Upper Limb

deep muscles of posterior compartment of forearm innervation

- all supplied by the posterior interosseous branch of the radial nerve -supinator -Abductor pollicis longus -Extensor pollicis brevis -Extensor pollicis longus -Extensor indicis

median nerve

-(C5-T1) -The median nerve forms from two "heads" from the lateral and medial cords. -It runs down the anteromedial aspect of the arm with the brachial artery. Midway along the arm, the median nerve crosses anterior to the brachial artery to lie medial to it, reaching the cubital fossa. -After passing between the heads of pronator teres, the median nerve descends through the forearm posterior and adherent to flexor digitorum superficialis (FDS) and anterior to flexor digitorum profundus, before emerging lateral to FDS to become superficial just proximal to the wrist. -It gives branches to pronator teres, FDS, palmaris longus, and flexor carpi radialis. -Just proximal to the carpal tunnel, it gives the palmar cutaneous branch to supply the skin over the thenar eminence, and enters the hand by passing deep to the flexor retinaculum. -In the hand, it gives a recurrent muscular branch to the three thenar muscles (flexor pollicis brevis, abductor pollicis brevis and opponens pollicis) and divides into digital branches to supply the thumb, index, middle and radial half of the ring fingers. -The anterior interosseous branch arises after the median nerve has pierced pronator teres and passes distally on the interosseous membrane. It supplies flexor pollicis longus, the radial half of flexor digitorum profundus and ends in pronator quadratus.

radial nerve

-(C5-T1) -The radial nerve is a branch of the posterior cord, and supplies triceps brachii in the posterior compartment of the arm. -It lies posterior to the axillary and brachial arteries -It runs with the profunda brachii artery in the spiral groove of the humerus, perforates the lateral intermuscular septum, and runs around the anterior aspect of the elbow to divide into the superficial branch and the deep posterior interosseous branch. -The nerve leaves the posterior compartment by piercing the lateral intermuscular septum to reach the cubital fossa, where it lies between brachialis and brachioradialis. -The superficial branch lies on the anterolateral aspect of the forearm deep to brachioradialis and lateral to the radial artery. Distally, it passes deep to the brachioradialis tendon and curves round the lateral side of the radius as it descends, pierces the deep fascia and divides into terminal digital branches. These supply the skin on the radial half of the dorsum of the hand, and the dorsal aspects of the thumb, index, middle and radial half of the ring fingers, but not beyond the distal interphalangeal joints. -The deep branch, the posterior interosseous nerve, supplies the extensors of the wrist and fingers and the supinator muscle. -The radial nerve also gives sensory branches which supply the posterior part of the arm and forearm, as well as the anterolateral aspect of the lower half of the arm.

ulnar nerve

-(C8, T1) -Arising from the medial cord, the ulnar nerve runs on the medial aspect of the arm close to coracobrachialis. -It pierces the medial intermuscular septum to lie posteriorly in the groove between the olecranon and medial epicondyle. -It then enters the anterior compartment of the forearm by passing between the two heads of flexor carpi ulnaris (FCU), which it supplies. It also supplies the ulnar half of flexor digitorum profundus. -The palmar cutaneous branch arises near the mid-forearm and supplies the skin of the medial side of the palm. -The dorsal cutaneous branch winds round the ulna deep to FCU to supply the ulnar one and a half fingers on their dorsal aspects. -The main nerve runs with the ulnar artery to the wrist and divides into a superficial branch and a deep motor branch. -The superficial branch supplies the palmar brevis muscle and the skin of the ulnar one and a half fingers via two digital branches -the deep terminal branch runs into the palm to supply the small muscles of the hypothenar eminence (flexor digiti minimi, abductor digiti minimi and opponens digiti minimi), all the palmar and dorsal interossei, and the ulnar two lumbricals. It ends by supplying adductor pollicis.

brachial artery divisions

-A continuation of the axillary artery, the brachial artery extends from the lower border of teres major to just distal to the elbow, at the level of the neck of the radius. -It runs along the medial border of coracobrachialis and biceps brachii, accompanied by venae comitantes. It ends by dividing into the radial and ulnar arteries. -In the proximal part of the arm, the brachial artery lies next to the ulnar nerve. In the distal part of the arm, the median nerve lies on its medial side. As it reaches the elbow, it runs deep to the bicipital aponeurosis, with the median nerve lying medially. -Its branches include: the profunda brachii artery, which runs posterolaterally with the radialnerve in the spiral groove of the humerus; nutrient branches to the humerus; the superior ulnar collateral artery which accompanies the ulnar nerve; the inferior ulnar collateral artery, and muscular branches to coracobrachialis, brachialis, and biceps brachii.

Fracture of the scaphoid

-A fracture at the waist of the scaphoid is a common fracture caused by a fall onto the outstretched hand. -Avascular necrosis of the proximal fragment is a common complication, as the blood supply to the scaphoid goes from distal to proximal. -As the scaphoid is palpable on the floor of the anatomical snuffbox, patients presenting to the Accident Department with snuff box tenderness must be treated as a fracture.

radial nerve injury

-A patient with a radial nerve injury typically presents with wrist drop, i.e. an inability to extend the wrist, fingers and thumb. -Lesions of the radial nerve also cause weakness of the power grip, which depends on the synergistic contraction of both flexors and extensors. -Wrist drop in association with loss of active extension of the elbow would indicate a more proximal injury, e.g. in the axilla.

supracondylar fractures

-A supracondylar fracture of the humerus is a common childhood fracture. -It is a fracture of the distal humerus proximal to the epicondyles and is usually caused by a fall on the outstretched hand. -This type of fracture may be associated with serious complications including rupture or compression of the brachial artery and injury to the median nerve, as these structures lie anteriorly. -Compression of the artery leading to a pulseless hand must be treated as an orthopaedic emergency.

Mallet Finger

-An isolated "mallet finger" deformity, i.e. an inability to extend the distal interphalangeal (DIP) joint of the finger, is indicative of an injury to the insertion of the extensor digitorum communis tendon at the base of the distal phalanx. -This is a common sports injury, sustained when there is forced hyperflexion of the DIP joint. -Treatment involves splinting the DIP joint in slight hyperextension. If this fails, surgery may be required to repair the ruptured tendon.

scapulothoracic disorders

-Any process that affects the scapulothoracic joint can affect the overall function of the glenohumeral joint and may present as posterior shoulder pain, periscapular pain, rotator cuff bursitis or tendinitis secondary to impingement

clavicular fracture

-Clavicle fractures are relatively common injuries that most often occur in young active males or in elderly individuals, as a result of direct trauma to the shoulder, most notably from a fall directly on the shoulder. -The force is transmitted through the clavicle from the acromioclavicular joint to the sternoclavicular joint.

