Human Anatomy PDF

INTRODUCTION TO HUMAN ANATOMY Definition: Anatomy is the science of study the structures of the human body Ana = through. Tom = cut or dissect.  Anatomical Position The body stands erect in upright position. The face & eyes look forward. Upper limbs beside the trunk and the thu...

INTRODUCTION TO HUMAN ANATOMY Definition: Anatomy is the science of study the structures of the human body Ana = through. Tom = cut or dissect.  Anatomical Position The body stands erect in upright position. The face & eyes look forward. Upper limbs beside the trunk and the thumb is directed laterally. Lower limbs and the heels beside each other.  ANATOMICAL PLANES Sagittal plane: It is the vertical plane that passes through the body from front to back. The median ( para or mid-sagittal plane): It is the vertical plane that divides the body into right and left halves. Coronal plane: It is vertical plane which pass through body from side to side divides body into ant. & post. Parts. Horizontal (transverse) plane: It is parallel to the floor and divides the body into upper and lower parts.  METHODS OF STUDYING ANATOMY (1) Systematic anatomy: Study the human body system by system; digestive, respiratory, cardio-vascular ect…… (2) Topographical or regional anatomy: Study the human body region by region. The body regions are: Head & Neck. Trunk : Thorax, Abdomen, Pelvis & Perineum. Limbs: Two Upper Limbs & Two Lower Limbs. Levels of Structural Organization Cellular Tissue Organ System Organism or Body Regions of the Trunk Thorax Abdomen Pelvis & Perineum Regions of Upper Limb Pectoral Shoulder Scapular Arm Forearm Hand Fingers 0f Hand 1. Thumb(Lat.) 2. Index 3. Middle 4. Ring 5. Little ( Med.) Regions of Lower Limb Gluteal Hip Thigh Knee Leg Foot  Toes of Foot 1st or Big toe ( Medial). 2nd toe. 3rd or middle toe. 4th toe. 5th or little toe (Lateral).  Anatomical Terms (1)- Terms of Position: Superior means nearer to the head. Inferior means farer from head or nearer to the feet. Anterior (or ventral) means nearer to front of body. Posterior(or dorsal) means nearer to back of body. Medial means toward or nearer the midline of body. Lateral means faraway from the midline of body. Proximal means nearer to shoulder joint or hip joint. Distal means away from shoulder joint or hip joint. Superficial means closer to the surface of body. Deep means toward the center of body or body part. (2) -Terms of movements: General Terms of Movements: Flexion: bending anteriorly. Extension: straightening or bending posteriorly. Abduction: movement away from median plane. Adduction: movement toward median plane. Medial rotation (internal rotation): brings the anterior surface of a limb closer to median plane. Lateral rotation (external rotation): takes the anterior surface away from the median plane. Circumduction: is a circular complex movement formed from rapid succeive movements; flexion, extension, adduction and abduction.  Special Terms of Movements (occure only in certain parts of the body) 1- Dorsi-flexion: flexion at the foot at the ankle joint occurs when lifting the toes off the ground. 2- Plantar-flexion: turns the foot or toes toward the surface (when standing on your toes). 3- Lateral flexion of trunk: bending of the trunk in the coronal plane. 4- Pronation: is a rotational movement of forearm so that the palm of hand faces posteriorly (upward). 5- Supination: is a rotational movement of forearm so that the palm of hand faces anteriorly (downward) 6- Protrusion or protraction: is a movement of a part of body anteriorly or forward; ex. Shoulder joint, Mandible and tongue. 7- Retrusion or retraction: is a movement of a part of body posteriorly or backward; ex. Shoulder joint, mandible and tongue. 8-Elevation: raises or moves a part superiorly; ex. Shoulder joint and mandible. 9-Depression: lowers or moves a part inferiorly; ex. Shoulder joint and mandible. 10-Eversion: turning sole of foot laterally (outside). 11-Inversion: turning sole of foot medially (inside). Dorsi-flexion: Describes flexion at the ankle joint, as occurs when lifting the toes off the ground. Plantar-flexion: Turns the foot or toes toward the plantar surface (e.g., when standing on your toes). lateral flexion of the body: Movement of the trunk in the coronal plane  Medial rotation or (internal rotation): brings the anterior surface of a limb closer to median plane lateral rotation or (external rotation): takes the anterior surface away from median plane. Pronation: is the rotational movement of the forearm so that the palm of the hand faces posteriorly. Supination: is the rotational movement of the forearm so that the palm faces anteriorly. Eversion: turning the sole laterally Inversion: facing the sole medially Elevation: Raises or moves a part superiorly Depression: lowers or moves a part inferiorly Protrusion: It is a movement anteriorly (forward). Retrusion: It is a movement posteriorly(backward). protraction & retraction are used most commonly for anterior and posterior movements of the shoulder  General Body Structures (1) - Skin (INTEGUMENT PROPER). (2) - Fascia superficial. (3) - Deep fascia. (4) - Muscles. (5) - Bones. (6) - Joints. (7) - Vessels; blood & lymphatic.  (1) - The SKIN It covers all the body surfaces, Has 2 layers: 1-Superficial or outer layer, The Epidermis is a layer of stratified squamous epithelium. 2-Deep or inner layer, The Dermis. It lies just beneath the epidermis. It is dense fibrous connective tissue. Contents of dermis: 1- Blood Vessels.2- Lymph vessels.3- Nerve Endings 4-Hair Follicles. 5- Glands as mammary gland. Types of skin: 1- Thick skin as in palm of hand & sole of foot. 2- Thin skin as in eyelids & scrotum.  Functions of Skin: 1- Sensation: skin contains nerve receptors for pain, temperature and touch sensations. 2- Protection: skin covers and protects all the deep structures of the body. 3-Regulates the body temperature. Derivatives of skin: 1. Hair follicle. 2. Sweat Glands. 3. Sebaceous Glands. 4. Nails. Contents of Dermis & Epidermis The Epidermis & Dermis 1. Hair follicle 2. Sweat Glands 3. Sebaceous Glands 4. Nails  (2) - SUPERFICIAL FASCIA It is a white fibro-fatty layer that lying directly under the skin. Contents: 1-Cutaneous nerves. 2- Arteries & veins. 3-Lymphatic's. 4- Roots of hairs. 5- Glands, mammary gland. 6- Muscles as platysma in neck. Functions of the superficial fascia: 1- Protective function to the underlying body structures. 2-Insulator function to keep the body temperature and preventing heat loss. 3-It gives the body its contour. 4-In females it gives the body a smooth outline which is a secondary sexual character. 5-It acts as a reservoir of fat. 6-It serves a soft bed for passage of vessels and nerves. 