (fight-or-flight) system, which prepares the body for action, and the parasympathetic (rest-and-digest) system, which conserves energy, with both working in balance

3. N.S. Classification

Central Nervous System (CNS): The body's command center, interpreting information and making decisions. Brain: Processes thoughts, memories, emotions, and controls motor skills. Spinal Cord: Relays messages between the brain and the rest of the body, protected by vertebrae. Peripheral Nervous System (PNS): Connects the CNS to limbs, organs, and skin. Cranial Nerves: Emerge from the brain. Spinal Nerves: Emerge from the spinal cord.

4. Organization of Nervous System

Somatic Nervous System (Voluntary): Controls skeletal muscles. Autonomic Nervous System (Involuntary): Controls internal organs, glands, and smooth muscles. Sympathetic Nervous System: Prepares the body for stress (e.g., increases heart rate). Parasympathetic Nervous System: Promotes relaxation and energy conservation (e.g., slows heart rate).

5. Autonomic Nervous System

Heart Rate & Blood Pressure: Regulates how fast your heart beats and your blood pressure. Respiration: Adjusts your breathing rate. Digestion: Manages digestion, nutrient absorption, and waste elimination. Metabolism: Controls metabolic processes and energy use. Temperature Regulation: Manages sweating and blood flow to cool or warm the body. Pupil Response: Controls pupil dilation and constriction. Sexual Arousal: Involved in sexual function

7. Somatic and ANS

Controls voluntary body movements by connecting the brain and spinal cord (CNS) to skeletal muscles, allowing conscious actions like walking or talking, and also manages voluntary sensory input from skin, muscles, and senses. It operates via sensory (afferent) nerves bringing info to the CNS and motor (efferent) nerves sending commands to muscles, handling both intentional actions and rapid reflex arcs (like pulling your hand from heat

9. A.N.S.

Sympathetic Nervous System (Accelerator): Prepares the body for stress or emergencies ("fight-or-flight") by increasing heart rate, diverting blood to muscles, and boosting alertness. Parasympathetic Nervous System (Brake): Calms the body down, conserving energy and promoting "rest-and-digest" functions, slowing heart rate and increasing digestion

10. Neurons Types

Neurons are categorized by function (Sensory, Motor, Interneurons) and structure (Unipolar, Bipolar, Multipolar), working together to process information: Sensory neurons detect stimuli, Motor neurons control muscles/glands, and Interneurons connect them within the CNS, while structural types describe axon/dendrite count, like Multipolar (most common, many dendrites, one axon) and Bipolar (one dendrite, one axon).

Multipolar Neuron Structure

Most common type of nerve cell, defined by having one axon and multiple dendrites branching from its cell body, allowing it to receive and integrate vast amounts of information, forming the backbone of the central nervous system (brain, spinal cord) and autonomic nervous system

Neuron Types

Bipolar: One axon and one dendrite, found in special senses (eyes, ears). Unipolar (Pseudounipolar): Single extension from the cell body splits into axon and dendrite; typically sensory neurons

Neuron Structure HD

Cell body (soma), which contains the nucleus; multiple branching dendrites that receive signals; and a single long axon that transmits signals away, ending in terminal buttons that form synapses with other cells, allowing communication via neurotransmitters.

Myelinated Neuron

The myelin sheath is a fatty, protein-rich insulating layer that wraps around certain neuron axons, speeding up electrical impulse transmission by allowing signals to "jump" between gaps called Nodes of Ranvier (saltatory conduction). Formed by glial cells (Schwann cells in PNS, oligodendrocytes in CNS), this lipid-packed sheath acts like electrical wire insulation, preventing signal loss and enabling rapid, efficient nerve communication.-pkk

Classification of Neuron 3

Anaxonic: No distinct axon; only dendrites, can't produce action potentials (e.g., in brain, retina) Multipolar: Most common; many dendrites, one axon (e.g., motor neurons, interneurons

Purkinje Cell -Brain

Purkinje cells are large, unique neurons in the cerebellum, famous for their massive, flat, branched dendritic trees that integrate vast amounts of sensory-motor information, acting as the sole output of the cerebellar cortex to control coordinated movement, motor learning, cognition, and emotion, primarily through inhibitory signals (GABA).