De Quervain's tenosynovitis

-De Quervain's disease refers to a thickening of the synovial tendon sheaths of two tendons to the thumb, abductor pollicis longus and extensor pollicis brevis. -Patients present with pain, tenderness, and swelling over the radial side of the wrist, and difficulty gripping. -Some consider this to be an overuse injury with repetitive movements of the thumb being a contributing factor. -Surgery may provide relief in severe cases, but there is a risk of injury to the sensory branches of the radial nerve.

innervation of skin receptors dermatomes nerves to upper limb

-Distribution of sensory receptors in the skin varies widely across the body, with modalities such as temperature, fine and crude touch, blunt and sharp touch, and pressure. -Meissner's corpuscles are responsible for light touch and are concentrated in sensitive areas such as the fingers and lips. -Pacinian corpuscles are sensitive to vibration and pressure. -The area of skin supplied by an individual spinal nerve is known as a dermatome. -Knowledge of the dermatomes is important in order to diagnose problems associated with nerve-related disorders, peripheral nerve or spinal injuries, and to administer local anaesthesia. -The nerves to the upper limb originate from five spinal root levels, extending from the 5th cervical (C5) to the 1st thoracic spinal nerves (T1). They form a network known as the brachial plexus, from which peripheral nerves emerge

extensor digitorum communis course innervation function

-EDC is the main extensor at the finger joints, but in crossing the wrist, it also contributes to wrist extension. -It arises from the CEO and inserts via four tendons which spread out onto the dorsum of the hand, passing to the index, middle, ring, and little fingers. -The tendons run in a common compartment deep to the extensor retinaculum. -As each tendon crosses the metacarpophalangeal joint, it forms a dorsal expansion which covers the proximal phalanx. This expansion is reinforced by the tendons of the corresponding interosseus and lumbrical muscles. -Over the proximal interphalangeal joint, the tendon divides into three slips. The middle slip attaches to the base of the middle phalanx, while the outer two slips pass distally and reunite to attach to the base of the distal phalanx. -EDC is supplied by the posterior interosseous nerve.

glands in skin

-Eccrine sweat glands control body temperature and are controlled by the sympathetic nervous system -apocrine sweat glands are limited to the axilla, mammary areola and anogenital region. -Sebaceous glands are present throughout the skin, except the palms and soles. They produce sebum which provides a protective covering for the skin.

intermediate layer of anterior compartment of forearm course innervation function

-Flexor digitorum superficialis (FDS) -This muscle is described as having two heads. The humeroulnar head arises from the anterior aspect of the medial epicondyle via the CFO, the coronoid process of the ulna, and the ulnar collateral ligament of the elbow joint. -There is also an extended origin from the radius. -Its four tendons run in a common sheath through the carpal tunnel. Over the proximal phalanx, each tendon divides into two slips (the decussation) to allow the tendon of flexor digitorum profundus (FDP) to pass through. The slips of each tendon then insert into radial and ulnar aspects of the base of the middle phalanx. -FDS is a weak flexor of the elbow and a strong flexor of the wrist and fingers (excluding the distal interphalangeal joint). -It is supplied by the median nerve.

Rupture of the extensor pollicis longus tendon

-Fractures of the distal radius may result in rupture of the tendon of extensor pollicis longus because of its association with the dorsal (Lister's) tubercle. -Patients are unable to extend the interphalangeal joint of the thumb.

humeral shaft fractures

-Fractures of the humeral shaft may lead to radial nerve injury due to its location in the spiral groove. -As branches of the radial nerve also supply the extensors of the wrist and fingers, injury will lead to wrist drop. In this condition, the patient cannot extend their wrist and the hand hangs flaccidly. - However, over 90% of cases of radial nerve palsy associated with closed fractures will recover spontaneously.

scapular fracture

-Fractures of the scapula are rare and are usually the result of a high energy, blunt force trauma. -Patients with scapular fractures present with the ipsilateral upper extremity adducted against the body and protected from movement.

joints in hand

-In the hand, there are intercarpal joints between the proximal and distal rows of carpal bones. -There is a common carpometacarpal joint between the bases of the medial four metacarpal bones and the distal rows of the carpal bones. -An independent saddle-shaped joint between the trapezium and the base of the first metacarpal enables the thumb to be fully opposable. -The metacarpophalangeal and interphalangeal joints have strong collateral ligaments which essentially restrict finger movements to flexion and extension.

Tenosynovitis

-Inflammation of the flexor tendons and synovial sheaths may occur with chronic repetitive use, trauma or arthritis. -Symptoms of tenosynovitis include pain, swelling and difficulty moving the inflamed joints. - The finger may sometimes remain in a flexed position, a condition that is commonly known as trigger finger.

langer's lines

-Langer's lines, also known as tension or cleavage lines, follow the orientation of collagen fibres. -They are of special interest to surgeons, as incisions made parallel to these lines heal more rapidly and produce neater scars.

Latissimus Dorsi course innervation function

-Latissimus dorsi arises from the posterior region of the iliac crest and via an aponeurosis from the vertebral spines inferior to T6. -The fibres converge on a flat tendon that inserts into the floor of the bicipital groove of the humerus near the crest of the lesser tuberosity. -The latissimus dorsi and its tendon undergo a 180-degree twist prior to reaching the humerus so that fibres arising from the ilium actually insert most proximally, whereas those arising from midthoracic vertebrae insert most distally. -The latissimus dorsi is an adductor, medial rotator, and extensor of the arm. It is important in all movements requiring powerful extension of the arm and is innervated by the thoracodorsal nerve.

Levator scapulae course innervation function

-Levator scapulae arises from C1-C4 and inserts along the vertebral border of the scapula from its superior angle to the root of its spine, where the rhomboid attachment begins. -It is innervated by branches of the 3rd and 4th cervical ventral rami, as well as a branch from the dorsal scapular nerve. -As its name suggests, levator scapulae contributes to elevation of the scapula and simultaneously pulls it forward.

median nerve injury

-Low (distal) lesions of the median nerve may be a result of carpal tunnel syndrome -Patients with high (proximal) lesions of the median nerve will present with the following symptoms: inability to flex the index and middle fingers and the distal phalanx of the thumb; weakness and wasting of the muscles of the thenar eminence; inability to oppose and abduct the thumb with impairment of precision grip; and ulnar deviation at the wrist.

upper limb lymphatics

-Lymphatic drainage follows the course of the arteries for deep structures and superficial veins for the skin. -Numerous lymph nodes are found in the axilla. They filter lymph from the upper limb, upper thoracic wall, upper abdominal wall, and the breast into the main lymphatic channels and ultimately into the bloodstream.

nails

-Nails provide a firm base for the pulp of the digit. Most of the nail bed appears pink due to underlying capillaries supplying from the dermis.

Tennis and golfer's elbow

-Patients with tennis elbow, or lateral epicondylitis, present with pain and tenderness over the common extensor origin, probably caused by overuse leading to a degenerative tear. -Resisted wrist extension aggravates the pain. Non-operative management with rest and/or steroid injections is effective in the majority of cases. -Golfer's elbow is a similar inflammatory condition affecting the medial epicondyle, where the forearm flexors attach.

muscles connecting trunk to humerus

-Pectoralis major -Latissimus Dorsi

Pectoralis Minor course innervation function

-Pectoralis minor is a true muscle of the upper limb and is innervated by the brachial plexus, specifically the medial pectoral nerve. -It typically arises from the anterior surfaces of the third, fourth and fifth ribs in the vicinity of their costochondral junctions. -The muscle fibres pass superolaterally, converging on a tendon that inserts into the medial lip of the coracoid crest near its tip. -Pectoralis minor pulls the scapula inferomedially.

ruptured biceps tendon

-Rupture of the proximal part of the biceps tendon account for over 90% of all biceps ruptures, and almost exclusively involve the long head. -The retracted muscle "bunches up" in the arm, leading to a bulge, the Popeye muscle. Functional loss is minimal as the short head is intact. -The injury is most commonly seen in individuals aged 40-60 with a history of shoulder problems, secondary to chronic wear and tear of the tendon. -Younger individuals may rupture the biceps tendon after a fall, during heavy weightlifting or other sporting activities. -Distal ruptures may occur at the insertion on the radial tuberosity. These are followed by reduced strength in forearm supination and elbow flexion, and require surgical repair.