7-It facilitates movements of the skin in some sites e.g. the scalp, the palm of the hand, the sole of the foot and the anterior abdominal wall. Contents of Superficial Fascia Superficial Fascia DEEP FASCIA  (3) - Deep Fascia It is an inelastic (not elastic) layer that forms a tight around limbs and a sheath around muscles to preserve their contours. Functions: 1- It keeps the underling structures in position. 2- It sends septa from its deep surface to the bones, called Inter-Muscular Septa. 3- It is markedly thick in some sites to form a band lick structure called “RETIACULUM” as in the front and back of the hand and foot. These retinacula hold tendons of muscles in position.  (4) - MUSCLES Types: 3 main types or groups (1)-involuntary, non-skeletal Smooth muscles They are controlled by autonomic nervous syst. They are not attached to bones. They are formed of smooth fibers. Examples are wall of visceral in GIT, respiratory, urinary, genital tracts and wall of blood vessels. They represent about 9% of all muscles in body. (2) - Cardiac muscle fibers It is a single and most important muscle. It is present in the wall of the heart, called the myocardium. (3) – Voluntary, Skeletal, striated muscles: They are under the control of will and supplied by central nervous system. They are attached and moves bones. They are formed of parallel fibers. They are 620 muscles on both sides. Each one has; origin, insertion, N. S. & action. They represent about 90% of all muscles in body. Forms of fibers in voluntary muscles: 1- Parallel or strap. 2-Quatrate. 3-Triangular. 4- Fusiform. 5-Pennate fibers: A-Uni-pennate. B-Bi-pennate. C-Poly-pennate. D- Circum-pennate. (1) parallel: (a) Quadrilateral muscles: as Thyrohyoid m. (b) Fusiform muscles as biceps m. (c) Strap as Sartorius m. (2) Triangular The fibers are convergent e. g., Temporalis m. (3) Pennate The fibers are oblique and converge: (a) unipennate :as palmar interossi (b) bipennate : as the Rectus femoris. (c) multipennate as deltoid muscle. (d) circumpennate as flexor policis longus muscle.  The Human Skeleton The skeleton forms the rigid supporting system in the human body. For descriptive purposes the human skeleton is divided parts into two main parts: (A)-AXIAL PART: 1-The Skull. 2-Vertebral Column, 3-Thoracic Cage. 4- Bony Pelvis. (B)- APPENDICULAR Part: 1- Bones of Upper Limb: Clavicle, Humerus, Ulna, Radius & bones of hand (carpal, metacarpal and phalanges). 2- Bones of Lower limb: Hip bone, Femur, Tibia, Fibula & bones of foot(tarsal, metatarsal and phalanges).  BONES Composition of bones: 1-Organic matters(35%):formed of collagen and muco-polysaccharids 2-Inorganic matters (65%): formed of minerals; as Calcium, Phosphates, Citrate, Radium, Fluoride, Magnesium & Sodium. Structures of bones: 1-Bone Cells (Osteocytes):They are branched flat cells, which are includes in lacunae. 2- Bone Matrix: It is formed of ; bundles of lamellae of calcified fibrous tissue with amorphous substance bounds in between. It contains the bone salts and blood vessels.  TYPES OF BONES (1)- ACCORDING TO STRUCTURE 1-Compact bone: It is found in the outer layer of flat and short bones as will as in the cylinders of long bone. It has formed of regularly arranged compressed bone lamellae. 2- Cancellous (spongy) bone: It is found in the dipole of flat bone, the inner mass of short bone and the terminal plugs of the long bone. It appears as thin irregularly arranged bone trabeculae separated by bone marrow spaces. (2)-ACCORDING TO SHAPE 1- Long bone as bones of the limbs; Humerus, femur, Ulna. They are cylindrical in shape formed of 2 ends; upper & lower with a body or shaft in-between. Ends called Epiphysis that is formed of cancellous bone. Shaft called Diaphysis is formed of compact bone contains bone marrow that produces RBC. The Metaphysis is the part of the Diaphysis near Epiphysis and is separated from it by the Epiphyseal Plate of Cartilage. Through this plate long bone grows in length till adult age. 2 – Short bone: as Carpal Bones at wrist of hand & Tarsal Bones at ankle of foot. They have different forms, but without medullary cavities along the bone length. Sesamoid bones are a variety of short bones. Patella is the largest seasamoid bone in the body. 3 – Short-long bones: as Metacarpal & Metarsal Bones in the dorsum of hand and foot. They are short cylindrical in shape without two ends, but with a bone marrow cavity inside. 4 – Flat bone: as bones of Skull, Ribs & Scapula. These are Thin, broad & formed of outer & inner plate of compact bones 5 – Irregular bone: as vertebrae in vertebral column & hip bone. It has ill-defined shape with many bone 6 – Pneumatic bones as some bones of face around nose. These bones contain small air cavities called para-nasal air sinuses. The para- nasal air sinuses lightening the weight of the skull, conditioning the air entering to respiratory system and clearing the tone of the voice. Functions of bones: (a) Gives body built, frame, contours and statures. (b) Gives areas for muscular attachments. (c) Bodily Support. (d) Protection of important internal organs. (e) Movements of the different parts of the body. (f) Postures. (g) Formation of Blood Cells (Hematopoiesis). (h) Storage of salts as calcium Long bone short bone flat bone irregular bone pneumatic bone (femur) (tarsal bones) (scapula) ( hip bone) (paranasal sinuses) BASIC STRUCTURE OF bONE  JOINTS Definition: joint or articulation is meeting, joining, union or connection “not fusion” between 2 or more bones. It is the site at which movement occur. Classification (a) Fibrous fixed Joints. (b) Cartilagenous Joints. (c) Synovial movable Joints.  Fibrous Fixed Joints The two bones are connected by Fibrous tissue formed of inelastic white fibers stretching between the two bony ends and tightly connects them together. NO MOVEMENT is present in this type of joint so, it is called FIXED JOINT. This type is the least common among all types of joints Examples of Fibrou Joints: 1 - Joints between the flat bone of the skull, called (SUTURES OF THE SKULL) as sagittal & coronal sutures. 2 - Joints between root of the teeth and their socket in the gum called (GOMPHOSIS). 3 - Joints between the tibia & fibula in the lower limb, specially the INFERIOR - TIBIO-FIBULAR JOINT called (SYNDESMOSIS).  