Neuron Cytoskeleton

A dynamic network of microtubules, neurofilaments (intermediate filaments), and actin filaments (microfilaments) that provides structural support, maintains cell shape, and enables crucial functions like axonal growth, intracellular transport (moving organelles/vesicles), and synaptic transmission, allowing neurons to form complex connections.-PKK

Cytoskeleton Neuron 2

Microtubules (MTs): Made of tubulin, these are hollow tubes (25nm) acting as tracks for motor proteins, essential for transporting materials (organelles, vesicles) from the cell body to axon terminals (axonal transport) and for neurite extension

Alzheimer's Neuron 1

In Alzheimer's, neurons (brain cells) die due to the buildup of abnormal proteins, forming amyloid plaques outside cells and tau tangles inside, disrupting communication and function, leading to progressive memory loss, cognitive decline, and eventually, widespread brain shrinkage and death of nerve cells, starting in memory centers like the hippocampus-PKK

Alzheimer's Neuron 2

Amyloid-beta: Normally cleared, but in AD, it forms sticky plaques outside neurons. Tau: Stabilizes microtubules; in AD, it becomes abnormal, forms tangles, and disrupts cell transport

Neuronal Synapse 1

A Crucial junction where one neuron communicates with another neuron or a target cell (like muscle/gland), allowing nerve impulses to pass via electrical or chemical signals, forming the basis for brain function, learning, and memory, with chemical synapses using neurotransmitters and electrical ones using direction flow.

Neuronal Synapse 2

Presynaptic Neuron: The neuron sending the signal, containing neurotransmitters in vesicles. Postsynaptic Neuron: The receiving neuron, with receptors on its surface (often a dendrite). Synaptic Cleft: The tiny gap between them

2. Parts of Brain- Lobes

Parts, Lobes and Sulcus of Brain-PKK

1. Parts of Brain- Medial Surface

The medial surface of the brain, seen in a midsagittal view, features major structures like the C-shaped Corpus Callosum, the surrounding Cingulate Gyrus (part of the limbic system), the Cerebellum, and the Brainstem, with key sulci (grooves) like the Cingulate Sulcus, Parieto-Occipital Sulcus, and Calcarine Sulcus defining lobes and areas crucial for memory (hippocampus), vision,and Emotion-pkk

3. Fifth Lobe - Insula of Brain

The insular region (insula) is a crucial, deep-seated brain structure, often called the "fifth lobe," hidden beneath the frontal, temporal, and parietal lobes, vital for integrating sensory, emotional, and cognitive information, especially relating to body states (interoception), emotions (like fear, empathy), risk-reward, taste, pain, and autonomic functions, acting as a key hub for linking feelings with decision-making and awareness-PKK

4. Inner Structures of Brain

The inner parts of the brain include the deep structures within the cerebrum (like the thalamus, hypothalamus, basal ganglia, hippocampus, amygdala), the cerebellum (coordination/balance), and the brainstem (midbrain, pons, medulla) controlling vital functions, all connected by white matter and protected by cerebrospinal fluid within ventricles, crucial for relaying signals and managing complex processes. -PKK

5. Brain- Parts in Saggital View

A sagittal view cuts the brain vertically, revealing major structures like the cerebrum, cerebellum, and brainstem, plus internal components such as the corpus callosum, thalamus, hypothalamus, and the ventricular system (including the 3rd and 4th ventricles), showing deep grooves (sulci) and folds (gyri) like the central sulcus, and lobes (frontal, parietal, occipital) on the medial surface-PKK

6. Lobes of Brain

Four main lobes—Frontal, Parietal, Temporal, and Occipital—each responsible for specific functions like reasoning, sensation, hearing, and vision, though they work together complexly. Some models also identify the Insular (deep within) and Limbic lobes, expanding the functional divisions-PKK

