9: Cubital fossa and musculo-neuro-vascular systems of the posterior forearm Flashcards
Muscles responsible for elbow flexion
Brachialis
Biceps brachii
Brachioradialis
Pronater Teres
Muscles responsible for wrist flexion
Flexor carpi ulnaris
Flexor carpi radialis
Palmaris longus
Flexor digitorum superficialis
Flexor digitorum profundus
Muscles responsible for radial deviation
Flexor carpi radialis
Muscles responsible for ulnar deviation
Flexor carpi ulnaris
Superior boundary of cubital fossa
Line between medial and lateral epicondyles
Medial boundary of cubital fossa
Pronator teres
Lateral boundary of cubital fossa
Brachioradialis
Roof of cubital fossa
Fascia of forearm and bicipital aponeurosis
Floor of cubical fossa
Biceps tendon
Brachialis
Supinator
Contents of cubital fossa (from lateral to medial)
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Radial nerve
Biceps tendon
Brachial artery
Median nerve
Muscles in posterior compartment of forearm
Superficial
Brachioradialis
Extensor carpi radialis longus
Extensor carpi radialis brevis
Extensor carpi ulnaris
Extensor digitorum
Extensor digit minimi
Deep
Supinator
Abductor Pollicis longus
Extensor pollicis brevis
Extensor pollicis longus
Extensor Indicis
Posterior forearm muscles supplied by the… except (2)
Posterior Interosseus branch of the radial nerve
Brachioradialis (supplied by radial nerve directly)
Extensor carpi radialis longus (supplied by radial nerve directly)
Superficial muscles of posterior compartment are attached to… Through the..
The lateral epicondyle
Common extensor tendon
Origin of brachioradialis
Proximal 2/3 of lateral supracondular ridge
Insertion of brachioradialis
Lateral surface of distal end of radius and styloid process
Innervation of brachioradialis
Radial nerve directly
Actions of brachioradialis
When forearm is pronated, BR supinates forearm and flexes elbow
When forearm is supinated, BR pronates forearm
Origin of extensor carpi radialis longus
Lateral supracondylar ridge
Insertion of extensor carpi radialis longus
Dorsal aspect of base of second metacarpal
Innervation of extensor carpi radialis longus
Radial nerve directly
Actions of extensor carpi radialis longus
Extends and abducts wrist at radiocarbon joint
Origin of extensor carpi radialis brevis
Lateral epicondyle
Insertion of extensor carpi radialis brevis
Dorsal aspect of base of 3rd metacarpal
Innervation of extensor carpi radialis brevis
Posterior interosseous branch of radial nerve
Actions of extensor carpi radialis brevis
Extends + abducts wrist at radiocarpal joint
Origin of extensor carpi ulnaris
Lateral epicondyle
Insertion of extensor carpi ulnaris
Dorsal aspect of base of 5th metacarpal
Innervation of extensor carpi ulnaris
Posterior interosseus branch of radial nerve
Actions of extensor carpi ulnaris
Extends +adducts wrist at radiocarpal joint
Origin of extensor digitorum
common extensor origin
Insertion of extensor digitorum
Dorsal aspect of base of middle and distal
Phalanges 2-5
Innervation of extensor digitorum
Posterior interosseus branch of radial nerve
Actions of extensor digitorum
Extends digits 2-5 at proximal and distal IP joints
Insertions of extensor digitorum
- Median band (median slip inserts into the dorsal aspect of the middle phalanx)
- Outer bands (the 2 outer slips reunite on the dorsal aspect of the distal phalanx)
The proximal extensor expansion insert….
Into the underlying MCP joint capsule
Origin of extensor digiti minimi
Common extensor origin
Insertion of extensor digiti minimi
Dorsal aspect of digit 5, base of middle and distal phalanx
Innervation of extensor digiti minimi
Posterior interosseous branch of radial nerve
Actions of extensor digiti minimi
Extends little finger at distal and proximal interphalangeal joints
Origin of supinator
Deep head: supinator crest of ulna
Superficial head: common extensor tendon
Insertion of supinator
Anterolateral surface of proximal 1/3 of radius
Innervation of supinator
Posterior interosseous branch of radial nerve
Actions of supinator
Supinates forearm
Origin of abductor Pollicis longus
Posterior ulna, interosseous membrane
Insertion of abductor pollicis longus
Lateral aspect of base of 1st metacarpal
Innervation of abductor Pollicis longus
Posterior interosseous branch of radial nerve
Actions of abductor pollicis longus
Extends and abducts thumb at CMC joint
Origin of extensor pollicis longs
Posterior surface of middle third ulna and interosseous membrane
Insertion of extensor Pollicis longus
Dorsal aspect of base of thumb + distal phalanx
Innervation of extensor pollicis longus
Posterior interosseous branch of radial nerve
Actions of extensor pollicis longus
Extends proximal and distal phalanges of thumb
Extends first MC joint
Origin of extensor pollicis brevis
Posterior surface of distal radius and interosseus membrane
Insertion of extensor pollicis brevis
Dorsal aspect of base of proximal phalanx of thumb
Innervation of extensor pollicis brevis
Posterior interosseous branch of radial nerve
Actions of extensor pollicis brevis
Extends proximal phalanx of thumb
Extends first MC joint
Origin of extensor indicis
Posterior surface of ulna and interosseous membrane
Insertion of extensor indicis
Dorsal aspect of index finger
Innervation of extensor indicis
Posterior interosseous branch of radial nerve
Actions of extensor indicis
Extends index finger
As brachial artery enters forearm deep to…. it bifurcates……
bicipital aponeurosis
Radial + ulnar artery
Superior and inferior ulnar collateral arteries anastomose with….
Ulnar recurrent arteries
Radial collateral artery anastomoses with…
Radial recurrent arteries
Common interosseous artery divides into
Anterior branch
Posterior branch
Posterior interosseus artery anastomoses with…
The middle collateral branch of the profunda brachii
Together these supply the middle posterior part of the elbow
Both anterior and posterior branches of the interosseous arteries supply….
The proximal radioulnar joint
Radial artery arises in…
Cubical fossa from bifurcation of brachial artery
Course of ulnar artery
Courses distally from its origin in the cubital fossa along the medial side of the forearm
Runs between flexor carpi ulnaris and flexor digitorum profundus
Ulnar artery and its branches supply
Medial part of the forearm
Deep veins
Radial
Ulnar
Posterior interosseous
Anterior interosseous
Superficial veins
Cephalic
Basilic
Median antebrachial
Forearm nerves (3)
Median nerve + anterior interosseous branch
Ulnar nerve
Radial nerve + posterior interosseous branch
Course of median nerve
Passes over ulnar artery and continues distally between flexor digitorum superficialis and profundus
Innervates most of the muscles in anterior compartment
Passes distally between flexor digitorum superficialis and profundus and exits forearm through carpal tunnel at wrist
Course of anterior interosseous nerve
Runs distally along the anterior part of interosseous membrane and innervates the anterior compartment muscles
Course of ulnar nerve
Descends posterior to medial epicondyle, enters forearm between 2 heads of flexor carpi ulnaris, descends distally between flexor digitorum profundus and flexor carpi ulnaris and medial to ulnar artery.
Ulnar nerve enters the hand superficial to flexor retinaculum and lateral to carpi ulnaris tendon
Branches of radial nerve
Superficial and deep
Posterior interosseous nerve course
Passes between two heads of supinator and courses distally in the posterior forearm compartment
Supplies most muscles of extensor compartment