Fibrous Fixed Joints Fibrous joint: Suture Suture: Bones abut with connective tissue between bones Periosteum (connective tissue covering on bone surfaces) Bone Suture  Cartilagenous Joints The two bones are connected by Fibro-Cartilage that extends between the two bony ends. LITTLE or LIMITED MOVEMENET is present in it. It is more common than fibrous joints TYPES OF CARTILAGENOUS JOINTS: PRIMARY CARTILAGENOUS JOINTS or (Synchondrosis): It is ossified later in life (transformed into bone at old age). Examples of this type: Epiphyseal Plates of long bones between epiphysis& metaphysis Spheno-Occipital joint at the base of the skull. SECONDARY CARTILAGENOUS JOINTS or (Symphysis): It is preserved allover the life, not ossified at old age. Examples of this type: Inter-Vertebral Disc (IVD) between bodies of the vertebrae. Symphysis Pubis between the two pubes bones. Manbrio-sternal joint between manbrium & body of sternum. (1) Primary (Synchondrosis) (2) Secondary (Symphysis)  Synovial Joints It is the most common and most movable types of joints in the body. The two bony are connected by many structure GENERAL STRUCTURES OF SYNOVIAL JOINTS 1– Two bony articular ends taking a part in articulation 2 – Fibrous capsule: It extends and connects the two opposed bony ends. It is thickened &strengthened by ligaments; called extra- capsular ligaments. It may be weekend by the presence of openings within it in some sites. Strength of capsule and ligaments are responsible for strength & stability of the joint. 3 - Articular cartilage: It is a thin smooth layer of cartilage covers the opposed articular surfaces of the two bony ends. It gives smooth surface for the site of articulation. It gives flexibility between the two bones, so it facilitates movements in-between.  4 – Synovial membrane: It is the most striking feature of synovial joints. It is a very thin highly vascular membrane. It covers all the intra-capsular structures of the joint except the articular surfaces. It lines the inner surface of the fibrous joint capsule. The synovial membrane contains synovial cells that secret the Synovial Fluid inside the joint cavity. Functions of the Synovial Fluid: 1 - Synovial fluid acts as a lubricant to prevent friction between the opposed bones. 2 - It facilitates movements in-between the two bones. 3 – It plays a role in nourishment of artricular cartilage 5 – Subsidiary structures inside the joint: 1-Articular disc of fibro cartilage; SternoClavicular, Acromio-Clavicular, Tempro-Mandibular joints. 2-Intra-capsular ligaments as Cruciate ligaments. 3-Menisci of cartilage that are present in knee joint. 4- Tendons of some muscles as long head of biceps.  6 – Blood and nerve supply: Synovial joints convey their blood and nerve supply by articular twigs that come from the surrounding vessels and nerves. They pierce the fibrous capsule to reach joint. MOVEMENTS & STABILITY OF SYNOVIAL JOINTS Movements are the most important characteristic features of synovial joints. All synovial joints are movable, but with Different degrees and ranges. Factors of Joint Stability: Bony Factor: Adaptation of two bones sharing in the joint. Capsular Factor: The strength of the fibrous joint capsule. Ligamentous Factor: The strength of overlying joint ligs. Muscular Factor: The strength of all the surrounding mus. The atmospheric pressure violent trauma.. Factors limiting joint movements: Soft tissue bulk: Prevents over movements, and keeps the articular surface close. The check action of muscle tension: Prevents the ligament stretch. Bone forms: It has a limiting action on the movement. This prevents over departure of the moving part thence keeps the articular surface coated. Example of this factor is the limiting and stopping extension of the elbow joint by the olecranon process. Factors of un-stability (dislocation) of synovial joints: 1-- Unadapted shape of the articular surfaces. 2 – Weakness of the capsule and ligaments. 3 – Weakness of the surrounding muscles. 4 – Atmospheric pressure and violent trauma. Classification of Synovial Joints (1) – According to exes of movements: A – Un-axial joints: They move around single axis; either transverse or longitudinal, e.g. Elbow & Ankle joints. The movements occur at this type of joints are Flexion & Extension. B – Bi-axial joints: They move around two axes, e.g. Wrist & Knee joints. The movements occur at this types of joints are Flexion & Extension and Adduction & Abduction. C – Poly-axial joints: They move in three axes, e.g. Shoulder & hip Joint. The movements occur at this type of joints are Flexion & Extension----adduction & Abduction----Medial rotation & Lateral rotation. (2)--ACCORDING TO THE SHAPE OF THE ARTICULATION 1-BALL& SOCKET TYPE: This type is poly-axial in nature e.g. Shoulder & Hip Joints. 2-HING TYPE: This type is uni-axial in nature e.g. Elbow, Ankle & Inter-phalangeal Joints. 3-SADDLE SHAPE TYPE: This type is bi-axial in nature where the opposing surfaces are reciprocally concavo-convex e.g.1st Carpo- metacarpal Joint of thumb. 4-GLIDING OR PLANE TYPE: This type has two smooth opposing surfaces e.g. Inter-carpal Inter-tarsal and Costo-vertebral Joints. 5- PIVOT TYPE: This type is uni-axial in nature where a pivot turns around longitudinal axis e.g. Superior Radio-Ulnar & Atlanto-Axial Joints. 6- CONDYLOID TYPE: This type is bi-axial in nature where two convex condyles articulate with two concave condyles e.g. Knee Joint. 7- ELLIPSID TYPE: This type is bi-axial in nature where one convex surface articulates with an elliptical concave surface e.g. Wrist joint  Uniaxial Synovial Joints (1)Plane joints (2)Hinge joints (3)Pivot joint Plane joints  Bi-Axial Synovial Joints (1)Condyloid joints )2(Ellipsoid joint )3(Saddle joint  Ellipsoid joint Biaxial ellipsoid joint: Wrist joint (Radiocarpal) Elliptical convex surface of carpal bones articulates with elliptical concave surface of radius Ulna Radius Radius Ulna Wrist Articular disc joint Lunate Scaphoid Triquetrum Radius Ulna  Saddle joint Biaxial saddle joint: Carpometacarpal joint of thumb Both articular surfaces are saddle-shaped: Flexion – extension, adduction - abduction Axis Axis Trapezium of carpus First metacarpal Atlas Atlas et joint: Joint: Multi-Axial Synovial Joints ension bduction teral rotation ction Hip bone Hip joint Head of femur  UPPER LIMB BONES OF THE UPPER LIMB CLAVICLE & SCAPULA: in the shoulder region HUMERUS: in the arm: RADIUS & ULNA: in the forearm SKELETON OF HAND: in the hand Muscles of the upper limb 59 muscles 15 Muscles in the shoulder region:3 groups (A)5 Muscles connect spines & transverse processes of vertebra (origin) with scapula, clavicle & humerus (insertion) 1-trapezius…..