8. Brain Anatomy- Medial Surface

The C-shaped corpus callosum (connecting hemispheres), the curved cingulate gyrus (part of the limbic system), and the deep grooves (sulci) separating lobes, such as the callosal, cingulate, and parieto-occipital sulci, revealing parts of the frontal, parietal (like the paracentral lobule), and occipital lobes, along with the diencephalon (thalamus, hypothalamus) and brainstem-PKK

9. Base Of Brain- Interpeduncular Fossa

The base of the brain primarily consists of the Brainstem, which connects the brain to the spinal cord and includes the Midbrain, Pons, and Medulla Oblongata, controlling vital functions like breathing, heart rate, and relaying signals; the Cerebellum, located at the back, handles coordination and balance; and structures like the Thalamus, Hypothalamus, and pituitary gland are also deep at the base, managing sensory relay, homeostasis, and hormones-PKK

10. Interpeduncular Fossa

The interpeduncular fossa is a crucial depression at the base of the brain, located on the midbrain between the two large cerebral peduncles (crura cerebri). Its floor contains important structures like the mamillary bodies, tuber cinereum, infundibulum, and the posterior perforated substance, while the optic chiasma forms its front, and it's where the oculomotor nerve (CN III) emerges-PKK

10. Interpeduncular Fossa Boundaries

A key depression at the brain's base, is bounded anteriorly by the optic chiasma, posteriorly by the pons, and laterally by the diverging cerebral peduncles, containing vital structures like the Circle of Willis and the origin of the oculomotor nerve (CN III), forming part of the midbrain's floor.

11. Structures of Base of Brain

The base of the brain is dominated by the brainstem, a crucial relay connecting to the spinal cord, comprising the Midbrain, Pons, and Medulla Oblongata (controlling vital functions like breathing, heart rate). Also at the base are the Cerebellum (coordinating movement/balance) and deep structures like the Thalamus (sensory relay) and Hypothalamus (hormones, hunger, thirst, temperature), forming the brain's survival and connection center-PKK

Brainstem

The crucial, stalk-like part of the brain connecting the cerebrum to the spinal cord, controlling essential involuntary functions like breathing, heart rate, consciousness, and relaying motor/sensory signals, comprising the midbrain, pons, and medulla oblongata. It's vital for life, acting as a pathway for nerves and regulating fundamental bodily processes-PKK

1. Spinal Cord Structure

Extends from upper border of posterior arch of first cervical vertebrae (C1) to lower border of first lumbar vertebra L1 in adults

2. Spinal Cord, Nerve, Meninges

Covered by spinal meninges: Outer dura mater, middle arachnoid mater, and innermost pia mater

3. Extent of Meninges of Spinal Cord

Dura mater: Extends from foramen magnum to lower border of second sacral vertebra Arachnoid mater (cobweb-like in Latin) Thin transparent membrane loosely surrounds spinal cord Also extends up to lower border of S2 vertebra Pia mater : Thin vascular membrane closely invests spinal cord

4. Spinal Nerves Origin

Thirty-one pairs of spinal nerves – attached to spinal cord Include 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, and 1 coccygeal pairs of nerves Each spinal nerve– attached to spinal cord by 2 roots: Ventral and dorsal nerve roots Ventral or anterior motor root carries motor or efferent fibers from spinal cord

5. Spinal Meninges

Dura mater: Extends from foramen magnum to lower border of second sacral vertebra Arachnoid mater- Thin transparent membrane loosely surrounds spinal cord Also extends up to lower border of S2 vertebra Pia mater : Thin vascular membrane closely invests spinal cord

6. Cauda Equina

Horsetail-like structure formed by bunch of lower spinal nerves surround conus medullaris and filum terminale Components (10 Pair of Nerves) Ventral and dorsal roots of lower four lumbar segments (L2–L5), five sacral (S1 to S5), and one coccygeal segments Filum terminale

6. Structure of Spinal Cord

Anterior median fissure Posterior median sulcus Ventrolateral (anterolateral) sulcus Dorsolateral (posterolateral) sulcus Dorsointermediate (posterointermediate) sulcus

9. Origin of Spinal Nerve

Roots: Nerves start as two distinct roots: the dorsal (posterior) root, carrying sensory info to the spinal cord, and the ventral (anterior) root, carrying motor commands from the spinal cord. Emergence: These roots join to form a spinal nerve just outside the spinal cord. Exit Point: Each nerve exits the vertebral column through an opening called the intervertebral foramen, located between adjacent vertebrae (except the first cervical nerve).

