functional organizations of the arm and hand

Question 1

compartments

Answer 1

each contains one or more functional groups of muscles, deep fascia divides the arm and forearm into post and ant components

Question 2

anterior/flexor compartment of arm

Answer 2

contains muscles that flex the elbow joint and supinate the radioulnar joint

Question 3

posterior/extensor compartment of arm

Answer 3

contains muscles that extend the elbow joint

Question 4

innervation of anterior compartment of arm

Answer 4

musculocutaneous: from lateral cord of the brachial plexus. C5-C7, C6 is the main contributor. Motor innervation to muscles in the anterior brachial compartment and carries sensory from the lateral portion of the forearm (C6 dermatome)

Question 5

innervation of posterior compartment of arm

Answer 5

radial nerve: derived from pot cord of brachial plexus, C5-T1, C5-7 are the main contributors. Motor to triceps and anconeus, sensation from post lat portion of arm (C5 dermatome)

Question 6

anterior compartment of the forearm

Answer 6

contains muscles that flex the wrist joint, pronate the radioulnar joint and flex the digits

Question 7

posterior compartment of the forearm

Answer 7

contains muscles that extend the wrist joint, supinate the radioulnar joint, and extend and abduct the digits

Question 8

innervation of the posterior compartment of the forearm

Answer 8

radial nerve

Question 9

innervation of the anterior compartment of the forearm

Answer 9

ulnar and medial nerve

Question 10

transition zones (3)

Answer 10

provide a passageway for the contents (particularly nerves and vessels) of one compartment to enter another 1. axilla 2. cubital fossa 3. wrist

Question 11

muscles in the anterior compartment of the arm (3)

Answer 11

1. biceps brachii 2. brachialis 3. coracobrachialis

Question 12

blood supply to muscles in ant compartment of arm

Answer 12

brachial artery, branches include: 1. muscular branches to the muscles in the ant compartment of the arm 2. collateral branches in elbow anastomosis 3. deep brachial artery: extensor compartment

Question 13

Muscles in the post compartment of the arm (2)

Answer 13

1. triceps brachii 2. anconeus

Question 14

Blood supply of the posterior compartment of the arm

Answer 14

Deep profunda brachial artery (1st brach of the brachial) gives off: -muscular branches to the muscles in the extensor compartment -collateral branches in elbow anastomosis

Question 15

Veins in the arm (3)

Answer 15

Cephalic (lateral) Basilic (medial) Median cubital (connects the 2)

Question 16

Biceps rupture

Answer 16

could tear the biceps from an attachment on the supraglenoid tubercle, the radial tuberosity or both. Make the bicep appear higher or lower on the arm depending on where it is torn. Sometimes if the person is not an athlete they won’t repair it, if they do, they sew the tendon back onto the bone

Question 17

Cubital Fossa

Answer 17

region anterior to the elbow joint, passageway for nerves and vessels traveling from the arm into the forearm, venipuncture usually performed here

Question 18

Cubital Fossa Boundaries

Answer 18

Superior: imaginary line connecting condyles Medial: pronator teres lateral: brachioradialis roof: skin, fascia, bicipital apaneurosis floor: medial: brachilis lateral: supinator

Question 19

Cubital Fossa Contents (4ish)

Answer 19

1. radial nerve 2. biceps tendon 3. brachial artery and vein terminal branches: radial and ulnar artery 4. median nerve

Question 20

Ulnar Artery branches

Answer 20

branches off into common interossius artery which is very short and splits very quickly into the anterior and posterior interossius artery

Question 21

Radius

Answer 21

-main articulation of the wrist -articulate with the ulna, humerus, scaphoid, and lunate bones -the tuberosity of the radius is where the biceps tendon attaches

Question 22

Ulna

Answer 22

-more stable because it has a hook -articulates with humerus and radius -has a fibrocartilagenous disc at the wrist

Question 23

Muscles of the anterior portion of the arm (characteristic)

Answer 23

common origin at the medial epicondyle of the humerus

Question 24

Radio-ulnar pronators

Answer 24

cause the radius to rotate on a fixed ulna bringing the forearm and hang “palms down” 1. pronator teres 2. pronator quadratus

Question 25

Wrist flexors

Answer 25

attach to the medial epicondyle of the humerus and bring the palm of the hand toward the elbow (flexion) 1. flexor carpi radialis 2. palmaris longus 3. flexor carpi ulnaris