…..to clavicle & scapula 2-latismus dorssi…………….to humers 3-levator scapulae………….to scapula 4-rhomboids minor…………to scapula 5-rhomboids major…………to scapula * muscles insert in clavicle & scapula act on shoulder girdle and muscles insert in humerus act in shoulder joint TRAPEZIUS Origin: medial third of the superior nuchal line, external occipital protuberance, ligamentum nuchae, spinous processes of vertebrae C7- T12 Insertion: lateral third of the clavicle, medial side of the acromion and the upper crest of the scapular spine, tubercle of the scapular spine Action: elevates and depresses the scapula (depending on which part of the muscle contracts); rotates the scapula superiorly; retracts scapula N.S.: motor: spinal accessory (XI), proprioception: C3-C4 Rhomboideus major Origin: spines of vertebrae T2-T5 Insertion: medial border of the scapula inferior to the spine of the scapula Action: retracts, elevates and rotates the scapula inferiorly N.S.: dorsal scapular nerve (C5) Rhomboideus minor Origin: inferior end of ligamentum nuchae, spines of vertebrae C7 & T1 Insertion: medial border of the scapula at the root of the spine of the scapula Action: retracts, elevates and rotates the scapula inferiorly N.S.: dorsal scapular nerve (C5) LATISSIMUS DORSI Origin: vertebral spines from T7 to the sacrum, posterior third of the iliac crest, lower 3 or 4 ribs, sometimes from the inferior angle of the scapula Insertion: floor of the intertubercular groove Action: extends the arm and rotates the arm medially N.S.: thoraco-dorsal nerve (C7,8) from the posterior cord of the brachial plexus. LEVATOR SCAPULAE Origin: transverse processes of C1-C4 vertebrae Insertion: medial border of the scapula from the superior angle to the spine Action: elevates the scapul N.S.: dorsal scapular nerve (C5); the upper part of the muscle receives branches of C3 & C4 Dorsal Scapular Muscles (B) 4 Muscles connect thoracic wall (costal cartilages) with scapula & clavicle and humers 1-pectoralis major…………. to humers 2-pectoralis minor…………. to scapula 3-serratus anterior………… to scapula 4-subclavius…………………….to clavicle Pectoral muscles (connect ribs with scapula and clavicle) Axilla anterior wall Medial wall of axilla Lateral wall of axilla Posterior wall of axilla Pectoralis major Origin: medial 1/2 of the clavicle, manubrium & body of sternum, costal cartilages of ribs 2-6. Insertion: lateral lip of bicepital groove of humerus. Action: flexes & adducts the arm, medially rotates the arm N.S.: medial and lateral pectoral nerves (C5-T1) Pectoralis minor Origin: ribs 3-5 Insertion: coracoid process of the scapula Action: draws the scapula forward and downward N.S.: medial pectoral nerve (C8, T1) Subclavius Origin: first rib and its cartilage Insertion: inferior surface of the clavicle Action: draws clavicle (hence the shoulder) down & forward N.S.: nerve to subclavius (C5) Serratus anterior Origin: ribs 1-8 or 9 Insertion: medial border of the scapula on its costal (deep or ventral) surface by 8 digitations Action: it draws the scapula forward. The most inferior fibers rotate the scapula superiorly by the assist of levator scapulae and lower fibers of trapezius muscle. N.S.: long thoracic nerve (nerve of Bill) from C.5 to C.7 ventral rami. (C) 6 Muscles connect the scapula & the clavicle with the humers 1-Deltoid 2-Supraspinatus………rotator cuff group. 3-Infraspinatus………..rotator cuff group. 4-Teres minor………….rotator cuff group. 5-Subscapularis……….rotator cuff group. 6-Teres major Deltoid Origin: lateral one-third of the clavicle, acromion, the lower lip of the crest of the spine of the scapula Insertion: deltoid tuberosity of the humerus Action: abducts arm (2nd stage from 18-90); anterior fibers flex & medially rotate the arm; posterior fibers extend & laterally rotate the arm N.S.: axillary nerve (C5,6) from the posterior cord of the brachial plexus. Subscapularis Origin: medial two-thirds of the costal surface of the scapula (subscapular fossa) Insertion: lesser tubercle of the humerus Action: medially rotates arm; assists extension of the arm N.S.: upper & lower subscapular nerves (C5,6) brachial plexus. Supraspinatus Origin: supraspinatous fossa Insertion: greater tubercle of the humerus (highest facet) Action: abducts the arm ( 1st stage 0-18 ; initiates abduction) N.S.: suprascapular nerve (C5,6) from the superior trunk of the brachial plexus. Infraspinatus Origin: infraspinatous fossa Insertion: greater tubercle of the humerus (middle facet) Action: laterally rotates the arm N.S.: as supraspinatus Teres major Origin: dorsal surface of the inferior angle of the scapula Insertion: medial lip of bicepital groove Action: adducts the arm, medially rotates the arm, assists in arm extension N.S.: lower subscapular nerve (C5,6) from the posterior cord of the brachial plexus Teres minor Origin: upper 2/3 of the lateral border of the scapula Insertion: greater tubercle of the humerus (lowest facet). Action: laterally rotates the arm N.S.: axillary nerve (C5,6) from the posterior cord of the brachial plexus Shoulder muscles Deltoid Rotator calf muscles 3 muscles of the rotator Supraspinatus cuff Infraspinatus group Teres major Teres minor Sub-scapularis  4 Muscles in the arm (A) 3 muscles in front 1-Biceps 2-Brachialis 3-coracobrachialis (B)1 muscle in back 1-Triceps Front of the arm  biceps brachii Origin: short head: tip of the coracoid process of the scapula long head: supraglenoid tubercle of scapula Insertion: tuberosity of the radius Action: flexes the forearm, flexes arm (long head), supinates N. S. : Musculo-cutaneous nerve (C5,6) from the lateral cord of brachial plexus. brachialis anterior surface coronoid process flexes the musculocutaneo of the lower one- of the ulna forearm us nerve (C5,6) half of humerus & associated intermuscular septa Coraco-brachialis coracoid process medial side of flexes and musculocutaneo of the scapula the humerus at adducts the arm us nerve (C5,6) mid-shaft Back of the arm Triceps muscle triceps brachii long head: olecranon process extends the radial nerve infraglenoid of the ulna forearm; the long tubercle of the head extends and scapula; lateral adducts arm head: posterolateral humerus & lateral intermuscular septum; medial head: posteromedial surface of the inferior 1/2 of the humerus Nerves of the arm: * Median. * Ulnar. * Musculo- cutaneous Radial nerve in back of arm  20 Muscles the in Forearm (A) 8 Muscles in front of forearm According to action: 2 Digital Flexors: 1-Flexor digitorium superficialis. 2-Flexor digitorum profundus. 2 Wrist Flexors: 1-Flexor carpi ulnaris. 2-Flexor carpi radialis. 2 Pronators: 1-Pronator teres. 2- Pronator quadratus. 2 Others: 1-palmaris longus. 2-flexor pollicis longus. According to position: A- 5 muscles in superficial layer: flex. carpi. Ulnaris & flex. Carpi. Radialis & palmaris longus & pronator teres & flex. Digitorum superficialis B- 1 muscle in middle layer: flex. Digitorum profundus C- 2 muscles in deep layer: flex. policius longus & pronator quadratus. According to nerve supply: A- 6 ½ muscles by median nerve. B- 1 ½ muscles by ulnar nerve.  