10. Lumbar Puncture

A Needle is inserted into the lower back's spinal canal to collect cerebrospinal fluid (CSF) for testing or to inject/remove substances, diagnosing neurological conditions like meningitis, multiple sclerosis, or bleeding-pkk

11. Ligamentum Denticulatum

extend from pia mater to dura mater stabilize side-to-side movement Each ligamentum denticulatum lies in between anterior and posterior roots of adjacent spinal nerves First ligamentum denticulatum lies at level of foramen magnum while last one lies between T12 and L1 spinal nerves

12. Ligamentum Denticulatum Location

Are 21 pairs of teeth-like projections of pia mater Extend from lateral surface of spinal cord and pierce arachnoid mater to get attached to inner surface of dura mater

13. Parts and Enlargement of Spinal Cord

Two thickened regions—the cervical (neck) and lumbar (lower back)—where the cord bulges to provide extra neurons and connections for the arms (cervical) and legs (lumbar), forming the brachial and lumbosacral nerve plexuses, respectively, allowing complex limb movements

14. Spinal Segment

Portion of spinal cord to which pair of spinal nerve is attached Consists of 31 spinal segments as follows: 8 cervical, 12 thoracic, 5 lumbar, 5 sacral, 1 coccygeal

15. Filum Terminale

Piamater Extension- Thin fibrous filament extends from tip of conus medullaris to first coccygeal vertebra Emerges from vertebral canal through sacral hiatus About 20 cm long

16. Tracts of Spinal Cord

Descending Tracts -- Pyramidal tracts • Lateral corticospinal • Anterior corticospinal Extrapyramidal tracts • Rubrospinal • Medial and lateral reticulospinal • Olivospinal • Lateral vestibulospinal • Tectospinal

19. Tracts of Spinal Cord

Ascending and descending tracts

22. Fissures and Sulci of Spinal Cord

A spinal cord fissure, primarily the deep Anterior Median Fissure (AMF), is a normal anatomical groove on the front (ventral) surface of the cord, dividing the white matter into symmetrical halves and housing the anterior spinal artery and pia mater,

24. CSF Circulation

The continuous flow of fluid through the brain's ventricles and the surrounding subarachnoid space, starting from the lateral ventricles, moving to the third, then fourth ventricle, exiting into the subarachnoid space (around brain and spinal cord) via small openings, and finally being reabsorbed into the bloodstream, primarily through arachnoid villi, providing cushioning, nutrient transport, and waste removal for the CNS

37. Medulla -External Features

Include prominent ridges and grooves on its anterior (ventral) and posterior (dorsal) surfaces, such as the anterior median fissure, paired pyramids (containing corticospinal tracts), and oval olives, with cranial nerves emerging from sulci between them, while the dorsal side shows the posterior median sulcus, gracile and cuneate tubercles, and inferior cerebellar peduncles, all connecting to the spinal cord and cerebellum.

