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UPPER LIMB ANATOMY Aaisha Sawlani Learning Objectives • Identify and describe the anatomy of: • Anterior arm • Muscles (coracobrachialis, short & long head of biceps, brachialis). Identify their origins, insertions, innervation, and action. • Nerves (musculocutaneous, median, ulnar) • Arteries (brachial, profunda brachii) • Veins (cephalic, basilic, and median cubital) • Posterior arm & shoulder • Extrinsic muscles of shoulder (trapezius, latissimus dorsi, serratus anterior, rhomboids, levator scapulae). Identify their origins, insertions, innervation, and action. • Intrinsic muscles of shoulder (rotator cuff muscles, deltoid, teres major).Identify their origins, insertions, innervation, and action. • Muscles of the posterior arm (long, lateral, and medial heads of triceps) • Nerves (accessory, axillary, radial) • Superficial muscles of the anterior forearm • Intermediate muscles of the anterior forearm • Deep muscles of the anterior forearm • Cubital fossa and its neurovascular structures • Muscles of the posterior forearm • Bones of the wrist and hand, including the carpal bones on the intact skeleton Learning Objectives • Extrinsic and intrinsic muscles of the hand, including their origins, insertions, innervation and function • Boundaries and contents of the carpal tunnel • Blood supply of the hand, including palmar arches • Cutaneous distribution of the ulnar, median, and radial nerves • Name and identify the structures that form the shoulder joint. • Identify the muscles (origins, insertions, and innervations) that produce the main movements of the shoulder and state their actions. • Describe the blood supply of the shoulder joint and nearby structures. • Describe the factors that contribute to the mobility and stability of the shoulder joint. • Describe the factors that contribute to the stability of the elbow joint. • Identify and describe the osteology of the scapula, clavicle, and humerus, elbow joint, radius, ulna, and proximal & radial radioulnar joints. • Name the bursae associated with the elbow joint and describe their importance. • Identify the muscles involved in the movement of the elbow joint, their origins and insertions, innervations, and function. Explain how these movements may be limited by ligaments and/or the shape of the bones. • Briefly describe the blood supply of the scaphoid bone. • Describe the movements of the fingers and thumb. BONTopic 1 JOINTS OF THE UPPER LIMBWhat bones make up the upper limb? Scapula Clavicle Humerus Radius Ulna Carpal bones (8) Metacarpal Phalanges bones (5) (14)Scapula The scapula is a large, triangular bone that lies over the posterolateral chest wall, extending from rib 2 to rib 7. • Surfaces: Anterior and Posterior • Borders: Superior, Medial, Lateral • Angles: Superior, Inferior, Lateral • Spine of the scapula • Fossae – supraspinous and infraspinous • Acromion • Coracoid Process • Glenoid Process • Supraglenoid tubercle • Infraglenoid tubercleClavicle The clavicle, also known as the collarbone, serves as the only point of attachlimb between the trunk and the upper • Surfaces: Superior and Inferior • Margins: Posterior and Anterior • Medial curvature • Lateral curvature • Trapezoid line • Conoid tubercle • Acromial facet • Sternal articular surfaceHumerus The humerus is the longest bone in the upper limb, and makes up the entirety of the arm. • Head of humerus • Anatomical neck • Surgical neck • Greater and lesser tubercles • Intertubercular groove • Shaft • Radial groove • Medial and lateral epicondyles • Capitulum • TrochleaShoulder Joint The shoulder (glenohumeral) joint is a synovial ball and socket joint that permits a wide range of movement. • Articulating surfaces • Humerus head •glenoid cavity!rface area of the • Glenoid cavity • Glenoid labrum • Fibrous capsule • Ligaments • Glenohumeral ligaments • Superior, middle, posterior • Coracohumeral ligament • Transverse humeral ligamentRadius & Ulna The radius is the lateral bone of the forearm, and is characterised by its round head. The ulna is the medial bone of the arm, and is characterised by the olecranon fossa • Radius • Ulna • Olecranon • Head • Trochlear • Neck notch • Radial • Coronoid tuberosity • Radial shaft process • Styloid • Ulnar process of tuberosity radius • Styloid process of • Radioulnar ulna joints Elbow Joint The elbow joint is made up of 3 joints: the humeroulnar, humeroradial, and the proximal radioulnar joints. • Range of motion: • The humeroulnar and humeroradial joints