Axillary clearance

-Surgical removal of axillary lymph nodes may be performed for breast carcinoma. -During axillary dissection, the nerves and vessels must be clearly identified. -Injury to the long thoracic nerve will cause paralysis of serratus anterior. -This results in weakness of shoulder abduction because of loss of scapular rotation. -In addition, it leads to a "winged scapula", i.e. protrusion of the scapula when the patient presses with his hand against a wall.

arm muscle innervation compartments

-The arm is located between the shoulder and the elbow joint. -It is divided into anterior and posterior muscle compartments by the medial and lateral intermuscular septa. -The muscles of the anterior compartment flex the elbow and are supplied by the musculocutaneous nerve. -Those in the posterior compartment extend the elbow and are supplied by the radial nerve.

axilla

-The axilla is a fat-filled pyramidal space between the arm and lateral thoracic wall, bounded by anterior and posterior axillary folds. -It communicates superiorly with the posterior triangle of the neck and contains neurovascular structures destined for the upper limb.

contents of axilla

-The axillary artery -The axillary vein -The axillary lymph nodes

basilic vein

-The basilic vein begins on the medial (ulnar) aspect of the wrist and runs up the forearm on the medial aspect of the cubital fossa. -About midway between the elbow and shoulder, it pierces the deep fascia and joins the venae comitantes (accompanying veins) of the brachial artery to form the axillary vein.

upper limb innervation segmental development

-The body develops segmentally, with each segment having its own nerve, artery, and vein. -As the limbs form and elongate, they take their nerves and vessels with them. -The upper limb is innervated by the brachial plexus, which is formed by the anterior primary rami of the lower four cervical spinal nerves (C5 to C8) and the first thoracic spinal nerve (T1). -The plexus is formed in the neck and passes into the axilla, where branches are given off to supply the arm, forearm and hand.

brachial plexus

-The brachial plexus is formed by the union and subsequent division of the anterior primary rami of the lower four cervical and part of the anterior ramus of the first thoracic nerves (C5 to T1). -These are the five roots, which emerge between scalenus anterior and medius in the neck. -The roots unite to from three trunks, which cross the posterior triangle of the neck. The upper two roots (C5, 6) form the upper trunk, the C7 root continues as the middle trunk, and the lower two roots (C8, T1) form the lower trunk. -Each trunk divides into anterior and posterior divisions at the apex of the axilla. -The cords are formed in the following way, and are named according to their relationship to the second part of the axillary artery deep to pectoralis minor: the anterior divisions from the upper and middle trunks form the lateral cord, the anterior division of the lower trunk forms the medial cord, and all the posterior divisions unite to form the posterior cord. -The branches from the cords are related to the third, most distal part of the axillary artery -The brachial plexus supplies the motor and sensory innervation of the whole upper limb with two exceptions. Trapezius is supplied by the spinal accessory nerve, and an area of skin on the medial arm is supplied by the intercostobrachial nerve, which is the lateral cutaneous branch of the second intercostal nerve (T2)

carpus

-The carpus consists of eight carpal bones arranged in two rows. -The proximal row comprises the scaphoid, lunate, triquetral and pisiform, while the distal row comprises the trapezium, trapezoid, capitate and hamate. -Minimal movement occurs between these bones, which are connected to each other by intercarpal ligaments that give the carpus its stability.

cephalic vein

-The cephalic vein begins on the lateral (radial) aspect of the hand, crosses the anatomical snuffbox and runs up the lateral aspect of the forearm and arm to lie in the deltopectoral groove. -This vein is important for intravenous cannulation and venous access at the wrist and distal forearm because of its size and fairly constant position. It pierces the clavipectoral fascia to join the axillary vein.

clavicular articulations

-The clavicle articulates laterally with the acromion of the scapula at the acromioclavicular joint and medially with the sternum at the sternoclavicular joint. -The clavicle forms part of the pectoral girdle, with the sternoclavicular joint connecting the upper limb to the axial skeleton.

clavicle

-The clavicle articulates with the manubrium and laterally with the acromion of the scapula to form the sternoclavicular and acromioclavicular joints respectively. -It provides attachments for muscles from the spine, e.g. trapezius, and upper limb muscles, e.g. the deltoid.

retinacula

-The deep fascia of the upper limb forms specialised thicker bands called retinacula. -The flexor retinaculum lies distal to the wrist joint and forms a fibro-osseous tunnel through which pass the tendons to the hand. -Similarly, the extensor retinaculum retains the extensor tendons in place as they pass through to the dorsum of the hand.

deep fascia

-The deep or investing fascial layer is composed of collagen fibres, often arranged to respond to lines of stress. -Over the limbs it can be seen as a tough white sheet of fibrous tissue which forms a non-elastic tight fitting sleeve. -This keeps underlying structures in position, and also assists venous and lymphatic return. -Fascial processes extend downwards from the sleeve forming septa which in the case of limbs mark out a series of compartments containing separate muscle groups and bundles of vessels and nerves. -Fascial compartments offer the benefit of limiting the spread of infection.

dermis layers

-The dermis supports the epidermis structurally and nutritionally. -It provides considerable strength to the skin due to the arrangement of its collagen and elastic fibres. It is vital for the survival of the epidermis. -Its thickness varies, being thin in the eyelids and thick on the back. In old age, the dermis thins and loses its elasticity. -The dermis is composed of two layers: a thin papillary layer and a thicker reticular layer.

elbow joint capsule stability movements muscles superior radioulnar joint nerve relations

-The elbow is a synovial hinge joint. -The radial head articulates with the ulna in supination and pronation, and slides on the capitulum of the humerus in flexion and extension. -The capsule is attached to the margins of the articular surfaces but is lax anteriorly and posteriorly to permit full flexion and extension. The epicondyles are extracapsular. -Stability is maintained by the congruous articular surfaces of the trochlea and trochlear fossa. It is also enhanced by medial and lateral collateral ligaments and the anular ligament around the radial neck. -Movements are primarily flexion and extension by brachialis and biceps anteriorly and triceps posteriorly. Forearm supination and pronation occur at the superior and inferior radio-ulnar joints. The former communicates with the elbow joint. -Important relations include the median nerve and brachial artery anteriorly, the ulnar nerve posteromedially, and the radial nerve anterolaterally. -The radial nerve perforates the lateral intermuscular septum just proximal to the elbow and winds around the radial neck before dividing into its main superficial branch and deep posterior interosseous branch.

elbow injuries

-The elbow is a very stable joint so dislocation is relatively uncommon. However, posterior dislocation may result from a fall on the outstretched hand in children whilst ossification is still incomplete. -A pulled elbow refers to subluxation of the head of the radius out of the anular ligament. This occurs when the hand of a child is suddenly pulled with force.

epidermal ridges

-The epidermis adheres to the dermis partly by the interlocking of its downward projections (epidermal ridges or pegs) with upward projections of the dermis (dermal papillae), at a site referred to as the dermoepidermal junction. -These pegs are important structural components which allow skin to withstand abrasive forces and without which the epidermis and dermis would move apart. When this happens, a blister is formed

epidermis layers

-The epidermis consists of many layers of closely packed cells, the most superficial of which are flattened and filled with keratin. It is therefore a stratified squamous epithelium. - Four layers are formed by differing stages of keratin maturation and are (from deep to superficial): stratum basale (basal cell layer): a single layer of cells which continually divide, forming new cells and replacing those that are shed from the skin surface. Melanocytes, which produce the pigment melanin, are located in this layer. stratum spinosum (spinous or prickle cell layer): the thickest layer, with "prickle cells" which are linked by numerous processes. stratum granulosum (granular cell layer): cells in this layer accumulate keratohyalin granules which eventually overfill the cells, destroying the nuclei and organelles. stratum corneum (horny layer): this layer is thickest in the palms and soles, and contains dead keratinocytes or squames which are continually shed from the surface. -An additional layer, the stratum lucidum, is present only in the hands and feet deep to the stratum corneum. Its cells contain tonofibrils (densely packed keratin filaments).

metacarpals

-The five metacarpals are long bones that form the skeleton of the hand. -Each consists of a base, shaft and head. -Minimal movement occurs between carpus and metacarpals, except for the saddle-shaped first carpometacarpal joint which allows free thumb movements. -The shafts are joined by transverse metacarpal ligaments, and the palmar and dorsal interossei, allowing abduction and adduction of the fingers at the condyloid metacarpophalangeal joints.