2 wrist flexors flexor carpi radialis common flexor base of the second flexes the wrist, median nerve tendon from the and third abducts the hand medial epicondyle metacarpals of humerus flexor carpi ulnaris common flexor pisiform, hook of flexes wrist, ulnar nerve tendon & (ulnar hamate, and base adducts hand head) from of 5th metacarpal medial border of olecranon & upper 2/3 of posterior border of the ulna  2 Digital Flexors flexor digitorum posterior border of base of the distal flexes the median nerve profundus ulna, proximal 2/3 phalanx of digits 2- metacarpophalange (radial one-half); of medial border of 5 al, proximal ulnar nerve (ulnar the ulna, interphalangeal and one-half) interosseous distal membrane interphalangeal joints flexor digitorum Humero-ulnar shafts of the middle flexes the median nerve superficialis head: common phalanges of digits metacarpophalange flexor tendon; 2-5 al and proximal radial head: middle interphalangeal 1/3 of radius joints Long thumb flexor anterior base of the flexes the median nerve flexor pollicis surface of distal phalanx metacarpophal longus radius and of the thumb angeal and interosseous interphalangea membrane l joints of the thumb Long palm flexor common palmar flexes the median nerve may be absent flexor tendon, aponeurosis wrist palmaris from the longus medial epicondyle of humerus  2 Pronators pronator medial side of anterior surface pronates the quadratus the anterior of the distal one- forearm surface of the fourth of the distal one-fourth radius of the ulna pronator teres common midpoint of pronates the median flexor tendon the lateral forearm nerve and (deep or side of the supplies ulnar head) shaft of the both the two from medial radius muscles. side of coronoid process of the ulna Front of the forearm (superficial group) Front of the forearm flexor digitorum superfialis Front of the forearm (deep group) Nerves on the front of forearm (B) 12 Muscles in Back of Forearm a- According to actions: 3 Digital Extensors: Extensor Digitorum. Extensor Indicis. Extensor Digiti minimi. 3 wrist extensors: Extensor carpi radialis longus. Extensor carpi radialis brevis. Extensor carpi ulnaris. 3 long thumb muscles: Abductor policies longus. Extensor pollicis brevis. Extensor pollicis longus. These 3 muscles share in formation of Anatomical Snuff Box. 3 Others: 1-Anconus. 2- Supinator. 3- Brachio-radialis. B- According to position: 7 superficial(3 wrist ext.,ext.digit.,ext.digit.minimi,brachio-rad.,anconus) 5 deep(3 policies, indicis, supinator ) c- according to nerve supply:All are supplies by radial nerve  3 Wrist (carpal) flexors extensor carpi radialis brevis Origin: lateral supracondylar ridge of the humerus (common extensor tendon Insertion: dorsum of the third metacarpal bone (base) Action: extends the wrist; abducts the hand extensor carpi radialis longus Origin: lower one-third of the lateral supracondylar ridge of the humerus Insertion: dorsum of the second metacarpal bone (base) Action: extends the wrist; abducts the hand extensor carpi ulnaris Origin: common extensor tendon & the middle one-half of the posterior border of the ulna Insertion: medial side of the base of 5th metacarpal Action: extends the wrist; adducts the hand. N.S. of the three muscles : deep radial nerve  3 Digital extensors Extensor digitorum Origin: common extensor tendon (lateral epicondyle of the humerus) Insertion: extensor expansion of digits 2-5 Action: extends the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints of the 2nd-5th digits; extends wrist Extensor indicis Origin: interosseous membrane and the posterolateral surface of the distal ulna Insertion: its tendon joins the tendon of the extensor digitorum to the second digit; both tendons insert into the extensor expansion Action: extends the index finger at the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints Extensor digiti minimi Origin: common extensor tendon (lateral epicondyle of the humerus) Insertion joins the extensor digitorum tendon to the 5th digit and inserts into the extensor expansion Action: extends the metacarpophalangeal, proximal interphalangeal and distal interphalangeal joints of the 5th digit N.S. of the three muscles : deep radial nerve.  3 Long thumb muscles extensor pollicis interosseous base of the distal extends the deep radial nerve longus membrane and phalanx of the thumb at the middle part of thumb interphalangeal the joint posterolateral surface of the ulna extensor pollicis interosseous base of the extends the deep radial nerve brevis membrane and proximal phalanx thumb at the the posterior of the thumb metacarpo- surface of the phalangeal joint distal radius abductor pollicis middle one-third radial side of the abducts the radial nerve, deep longus of the posterior base of the first thumb at carpo- branch surface of radius, metacarpal metacarpal joint interosseous membrane, mid- portion of postero-lateral surface of ulna  3 Others Brachio-radialis upper two-thirds lateral side of the flexes the elbow, radial nerve of the lateral base of the assists in supracondylar styloid process pronation & ridge of the of the radius supination humerus anconeus lateral lateral side of the extends the nerve to epicondyle of the olecranon and forearm anconeus, from humerus the upper one- the radial nerve fourth of the ulna supinator lateral lateral side of supinates the deep radial nerve epicondyle of the proximal one- forearm humerus, third of the supinator crest & radius fossa of the ulna, radial collateral ligament, annular ligament  Superficial muscles: Superficial group of muscles on the back of forearm:  Deep group of Deep muscles muscles on back of forearm Nerves on back of forearm  20 Short muscles in the hand 4 Theaner muscles: 1-Adductor pollicis. 2-Flexor pollicis bervis. 3-Abductor pollicis bervis. 4-Opponinous pollicis. 3 Hypo-theaner muscles: 1-Abductor digiti minimi. 2-Flexor digiti minimi. 3-Opponinous digiti minimi. 8 Inter-ossious muscles: 4 Palmar interossi: (1st is the most lateral one). 4 Dorsal interossi: (1st is the most lateral one). 4 Lumbricles: (1st is the most medial one). 1 Palmaris brevis. Cutaneous innervations on the dorsum of the hand (sensation) Cutaneous innervation of the palm of the hand (sensation) Thenar and hypo-thenar muscles Dorsal inter-ossei (finger abductors) (finger adductors) Palmar inter-ossei  Thumb adductor Adductِ or pollicis 4 Lumbrical muscles (Writing Position) Ulnar nerve in the hand Median nerve in the hand  Motor distributions of nerves in upper limb (1)-Ulnar nerve (C.8 & T.1) is motor to: 16 ½ muscles: 1 ½ muscles in front of forearm: Flexor carpi ulnaris. Medial ½ of flexor digitorum profundus. 15 short muscles in the hand: 3 hypotheaner muscles. 2 lumbricles( the medial two). 8 interossi muscles (palmar & dorsal) 1 adductor pollicis. 1 palmaris brevis. Motor lesion lead to partial (ulnar)claw hand. It can be felt behind medial epicondyle of humers.  (2)Median nerve (C.5,6,7,8 &T.1) is motor to 11 ½ muscles: 6 ½ muscles in front of forearm: Flexor carpi radialis. Lateral ½ of flexor digitorum profundus. Flexor digitorum superficialis. Flexor pollicis longus. Pronator teres. Pronator quadratus. 5 short muscles in the hand: 3 theaner muscles. 