CHA 101L - Quiz 2 (4 out of 5)

Posterior compartment of the forearm is innervated by the...

Radial nerve

Superficial layer: BLB Don't Mess Up

Brachioradialis

extensor carpi radialis Longus

extensor carpi radialis Brevis

extensor Digitorum (communis)

extensor digiti Minimi

extensor carpi Ulnaris

Deep layer: SLBLI

Supinator

ABductor pollicis Longus

Extensor pollicis Brevis

Extensor pollicis Longus

Extensor Indicis

Brachioradialis (HINT: Big brother)

Lateral supracondylar ridge

Distal radius

Main action of the brachioradialis

Flexion of forearm, supination of forearm

Extensor carpi radialis longus (HINT: Little sister b/w older siblings)

Lateral supracondylar ridge

Base of 2nd metacarpal

Main action of the extensor carpi radialis longus

Extension of hand, ABduction of hand

Extensor carpi radialis brevis (HINT: Big sister)

Lateral epicondyle of humerus

3rd metacarpal

Main action of the extensor carpi radialis brevis

Extension of hand, ABduction of hand

Extensor digitorum (communis)

Lateral epicondyle of humerus

Extensor expansion of digits 2-5

Main action of the extensor digitorum

Extension of metacarpophalangeal joints, extension of wrist

Extensor digiti minimi

Lateral epicondyle of humerus

Extensor expansion of digit 5

Main action of the extensor digiti minimi

Extension of metacarpophalangeal joints, extension of interphalangeal joints of digit 5

Extensor carpi ulnaris

Lateral epicondyle of humerus, ulna

5th metacarpal

Main action of the extensor carpi ulnaris

Extension of hand, ADduction of hand

Supinator

Lateral epicondyle of humerus, ulna

Shaft of radius (proximal to pronator teres)

Main action of the supinator

Supination of forearm

ABductor pollicis longus

Posterior ulna, radius, interosseous membrane

Base of 1st metacarpal

Main action of the ABductor pollicis longus

ABduction of digit 1, extension of digit 1 at carpometacarpal joint

Extensor pollicis brevis

Radius, interosseous membrane

Proximal phalanx of digit 1

Main action of the extensor pollicis brevis

Extension of digit 1 at metacarpophalangeal joint

Extensor pollicis longus

Ulna, interosseous membrane

Distal phalanx of digit 1

Main action of extensor pollicis longus

Extension of digit 1 at interphalangeal joint

Extensor indicis

Ulna, interosseous membrane

Extensor expansion of digit 2

Main action of extensor indicis

Extension of digit 2

What is the anatomical snuff box?

Indent on wrist when thumb is extended

Medial: Extensor pollicis longus

Lateral: Extensor pollicis brevis + ABDuctor pollicis longus

Clinical significance of the anatomical snuff box?

Tenderness of snuff box -> fracture of scaphoid

If fractured -> Can cut the radial artery -> Avascular necrosis

Relationship between radial artery and anatomical snuff box?

Radial artery is deep to the anatomical snuff box

Extensor retinaculum

What is the function of this fascial sheath (extensor retinaculum)?

Keeps the tendon aligned and prevents deviations

Cubital fossa

"Sheesh" region of arm

Boundaries of cubital fossa

Brachioradialis m.

Pronator teres m.

Horizontal line through humeral epicondyles

Lateral border =

Medial side of Brachioradialis m.

Medial border =

Lateral side of pronator teres m.

Cubital fossa (Lat -> Med): BCRTB(R,U)MBP + MCV

Brachioradialis m.

Cephalic v.

Radial n.

bicep brachii Tendon and aponeurosis

Brachial a.

Radial a.

Ulnar a.

Median n.

Basilic v.

Pronator teres m.

Median cubital v.

What vein is most commonly used for venipuncture (IV, blood drawn, etc.)?

Medial cubital vein