skin and aging

-The flattening of the dermoepidermal junction with age accounts in part for some of the visual signs of ageing. -Loss of elastin causes skin to become loose and lined.

boundaries of axilla

-The floor of the axilla is formed by deep fascia, subcutaneous tissue and skin. -The anterior wall is formed by pectoralis major and minor, subclavius, and the clavipectoral fascia. -The posterior wall extends lower and is formed by subscapularis, teres major and the tendon of latissimus dorsi winding around the latter. -The medial wall is formed by serratus anterior -The lateral wall is the intertubercular or bicipital groove of the humerus.

forearm muscle innervation compartments

-The forearm is located between the elbow and wrist joints. -The muscles in the anterior compartment flex the wrist and fingers, and are supplied by the median and ulnar nerves. -Those in the posterior compartment extend the wrist and fingers, and are supplied by the radial nerve. -The flexor compartment is much more bulky for the necessary power of gripping. There are also muscles involved in pronation and supination.

lumbricals

-The four lumbricals arise from the tendons of flexor digitorum profundus (FDP), with the medial two supplied by the ulnar nerve, and the radial two by the median nerve. -Each tendon passes round the radial side of the finger to insert onto the dorsal expansion. -The interossei and lumbricals act together to flex the metacarpophalangeal joints and extend the interphalangeal joints in association with the extensor tendons.

glenohumeral joint ligaments movements associated muscles movements and their muscles neurovascular structures

-The glenohumeral (shoulder) joint is a synovial ball-and-socket joint. The surface area of the humeral head is three times that of the glenoid fossa, whose margins are extended by a fibrocartilaginous labrum to provide stability. -The capsule is attached at the margins of the anatomical neck, and is lax inferiorly to allow abduction. It is strengthened by the coracohumeral ligament and three anterior glenohumeral ligaments. -Movements occur in three planes: flexion/extension, abduction/adduction, medial/lateral rotation. -Circumduction is a combination of flexion, extension, abduction and adduction, resulting in a circular movement of the limb. -Prime movers of the joint are the deltoid, pectoralis major, latissimus dorsi, teres major and coracobrachialis muscles. -The rotator cuff muscles (supraspinatus, infraspinatus, teres minor and subscapularis) act to hold the humeral head within the glenoid, giving strength and dynamic stability. -Abduction is initiated by supraspinatus and continued by the lateral fibres of deltoid. -The only true adductor is coracobrachialis, but pectoralis major, latissimus dorsi, and teres major can also adduct the abducted shoulder. -Infraspinatus and teres minor laterally rotate, while medial rotation is by subscapularis and teres major, as well as latissimus dorsi and pectoralis major. -Important neurovascular structures that neighbour the shoulder joint include the brachial plexus, axillary artery and vein, as well as the axillary nerve and circumflex humeral artery around the surgical neck of the humerus.

palmar arches

-The hand is supplied by the superficial and deep palmar arches. -The former is the continuation of the ulnar artery which enters the palm with the ulnar nerve, superficial to the flexor retinaculum. -The latter is formed by the radial artery after it has passed between the first dorsal interosseus and adductor pollicis to enter the palm from its dorsal aspect. -There are rich anastomoses between the two palmar arches.

hand muscles

-The hand lies distal to the wrist joint, and its dexterity results from a combination of thumb mobility, finger movements controlled by numerous intrinsic muscles, and the amazing tactile sense of the skin in the hand and fingers. -Loss of the thumb may lead to severe disability.

humerus

-The head of this long bone articulates with the glenoid fossa of the scapula. -The anatomical neck separates the head from the greater and lesser tuberosities, which provide attachment for the rotator cuff muscles. -The tendon of the long head of biceps lies in the intertubercular groove. -The surgical neck separates the proximal end from the humeral shaft. -The spiral groove on the posterior aspect of the shaft houses the radial nerve and profunda brachii artery. -Distally, the medial and lateral supracondylar ridges continue into the medial and lateral condyles. Their tips form the medial and lateral epicondyles. -At the elbow joint, the trochlea articulates with the trochlear notch of the ulna and the capitulum with the head of the radius. -Anteriorly, the coronoid fossa accepts the coronoid process of the ulna during elbow flexion. Posteriorly, the olecranon fossa accepts the olecranon during elbow extension.

venous cannulation upper limb

-The median cubital vein is often used for venepuncture to take blood for diagnostic purposes. -The cephalic vein in the forearm is a good vein for successful insertion of a cannula, as it is fairly large and has a constant position.

fracture of metacarpals

-The metacarpals can be fractured due to direct violence, e.g. when a clenched fist strikes a hard object. -A transverse fracture at the neck of the fourth or fifth metacarpal is commonly known as a boxer's fracture.

musculocutaneous nerve

-The musculocutaneous nerve arises from the lateral cord of the brachial plexus. -It perforates and supplies coracobrachialis, then passes to the lateral aspect of the arm between biceps brachii and brachialis, both of which it supplies. - Just above the elbow, it becomes cutaneous as the lateral cutaneous nerve of the forearm.

Pectoralis major course innervation function

-The origin of pectoralis major is the midpoint of the anterior surface of the clavicle and extends medially towards the sternoclavicular joint. Crossing the anterior surface of the sternoclavicular joint, this origin continues onto the front of the sternum, where it descends to the 7th sternochondral junction, finally passing along the 7th costal cartilage onto the aponeurosis of the external oblique muscle. -The fibres arising from the clavicle form a distinct bundle known as the clavicular head, while the fibres from the sternum and costal cartilages form the sternocostal head. -The clavicular head is innervated by the lateral pectoral nerve. The sternocostal head is innervated by the medial pectoral nerve. -The fibres of the sternocostal head converge on a flat tendon that inserts onto the lateral lip of the bicipital groove of the humerus. The fibres of the clavicular head insert onto the anterior surface of this tendon. -Both portions of the muscle adduct and medially rotate the arm at the glenohumeral joint, but the clavicular head is also a major flexor of the arm. With the upper limb fixed in abduction, pectoralis major is also an accessory muscle of respiration.

pectoral girdle articulations glenohumeral relation

-The pectoral girdle connects the upper limb to the axial skeleton and is composed of the scapula and clavicle with their interposing joints. -The clavicle acts as a supporting strut. -The joints of the pectoral girdle consist of two anatomical joints, the sternoclavicular and acromio-clavicular joints, and a physiological joint, the scapulothoracic articulation. -Each of these joints assist the movement of the glenohumeral joint and contribute greatly to the mobility of the shoulder region.

muscles of pectoral girdle

-The pectoral girdle is attached to the trunk by muscles from the axial skeleton. These include pectoralis major and minor, trapezius, rhomboid major and minor, latissimus dorsi and serratus anterior. -No anatomical joints exist between the scapula and the thoracic cage. Instead, their muscular connections permit great mobility in the pectoral girdle, which in turn enhances the mobility of the glenohumeral joint.

radioulnar joints

-The radius and ulna articulate at the proximal, middle, and distal radioulnar joints, which together allow important pronation and supination movements.

