Unit 11: Cubital Fossa, Anterior Forearm and Wrist

Question 1

What are the boundaries of the cubital fossa?

Answer 1

pronator teres, brachioradialis, epicondyles of humerous (line), brachialis, deep fascia

Question 2

What is found in the cubital fossa?

Answer 2

a. tendon of biceps brachii muscle
b. brachial vessels and terminal branches
(1) radial artery
(a) radial recurrent artery
(2) ulnar artery

c. median nerve
d. radial nerve and its branches in lateral wall of fossa

Question 3

What are the branches of the ulnar artery?

Answer 3

(2) ulnar artery
(a) common interosseous artery
i. anterior interosseous artery
ii. posterior interosseous artery
a. interosseous recurrent artery
(b) anterior and posterior ulnar recurrent arteries

Question 4

What structures are important on the radius?

Answer 4

radius - on lateral side of forearm

1. head
2. neck
3. radial tuberosity
4. ulnar notch
5. styloid process
6. dorsal tubercle

Question 5

What medial structures are important on the ulna?

Answer 5

1. olecranon process
2. trochlear notch
3. coronoid process
4. radial notch
5. ulnar tuberosity
6. styloid process

Question 6

What is the proximal row of carpal bones?

Answer 6

1. proximal row
   a. scaphoid (boat-like)
   b. lunate (moon-shaped)
   c. triangular (or triquetrum)
   d. pisiform (pea-sized sesamoid bone developed in the tendon of the
   flexor carpi ulnaris)

Question 7

What is the distal row of carpal bones?

Answer 7

a. trapezium (a table or counter)
b. trapezoid (geometric figure)
c. capitate (head-shaped)
d. hamate (having a hook)

Question 8

What is the function of the antebrachal fascia?

Answer 8

surrounds muscles

Question 9

What is the palemr carpal ligament?

Answer 9

thickening of fascia above wrist

Question 10

What are the functions of the flexor retinaculum?

Answer 10

1. attached laterally to the tubercle of the scaphoid and crest of the trapezium and medially to the pisiform and hamulus of hamate
2. may prevent flexor tendons from “bow-stringing”
3. serves as boundaries of the carpal tunnel

Question 11

What is the palmar aponeurosis?

Answer 11

thick fasica that covers central component of hand

Question 12

Which muscles of the forearm have an origin from the medial epicondyle of the humerus?

Answer 12

pronator teres, flexor carpi radialis, palmaris longus, flexor carpi ulnaris, flexor digitorum superficialis (second layer)

Question 13

Where is the insertion of the pronator teres?

Answer 13

radius mid shaft (has second origin on ulna)

Question 14

Where is the insertion of the flexor carpi radialis?

Answer 14

2nd and 3rd metacarpal

Question 15

Where is the inseriton of the palmaris longus?

Answer 15

on flexor retinaculum and palmar aponeurosis

Question 16

Where does the flexor carpi ulnaris insert?

Answer 16

inserts on pisiform (innervated by ulnar nerve)

Question 17

Where does the flexor digitorum superficialis insert?

Answer 17

middle phalanges of four fingers

Question 18

What are the two muscles of the third layer of forearm muscle?

Answer 18

flexor pollicis longus and flexor digitorum profundus

Question 19

from where does the flexor pollicis longus originate? Where does it insert?

Answer 19

originates from the anterior surface of the radius and the interosseous membrane; inserts on the distal phalanx of the thumb (therefore action is to flex the thumb)

Question 20

From where does the flexor digitorum profundus originate? Where does it insert?

Answer 20

originates from the posterior and medial surface of the ulna (remember this muscles receives innervation from both the interosseous muscle as well as the ulnar depending on side); it inserts on the distal phalanges of four fingers

Question 21

Give the orientation, origin, and insertion of the one muscle that makes up the fourth layer.

Answer 21

muscle is called the pronator quadratus, it is transversely oriented ust above the wrist…it originates from the ulna and inserts on the radius

Question 22

At what level does the brachial artery bifurcate into the radial and ulnar arteries?

Answer 22

neck of the radius

Question 23

Describe the track of the radial artery.

Answer 23

1. crosses superficial to pronator teres muscle, but deep to the brachioradialis muscle
2. lies lateral to flexor carpi radialis tendon in lower forearm
3. goes to dorsal aspect of hand at lower end of radius
4. branches given off at wrist
   a. superficial radial artery
   b. palmar carpal branch
5. forms deep palmar arch in the hand

Question 24

Describe the track of the ulnar artery.

Answer 24

1. passes under median nerve and deep to both heads of pronator teres muscle,
   then deep to flexor digitorum superficialis
2. descends on surface of the flexor digitorum profundus lateral to the ulnar
   nerve
3. continues into the hand by passing superficial to the flexor retinaculum
4. gives off common interosseous artery
5. forms superficial palmar arch in hand

Question 25

Describe the path of the common interosseous artery.

Answer 25

1. short branch given off the ulnar artery near its origin 2. divides into anterior and posterior interosseous arteries

Question 26

What is unique about the circulation around the elbow?

Answer 26

1. branches of arteries proximal to the elbow joint anastomose with branches of arteries distal to the joint

Question 27

What are the branches of the brachial artery in the elbow region?

Answer 27

(1) superior ulnar collateral artery (2) inferior ulnar collateral artery

Question 28

What are the branches of the deep brachial artery?

Answer 28

(1) radial collateral artery (2) middle collateral artery

Question 29

What branches from the radial artery?

Answer 29

radial recurrent

Question 30

What branches from the ulnar artery?

Answer 30

a. anterior ulnar recurrent artery b. posterior ulnar recurrent artery

Question 31

What branches from the posterior interosseous artery?

Answer 31

recurrent interosseous

Question 32

Summarize the anastomoses of the forearm.

Answer 32

a. superior ulnar collateral artery - posterior ulnar recurrent artery b. inferior ulnar collateral artery - anterior ulnar recurrent artery c. middle collateral artery - interosseous recurrent artery d. radial collateral artery - radial recurrent artery

Question 33

describe the track of the median nerve.

Answer 33

1. passes between the humeral and ulnar heads of the pronator teres, then deep to the flexor digitorum superficialis where it descends to the wrist 2. at the wrist it can be located between the tendons of the palmaris longus and flexor carpi radialis muscles 3. passes through the carpal tunnel to reach the hand 4. innervates muscles of the first and second layer in forearm 5. gives off anterior interosseous nerve in the cubital fossa a. supplies the muscles of the third and fourth layers b. lies on the interosseous membrane

Question 34

Describe the track of the ulnar nerve.

Answer 34

1. enters the forearm from behind the medial epicondyle of the humerus by passing between the humeral and ulnar heads of the flexor carpi ulnaris muscle 2. travels on the flexor digitorum profundus muscle to the wrist 3. enters the hand by passing superficial to the flexor retinaculum, grooving the lateral surface of the pisiform bone and is held in place by the palmar carpal ligament, a thickening of deep fascia 4. innervates flexor carpi ulnaris muscle and ulnar half of flexor digitorum profundus muscles