TBL6 - Fascia of Forearm and Hand

Question 1

What are continuations of the brachial fascia?

Answer 1

1) The brachial fascia of the arm is located in the biceps region, superior to the elbow
2) Inferior to the elbow, the brachial fascia becomes the antebrachial fascia
3) Inferior to the wrist (beginning of the palm), the antebrachial fascia becomes the palmar fascia
4) Upon reaching the center of the palm of the hand, the palmar fascia thickens and becomes the palmar aponeurosis

Question 2

What is the function of the bicipital aponeurosis? What enters the cubital fossa? What does the artery that enters the cubital fossa bifurcate into?

Answer 2

1) The bicipital aponeurosis reinforces the brachial and antebrachial fasciae covering the cubital fossa, a depression on the anterior aspect of the elbow
2) The median nerve and brachial artery enter the fossa
3) The brachial artery bifurcates into the radial and ulnar arteries

Question 3

What type of sensory nerves are found within the shoulder, arm, forearm, & hand?

Answer 3

Somatic sensory nerves course within the superficial fascia of the shoulder, arm, forearm, and hand

Question 4

Compare sources, courses, & distributions of the medial (antebrachial) and posterior cutaneous nerves of the forearm

Answer 4

1) Medial antebrachial cutaneous nerve of forearm:
a) Source: Medial cord of brachial plexus (in axilla)
b) Course & Distribution: Descends medial to brachial artery, pierces deep fascia with basilic vein in midarm, dividing into anterior and posterior branches that enter forearm and supply skin of anteromedial aspect to wrist
2) Posterior cutaneous nerve of forearm:
a) Source: Radial nerve (with inferior lateral cutaneous nerve of arm)
b) Course & Distribution: Perforates lateral head of triceps, descends laterally in arm, then runs along and supplies posterior forearm to wrist

Question 5

Compare sources, courses, & distributions of the superior lateral and medial cutaneous nerves of the arm

Answer 5

1) Superior, lateral cutaneous nerve of arm:
a) Source: Terminal branch of axillary nerve
b) Course & Distribution: Emerges from beneath posterior margin of deltoid and supplies skin over lower part of this muscle and on lateral side of midarm
2) Medial brachial cutaneous nerve of arm:
a) Source: Medial cord of brachial plexus (in axilla)
b) Course & Distribution: Communicates with intercostobrachial nerve, continuing to supply skin of medial aspect of distal arm

Question 6

What does the lateral aspect of the dorsal venous network drain into? The medial aspect?

Answer 6

1) The lateral aspect of the dorsal venous network drains into the cephalic vein
2) The medial aspect of the network drains into median veins of the forearm that empty into the basilic vein

Question 7

What does the median cubital vein do?

Answer 7

The cephalic and basilic veins are interconnected in the cubital fossa by the median cubital vein

Question 8

Where does the cephalic vein ascend through? What vein does the cephalic vein join?

Answer 8

The cephalic vein ascends laterally to the deltopectoral groove where it pierces the axillary fascia and joins the axillary vein

Question 9

Where does the basilic vein go through? What vein does the basilic vein join?

Answer 9

The basilic vein pierces the brachial fascia and ascends medially to join the axillary vein

Question 10

How are the median nerve and brachial artery somewhat protected when the median cubital vein is used for venipuncture?

Answer 10

1) The cubital fossa is the common site for sampling and transfusion of blood and intravenous injections because of the prominence and accessibility of veins. When the most common pattern of superficial veins is present, the median cubital vein is selected
2) This vein crosses the bicipital aponeurosis, which separates it from the underlying brachial artery and median nerve and provides some protection to the latter