Radius

-The radius has a proximal head which articulates with the capitulum of the humerus and the radial fossa of the ulna. -The biceps tendon inserts into the radial tuberosity. -The shaft has a lateral area of maximum convexity for the insertion of pronator teres. -Distally, the lateral aspect of the shaft extends into a projection known as the styloid process. -Posteriorly is a groove for the extensor pollicis longus tendon, with the dorsal (Lister's) tubercle on the radial side. -A notch articulates with the ulna to form the distal radio-ulnar joint.

rhomboids course innervation function

-The rhomboid muscle sheet arises from the lower end of the ligamentum nuchae and the spines of the upper thoracic vertebrae. -From this origin the muscle fibres pass inferolaterally to reach their insertion on vertebral border of the scapula from the root of its spine down to its inferior angle. -The highest fibres that may be visualised are rhomboideus minor; the bulk of the muscle sheet is rhomboideus major. -Both are innervated by the dorsal scapular nerve (nerve to the rhomboids), a branch of the anterior ramus of the 5th cervical spinal nerve. -The rhomboids retract and, to a lesser extent, elevate the scapula.

branches in brachial plexus from roots

-The roots lie deep to the prevertebral fascia behind scalenus anterior. There are 3 branches: 1. The dorsal scapular nerve (C5), which supplies levator scapulae and the rhomboids. 2. The nerve to subclavius (C5, 6), which comes off at the junction of C5 and C6. 3. The long thoracic nerve (C5, 6, 7), which supplies serratus anterior.

scapulothoracic articulation glenohumeral relations movements

-The scapula moves in different planes to produce a combination of movements that culminate in protraction or retraction. -For everyday activities, scapulothoracic motion provides only 15 degrees of internal rotation. The scapulothoracic articulation allows increased shoulder movement beyond the initial 120 degrees provided by the glenohumeral joint. -The coordinated movement between the scapulothoracic joint and the glenohumeral joint has been termed the scapulothoracic rhythm. -Movement of the scapula on the thoracic wall may be independent of any motion of the upper limb. Shrugging the shoulders is an example of this. -However, most movement at the scapulothoracic joint is part of a coordinated movement of the upper limb. Of particular importance is the fact that elevation of the upper limb occurring by either flexion or abduction of the glenohumeral joint involves both an elevation of the scapula relative to the thoracic wall and an active rotation of the scapula so that the glenoid fossa faces more superiorly.

burns

-The severity of a burn is a measurement of the depth of burning and the size of the burn. (a)Depth -First degree burns are superficial burns where the epidermis is damaged but still intact. -Second degree or partial thickness burns extend through the epidermis to the dermis. Blisters are the first sign of a second degree burn. As the epidermis cannot perform its functions, the victim may lose heat, fluid and the ability to combat infection. -Third degree or full thickness burns involve destruction of both epidermis and dermis. (b) Surface area -This is calculated as a percentage of the total body area, using the rule of nines. -The body is divided into 11 sections: head, right upper limb, left upper limb, chest, abdomen, upper back, lower back, right thigh, left thigh, right leg, left leg. Each section is covered by about 9% of the total area of skin in the body, with the genitals making up the remaining 1%.

shoulder muscles

-The shoulder is the region where the upper limb is attached to the pectoral girdle by the deltoid and short scapular or rotator cuff muscles, as well as the biceps brachii and the long head of triceps brachii. These muscles contribute greatly to the stability of the glenohumeral joint.

shoulder dislocation

-The shoulder joint has an extensive range of movement but poor stability. It is the most commonly dislocated large joint, with anteroinferior dislocations being commonest. -The head of the humerus comes to lie anteriorly under the coracoid process. -Recurrent dislocation is common in this joint. -Damage to the axillary nerve may occur, resulting in paralysis of deltoid and loss of sensation in the 'regimental badge' area of the arm.

skin function components

-The skin is the largest organ in the body, comprising 16% of the body weight and with a surface area of around 1.8m2 -It forms a barrier between body tissues and the environment, providing protection, thermoregulation and sensation. -The skin consists of the epidermis and dermis. Although structurally consistent throughout the body, skin varies in thickness according to site and age. -The epidermis is a physical and chemical barrier between the body and the exterior, while the dermis provides structural support. -Deep to the dermis is a layer of loose connective tissue which is an important deposit of fat.

skin and deep fascia of hand palmaris brevis venous return

-The skin of the palm is characterised by flexure creases and papillary ridges. -A small muscle, palmaris brevis, is attached to the dermis and lies across the base of the hypothenar eminence. It improves grip by stabilising the skin on the ulnar side of the palm. -Elsewhere, the skin is firmly attached to the palmar aponeurosis, which is the deep fascia of the palm. Fibrous bands connect the two and divide the subcutaneous fat into small loculi. -In contrast, the skin of the dorsum of the hand moves freely over the underlying extensor tendons. -Large subcutaneous veins drain from the palm, so that the pressure of gripping does not impede venous return. -The palmar aponeurosis consists of a central part that is thick and unyielding, and occupies the centre of the palm. Proximally it receives the tendon of palmaris longus, and distally, it divides into four slips which are continuous with the fibrous flexor sheaths for the fingers. Over the thenar and hypothenar eminences, the aponeurosis is much thinner for increased mobility.

sternoclavicular joint

-The sternoclavicular joint is a synovial joint between the articulating surfaces of the medial end of the clavicle and the clavicular notch of the manubrium, together with the adjacent superior aspect of the first costal cartilage. -The joint contains a fibrocartilaginous intra-articular disc that divides it into two separate synovial cavities. -Elevation and depression of the pectoral girdle involves a rocking motion of the medial end of the clavicle on the disc. -Protraction and retraction of the pectoral girdle is accomplished by a rocking motion of the medial end of the clavicle and the disc, as a unit, on the manubrium.

upper limb arterial supply

-The subclavian artery supplies the upper limb, and as its name implies, begins deep to the clavicle. -It continues as the axillary artery at the outer border of the first rib, and then becomes the brachial artery in the anterior compartment of the arm. -Anterior to the elbow, it divides into the radial and ulnar arteries that travel down the anterior compartment of the forearm, giving palpable pulses at the wrist. -They anastomose in the superficial and deep palmar arches to supply the hand and fingers.

posterior compartment of forearm

-The superficial muscles are extensors and supinators, except brachioradialis and anconeus. -Brachioradialis and extensor carpi radialis longus arise from the lateral supracondylar ridge, while the common extensor origin (CEO) on the anterior aspect of the lateral epicondyle gives attachment to extensors carpi radialis brevis, digitorum communis, digiti minimi and carpi ulnaris. -Anconeus arises from the posterior aspect of the lateral epicondyle.

branch in brachial plexus from upper trunk

-The trunks lie in the floor of the posterior triangle of the neck. There is only one branch: 1. The suprascapular nerve (C5, 6), which supplies supraspinatus and infraspinatus.

ulna

-The ulna is shaped proximally to articulate precisely with the trochlea of the humerus. -The coronoid process and olecranon articulate with the corresponding fossae of the humerus. -The shaft has a subcutaneous border and a sharp margin for the interosseous membrane. -Distally, the shaft expands to form the head, with a small styloid process. -On the lateral aspect is a convex articulating surface that articulates with the distal radius in supination and pronation.

ulnar nerve injury

-The ulnar nerve may be compressed at the wrist as it passes through a fibro-osseous tunnel, known as Guyon's canal, between the pisiform and the hook of the hamate. This is much less common than median nerve compression in the carpal tunnel. -The characteristic sign of a low (distal) ulnar nerve lesion is a "claw hand", where there is extension of the metacarpophalangeal joints and flexion of the interphalangeal joints of the ring and little fingers. -This is due to paralysis of the interossei and lumbrical muscles. -The index and middle fingers are relatively unaffected as their lumbricals are supplied by the median nerve. -In a high (proximal) ulnar nerve lesion at or above the elbow, there is less deformity as the ulnar branches to flexor digitorum profundus are also lost. -This is known as the "ulnar paradox". However, the functional disability is greater.

overview upper limb function articulations separations anatomical spaces

-The upper limb of man is designed for prehension, with an end-organ, the hand, which is a highly tactile and efficient grasping mechanism. In grasping, the opposable thumb is equal in functional value to the other four fingers. -The upper limb is connected to the axial skeleton via the pectoral girdle, which consists of the clavicle and scapula. -The many articulations in the upper limb enable the hand to be placed in a wide variety of positions relative to the trunk. -The upper limb may be divided into four regions: shoulder, arm, forearm and hand. Important structures pass between these regions through three anatomical spaces known as the axilla, cubital fossa and carpal tunnel.

