Upper extremity #2

Question 1

What’s the purpose of the forearm?

Answer 1

helps shoulder/arm in force application and with precise placement of hand in space

Question 2

What are the 2 compartments of the forearm?

Answer 2

radius and ulna – articulating with each other at 2 locations to allow pronation & supination

Question 3

What connects the radius and ulna?

Answer 3

interosseous membrane to stabilize, transfer loads, muscle attachments, where the anterior interosseous artery passes

Question 4

What is in the anterior compartment of the forearm?

Answer 4

• flexors and pronators
• 8 muscles located in anterior compartment btwn superficial and deep
• held in place by palmar carpal ligament & flexor retinaculum

Question 5

What is in the superficial anterior layer of the forearm (wrist flexion)?

Answer 5

flexor carpi ulnaris - ulnar (wrist adduction)
palmaris longus - median (deep and medial to median nerve)
flexor carpi radialis - median (wrist abduction)
pronator teres - median (pronation)

Question 5

T/F: flexors are smaller than extensors because they work against gravity

Answer 5

false - flexors are BIGGER

Question 6

What is in the deep layer of the anterior compartment of the forearm (wrist and finger flexion/pronation)? (4)

Answer 6

flexor digitorum superficialis - median (flexes MCP and PIP joint of 4 fingers), largest muscle

flexor digitorum profundus - ulnar and median (only muscle that can flex DIP, SLOW, strong grip)

flexor pollicis longus - median (IP & MCP of thumb)

pronator quadratus - median (pronation) but works with pronator teres

Question 7

Fascial compartments generally end at ____ thus containing spread of _______

Answer 7

joints, infection

Question 8

How does the anterior compartment have communication with the central compartment?

Answer 8

carpal tunnel

Question 9

What does the flexor carpi radialis do?

Answer 9

flexes and abducts the hand at the wrist

guide to the radial artery which lies lateral to the FCR

Question 10

What does the palmaris longus do?

Answer 10

absent in 14% of people – attached to the palmer aponeurosis and serves as a guide for MEDIAN nerve

Question 11

What is the flexor carpi ulnaris?

Answer 11

guide for the ulnar nerve and ulnar artery, lateral to the tendon at the wrist

Question 12

What is the posterior compartment of the forearm?

Answer 12

extensors and supinators – contains 11 muscles, divided into deep and superficial layers, held by extensor retinaculum and entirely innervated by the radial nerve!

Question 13

What’s in the superficial layer of the posterior compartment of the forearm? (6)

Answer 13

mobile wad of Henry - brachioradialis (actually a flexor)
extensor carpi radialis longus & brevis (abd and ext wrist)
extensor digitorum
extensor digiti minimi
extensor carpi ulnaris (add and ext wrist)

Question 14

What’s in the deep layer of the posterior compartment of the forearm? (5)

Answer 14

supinator
extensor pollicis longus (extends all joints of thumb)
extensor pollicis brevis (ex MCP and CMP joints)
abductor pollicis longus (ab thumb)
extensor indices (allows index to be independent)

Question 15

What landmarks make up the cubital fossa?

Answer 15

medial epicondyle superior border, pronator teres (medial border), brachioradialis (lateral)

Question 16

What’s the rule of 3, 3 wrist flexors?

Answer 16

flexor carpi radialis
flexor carpi ulnaris
palmaris longus

Question 17

What’s the rule of 3, 3 finger flexors?

Answer 17

flexor digitorum superficialis
flexor digitorum profundus
flexor pollicis longus

Question 18

What’s the rule of 3, 3 wrist extensors?

Answer 18

extensor carpi radialis longus
extensor carpi radialis brevis
extensor carpi ulnaris

Question 19

What’s the rule of 3, 3 finger extensors?

Answer 19

extensor digitorum
extensor indicis
extensor digiti mini

Question 20

What’s the rule of 3, 3 thumb extensors?

Answer 20

abductor pollicis longus
extensor pollicis brevis
extensor pollicis longus

Question 21

What is a triangular hollow between the tendon of the extensor pollicis longus medially and tendons of extensor pollicis brevis and abductor pollicis longus laterally, and best seen when thumb is extended?

Answer 21

anatomical snuff box

Question 22

What is the floor of the anatomical snuff box?

Answer 22

scaphoid and trapezium bones - radial artery crosses the bones

Question 23

What does pain/tenderness in the snuff box?

Answer 23

scaphoid fracture – common when falling on outstretched hand, and at risk for avascular necrosis

Question 24

Where does the ulnar nerve lie compared to the ulnar artery?

Answer 24

medial

Question 25

What are the branches of the ulnar forearm?

Answer 25

anteromedial forearm
anterior and posterior ulnar recurrent arteries form an anastamosis w/ inferior and superior ulnar collateral arteries around elbow

Question 26

Where can you feel the ulnar artery?

Answer 26

lateral side of the FCU tendon

Question 27

Where can you feel the radial artery?

Answer 27

throughout the arm, demarcating flexor and extensor compartments of the forearm

Question 28

What are the branches of the radial arteries?

Answer 28

posterolateral forearm
radial recurrent - anastomosis around elbow w/ radial collateral
palmar & dorsal carpal - form periarticular anastomosis around wrist w/ corresponding branches from ulnar artery

Question 29

What does the anastamosis of ulnar and radial arteries form?

Answer 29

two arches - superficial palmar arch and deep palmar arch

Question 30

Where does the ulnar artery and ulnar nerve pass through?

Answer 30

Guyon’s Canal - ulnar tunnel

Question 31

What is the largest branch of the radial artery?

Answer 31

radial recurrent; lies proximal on supinator

Question 32

If the median nerve is severed in the elbow region , what is affected?

Answer 32

flexion of PIP joints of 1-3 fingers
flexion of 4th & 5th fingers is weakneed

Question 33

What’s not affected with median nerve damage?

Answer 33

flexion in DIP joints of 4th and 5th fingers is NOT affected

Question 34

Where is an ulnar nerve injury most common?

Answer 34

where the nerve passes posterior to the medial epicondyle of the humerus (funny bone)

Question 35

What can a fracture of the medial epicondyle w compression cause?

Answer 35

cubital tunnel syndrome – causes numbness

Question 36

In an ulnar nerve injury, what is affected?

Answer 36

4th and 5th fingers are now affected; flexion in DIP joints; claw hand

Question 37

What’s mallet or baseball finger?

Answer 37

DIP joint being forced into extreme flexion and cannot extend from injury

Question 38

What innervates the medial side of the entire arm and the posterior forearm?

Answer 38

medial cutaneous nerve C8-T1

Question 39

What innervates the lateral anterior middle arm and majority of posterior arm with the exception of the medial distal side and upper arm?

Answer 39

posterior cutaneous nerve (radial)

Question 40

What innervates the lateral forearm and a teensy little bit of the posterior forearm?

Answer 40

lateral cutaneous nerve (C5 and C6)

Question 41

What innervates the circular area you normally get shots (sorry idk how else to describe it on the arm)?

Answer 41

superior lateral cutaneous nerve of the arm (C5 and C6 and axillary nerve)

Question 42

What innervates the shoulder area?

Answer 42

supraclavicular nerves (C3 and C4)

Question 43

What innervates the armpit area of the arm?

Answer 43

intercostobrachial nerve (T2)

Question 44

What innervates the inner upper arm?

Answer 44

posterior cutaneous nerve (C5, C8), radial nerve