Upper Limb 2

8/8/2019 Upper Limb 2

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Frolich, Human Anatomy,UpprLimb

UPPER LIMB What is a limb? Skeleton Joints Shoulder/Scapula

muscles

Brachial plexus²getting spinal nervesout onto limb

Muscles²anterior

and posterior compartments Sensory innervation Surface anatomy

From Royal Collection daVinci drawings




What is a limb?

Ventral somatic outgrowth of outer tube ± Bones (made of bony tissue,

cartilage, and other tissues)

± Joints

± Muscles

± Nerves (with motor neurons tomuscles, sensory neurons toskin, proprioceptors)

No viscera--all innervation issomatic (motor or sensory)from ventral ramus of spinalnerve (except autonomics to

blood vessels)




Upper Limb Skeleton

Scapula

Humerus

Radius, ulna

Carpals--proximal, distal

Digits

± Metacarpals ± Phalanges




JointsJOINT BETWEEN MOVEMENT TYPE







Muscle origins and insertions

Muscle crosses joint Origin is usually proximal andinsertion is usually distal

Origin is considered fixed inanalyzing muscle action

Muscle action (concentric) isgiven by movement of insertion relative to originacross joint

Remember: ± Sometimes insertion might be

fixed

± Muscle may be activeisometrically and concentricallygiving different real functionduring real activity




Muscles of Scapula

If INSERTION onscapula, muscle movesscapula ± Trapezius

± Rhomboids ± Pectoralis Minor

± Serratus Ventralis

± Levator Scapulae

If ORIGIN on scapula,muscle moves arm ± Teres Major

± Latissimus Dorsi (partially

on scapula)




Rotator Cuff

Muscles originate onfossae of scapula

Help support ³opensocket´ of shoulder joint

Insert around ball of

femur Medial and lateral

rotation of upper limb

Typical baseballpitcher injury

Supraspinatus

Infraspinatus

Teres minor

Subscapularis




Axilla = Armpit Region between arm and chest

Boundaries

± Ventral - pectoral muscles

± Dorsal = latissimus dorsi, teres major subscapularis

± Medial = serratus ventralis

± Lateral = bicipital groove of humerus

Contents

± Axillary nerves and blood vessels ± Axillary lymph nodes

± And«.the««Brachial plexus







Posterior Compartment²posterior cord Anterior compartment²medial, lateral cords Name of cord is relative to axillary artery

Brachial Plexus




Brachial plexus organizes nerves out tomuscles of upper limb

One posterior nerve

± Radial n.

Three anterior nerves ± Musculocutaneous n.

± Median n.

± Ulnar n.




Muscles and nerves by compartment

A TERI R P STERI R

ER ES M-C, ulnar,

median

Radial

M EME T Flexion Extension

MUSCLES Biceps,

flexors

Triceps,

extensors

T IST Flexors frommedial

epicondyle

Extensors fromlateral

epicondyle




POSTERIOR AND ANTERIOR COMPARTMENTS




Biceps²anterior compartment, flexion (M-C n.)

Triceps²posterior compartment, extension (radial n.)




Anterior Compartment Forearm--flexors

Flexor Carpi Radialis

Flexor Retinaculum

edial Epicondyle

Flexor Digitorum Superficialis

is deep to other flexors

Flexor Carpi Ulnaris

Brachioradialis

Pronator Teres

Anterior View




Posterior Compartment of Forearm--extensors

Extensor digitorum

Extensor carpi ulnarisExt Carpi Radialis Longus

Brachioradialis

Lateral Epicondyle

Posterior View




ANTERIOR MUSCLES

M-C nerve

± Biceps

± brachialis

Median nerve

± Forearm flexors

± Thumb intrinsics (1M$nerve)

Ulnar nerve

± Flexor carpi ulnaris ± Hand intrinsics

POSTERIOR MUSCLES

Muscles (radial nerve)

± Triceps

± Anconeus

± Brachioradialis

± Carpal, digit extensors




Sensory from limb(dermatomes/sensory skin

segments from spine)

Dermatomes extendover limbs

Twisted orientationreflects twisting of limb duringdevelopment

Named nervesgenerally innervateskin over musclesthat they innervate




Sensory territory of nerves

REMEMBER: Brachialplexus re-directs spinalroutes into named nervescovering certain territory

Cutaneous branches of

medial cord/ulnar nerve




Routes of nerves (in human)

M-C: between biceps brachii and brachialis Median: medial/posterior to biceps, branches

into forearm flexors at elbow then to handthrough carpal tunnel

± Recurrent median (1M$) superficial at wrist to thumbover thenar emminence) deficit - ape¶s hand

Ulnar: medial in arm, posterior to medialepicondle of humerus (funny bone) down medialforearm medial to carpal tunnel into palm

Radial: deep posterior arm around lateralepicondyle of humerus to forearm (deep and

superficial branches)




Ulnar Nerve

Brachial Artery

Median Nerve

Ulnar NerveMedian Nerve

Radial Artery

Musculocutaneous Nerve UlnarArtery

Where¶s Radial Nerve?




Surface Anatomy of Upper Limb Biceps + Triceps brachii

Olecranon Process Medial Epicondyle

Cubital Fossa

± Anterior surface elbow

± Contents Brachial Artery

Median Nerve

± Boundaries Medial = Pronator teres

Lateral = Brachioradialis

Superior = Line between epicondyles




Surface Anatomyof Upper Limb

Carpal Tunnel

± Carpals concaveanteriorly

± Carpal ligament covers it

± Contains: long tendons,Median nerve

± Inflammation of tendons =

compression of Mediannerve

Anatomical Snuffbox

± Lateral = E.pollicis brevis

± Medial = E. pollicis longus

± Floor = scaphoid, styloidof radius

± Contains Radial Artery

(pulse)




Suggestion: a muscle tableorganized by

Joint crossed?

Nerve innervating? Action?Compartments? All of the above?

MUSCLE ACTIO O IGI I SER TIO I ERVATIO

(cord to nerve)

iceps lex, sup. Humerus,

glenoid

R adial

tuberosity

Medial cord² M-C.




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Upper Limb 2