2 lumbricles ( the lateral two). * Motor lesion of median nerve lead to ape hand. * Motor lesion of both ulnar & median nerves lead to complete claw hand. * The nerve can be compressed as it passes in carpal tunnel lead to (carpal tunnel syndrome).  It is an osseofibrous carpal tunnel contains Carpal tunnel in the hand the tendons of the formed by the flexor flexors of the digits tunnel retinaculum and the (flexor pollicis longus carpal bones m., flexor digitorum superficialis m. flexor digitorum profundus m.) and the median nerve which may be compressed in this location resulting in carpal tunnel syndrome  (3)Radial nerve (C.5,6,7,8 &T.1) is motor to 13 muscles: 1 muscle in back of the arm ( triceps) 12 muscles in back of the forearm ( all the muscles). * Motor lesion lead to drop wrist & drop fingers. * It passes in radial groove behind middle of the shaft of humers (4) Muscluo-cutaneous n. (C.5 & 6) is motor to 3 muscles in front of arm: Biceps, Coraco-brachialis, Brachialis (5)Dorsal scapular nerve (C.5 & 6) is motor to 3 muscles: Levator scapula, Rhomboids minor & Rhomboids major. (6)Axillary nerve (C.5 & 6 ) is motor to 2 muscles: Deltoid muscle & Terem minor muscle. It passes around surgical neck of humers. Motor lesion lead to loss of arm abduction (from 18-90) and flat shoulder. (7)Supra-scapular nerve (C.5 & 6) is motor to 2 muscles: Supraspinatus & Infraspinatus. Motor lesion leads to loss of start shoulder abduction. (8)Sub-scapular nerves ; upper & lower (C 7, 8 & T1) are motor to 2 muscles: Subs-capularis &Teres major. (9)Pectoral nerves ( lateral & medial) are motor to 2 muscles: Pectoralis major & Pectoralis minor. (10)Long thoracic nerve (Nerve of Bill’s) is motor to 1 muscle: Serratus anterior. Motor lesion lead to winging of scapula (11)Thoraco-dorsal nerve ( nerve to latismuss dorsi muscle) is motor to 1 muscle: Latismuss dorsi. (12)Nerve to subclavius is motor to 1 muscle: (13)Spinal accessory nerve ( the only nerve not arises from the brachial plexuses) is motor to 1 muscle: Trapezius muscle. Motor lesion leads to drop shoulder.  Shoulder joint (gleno-humeral) Type: synovial, polyaxial, ball & socket Movements: Flexion by: pectoralis major, teres major, coraco-brachialis, anterior part of deltoid & long head of biceps. Adduction by; pectoralis major, teres major coraco-brachialis. Extension by; latissmus-dorsi, long head of triceps, posterior part of deltoid. Medial (internal) rotation by pectoralis major, teres major, sup-scapularis and latissmus-dorsi. lateral (external) rotation by teres minor, infra-Spinatus and posterior part of deltoid. Abduction; three stages: From 0 to 18 degrees by supra-spinatus. From 18 to 90 degrees by middle part of deltoid. From 90 to 180 in rasinig the hand above head (rotation of scaula) by serratus anterior and trapezius muscles. Circumduction is a compined successive movement formed of ; flexion, extension, adduction and abduction.  Shoulder joint is an articulation between the head of the humerus and the glenoid fossa of the scapula It is a synovial ball and socket joint; the glenoid labrum deepens the socket; glenohumeral ligaments reinforce the joint capsule anteriorly; the tendon of the long head of the biceps brachii m. passes through the shoulder joint cavity; the shoulder joint is supported by the muscles of the rotator cuff group (supraspinatus, infraspinatus, teres minor and subscapularis). It is the glenohumeral joint; it is frequently dislocated the joint what connects the clavicle with the sternum a synovial joint; its joint capsule is subdivided by a fibrous articular disc; it is strengthened by the sternoclavicular, interclavicular and costoclavicular ligaments. a ligament that reinforces the capsule of the sternoclavicular joint.the sternoclavicular ligament has two parts: anterior and posterior; it is a very strong ligament; the combined effect of this ligament, the costoclavicular ligament and the interclavicular ligament is to produce a very strong sternoclavicular joint that seldom dislocates Transvers humoral ligament that spans the intertubercular sulcus of the humerus it connects the greater tubercle of the humerus to the lesser tubercle of the humerus and acts to retain the tendon of the long head of the biceps brachii m. in the intertubercular sulcus Transvers scapular ligament that spans the suprascapular notch of the scapult it converts the suprascapular notch into a foramen; the suprascapular a. passes superior to the ligament and the suprascapular n. passes inferior to the ligament (Army over the bridge, Navy under the bridge).  Shoulder girdle (acromio-clavicular & sterno-clavicular joints) Type: Synovial, poly-axial, plane Movemrnts: a-Elevation by trapezius (upper fibers) and levator scapula. b-Depression by trapezius (lower fibers) and pectoralis minor. c- Protraction by serratus anterior and pectorlis minor. d-Retraction by middle fibers of trapezius and two rhomboids. e-Rotation of scapula upwards by combined action of levator scapula and serratus anterior. Elbow joint Type: synovial, uniaxial, hing. Movements: a-Flexion by biceps, brachialis and brachio-radialis. b-Extension by triceps. Wrist (radio-carpal) joint Type: synovial, biaxial, ellipsoid. Movements: A-Flexion by the 2 wrist flexors; flexor carpi radialis & flexor carpi ulnaris. B-Extension by 3 wrist extensors; extensor carpi radilais longus & bervis and extensor carpi ulnaris. C-Abduction by flexor carpi radialis and the 2 extensor carpi radialis (longus & brevis). D-Adduction by flexor carpi ulnaris and extensor carpi ulnaris.  Elbow joint It is the joint between the distal humerus and the proximal radius and ulna a synovial hinge joint; the elbow joint is a complex joint consisting of humeroradial, humeroulnar and proximal radioulnar articulations all within a common articular capsule; it is strengthened by the ulnar and radial collateral ligaments  Wrist joint It is articulation between the distal end of the radius and the proximal row of carpal bones a synovial ellipsoid joint; two primary degrees of motion are permitted: abduction/adduction and flexion/extension - these motions are combined to produce circumduction; the radius actually articulates with the articular disk which in turn articulates with the proximal row of carpal. Ulnar collateral ligament of the wrist it connects the styloid process of the ulna to the pisiform and triquetrum it reinforces the articular capsule on the medial side of the wrist bones (scaphoid, lunate and triquetrum) Radial collateral ligament of the wrist it connects the styloid process of the radius with the scaphoid and trapezium it reinforces the articular capsule on the lateral side of the wrist  Radio-ulnar joints (superior & inferior) Type: synovial, uniaxial, pivot. Movement: Supination by 2 muscles: Biceps and supinator. Pronation by 2 muscles: Two pronators; teres & quadratus. Mid-porn position (starts pronation & supination) by: Brachio-radialis. Shoulder joint Ligaments of shoulder joint  Ligaments of shoulder joint 1- Three gleno-humeral: superior, inferior and middle ligaments. 