wrist joint capsule movements

-The wrist is a synovial ellipsoid joint. -The concave distal surface of the radius articulates with the convex proximal surfaces of the scaphoid and lunate. -The head of the ulna is separated from the triquetral bone by a triangular fibrocartilaginous disc, which is attached to the edge of the ulnar notch of the radius and the base of the styloid process of the ulna. It separates the wrist joint from the distal radioulnar joint. -The capsule is strengthened on either side by medial and lateral collateral ligaments which run from the styloid processes of the ulna and radius to the carpal bones. -Movements consist of flexion, extension, abduction (radial deviation), adduction (ulnar deviation) and circumduction. Adduction is much more extensive than abduction.

interossei

-There are four palmar and four dorsal interossei, arising from the shafts of the metacarpals and inserting into the proximal phalanges. Finger abduction and adduction occur from an axis represented by the middle finger. -Each palmar interosseus arises from one metacarpal and adducts (PAD). Each dorsal interosseus arises from two metacarpals and abducts (DAB). -They are all supplied by the ulnar nerve.

veins in upper limb

-There are two main superficial veins in the upper limb: the cephalic and basilic veins. -They form from an arch of veins on the dorsum of the hand, the dorsal venous arch, which receives blood from the fingers and hand.

deep veins of arm

-These accompany the main arteries and are usually paired, the venae comitantes. -They also communicate with the superficial veins. The radial and ulnar veins unite to form the brachial veins. -After receiving tributaries which correspond to the branches of the brachial artery, they form the axillary vein at the lower border of teres major. They are also joined by the basilic vein which pierces the deep fascia at the level of the mid-arm.

phalanges

-These are small bones with a base, shaft and head, with three (proximal, middle and distal) in each digit and two in the thumb. -The interphalangeal joints are hinge joints, allowing flexion and extension, which are controlled by the finger flexors, extensors, and the small muscles of the hand. -They are stabilised by radial and ulnar collateral ligaments

extensor carpi radialis longus and brevis course innervation function

-These two radial extensors of the wrist arise from the distal third of the lateral supracondylar ridge and the CEO respectively. -Their tendons insert into the bases of the second and third metacarpals. -ECRL is supplied by the radial nerve, while ECRB is supplied by its posterior interosseous branch. -When acting with extensor carpi ulnaris, the wrist is neutrally extended. -While acting with flexor carpi radialis, the wrist is pulled into radial deviation.

scapula

-This flat, triangular bone is attached to the thorax and vertebral column by a number of stabilising muscles, providing a platform for the arm to hang from the shoulder. -At rest, its medial border lies parallel to the vertebral column. -Posteriorly, the spine separates the supraspinous and infraspinous fossae. -The acromion is a superolateral prolongation of the spine and articulates with the lateral end of the clavicle to form the acromioclavicular joint. -The subscapular fossa lies anteriorly. Laterally, the glenoid fossa articulates with the humeral head at the glenohumeral joint. Above this is the beak-like coracoid process.

Dupuytren's contracture

-This is a contracture of the palmar fascia resulting in fixed deformities in the hand and finger joints. -Surgical treatment for this disabling condition involves removing the strands of contracted fascia without damaging the digital nerves that are intricately interwoven in the bands of fascia.

carpal tunnel syndrome

-This is a nerve entrapment syndrome caused by compression of the median nerve within the carpal tunnel. -Affected individuals present with pain and paraesthesia in the distribution of the median nerve, with weakness of the muscles of the thenar eminence. -Management includes the use of night splints to prevent wrist flexion, steroid injections and ultimately surgery to divide the flexor retinaculum.

Colles' fracture

-This is a non-articular fracture of the distal radius resulting from a fall on the outstretched hand. -It commonly occurs in patients over 50 years of age. -The distal fragment is driven posteriorly and superiorly, producing a typical dinner-fork deformity. -Reduction of the fracture is necessary to restore the normal alignment of the radius and its articular surface.

pronator quadratus course innervation function

-This is a square-shaped muscle that pronates the forearm. -It arises from the anterior surfaces of the distal radius and ulna. It is a flat muscle whose fibres run from medial to lateral rather than proximal to distal. -It is supplied by the terminal motor branch of the anterior interosseous branch of the median nerve.

Allen's test

-This is a test used to assess collateral circulation to the hand by evaluating the patency of the radial and ulnar arteries. -Most people have a dual supply to the hand provided by anastomoses between the superficial and deep palmar arches formed by the ulnar and radial arteries respectively. -Puncture or cannulation of the radial artery may lead to injury and ischaemia in subjects without this dual blood supply.

Klumpke's palsy

-This is caused by an injury to the lower fibres (T1) of the brachial plexus. -This can result from hyperabduction of the shoulder as in a breech delivery, and leads to wasting of the intrinsic muscles of the hand.

Erb's palsy

-This is caused by an injury to the upper trunk (C5, 6) of the brachial plexus. -This can result from excessive downward traction on the upper limb during a difficult delivery. -Shoulder abduction, elbow flexion and supination of the forearm are affected, leading to the characteristic "waiter's tip" sign, i.e. the arm hangs down by the side with a pronated forearm and the palm facing posteriorly.

superficial fascia

-This is composed of loose connective tissue and fat. -Naturally thicker in women than in men, this is the layer which is built up when weight is gained. -It exists in all areas but the fat is absent in some areas, notably the eyelids, scrotum and penis. -It is not homogeneous as it may be differentiated into layers by fibrous tissue, as in the anterior abdominal wall where a fatty layer (Camper's fascia) and a membranous layer (Scarpa's fascia) exist.

dislocation of elbow

-This is the commonest dislocation in children, also as a result of a fall on the outstretched hand. -In adults, it is the second most common dislocation after the shoulder. -Posterior dislocation is the commonest from of elbow dislocation. -The close proximity of the ulnar nerve as it runs posterior to the medial epicondyle increases the likelihood of entrapment in a posterior dislocation. The brachial artery and median nerve may also be injured, albeit less frequently.

extensor digiti minimi course innervation function

-This muscle arises from the CEO and inserts into the medial aspect of the dorsal expansion of the little finger. -It supplements the extensor action of the EDC tendon to the little finger, which only joins EDM just proximal to the metacarpal head. -It is supplied by the posterior interosseous nerve and extends the joints of the little finger.

extensor carpi ulnaris course innervation function

-This muscle arises from the CEO, with an additional proximal attachment to the subcutaneous border of the ulna. -It inserts into the base of the fifth metacarpal. -It extends or adducts the hand at the wrist, depending on whether it works with extensor carpi radialis longus and extensor carpi radialis brevis, or with flexor carpi ulnaris. -It is supplied by the posterior interosseous nerve.

Flexor carpi radialis course innervation function

-This muscle arises from the CFO and inserts into the bases of the second and third metacarpals. -Its tendon does not run in the carpal tunnel but in a separate compartment, lying in a groove in the trapezium. -It is supplied by the median nerve. -FCR works with flexor carpi ulnaris to flex the wrist, and with the radial extensors to abduct the wrist. -It also assists in stabilising the wrist during powerful finger movements.

Pronator teres course innervation features

-This muscle arises from the CFO and the distal part of the supracondylar ridge of the humerus. -An additional deep origin comes from the medial aspect of the coronoid process of the ulna. -It inserts into the maximum convexity of the radius at the midpoint of the lateral aspect of the bone and pronates the forearm. -It is supplied by a branch of the median nerve. -The median nerve passes between the two heads of the muscle, while the ulnar artery lies deep to both heads. The radial artery passes over its tendon of insertion.