38. Medulla External Features2

Pyramids: Two vertical bulges on either side of the fissure, housing the corticospinal (motor) fibers. Olive: An oval swelling lateral to the pyramids, containing the olivary nucleus, important for movement Posterolateral Sulcus (Post-olivary): Lateral to the olive, where the Glossopharyngeal (CN IX), Vagus (CN X), and Accessory (CN XI) nerves emerge

39. Brainstem -Anterior View

The brainstem's anterior parts, from top to bottom, are the Midbrain, Pons, and Medulla Oblongata, with the anterior surface featuring key motor tracts (like the crus cerebri in the midbrain and pyramids in the medulla) and nuclei for cranial nerves, all vital for connecting the brain to the spinal cord and controlling essential functions like breathing, heart rate, and consciousness

40. Brainstem -Posterior View

The posterior parts of the brainstem include the tectum (midbrain's roof with superior/inferior colliculi), the tegmentum, and crucial white matter tracts like the cerebellar peduncles, forming the dorsal surface alongside the fourth ventricle, while deeper structures like nuclei for cranial nerves (V-XII) and sensory pathways (gracile/cuneate fasciculi) reside within the pons and medulla, connecting to the cerebellum and spinal cord for vital functions.

41. T.S. Medulla -Pyramidal Decussation

shows the crucial crossing (decussation) of most corticospinal motor fibers, forming the lateral corticospinal tract, while dorsal sensory nuclei (gracile and cuneate) are prominent posteriorly, with internal arcuate fibers from them beginning to form the medial lemniscus, marking the transition from brainstem to spinal cord.

42. T.S. Medulla -Sensory Decussation

The crucial crossing point where second-order sensory neurons (internal arcuate fibers) from the gracile and cuneate nuclei cross the midline to form the medial lemniscus, transmitting fine touch, vibration, and proprioception from the body to the opposite side of the brain, ensuring contralateral sensory processing. This crossing happens at the upper part of the closed medulla, anterior to the central gray matter.

43. T.S. Medulla- Sensory Decussation2

First-order neurons enter the spinal cord via the dorsal columns (fasciculus gracilis/cuneatus). They synapse in the gracile or cuneate nuclei in the medulla. The second-order neurons (internal arcuate fibers) then arc around the central gray matter, crossing the midline (decussate). After crossing, they form the medial lemniscus, a major ascending sensory tract.

44. T.S. Medulla -Open Part , At Level of Olive

"open part" (upper medulla) reveals the floor of the fourth ventricle with characteristic features like the median sulcus, hypoglossal and vagal triangles, vestibular area, and area postrema (a chemoreceptor zone). Internally, it shows nuclei for cranial nerves IX-XII, sensory tracts, and the inferior olivary nuclei, with the central canal expanding into the ventricle, contrasting with the "closed" lower medulla.

45. Lateral and Medial Medullary Syndrome

LMS- Sensory and motor deficits: Decreased sensation for pain and temperature on the same side of the face as the stroke, but on the opposite side of the body. Coordination and balance: Vertigo, nausea, vomiting, and loss of balance (ataxia). Speech and swallowing: Hoarseness, difficulty swallowing (dysphagia), and a decreased gag reflex. Other symptoms: Nystagmus (involuntary eye movements), and Horner's syndrome (ptosis, miosis, and anhidrosis).

47. Circle of Willis

he Circle of Willis is a ring of arteries at the base of the brain that connects the internal carotid arteries and the vertebrobasilar system, ensuring continuous blood flow to the brain. It acts as a "fail-safe" system, allowing blood to be rerouted to bypass blockages in one of the major arteries supplying the brain. This collateral circulation reduces the risk of ischemic events, such as stroke. Anterior Circulation: Internal carotid arteries, anterior cerebral arteries, and the anterior communicating artery. Posterior Circulation: Vertebral arteries, basilar artery, posterior cerebral arteries, and the posterior communicating arteries.

PPT File

SECTIONS OF BRAIN

Well labelled Dissected Sectioned Brain- Different Sections of Brain-PKK

49. Pons in Brainstem

Acting as a bridge that connects the cerebral cortex with the medulla and cerebellum. It plays a vital role in regulating essential functions, including breathing, sleep cycles, balance, and facial sensations. It is also responsible for controlling eye movements and chewing.

