Arm + Axilla

Question 1

how many muscles are in the posterior compartment?

Answer 1

one - triceps brachii

Question 2

what are the loose major functions of the two compartments?

Answer 2

posterior = extensor
anterior = flexor

Question 3

name the three heads of the triceps, and where their joint tendon inserts

Answer 3

long, lateral and medial (medial deepest, covered by the other two)
insert onto olecranon of ulna

Question 4

what is the action and innervation of triceps brachii?

Answer 4

radial nerve (C6-8, mainly C7)
extension @ elbow

Question 5

how many muscles are in the anterior compartment?

Answer 5

3 (BBC) - biceps / brachialis / coracobrachialis

Question 6

which nerve innervates the anterior compartment muscles?

Answer 6

musculocutaneous

Question 7

what is the main action of biceps brachii?

Answer 7

supination of forearm when flexed at elbow

also flexes @ arm and shoulder

Question 8

what forms the roof of the cubital fossa?

Answer 8

bicipital aponeurosis

Question 9

what do the two heads of the biceps combine to attach to?

Answer 9

radial tuberosity

Question 10

what is the action of the coracobrachialis?

Answer 10

flexor @ shoulder

Question 11

what is the action of the brachialis?

Answer 11

main flexor @ elbow

Question 12

which muscle forms the base of the cubital fossa?

Answer 12

brachialis

Question 13

what makes up the anterior border of the axilla?

Answer 13

pectoralis major and minor

Question 14

what makes up the medial border of the axilla?

Answer 14

serratus anterior and thoracic wall

Question 15

what makes up the posterior border of the axilla?

Answer 15

scapularis, teres major, lattissimus dorsi

Question 16

what makes up the lateral border of the axilla?

Answer 16

bicipital groove on the humerus

Question 17

what are the 3 pathways exiting the axilla?

Answer 17

main one is straight into the upper limb.
quadrangular space - gap in posterior wall of axilla, access to posterior arm and shoulder area
clavipectoral triangle - opening in anterior wall

Question 18

what passes through the quadrangular space?

Answer 18

axillary nerve and posterior circumflex humeral artery

Question 19

what passes through the clavipectoral triangle?

Answer 19

cephalic vein enters, medial and lateral pectoral nerves leave

Question 20

what 3 structures border the clavipectoral triangle?

Answer 20

pectoralis major, deltoid and clavicle

Question 21

name the contents of the axilla (6 structures)

Answer 21

axillary artery (medial and posterior parts)
axillary vein
brachial plexus
corachobrachialis
biceps brachii
axillary lymph nodes