Axilla/Brachial Plexus

Question 1

borders of axilla

Answer 1

anterior wall = pectoralis major and minor
posterior wall = latissimus dorsi, teres major, and subscapularis
medial wall = serratus anterior
lateral wall = intertubercular sulcus of humerus
base = skin and fascia of armpit

Question 2

contents of axilla

Answer 2

• fat and connective tissue
• axillary v and lymphatics (outside sheath)
• cutaneous nerves
• axillary sheath with axillary a. and brachial plexus

Question 3

5 principal groups of nodes in the axilla

Answer 3

• pectoral
• subscapular
• humeral
• central
• apical

Question 4

central nodes receive lymph from ____ to ____

Answer 4

pectoral, subscapular, and humeral nodes; apical nodes

Question 5

apical nodes receive lymph from ____ plus the ____ nodes

Answer 5

all other axillary nodes; proximal cephalic vein

Question 6

axillary a. continues as___artery

Answer 6

brachial artery

Question 7

1st part of axillary a. is between ___ and ____ and gives off ____

Answer 7

1st rib; pec minor m. ; superior thoracic a.

Question 8

2nd part of axillary a. gives off ____ and ____

Answer 8

thoracoacromial a. ; lateral thoracic a.

Question 9

3rd part of axillary a. gives off ____ and ____

Answer 9

subscapular a.; anterior & posterior circumflex humeral aa.

Question 10

brachial plexus composed of ventral rami ____; supplies all UL mm. except ____

Answer 10

C5-T1; trapezius (inn by CN XI)

Question 11

the lateral cord contains ___ divisions from the upper and middle trunks, thus containing contributions from ____ rami

Answer 11

anterior; C5-C7

Question 12

the posterior cord contains ____ divisions of all the trunks, thus containing contributions from ____ rami

Answer 12

posterior; upper, middle and lower trunks posterior diisions

Question 13

the medial cord contains the ___ division of the lower trunk, thus containing contributions from ____ rami

Answer 13

anterior; C8-T1

Question 14

5 terminal branches of the brachial plexus

Answer 14

musculocutaneous (C5, C6, C7)
median (C5-T1)
axillary (C5 and C6)
radial (C5-T1)
ulnar (C8, T1)

Question 15

major nerve of the anterior arm

Answer 15

musculocutaneous n. (C5-C7)

Question 16

musculocutaneous n. is formed from the ___ cord and passes through _____ m. ; also innervates ____ and ____ mm.

Answer 16

lateral; coracobrachialis; biceps brachii; brachialis

Question 17

what does musculocutaneous n. innervate?

Answer 17

coracobrachialis, biceps brachii, and half of brachialis m.

Question 18

median nerve (C5-T1) is formed from ___ and ____

Answer 18

half of the lateral cord; half of the medial cord

Question 19

the median n. is the major nerve of the ____ and passes ____ to arm muscles

Answer 19

anterior forearm; medial

Question 20

what does the median n. innervate?

Answer 20

most of the anterior forearm, 3 thenar eminence mm. and first 2 lumbricals in the hand

Question 21

the ulnar n. is formed from the ____ cord; runs behind the ____ and is the major n. of the ____

Answer 21

medial; medial epicondyle; hand

Question 22

what does the ulnar n. innervate?

Answer 22

most of the mm of the hand, flexor carpi ulnaris m., and the ulnar half of flexor digitorum profundus m. in the forearm

Question 23

the axillary n. (C5-C6) is formed from the ____ cord; circles behind the ___ in the _____

Answer 23

posterior; humerus; quadrangular space

Question 24

what does the axillary n. innervate?

Answer 24

deltoid and teres minor mm.

Question 25

the radial n. (C5-T1) is formed from the ____ cord; it passes posterior to the humerus in the ____ and within the ____

Answer 25

posterior; radial groove; triangular interval

Question 26

radial n. is the major n. of the ____ and ____

Answer 26

posterior arm; forearm

Question 27

what does the radial n. innervate?

Answer 27

all muscles in the posterior arm and forearm plus half of the brachialis m.

Question 28

other nerves of the brachial plexus are formed directly from ___, ____, and ____

Answer 28

rami; trunks; cords

Question 29

other nerves of the brachial plexus include: ____, ____, ____ and additional nn.

Answer 29

upper plexus nn; pectoral nn; lower plexus nn

Question 30

upper plexus includes branches from ____

Answer 30

C5-C7

Question 31

pectoral nn. are from ____

Answer 31

upper and lower trunks

Question 32

lower plexus nerves are from the ____ portions of all 3 trunks

Answer 32

posterior

Question 33

upper plexus nn. include:

Answer 33

dorsal scapular n. (C5)
long thoracic n. (C5-C7)
suprascapular n. (C5-C6)

Question 34

dorsal scapular n. innervates?

Answer 34

rhomboid and levator scapulae mm.

Question 35

long thoracic n. innervates?

Answer 35

serratus anterior m.

Question 36

suprascapular n. innervates?

Answer 36

supraspinatus and infraspinatus mm.

Question 37

pectoral nn. include:

Answer 37

lateral pectoral n. (C5-C7)

medial pectoral n. (C8-T1)

Question 38

lateral pectoral n. innervates?

Answer 38

pectoralis major m.

Question 39

medial pectoral n. innervates?

Answer 39

pectoralis major and minor mm.

Question 40

lower plexus nn. include:

Answer 40

upper subscapular n. (C5-C6)
thoracodorsal n. (C6-C8)
lower subscapular n. (C5-C6)

Question 41

upper subscapular n. innervates?

Answer 41

subscapularis m.

Question 42

thoracodorsal n. innervates?

Answer 42

latissimus dorsi m.

Question 43

lower subscapular n. innervates?

Answer 43

subscapularis and teres major mm.

Question 44

additional brachial plexus nn. include:

Answer 44

nerve to subclavius m. (C5-C6)
medial brachial cutaneous n. (C8-T1)
medial antibrachial cutaneous n. (C8-T1)

Question 45

nerve to subclavius innervates?

Answer 45

subclavius m.

Question 46

medial brachial cut. n. innervates?

Answer 46

sensory to medial arm

Question 47

medial antibrachial cut. n. innervates?

Answer 47

sensory to medial forearm