50. T.S. Lower Part of Pons

Ventral (Basilar) Part: Contains massive transverse pontine fibers, pontine nuclei, and the descending corticospinal and corticonuclear tracts. Dorsal Part (Tegmentum): Abducens Nucleus (CN VI): Located medially beneath the facial colliculus. Facial Nerve (CN VII) Fibers: The motor root of the facial nerve hooks around the abducens nucleus, forming the facial colliculus. Vestibular Nuclei: Located in the lateral area of the floor of the fourth ventricle. Medial Lemniscus: Situated at the junction of the ventral and dorsal parts, arranged horizontally (different from the vertical orientation in the medulla). Spinal Tract and Nucleus of Trigeminal Nerve (CN V): Positioned laterally. Trapezoid Body: Fibers related to the auditory pathway

51. T.S. Upper part of Pons

Ventral (Basilar) Part: Bulky area containing pontine nuclei, transverse fibers, and descending corticospinal/corticopontine tracts. Dorsal Part (Tegmentum): Superior Cerebellar Peduncles (SCP): Prominent, located in the dorsolateral aspect of the tegmentum. Locus Coeruleus: Pigmented nucleus situated in the upper dorsal pons. Medial Longitudinal Fasciculus (MLF): Located paramedially near the floor of the fourth ventricle. Lemnisci (Lateral to Medial): Lateral lemniscus, spinal lemniscus, trigeminal lemniscus, and medial lemniscus.

52. T.S. Pons Lower Part

Medial Lemniscus: Situated at the junction of the ventral and dorsal parts, arranged horizontally (different from the vertical orientation in the medulla). Spinal Tract and Nucleus of Trigeminal Nerve (CN V): Positioned laterally. Trapezoid Body: Fibers related to the auditory pathway

54. Millard Gubler Syndrome-Pons

Ipsilateral facial paralysis: Weakness or paralysis of the facial muscles on the same side as the lesion. This can affect the upper and lower face. Ipsilateral abducens nerve palsy: Difficulty moving the eye on the same side as the lesion, leading to crossed eyes (diplopia). Contralateral hemiparesis: Weakness or paralysis of the limbs on the opposite side of the lesion.

Holden's Line

A horizontal anatomical landmark, roughly 8 cm lateral to the pubic tubercle, marking the firm attachment of the deep membranous layer of superficial fascia (Scarpa’s fascia) to the deep fascia of the thigh (fascia lata). It indicates the surface projection of the hip joint capsule and acts as a barrier, preventing superficial, extravasated urine from the abdomen from entering the thigh.

Holden's Line 2

Anatomical Significance: It is the line of fusion for the Scarpa's fascia and the fascia lata. Clinical Significance: It acts as a barrier against superficial infections and urine extravasation (e.g., from ruptured urethra), keeping fluid in the abdominal area and preventing it from descending into the lower limbs. Extension: The line runs horizontally from the pubic symphysis towards the anterior superior iliac spine.

Cutaneous nerves of Lower Limb

Derived from lumbar (L{1}–L{4})) and sacral ((S{1}–S{3}) plexuses, provide sensory innervation to the skin. Key nerves include the femoral nerve (anterior thigh/leg), obturator nerve (medial thigh), lateral femoral cutaneous nerve (lateral thigh), and sciatic branches like the sural nerve (posterior leg/lateral foot)

Compartments of Thigh

Three main muscular compartments—anterior, medial, and posterior—by deep fascia (fascia lata) and intermuscular septa. These compartments are organized by function, with the anterior compartment extending the knee, the medial adducting the hip, and the posterior flexing the knee.

Vastii Muscles

The 3 vastii muscles—vastus lateralis, vastus medialis, and vastus intermedius—are three of the four muscles forming the quadriceps femoris on the anterior thigh. These powerful muscles originate on the femur, converge on the patella, and act as primary knee extensors, crucial for walking, standing, and stabilizing the knee joint.

