Arm

Question 1

What does the C6 dermatome include?

Answer 1

lateral arm, forearm, thumb

Question 2

What does the C7 dermatome include?

Answer 2

back of arm, back of forearm, 2nd and 3rd digits

Question 3

What does the C8 dermatome include?

Answer 3

medial arm, forearm and hypothenar

Question 4

What is the more powerful flexor of muscle?

Answer 4

brachialis because only crosses 1 joint. ulnar tuberosity

Question 5

What does the tendon of the long head of the biceps do?

Answer 5

runs over the head of the humerus in a synovial sheath that follows the tendon as far as the surgical neck.

Question 6

What holds the tendon of the long head of the biceps in place?

Answer 6

its held in place in the intertubercular groove by the transverse humeral ligament and the tendon of the pectoralis major

Question 7

What is the bicipital aponeurosis? What does it do?

Answer 7

protects the deep arteries and veins in the cubital fossa.

overlies and protects the brachial artery and supports the median cubital vein during venipuncture

Question 8

Describe the three triceps muscles and their functions.

Answer 8

long head- least active. aids in extending the arm
medial head- workhorse of forearm extension (deep to other two)
lateral head- strongest generator of force, functions mostly against active resistance (not during passive motions)

Question 9

Anterior and posterior compartments of blood supply across humerus

Answer 9

brachial artery- anterior compartment

profunda brachii a. - posterior compartment blood to triceps muscles

Question 10

Describe the brachial artery.

Answer 10

it is the continuation of the axillary artery at the inferior border of the teres major muscle; it terminates in the cubital fossa, where it divides into the radial and ulnar arteries

It lies anterior to both triceps and brachialis muscles; its pulsations can be felt throughout its course

Question 11

The brachial artery lies successively on 3 muscles, gives 3 main branches, is in contact with 3 important nerves, and is associated with 3 veins. Name them.

Answer 11

3 muscles constitute the floor on which artery runs (superiorly to inferiorly) triceps, coracobrachialis, brachialis

3 main branches- deep brachial (profunda brachii; runs in radial groove posteriorly), the superior ulnar collateral, and inferior ulnar collateral arteries

3 important nerves - radial ulnar and median

3 veins- 2 venae comitantes (brachial veins) and basilic vein.

Question 12

Describe 4 nerves of the arm

Answer 12

musculocutaneous - anterior compartment
radial - posterior compartment
ulnar - no branches in arm
median - no branches in arm

Question 13

Describe musculocutaneous nerve. Innervation. Location. If injury…

Answer 13

(C5-C7)
Pierces coracobrachialis, biceps, and brachialis

Injury causes great loss of flexion of the elbow, although not complete due to brachioradialis and flexor forearm muscles.

Continues as the lateral antebrachial cutaneous nerve.

Question 14

Describe pathway of Radial Nerve and muscles it innervates.

Answer 14

C5-C8, T1)
Passes in the radial groove on the back of the humerus with the deep brachial artery (profunda brachii artery), pierces the lateral intermuscular septum, and divides into superficial and deep branches in front of the lateral epicondyle

In arm gives branches to triceps, brachioradialis and supplies skin of posterior arm and forearm

Question 15

What are the branches of the radial nerve that supply the skin of posterior arm and forearm?

Answer 15

posterior brachial, inferior lateral brachial, and posterior antebrachial cutaneous nerves

Question 16

Describe ulnar nerve.

Answer 16

C8, T1
Medial to axillary and brachial arteries to the middle of the arm, pierces the medial intermuscular septum, and runs with the superior ulnar collateral artery to a groove behind the medial epicondyle of the humerus.

no branches in the arm.

Question 17

Describe the process of “hitting your funny bone”

Answer 17

A sharp blow to medial side of elbow will result in paraesthesia in ulnar nerve and a shock-like feeling in the hand and forearm.

Question 18

Describe the median nerve.

Answer 18

(C5-C8, T1)
1st lateral to, then crosses, and, finally, is medial to the brachial artery
No branches in the arm
Passes through cubital fossa deep to the bicipital aponeuronsis

Question 19

What is the cubital fossa?

Answer 19

a triangular shaped, fat filled depression of the anterior elbow.
Superficial veins good for drawing blood here - cephalic v, median cubital v, basilic v.

Question 20

Describe the boundaries of the cubital fossa:
superior:
medial: 
lateral:
floor:
roof:

Answer 20

superior- an imaginary line connecting the medial and lateral epicondyles
medial- the forearm flexors originating from the medial epicondyle
lateral- the forearm extensors originating from the lateral epicondyle
floor- brachialis and supinator mm.
roof- brachial and antebrachial fascia and reinforced by the bicipital aponeurosis

Question 21

What are the deep contents of the cubital fossa?

Answer 21

terminal part of brachial artery (branches into ulnar and radial arteries)
deep veins in the area
tendon of the biceps brachii m.
median n.
radial n.