2- Coraco-acromial ligament. 3- Coraco-clavicular ligament. 4- Coraco-humeral ligament. 5- Transverse humeral ligament. Section in shoulder joint Elbow joint Ligaments of elbow joint Superior radio-ulnar joint Movements of elbow joint Sterno-clavicular joint Acromio-clvicular joint  BRACHIAL PLEXUSES 5 STAGES: 5 ROOTS: C. 5,6,7,8 T.1. 3 TRUNKS: UPPER – MIDDLE - LOWER 6 DIVISIONS:3 ANTERIOER 3 POSTERIOR 3 CORDS: MEDIAL-LATERAL-POSTERIO 13 BRANCHES: 5 from posterior cord (radial - axillary- nerve to latismuss dorsi-upper & lower subscapular). 5 from medial cord ( ulnar- medial pectoral- medial cutanous nerve of arm & forearm- medial root of median nerve). 3 from lateral cord ( musculo-cutaneous-lateral pectoral- lateral root of median nerve)  Other branches of the brachial plexuses * Branches of the trunks ; upper trunk: 1- Suprascapular nerve. 2- Nerve to subclavius. * Branches from roots: 1- C.5 dorsal scapular nerve. 2- C.5,6,7 long thoracic nerve (nerve to serratus anterioo)  Motor distribution of ulnar nerve Ulnar nerve (C.8 & T.1) is motor to 16 ½ muscles: 1 ½ muscles in front of forearm: Flexor carpi ulnaris. Medial ½ of flexor digitorum profundus. 15 short muscles in the hand: 3 hypotheaner muscles. 2 lumbricles( the medial two). 8 interossi muscles (palmar & dorsal) 1 adductor pollicis. 1 palmaris brevis. Motor distribution of median nerve Median nerve (C.5,6,7,8 &T.1) is motor to 11 ½ muscles: 6 ½ muscles in front of forearm: Flexor carpi radialis. Lateral ½ of flexor digitorum profundus. Flexor digitorum superficialis. Flexor pollicis longus. Pronator teres. Pronator quadratus. 5 short muscles in the hand: 3 theaner muscles. 2 lumbricles ( the lateral two).  Motor distribution of Radial nerve Radial nerve (C.5,6,7,8 &T.1) is motor to 13 muscles: 1 muscle in back of the arm ( triceps) 12 muscles (all ms.) in back of forearm. Motor distribution of Axillary nerve (C.5 &6),It is motor to 2 muscles: Deltoid muscle Terem minor muscle. Motor distribution of Muscluo-cutaneous nerve (C.5 & 6) is motor to 3 muscles: 3 muscles in front of the arm (all the muscles in front of arm). Motor distribution of Dorsal scapular n. (C.5 & 6) to 3 ms. Levator scapula. Rhomboids minor. Rhomboids major Motor distribution of Supra-scapular n. (C.5 & 6) to 2 ms. Supra-spinatus. Infra-spinatus Motor distribution of Sub-scapular ns. (upper & lower) to 2 muscles: Subscapularis. Teres major. Motor distribution of Pectoral ns. (lateral & medial) to 2 muscles: Pectoralis major. Pectoralis minor Motor distribution of Long thoracic nerve (Nerve of Bill's) to1 muscle: Serratus anterior. Motor distribution of Thoraco-dorsal n. ( n. to latismuss dorsi) to 1 muscle: Latismuss dorsi. Motor distribution of Nerve to sub-clavius to 1 muscle: Subclavius. Spinal accessory n. ( the only nerve not arises from the brachial plexuses) is motor to1 muscle: Trapezius muscle. Axillary nerve branches supply: Teres major and minor and deltoid The badge of skin overlying deltoid Radial nerve branches supply: Nearly all extensor muscles Skin of the posterior aspect of the upper limb (as the posterior cutaneous nerves of the arm and forearm) The dorsal aspect of the lateral 3½ digits. Tendon reflexes are fundamental to the examination of the peripheral nervous system. Diminished or brisk reflexes suggests lesion of the upper or lower motor neuron (upper motor neurons are first- order neurons which do not leave the central nervous system; lower motor neurons are the second-order neurons (cranial & spinal nerves). By tapping specific tendons, a monosynaptic reflex arc is triggered. The muscle spindle is stretched, which stimulates afferent fibers, and these synapse with efferent motor neurones of the anterior horn. This results in the muscle contracting and a subsequent ‘jerk’. Important ‘jerk’ reflexes in upper limb and their nerve roots are Biceps jerk: C5 Brachio-radialis jerk: C6 Triceps jerk: C7. INJURY NERVE AFFECTED CLINICAL FINDING ETIOLOGIES Fracture of the surgical neck Axillary n. Impaired shoulder abduction (deltoid) and lateral rotation (teres minor); flattened deltoid and loss of sensation over deltoid/lateral arm Trauma Shoulder Dislocation Axillary n. Impaired shoulder abduction (deltoid) and lateral rotation (teres minor); flattened deltoid and loss of sensation over deltoid/lateral arm Occurs during sports (overhead reaching) Midhumerus fracture Radial n. Wrist drop (triceps is spared because innervation by radial n. is above this area of injury) Trauma Radial head Dislocation Radial n. Wrist drop (triceps is spared because innervation by radial n. is above this area of injury) Falling on outstretched arm or pulling on child’s arm Bullet shot to biceps Musculocutaneous n. Impaired elbow flexion and forearm supination Trauma Supracondylar fracture (elbow) Median n. Impaired wrist flexion, flexion of digits 1–3, and pronation of the forearm → deficits make “hand of benediction”; can cause interruption of brachial artery and subsequent Volkmann ischemic contracture of the forearm/arm Fall on outstretched arm Fracture of lateral epicondyle Median n. Impaired wrist flexion, flexion of digits 1–3, and pronation Trauma of the forearm → deficits make “hand of benediction” INJURY NERVE AFFECTED CLINICAL FINDING ETIOLOGIES Carpal tunnel Median n. (superficial branch spared) Sensory/muscular deficits in digits 1–3, impaired thenar muscles, palm sensation intact Wrist overuse, obesity, pregnancy, volume overload, synovitis Fracture of medial epicondyle Ulnar n. Impaired interossei muscles, impaired digit 4–5 flexors and lumbricals, impaired hypothenar; impaired wrist flexion on ulnar side, leading to a claw-hand deformity trauma Fracture of hook of Hamate Ulnar n. Impaired interossei muscles, impaired digit 4–5 flexors and lumbricals, impaired hypothenar Fall onto hand Guyon canal Syndrome Ulnar nerve Clawing of ring and little fingers Pain and paresthesias in ring and little fingers Entrapment of the ulnar nerve at the wrist, often seen in cyclists due to pressure from the handlebars Saturday night palsy Radial nerve Wrist drop: loss of elbow, wrist, and finger extension Loss of sensation over posterior arm/forearm and dorsal hand Midshaft disruption of radial nerve, either due to compression or fracture Erb palsy C5-C6 roots Impaired shoulder abduction (loss of deltoid/ supraspinatus), impaired lateral rotation of arm (loss of infrapsinatus), loss of flexion and supination Lateral traction on neck during delivery in infants, trauma in adult