Femoral Triangle 4

The femoral triangle is clinically vital for accessing major blood vessels (femoral artery/vein) for procedures like catheterization, assessing peripheral circulation via the femoral pulse, and managing hernias; its superficial location and key contents (Femoral Nerve, Artery, Vein, Lymphatics - NAVEL mnemonic) make it crucial for vascular access, surgery (e.g., great saphenous vein), and lymph node dissection

Femoral Nerve 2

Femoral nerve is the largest nerve arising from the lumbar plexus (spinal nerves L2-L4), responsible for motor and sensory innervation of the anterior thigh and medial leg. It controls hip flexion (iliacus, pectineus) and knee extension (quadriceps). Damage causes weakness, numbness, and difficulty with activities like climbing stairs.

Femoral Triangle Boundary 3

The femoral triangle is a triangular, subfascial space located in the superior-medial thigh, essential for vascular access. It is bounded superiorly by the inguinal ligament, medially by the adductor longus muscle, and laterally by the sartorius muscle, with the apex formed by the crossover of the latter two

Femoral Triangle Content 3

Arranged laterally to medially, are the femoral nerve, femoral artery, femoral vein, and deep inguinal lymph nodes (NAVEL)

Nerves of Lower Limb

Derived from the lumbar (L2–L4) and sacral (L4–S3) plexuses, enable motor, sensory, and postural function. Key nerves include the femoral (anterior thigh), obturator (medial thigh), sciatic (posterior thigh), and its terminal branches, the tibial (posterior leg) and common fibular (lateral/anterior leg) nerves.

9. Scalp Layers

The loose areolar tissue (fourth layer) is known as the "dangerous layer" of the scalp because it acts as a space where pus or blood can collect and spread, potentially leading to life-threatening infections (e.g., meningitis) via valveless emissary veins that drain directly into the cranial cavity.

10. Blood supply Scalp

It is supplied by five pairs of arteries—three from the external carotid artery (superficial temporal, posterior auricular, occipital) and two from the internal carotid artery (supratrochlear, supraorbital)—which anastomose extensively, often leading to profuse bleeding from injuries

11. Nerves of Scalp

Sensory Nerve Supply (Anterior to Auricle) Supratrochlear nerve (V1): Supplies the forehead and scalp up to the vertex. Supraorbital nerve (V1): Supplies the anterior scalp up to the vertex. Zygomaticotemporal nerve (V2): Supplies the temple area. Auriculotemporal nerve (V3): Supplies the skin in front of the ear and the temporal

12. Sensory Nerve of Scalp

Sensory Nerve Supply (Posterior to Auricle) Greater occipital nerve (Posterior ramus of C2): Supplies the occipital region up to the vertex. Lesser occipital nerve (Cervical plexus, C2/C3): Supplies the scalp behind the ear. Third occipital nerve (Posterior ramus of C3): Supplies the lower occipital region. Great auricular nerve (C2/C3): Supplies the scalp posterior to the ear.

13. Sensory Nerve Supply of Scalp

Greater occipital nerve (Posterior ramus of C2): Supplies the occipital region up to the vertex. Lesser occipital nerve (Cervical plexus, C2/C3): Supplies the scalp behind the ear

16. Veins of Scalp and face

Facial portion: supratrochlear, supraorbital, external nasal, inferior palpebral, superior and inferior labial, deep facial vein, buccinator, parotid and masseteric veins Cervical portion: submental, tonsillar, external palatine, lingual, submandibular, pharyngeal and superior thyroid veins

20. Facial Muscles-1

Orbicularis oculi: Closes the eyelids. Frontalis: Elevates eyebrows and wrinkles the forehead. Orbicularis oris: Closes and protrudes the lips. Buccinator: Flattens the cheeks and assists with chewing. Zygomaticus major: Elevates the corners of the mouth (smiling). Platysma: A large neck muscle that pulls down the corners of the mouth.