Flexor carpi ulnaris course innervation function features

-This muscle arises from the CFO and the medial margin of the olecranon process of the ulna. It has an aponeurosis that attaches to the upper two-thirds of the subcutaneous border of the ulna. -Its tendon is attached to the pisiform, a sesamoid bone, with extensions to the hamate and the fifth metacarpal via the pisohamate and pisometacarpal ligaments respectively. -There is also an attachment to the anterior aspect of the flexor retinaculum. -It is supplied by the ulnar nerve which runs posterior to the medial epicondyle, between its two heads. -It adducts and flexes the wrist.

flexor pollicis longus course innervation function

-This muscle arises from the anterior surface of the distal radius proximal to pronator quadratus. -It passes through the carpal tunnel to insert into the base of the distal phalanx of the thumb. -It is a strong flexor of the thumb -is supplied by the anterior interosseous branch of the median nerve.

Serratus Anterior course innervation function

-This muscle arises from the outer surfaces of the upper 8 or 9 ribs, along the anterior axillary line. The portion arising from each rib is called a digitation. -The digitations from ribs 1 and 2 insert on the ventral surface of the scapula along a narrow strip immediately adjacent to its vertebral border. This insertion passes all the way from the superior angle to near the inferior angle of the scapula. The ventral surface of the inferior angle itself receives the insertion of the remaining digitations. -It is supplied by the long thoracic nerve. -protraction of scapula

Extensor indicis course function

-This muscle arises from the posterior aspect of the ulna, distal to the thumb extensors, and from the interosseous membrane. -The EI tendon runs in the same compartment as the EDC deep to the extensor retinaculum, and crosses the EDC tendon to the index finger to lie on its medial (ulnar) side. It inserts into the dorsal expansion of the index finger.

flexor digitorum profundus course innervation function

-This muscle arises from the ulna and the adjacent interosseous membrane. -Its tendons run deep in the carpal tunnel to each of the four fingers, inserting into the base of the terminal phalanges beyond the decussation of the FDS tendon. -It is supplied by the median nerve (anterior interosseous branch) for the part supplying the radial two fingers, and the ulnar nerve for the ulnar two fingers. -Its primary action is flexion of the distal interphalangeal joints, and secondarily, flexion of the proximal interphalangeal joints, the metacarpophalangeal joints, and the wrist.

brachoradialis course innervation function

-This muscle arises from the upper two-thirds of the lateral supracondylar ridge of the humerus and inserts into the radial styloid process. -It flexes the elbow in a position midway between supination and pronation. -It is supplied by the radial nerve.

biceps brachii course function at shoulder and elbow MCN/brachial artery/median nerve course cubital fossa

-This muscle extends from the scapula to the radius, crossing both shoulder and elbow joints. -The long head has a tendinous origin from the supraglenoid tubercle of the scapula within the cavity of the shoulder joint. It emerges in a sleeve of synovial tissue in the intertubercular (bicipital) groove of the humerus. -The short head arises from the coracoid process, and joins the long head to form the belly of the muscle about midway down the arm. -It inserts by a common tendon into the radial (bicipital) tuberosity. A fascial band, the bicipital aponeurosis, extends from the medial side of the tendon into the deep fascia of the medial forearm and onto the subcutaneous border of the ulna. The aponeurosis protects the underlying nerves and vessels, and helps biceps to flex the elbow more effectively. -The musculocutaneous nerve passes deep to biceps and superficial to brachialis. -Biceps brachii is primarily a supinator of the forearm when the elbow is flexed, acting by pulling the radial tuberosity forwards. -When the forearm is supinated, biceps is an important elbow flexor. -At the shoulder joint, it acts to stabilise the humeral head within the glenoid and is a weak flexor. -The brachial artery and median nerve lie in a groove along the medial border of biceps. -At the cubital fossa, the basilic vein and medial cutaneous nerve of the forearm are superficial to the bicipital aponeurosis, while the brachial artery and median nerve lie deep to it.

triceps brachii

-This muscle has three heads. The long head originates from the infraglenoid tubercle of the scapula. The lateral head arises from the lateral lip of the spiral groove, above the deltoid tuberosity of the humerus. -These two heads converge and fuse into a tendon which is inserted into the posterosuperior aspect of the olecranon. -The medial head arises on the medial aspect of the spiral groove of the humerus. In its upper part, it lies medial to the lateral head, with the radial nerve and profunda brachii artery running between them. -Below the spiral groove, its origin widens to include the whole posterior surface of the humerus and both intermuscular septa. -The medial head is thus the deepest of the three heads. Its fibres are inserted into the olecranon and the deep part of the tendon formed by the other two heads. -Some fibres are also inserted into the capsule of the elbow joint. -Triceps brachii is the extensor of the elbow joint. The long head plays a role in stabilising the shoulder joint, and also aids in extending it.

brachialis course function

-This muscle lies deep to biceps, -arising from the distal half of the anterior humeral shaft and the medial intermuscular septum. It converges distally to form a strong tendon that inserts into the coronoid process of the ulna. -It is the main flexor of the elbow.

coracobrachialis course function

-This muscle originates from the coracoid process and inserts midway down the humerus on its medial aspect. -It adducts the shoulder, enabling one to hold items under the arm. It is also a weak flexor of the shoulder joint.

Abductor pollicis longus course function

-This muscle originates from the proximal part of the dorsum of the ulna, the interosseous membrane, and the dorsum of the mid-portion of the radius. -It inserts into the lateral aspect of the base of the thumb metacarpal. -It abducts and extends the thumb metacarpal at the carpometacarpal joint. -In crossing the wrist, it also abducts the hand at the wrist.

supinator course innervation function

-This muscle originates from the supinator crest of the ulna and the area just distal to the radial notch. -More oblique superficial fibres originate from the posterior aspect of the lateral epicondyle, as well as from the lateral and anular ligaments of the elbow. -It inserts into the lateral aspect of the proximal shaft of the radius. -It supinates the pronated radius, but is weaker than biceps brachii. In a fully extended elbow, it is the prime mover for supination, which is much weaker in this position. -The posterior interosseous nerve runs dorsally between its oblique and transverse fibres.

Extensor pollicis brevis course function

-This muscle originates on the dorsum of the radius distal to AbPL, with an additional origin from the adjacent part of the interosseous membrane. -It inserts into the base of the proximal phalanx of the thumb. -It does not have an extensor action on the IP joint of the thumb, but extends the thumb at both the metacarpophalangeal (MCP) and carpometacarpal (CMC) joints.

Extensor pollicis longus course function

-This muscle originates on the dorsum of the ulna distal to AbPL, with an additional origin from the adjacent part of the interosseous membrane. -Its long tendon winds around the dorsal (Lister's) tubercle of the radius, changing its direction to reach the thumb. -EPL inserts into the dorsum of the base of the terminal phalanx of the thumb, thus extending both metacarpophalangeal and interphalangeal (IP) joints of the thumb. It is also a weak extensor of the wrist.

Medial cutaneous nerve of the forearm

-This nerve pierces the deep fascia on the medial aspect of the arm with the basilic vein. It supplies skin over the inferior part of the arm, then passes into the medial side of the forearm

Acromioclavicular joint

-This small synovial joint permits a small degree of motion about all three potential axes. -The movement around the mediolateral axis is called rotation, and is particularly important during normal elevation of the upper limb. -Rotation at the acromioclavicular joint accounts for about half of the 'glenoid-up' rotation of the scapula relative to the chest wall. -During movement, the acromion is kept away from the chest wall by the clavicle, which acts as a strut. The lateral end of the clavicle travels in an arc around the sternoclavicular joint, which acts as a pivot

triangle of auscultation

-This triangle is bounded by the latissimus dorsi, trapezius and medial margin of the scapula. -It overlies the 6th intercostal space and is used for auscultation of respiratory sounds.

anconeus course innervation function

-This triangular muscle arises from the posterior aspect of the lateral epicondyle, and inserts onto the lateral aspect of the proximal ulna. -It is supplied by the radial nerve, via its branch to the medial head of triceps. - It extends the elbow and pulls the ulna posterolaterally in pronation.

rupture of supraspinatus tendon

-Traumatic rupture of the supraspinatus tendon may lead to difficulty in initiating abduction. -The patient may compensate for this by leaning over to the affected side, so that gravity assists abduction before deltoid can act.