form a complex hinge joint, facilitating flexion and extension of the forearm. • The humeroradial and proximal radioulnar joints facilitate supination and pronation of the forearm • Stability of this joint is achieved by the medial and The olecranon bursa is a fluid- lateral collateral ligaments filled sac that sits between the alongside the force applied olecranon of the ulna and the by the muscles crossing the overlying subcutaneous tissue – joint. can get inflamed in olecranon bursitis!Carpal Bones The carpal bones are a group of 8 bones which are irregularly shaped and are perfectly arranged. They articulate with the inferior articulating surface of the radius. • Proximal • Tip to remember row (starting from the distal row of the • Scaphoid thumb) • Lunate • To • Triquetrum • Save • Pisiform • Lives • The • Distal row • Physician • Trapezium • Helps • Create • Trapezoid • Treatments • Capitate • HamateWrist Joint The wrist joint (radiocarpal joint) is an ellipsoid joint formed by the articulation of the radius with some of the carpal bones. • The joint is composed of: • Carpal bones – scaphoid, lunate, triquetrum (no pisiform) • Distal end of radius (remember, the ulna is NOT involved in the wrist joint) • Articular disc of the distal radioulnar joint • Stability is achieved primarily with the help of ligaments. Muscles around the wrist also contribute to its dynamicMetacarpals and Phalanges The metacarpals are long, cylindrical bones in the hand which attach to the phalanges, the bones that make up the fingers of the hand • 5 metacarpals • 1 for each finger • First metacarpal = thumb • Fifth metacarpal = little finger • Attached to the phalanges by the metacarpophalangeal (MCP) joint . • 14 phalanges • Each finger has a proximal, middle, and distal phalange except the thumb • The thumb only has a proximal and distal phalange • The joints between the phalanges are known as interphalangeal joints • All fingers have a proximal and distal interphalangeal singular interphalangeal jointMUSCLTopic 1HE UPPER LIMB Anterior Arm Coracobrachialis Origin: coracoid process Insertion: middle 1/3 of the medial surface of the humerus Innervated by: musculocutaneous nerve Function: adducts and flexes arm at the glenohumeral joint Brachialis Origin: anterior aspect of distal half of humerus Insertion: ulnar tuberosity and coronoid process of ulna Innervated by: musculocutaneous nerve + radial nerve supplies a small lateral part Function: flexes the forearm at the elbow jointAnterior Arm Biceps brachii (2 heads) process short head: coracoid tubercule of the scapula Insertion: radial tuberosity musculocutaneous nerve (segmental branches pass to each belly) Function: flexes the forearm at forearmow joint, supinates the Posterior Arm Triceps brachii (3 heads) Origin: long head: infraglenoid tubercle medial head: posterior surface of the humerus below the radial groove lateral head: posterior surface of the humerus above the radial groove Insertion: all 3 fibres converge to a single tendon which inserts onto both antebrachial fasciae ulna and the branches for each headnerve – separate Function: extends the forearm at the elbow jointAnterior Forearm Superficial layer: Pronator teres – pronates forearm Flexor carpi radialis – flexes and abducts hand Palmaris longus – flexes hand Flexor carpi ulnaris – flexes and adducts hand Intermediate layer: Flexor digitorum superficialis – flexes index, middle, ring, and little fingers Deep layer: Flexor digitorum profundus - flexes index, middle, ring, and little fingers Flexor pollicis longus – flexes thumb Pronator quadratus – pronates forearm All muscles are innervated by the median nerve ulnar/medial half of the flexor digitorum profundus, which are innervated by the ulnar nerve.Posterior Forearm Superficial layer: Brachioradialis – weakly flexes forearm Extensor digitorum – extends index, middle, ring, and little fingers Extensor digiti minimi – extends little finger Extensor carpi ulnaris – extends and adducts hand handnsor carpi radialis longus – extends and abducts handnsor carpi radialis brevis – extends and abducts All posterior Anconeus – extends forearm forearm muscles are Deep layer: innervated by Abductor pollicis longus – abducts thumbl nerve. Extensor indicis – extends index finger Extensor pollicis brevis – extends thumb Extensor pollicis longus – extends thumb Supinator – supinates forearm at radioulnar joints Hand – Intrinsic muscles Extrinsicmuscles are found within the hand itself, and control fine motor functions of the