21. Facial Muscles-2

Auricular muscles (ear muscles) Auricularis anterior Auricularis posterior Auricularis superior

22. Muscles of Face -3

Buccolabial muscles (mouth muscles) Your buccolabial muscles are in and around your mouth. They are: Buccinator, a thin muscle in your cheek that holds it toward your teeth Depressor anguli oris, which is on the side of your chin and works with other muscles to produce a frown Depressor labii inferioris, a muscle in your chin that helps control movement in your lower lip Levator anguli oris, a muscle that helps you smile Levator labii superioris, which can enable you to smile or show disgust Levator labii superioris alaeque nasi, which can open your nostrils and lift your upper lip

23. Muscles of Face -4

Buccolabial muscles (mouth muscles) Mentalis, a muscle toward the center of your chin that helps control your lower lip Orbicularis oris, a circle of muscle around your mouth that closes or purses your lips Risorius, which aids in smiling Zygomaticus major and minor, which allow you to smile

24. Facial Muscles-5

Epicranial muscles (forehead, skull and neck muscles) around forehead, skull and neck. : Occipitofrontalis, a muscle that extends from your eyebrow to the top of your skull, lets you raise your eyebrow and wrinkle your forehead Platysma, a muscle that wrinkles the skin of your neck, helps open your mouth and allows you to lower the corners of your mouth and lower lip

25. Muscles of Face-6

Nasal muscles (nose muscles) Nasalis, (Compressor Naris and Dilator Naris)which allows you to flare your nostrils Procerus, a muscle (you just have one) between your eyebrows that can pull your brows downward and help flare your nostrils Depressor Septi

26. Muscles around orbit(Face)-7

Orbital muscles (eye muscles) Levator Palpebrae superioris Corrugator supercilii, which is near your eyebrow and enables frowning Orbicularis oculi, which closes your eyelid

27. Facial Muscles-8

functions of the muscles of face include: Giving your face its unique appearance Keeping food and drink in your mouth (preventing drooling) Protecting your eyes Singing Talking Whistling

28. Muscles of Face-9

The muscles of facial expression primarily develop from the mesoderm of the second pharyngeal (branchial) arch. As they develop and migrate from this arch during embryonic growth, they carry the facial nerve (cranial nerve VII) with them, which provides their innervation

29. Muscles of Face -10

In humans, several muscles of the head and neck are considered evolutionary remnants of the panniculus carnosus, a subcutaneous muscle layer well-developed in many other mammals for skin movement.

Laughing Muscle

Zygomaticus Major- . Laughing or "smiling muscle", which pulls the corners of the mouth upward and outward

Anger Muscle

Dilator Naris and Depressor Septi - Causes Expression of Anger

32. Muscle Causing Sad Expression

Levator labii Superioris and Levator Anguli oris

Muscle Causing Surprise

Frontalis part of Occipitofrontalis Muscle

34.Muscle Causing Horror Expression

Platysma Causes Horror or Terror expression- Action: The platysma is a broad, thin, sheet-like muscle located in the neck. When it contracts, it pulls the corners of the mouth down and sideways, tenses the skin of the neck, and lowers the jaw, creating the characteristic "shocked" or horrified look.

35. Whisteling Muscle

Buccinator and Orbicularis Oris - Orbicularis Oris: Encircles the mouth, allowing the lips to pucker, purse, and close. Buccinator: Located in the cheek, this muscle compresses the cheeks against the teeth to help force air out, making it essential for whistling and playing wind instruments. Also called- Buggler's or Trumpeter's muscle

36. Muscle causing Grief Expression

Depressor Labii inferioris and Depressor Anguli Oris -(which pulls down the corners of the mouth) - Long term Sadness

37. Frowning Muscle

Procerus and Corrugator Supercilli- (which draws eyebrows together) and the procerus (which pulls the skin between the brows down). These muscles create vertical and horizontal wrinkles on the forehead and bridge of the nose, often in response to anger, sadness, or concentration

38. Contempt Muscle

Zygomaticus Minor - The feeling that somebody/something does not deserve any respect or is without value

39. Doubt or Thinking Muscle

Mentalis- Located at the tip of the chin, this muscle elevates, everts (turns outward), and protrudes the lower lip, creating a "pouting" or skeptical look often associated with doubt, contempt, or displeasure

40. Grinning Muscle

Risorius -This muscle pulls the corners of the mouth sideways, which is characteristic of a grin, smirk, or strained smile.- Artificial Smile