Palmaris longus course innervation function

-When present, this muscle arises from the CFO and inserts into the palmar aponeurosis, with a superficial tendon which is adherent to the flexor retinaculum. -It is supplied by the median nerve. -It tenses the palmar fascia and flexes the wrist.

paralysis of serratus anterior and trapezius

-When the serratus anterior is paralysed, the inferior angle of the scapula moves posteriorly away from the chest wall to make a noticeable ridge beneath the skin of the back, a condition known as winging of the scapula. -Paralysis of the trapezius yields a similar change in the appearance of the back.

muscles connecting trunk to scapula

-With the exception of pectoralis minor, the muscles that run between the trunk and the scapula are not derived from the limb bud mesenchyme and, consequently, are not innervated by the brachial plexus. -However, these muscles are primarily recruited to reposition the pectoral girdle during movements of the upper limb, thus they are functionally upper limb muscles. -Many muscles within this group also contribute to the superficial muscular layer of the back. -trapezius -rhomboids -Levator scapulae -Serratus Anterior -Pectoralis Minor

Medial cutaneous nerve of the arm

-arises from medial cord of brachial plexus -This nerve pierces the deep fascia in the superior part of the arm to supply the skin on the anterior and medial aspects.

anterior compartment of forearm

-contained within the deep fascia which sends septa between them, and is attached posteriorly to the subcutaneous border of the ulna.

axillary artery

-continuation of the subclavian artery at the outer border of the first rib. -It ends by becoming the brachial artery at the lower border of teres major. -Branches include the subscapular artery which passes backwards to form part of the important scapular anastomosis, the anterior and posterior circumflex humeral arteries, which anastomose around the surgical neck of the humerus and supply the shoulder joint and deltoid, as well as branches which supply the pectoral muscles, breast and chest wall.

axillary vein

-formed by the venae comitantes of the brachial artery and the basilic vein. -It receives the cephalic vein which pierces the clavipectoral fascia.

serratus anterior

-originates from the outer surfaces of the upper eight ribs and inserts into the whole length of the medial border of the scapula. -It protracts the scapula and acts with trapezius to rotate the scapula in abduction of the shoulder.

deltoid innervation course

-supplied by the axillary nerve -has a broad origin from the spine of the scapula, the acromion, and the clavicle. The origin from the scapular spine is by means of an aponeurosis at the inferior lip of its crest. The origin from the lateral edge of the acromion and from the anterior surface of the lateral third of the clavicle is by fleshy fibres. -Multiple tendons form within the deltoid, and these tendons converge towards an insertion onto the anterolateral surface of the humerus just above its midshaft. A prominent deltoid tuberosity marks this site. -The deltoid can be divided into regions with different actions. These regions correspond to the different specific sites of origin. -Thus, the spinodeltoid (posterior fibres) is the part of the muscle arising from the crest of the scapular spine; the acromiodeltoid (middle fibres) is the part of the muscle arising from the acromion, and the clavideltoid (anterior fibres) is the part arising from the clavicle.

autonomous zones for clinical testing of each peripheral nerve

-the dorsal aspect of the first web space (radial), -the tip of the index finger (median) -the tip of the little finger (ulnar)

branches from lateral cord of brachial plexus

1. The lateral pectoral nerve (C5, 6, 7), which pierces the clavipectoral fascia to reach the deep surface of pectoralis major. 2. The musculocutaneous nerve, which supplies the 3 muscles of the anterior compartment of the arm and terminates as the lateral cutaneous nerve of the forearm. 3. The lateral head of the median nerve

branches from medial cord of brachial plexus

1. The medial pectoral nerve (C8, T1), which passes between the axillary artery and vein to supply pectoralis minor. It continues on to supply pectoralis major. 2. The medial cutaneous nerve of the arm (T1), which gives sensory supply to the skin of the medial side of the arm as far as the medial epicondyle. 3. The medial cutaneous nerve of the forearm (C8, T1), which gives sensory supply to the skin of the lower part of the arm and the medial side of the forearm. 4. The medial head of the median nerve. 5. The ulnar nerve

intrinsic muscles of hand innervation

1. The thenar eminence: abductor pollicis brevis (lateral), flexor pollicis brevis (medial) and opponens pollicis (deep), supplied by the recurrent branch of the median nerve. 2. The hypothenar eminence: abductor digiti minimi (medial), flexor digiti minimi (lateral) and opponens digiti minimi, supplied by the ulnar nerve. 3. The deep muscles: adductor pollicis, interossei and lumbricals. These are supplied by the ulnar nerve, except for lateral two lumbricals (median nerve).

branches from posterior cord of brachial plexus

1. The upper subscapular nerve (C6), which supplies the upper part of subscapularis. 2. The thoracodorsal nerve (C6, 7, 8), which supplies the latissimus dorsi muscle. 3. The lower subscapular nerve (C6, 7), which supplies the lower part of subscapularis and teres major. 4. The axillary nerve (C5, 6), which supplies teres minor and deltoid. It passes posteriorly inferior to the shoulder joint and is closely related to the surgical neck of the humerus. It supplies the shoulder joint and the skin over the lateral part of the deltoid. 5. The radial nerve.

muscles forming anatomical snuffbox

Abductor pollicis longus Extensor pollicis brevis Extensor pollicis longus

anterior compartment of arm innervation

Coracobrachialis Biceps brachii Brachialis All supplied by MCN

Pairing of Glenohumeral Joint and Pectoral Girdle Movement

G - P Abduction - Superior rotation Adduction - Inferior rotation Flexion - Elevation Extension - Depression Internal (medial) rotation - Protraction External (lateral) rotation - Retraction

median cubital vein

In the cubital fossa there is usually a connection between the cephalic and basilic veins, the median cubital vein. Many other communications may exist, with many variations.

blood supply to skin

The blood supply of the skin is important in thermoregulation. Good perfusion in warm weather allows greater heat loss, while blood supply to the skin is reduced to preserve body heat in cooler conditions. This is mediated by arteriovenous anastomoses.

hand

The human hand is an amazing grasping mechanism which combines great strength with finely controlled accuracy. It also functions as the main tactile organ of the body.

interosseous membrane

The two long bones of the forearm articulate with each other proximally and distally. The interosseous membrane connects them throughout the length of their shafts

superficial layer of anterior compartment of forearm common origin muscles

These 4 muscles arise from the common flexor origin (CFO) on the anterior aspect of the medial epicondyle of the humerus, from the overlying fascia and the septa between them. -pronator teres -FCR -palmaris longus -FCU

blisters

When the epidermis and dermis separate, typically due to prolonged friction, fluid moves between the layers and a blister forms.

subclavius

a small muscle connecting the upper border of the first rib and the inferior surface of the clavicle

joints of upper limb

acromioclavicular glenohumeral elbow wrist

superficial muscles of posterior compartment of forearm

anconeus brachoradialis extensor carpi radialis longus and brevis extensor digitorum communis extensor digiti minimi extensor carpi ulnaris

divisions of brachial plexus from trunks to cords

apex of axilla no branches posterior to clavicle

deep layer of anterior compartment of forearm

flexor digitorum profundus flexor pollicis longus pronator quadratus

axillary lymph nodes

receive lymph from the upper limb, breast, and the abdominal wall above the umbilicus.