Question 26

Digital Flexors

Answer 26

extrinsic, bellies of origin in forearm but exert actions of wrist and hand 1. flexor digitorum superficialis 2. flexor digitorum profundus 3. flexor pollicis longus

Question 27

Movement of the thumb

Answer 27

Question 28

median motor nerve muscle supply (7)

Answer 28

1. pronator teres 2. pronator quadratus 3. flexor carpi radialis 4. palmaris longus 5. flexor digitorum superficialis 6. radial 1/2 of flexor digitorum profundus 7. flexor pollicis longus

Question 29

ulnar motor nerve supply (2)

Answer 29

1. flexor carpi radialis 2. ulna portion of the flexor digtorum profundus

Question 30

cutaneous innervation of the forearm

Answer 30

Lateral/radial side * lateral antibrachial cutaneous (C6), cutaneous branch of musculocutaneous nerve Medial/ulna side * medial antibrachial cutaneous carries sensory axons from T1. Branch of medial cord of brachial plexus

Question 31

blood supply to flexor compartment of the forearm

Answer 31

provided by radial and ulnar arteries which brach from brachial artery

Question 32

branches of the radial artery

Answer 32

1. muscular branches to muscles in flexor compartment 2. recurrent branch in elbow anastomosis

Question 33

branches of the ulnar artery

Answer 33

1. muscular branch to the muscle in the flexor compartment 2. recurrent in elbow anastomosis 3. common interosseous branch 1. anterior: deep lying muscles in flexor 2. posterior: main blood supply to muscles in extensor

Question 34

posterior compartment of the forarm characteristic

Answer 34

wrist and finger extensors have a common attachment from the lateral epicondyle of the humerus

Question 35

Anatomical Snuff box muscles

Answer 35

act on the 1st metacarpal and joints of the thumb 1. abductor pollicis longus 2. extensor pollicis brevis 3. extensor pollicis longus

Question 36

wrist extensors

Answer 36

1. extensor carpi radialis longus 2. extensor carpi radialis brevis 3. extensor carpi ulnaris (weaker than other 2, why extension usually occurs along with radial deviation)

Question 37

finger extensors

Answer 37

1. extensor digitorum 2. extensor digiti minimi 3. extensor indicis

Question 38

misc. muscles in the forearm

Answer 38

1. supinator: weak supinator of the radioulnar joint (biceps is the strongest) 2. brachioradialis: flexes elbow when the hand is in neutral position

Question 39

Extensor compartments

Answer 39

6 tunnels that are comprised of a tendon(s) surrounded by a synovial sheath. located within tunnels bound by portions of the extensor retinaculum

Question 40

Compartment 1

Answer 40

abductor pollicis longus and extensor pollicis brevis. most clincally significant. repetitive movements of the thumb and wrist can result in De Quervain's Disease

Question 41

Compartment 2

Answer 41

extensor carpi radialis longus and brevis tendons

Question 42

Compartment 3

Answer 42

Extensor pollicis longus tendon (wraps around tubercle on radius)

Question 43

Compartment 4

Answer 43

extensor digitorum and etensor indicis

Question 44

Compartment 5

Answer 44

Extensor digiti minimi

Question 45

Compartment 6

Answer 45

extendor carpi radialis tendon

Question 46

De Quervain's Disease

Answer 46

caused by repetitve movents of the thumb and wrist, especially flexion of the thumb and ulnar deviation of the wrist results in pain to the dorsal aspect of wrist asking the patient to fold their thumb under the fingers and move the wrist toward the ulna (ulnar deviation) produces a pain that tests positive for this condition

Question 47

Innervation of the extensor compartment

Answer 47

Radial Nerve: enters the cubital fossa and winds arounf the shaft of the humerus. Branches into: * muscular branches that supply extensor carpi radialis longus and brachioradialis * a superficial branch that conveys sensory ONLY from the dorsum of the hand and thumb * a deep branch: pierces the supinator muscle and supplies ECRB

Question 48

blood supply of the extensor compartment of the forearm

Answer 48

posterior interosseus branch of the common interosseus artery to all of the muscles

Question 49

tennis elbow

Answer 49

overuse of extensors, tearing or inflammation on or around the lateral epicondyle. common treatment is to put a strap around the tendons also medial epicondylitis which is the same thing only on the lateral epicondyle