Klumpke palsy C8-T1 roots Total claw hand (loss of intrinsic hand muscles; lumbricals, interossei, thenar, hypothenar) Upward force on arm during delivery in infants, trauma in adults Winged scapula Long thoracic n. Inability to anchor scapula to thoracic cage so it sticks out (loss of serratus anterior) Axillary node dissection after mastectomy, stab wounds  Important anatomical features of upper limb The axilla: Lies between the upper end of the arm and the chest wall. It is continuous above with the space between the upper ribs and the shoulder girdle. Its inferior limit is the armpit. It is a three-sided pyramid Anterior wall is formed by pectoralis major and minor, together with clavicle Medial wall is formed by the upper ribs and serratus anterior Posterior wall is formed by scapula & muscles covering its anterior surface. The axilla contains: 1-The cords and branches of the brachial plexus 2-Axillary artery 3- Axillary vein. 4-Lymph vessels & nodes which are surrounded and protected by fat. The cubital fossa: Is a triangular region anterior to elbow Lateral boundary is brachio- radialis Medial boundary is pronator teres Base is the line between the epicondyles of the humerus Floor is supinator Roof is fascia and skin. The biceps tendon can be palpated within the cubital fossa. The brachial artery and median nerve are found medial to the tendon within the fossa. The radial and ulnar nerves are outside the fossa. The carpal tunnel: is formed by the concavity of the palmar surface of the carpal bones and its overlying flexor retinaculum, a fi brous band attached to the pisiform, hook of hamate, scaphoid, and trapezium. The tunnel contains: Long flexor tendons of thumb and fingers (except flexor carpi-radialis). The median nerve but lacks veins and arteries. Compression of the median nerve results in carpal tunnel syndrome with motor and sensory impairment. The anatomical snuffbox: is a depression on the dorsal aspect of the hand. It is defined by: The scaphoid and trapezium, which form its base The tendons of abductor pollicis longus and extensor pollicis brevis on the anterior aspect The tendon of extensor pollicis longus posteriorly. The radial artery passes through the snuffbox. Scaphoid fractures result in acute tenderness in this region  Upper limb blood and lymphatic Arterial supply The upper limb is supplied by the subclavian artery which arises on the left from the aorta and on the right from the brachiocephalic trunk. The subclavian artery passes beneath the clavicle and enters the axilla, giving branches to the anterior and lateral chest wall. At the outer border of the first rib, it becomes the axillary artery and the artery accompanies the brachial plexus, located medially within the axillary sheath. Branches of axillary artery: To the chest wall and breast (superior and lateral thoracic arteries) To medial superficial shoulder tissue (thoraco-acromial artery) Around the upper shaft of the humerus (circumflex humeral artery) Along the lateral scapula (subscapular artery). On leaving the axilla, the artery becomes the brachial artery. It runs along the medial aspect of arm; its superficial lie allows it to be felt at the front of elbow. Branches of brachial artery: Near its origin to supply posterior compartment muscles and elbow joint (profunda brachii artery); this follows the course of the radial nerve to supply the humerus (nutrient artery) and anterior compartment muscles. As the artery enters the forearm, it divides into the radial artery & ulnar arteries which pass towards the wrist beneath the superficial muscles in the anterior compartment The ulnar artery branches soon after formation to establish the common inter-osseous artery, which in turn branches into the anterior (to the flexor compartment) and the posterior (to the extensor compartment) Inter-osseous arteries.Ulnar artery & radial arteries pass through the wrist into palm and divide into: 1-Superficial branches anastomose to form superficial palmar arch. 2-Deep branches anastomose to form the deep palmar arch. The superficial arch gives rise to four digital arteries; the deep arch gives rise to three metacarpal arteries. These unite to supply the digits. Princeps pollicis and radialis indicis arise from the radial artery to supply the thumb and index finger. Radial pulse can be felt at wrist where artery lies on the distal radius. In general, muscles and joints are supplied by adjacent arteries. Anastomoses between adjacent arteries are present at joints and provide a collateral circulation to sustain perfusion should the primary supply be compromised by joint movement.  Venous drainage Venous drainage can be divided into superfi cial and deep systems. Digital veins drain along with veins in the palm into dorsal venous arch on the back of the hand. This network is drained by superficial veins: Ulnar side of arch drains to basilic vein, ascends along medial forearm Radial side is drained by cephalic vein passes laterally up the forearm. Tributaries draining superficial tissues join these two vessels as they ascend.The two veins are connected by the median cubital vein which crosses the front of the elbow in the cubital fossa, and is often used for vene puncture. Deep veins (the venae comitantes) usually run in pairs alongside arteries. Above the elbow, the basilic vein unites with veins draining deeper structures of the forearm and upper arm (the venae comitantes of the brachial artery). The united vessels form the axillary vein, into which other venae comitantes in turn drain. The cephalic vein drains into the axillary vein beneath the clavicle. The axillary veins progress into the base of the neck where they become the subclavian veins. These unite with veins draining the head to form the superior vena cava.  Lymphatic drainage Lymphatic drainage parallels venous drainage. There are superficial and deep lymphatic vessels, with few interconnections. Superficial drainage: Of radial side is through vessels accompanying the cephalic vein Of ulnar side occurs through vessels running alongside the basilic vein. Deep tissue drains through vessels accompanying deep blood vessels. Most superfi cial and deep vessels ultimately drain into axillary lymph nodes which lie along the axillary artery. There are up to 50 such nodes: The lateral nodes, medial to axillary vein, drain most of lymph from arm In turn, the lateral nodes drain into the central nodes The central nodes feed into the apical nodes. Vessels accompanying the cephalic vein drain directly into the apical nodes. Lymph passes from the nodes to the subclavian lymph trunk alongside the subclavian artery. The trunk joins others, including the thoracic duct on the left side, to drain into the venous system at the unifi cation of the subclavian and internal jugular veins.