hand.intrinsic • Th• Flexor pollicis brevis m. – flexes thumb • Abductor pollicis brevis m. - abducts thumb • Opponens pollicis m. – opposes thumb towards other fingers • Hypothenar group • Flexor digiti minimi brevis m. – flexes little finger • Abductor digiti minimi m. – abducts little finger • finger towards thumbmi m. – opposes little • Lumbricals m. – flex the MCP and extend the IP joints of the fingersHand – Intrinsic muscles • Interossei mm. • Dorsal interossei – abduct the fingers (except thumb) from the midline - DAB • Palmar interossei – adduct the fingers (except thumb) towards the midline - PAD • Adductor pollicis m. – adducts thumb • Palmaris brevis m. – wrinkles skin on the hypothenar eminence, deepening the curvature of the hand, thus improving grip All the intrinsic muscles are innervated by the ulnar nerve except the thenar group and the lateral 2 lumbricals, which are innervated by the median nerve. Anatomical Snuffbox A triangular depression found on the dorsolateral aspect of the hand, proximal to the thumb. Formed by the boundary of the tendons of: • Extensor pollicis longus m. • Extensor pollicis brevis m. • Abductor pollicis longus m. • and trapezium bonesp of the scaphoid Important structures that lie in this area: • Radial artery (supplies the scaphoid!) • Superficial branch of radial nerve • Cephalic veinNEUROVTopic 1UR E OF THE UPPER LIMBBrachial Plexus A network of nerves formed from the anterior rami of cervical spinal nerves C5 to C8 and thoracic spinal nerve T1. Nerves – Motor Innervation • sternocleidomastoid and trapezius. • Axillary nerve: teres minor and deltoid. • Radial nerve: muscles of the posterior arm and forearm. • Musculocutaneous nerve: muscles of the anterior arm • Median nerve: most (not all!) muscles of the anterior forearm the ulnar/medial half of the flexord digitorum profundus) and 5 intrinsic muscles in the thenar half of the palm. • medial half of the flexor digitorum profundus, and most (except 5!) intrinsic muscles of the hand.Nerves – Motor Innervation Radial n. Musculo- Median n. Ulnar n. cutaneous n. Axillary n.Nerves – Sensory Innervation • Axillary nerve: skin of the deltoid + lateral aspect of theng shoulder). • Radial nerve: skin of the posterior arm, forearm, and dorsum of the hand (only the middle, index, and distal interphalangeal joints).till the • Musculocutaneous nerve: skin of the lateral aspect of the forearm. • Median nerve: lateral part of the palmar skin till radial half of the ring finger + tips of respective fingers dorsally. • Ulnar nerve: skin of the medial hand, and the medial one and a half digits.Arterial Supply Subclavian artery Digital arteries Superficial & Axillary artery Deep palmar arches Brachial artery & Profunda brachii Radial artery & (deep brachial Ulnar artery artery) Venous Drainage Superficial drainage Superficial venous arch of the palm Deep drainage Basilic vein Cephalic vein (ulnar side) (radial side) Median cubital v. Deep venous Ulnar and Brachial Axillary Subclavian arch of the radial veins vein vein vein palmANATOMITopic 1CES IN THE UPPER LIMB Axilla A convex pyramidal space located between the upper thoracic wall and the arm. Boundaries: • Anterior: Pectoralis major, pectoralis minor • Posterior: Subscapularis, teres major, latissimus dorsi • Medial: First 4 ribs and their associated of serratus anterior together with the upper part Content • Infraclavicular part of the brachial plexus and its branches • Axillary vessels • Lateral branches of some intercostal nerves • Lymph nodes • In females: ‘axillary tail’ of the breast Cubital Fossa A triangular depression in the anterior aspect of the upper forearm where important vessels pass through. Boundaries: • Proximally: the epicondylar line • Medially: Lateral margin of pronator teres • Laterally: Medial face of brachioradialis • Bisected by the tendon of biceps brachii Content • Biceps tendon • Brachial artery • Median nerve • Radial nerve • Basilic vein • Medial cubital vein • Cephalic veinCarpal Tunnel A narrow passageway on the palmar surface of the wrist formed by ligament and bone. Boundaries: • The carpal arch • Pisiform, triquetrum, hamate, capitate, trapezoid, trapezium, tubercle • Flexor retinaculum (transverse carpal ligament) Content** • 4 tendons of flexor digitorum superficialis m. • 4 tendons of flexor digitorum profundus m. • Tendon of flexor pollicis m. • Median nerve • **the ulnar nerve does NOT usually pass through the carpal tunnel! It enters superficially through the flexor retinaculum.QUTopic 1?