axilla and arm

Question 1

axilla

Answer 1

gateway to the upper limb providing an area of transition between neck and arm
- major vessels and nerves pass between neck and the axilla by crossing over the lateral border of the rib 1 through axillary inlet

Question 2

axilla anatomy

Answer 2

Question 3

axilla lymphatics

what 5 groups is it divided into?

Answer 3

• all lymphatics from the upper limb drain into lymph nodes in the axilla
• receive from 75% mammary gland
• divided into 5 groups ; humeral, pectoral subscapular, central, apical

Question 4

what is the superolateral region of the mammary gland? and where does it extend?

Answer 4

• axillary process of the mammary gland or tail of spence
• extends along the inferior margin of the pectoralis major muscle toward the axilla

Question 4

arm

Answer 4

region of the upper limb b/w shoulder and the elbow
- superior communicates medially w/axilla inferiorly w/cubital fossa

Question 5

anterior compartemtn of the arm

Answer 5

contains muscles that flex the elbow

Question 6

posterior compartment of the arm

Answer 6

contain muscles that extend the joint

Question 7

shaft and distal end of the humerus

Answer 7

• shaft is som what triangular shape
• distal: capitulum and trochlea articulate with two bones of the foream (radius ulna)
• epicondyles serve as sites of attachement for muscles of the forearm

Question 8

muscles of the arm are grouped into two compartments

Answer 8

• anterior compartment
• posterior compartment

Question 9

anterior compartement muscles of the arm

function?

Answer 9

• coracobrachialis
• bicep brachii
• brachialis

flex the forearm at the elbow joint, bicep brachii aid in supination

Question 10

posterior compartment muscles of the arm

function?

Answer 10

triceps brachii

extend the forearm at the elbow joint

Question 11

origin, insertion, innervation, function

coracobrachialis

Answer 11

Question 12

origin, insertion, innervation, function

biceps brachii

Answer 12

Question 13

origin, insertion, innervation, function

brachialis

Answer 13

Question 14

origin, insertion, innervation, function

triceps brachii

Answer 14

Question 15

major artery of the arm and where is it located

Answer 15

brachial artery
- found in the anterior compartment
- divides into the radial and ulanar arteries

Question 16

arm venous drainage

where does the deep paired brachial veins

Answer 16

passes along the medial and lateral sides of the brachial artery

Question 17

arm venous drainage

what are the two large subcutaneous veins?

Answer 17

• basilic vein = becomes the axillary vein
• cephalic vein = passes superiorly on the anterolateral aspect of the arm and through the anterior wall of the axilla to reach axillary vein

Question 18

musculocutaneous nerve

motor/sensory

Answer 18

passes diagonally down the arm in the plane b/w the biceps brachii and brachialis musles

motor innervation: muscles in the anterior comp of the arm
sensory innervation: skin on the lateral surface of the forearm

Question 19

median nerve

these nerves are no major branches of the arm

Answer 19

passes vertically down the medial side of the arm in the anterior comp. and is related to the brachial artery throughout its course

Question 20

ulnar nerve

these nerves have no major branches on the arm

Answer 20

enters the arm with the median nerve and axillary artery. passes posterior to the medial epicondyle of the humerus and then into the anterior compartment of the forearm.

Question 21

radial nerve

motor/sensory

Answer 21

passes diagonally from medial to lateral through the posterior comp, it lies in the radial groove of the humerus. enters forearm anterior to the lateral epicondyle of the humerus

motor: innervation to the triceps
sensory innervation to skin of the posterior aspect

Question 22

clinical correlations

saturday night palsy

Answer 22

arm draped over the back of a chair or in an unusual position compressing the radial nerve as it passes through the axilla
- wrist drop
- weakness in forearm and hand extensors
- loss of sensation in the dorsum of the hand

Question 23

clinical correlation

rupture of biceps tendon

Answer 23

tendon that most commonly ruptures in the upper limb is the tendon of the long head of the biceps brachii muscle
- popeye sign

Question 24

clinical correlations

fracture of the midshaft of the humerus

Answer 24

radial nerve intimate contact w/midshaft of the humerus passing through the radial groove
- wrist drop
- sensory changes over the dorsum of the hand