The Axilla & Brachial Plexus II

Question 1

upper lesions of the brachial plexus:

___ palsy

usually caused by an excessive increase in the angle b/n the ___ & ___

results in excessive ___ & ___ (___) of the nerve roots C5 & C6

examples:

• newborns during a difficult ___
• adults following a severe blow or fall on the ___

Answer 1

erb-duchenne

neck & shoulder

traction & tearing (avulsion)

• delivery
• shoulder

Question 2

upper lesions of the brachial plexus:
nerve lesions & muscle paralysis may involve the following:
nerves (4)

Answer 2

suprascapular nerve
nerve to the subclavius
musculocutaneous nerve
axillary nerve

Question 3

upper lesions of the brachial plexus:
nerve lesions & muscle paralysis may involve the following:
muscles:

suprascapular nerve (2)

nerve to the subclavius (1)

musculocutaneous nerve (3)

axillary (2)

Answer 3

supraspinatous
infraspinatous

subclavius

biceps brachii
brachialis
coracobrachialis

deltoid
teres minor

Question 4

upper lesions of the brachial plexus:
nerve lesions & muscle paralysis may involve the following:
suprascapular nerve:
action(s):

supaspinatous m

infraspinatous m

Answer 4

abductor of the arm at the shoulder

lateral rotator of the arm at the shoulder

Question 5

upper lesions of the brachial plexus:
nerve lesions & muscle paralysis may involve the following:
nerve to the subclavius:
action(s):

subclavius m

Answer 5

depresses the clavicle

Question 6

upper lesions of the brachial plexus:
nerve lesions & muscle paralysis may involve the following:
musculocutaneous nerve:
action(s):

biceps brachii

brachialis

coracobrachialis

Answer 6

supinator of forearm
flexor of forearm at the elbow
weak flexor of arm at the shoulder

chief flexor of forearm at elbow

flexes arm at shoulder

Question 7

upper lesions of the brachial plexus:
nerve lesions & muscle paralysis may involve the following:
axillary nerve:
action(s):

deltoid

teres minor

Answer 7

abductor of arm at shoulder

lateral rotator of arm at shoulder

Question 8

upper lesions of the brachial plexus:
result:

the upper limb hangs ___ by the side, medially ___ by the unopposed action of the ___ muscle

the forearm is ___ due to loss of action of the ___ (supination of the forearm)

loss of sensation along the (medial/lateral) side of the limb

“___” position

Answer 8

limply
rotated
pectoralis major muscle

pronated
biceps

lateral

waiter’s tip position

Question 9

lower lesions of the brachial plexus:

___ palsy

traction injuries caused by excessive (abduction/adduction) of the arm

results in ___ (___) of the C& & T1 roots of the plexus

the nerve most affected is the ___ nerve which supplies most of the small muscles of the ___

Answer 9

klumpke’s palsy

abduction

tearing (avulsion)

ulnar nerve
hand

Question 10

lower lesions of the brachial plexus:
examples:

newborn: forceful pull of the ___ limb during a difficult ___

child falling from a ___ (e.g., tree), clutching an object (single/double) handed (e.g., tree branch) to stop the fall

Answer 10

upper limb
delivery

height
single handed

Question 11

lower lesions of the brachial plexus:
result:

the hand has a ___ appearance caused by hyperextension of the ___ joints & flexion of the ___ joints

the ___ is unopposed by the lumbricals & interossei & extends the ___ joints

the ___ & lateral portion of the ___ are unopposed by the lumbricals & interossei & flex the middle & terminal ___ respectively

in addition, loss of sensation will occur along the (medial/lateral) side of the upper limb

Answer 11

clawed
metacarpophalangeal joints
interphalangeal joints

extensor digitorum
metacarpophalangeal joints

flexor digitorum superficialis

flexor digitorum profundus
phalanges

medial

Question 12

lesion of the long thoracic nerve:

the long thoracic nerve (C5, C6, C7) may be injured by blows or pressure on the (anterior/posterior) triangle of the neck, ___ wounds, during a ___ surgical procedure, or ___ injuries

Answer 12

posterior
stab
mastectomy
athletic

Question 13

lesion of the long thoracic nerve:

paralysis of the ___ muscle

the medial border of the ___ becomes prominent & protrudes (anteriorly/posteirorly) when someone pushes against a fixed object (___)

Answer 13

serratus anterior muscle

scapula
posteriorly
winging of the scapula

Question 14

lesion of the long thoracic nerve:

since the ___ can no longer be fixed to the (anterior/posterior) chest wall, the ___ is seriously weakened

(abduction/adduction) of the arm is seriously impaired b/c of weakened upward rotation of the ___

Answer 14

scapula
posterior
triceps brachii

abduction
scapula

Question 15

thoracic outlet syndrome (tos):

condition involving compression of ___ nerves, ___ vessels, or both, b/c of an inadequate passageway just above the ___ rib & behind the ___

symptoms include:

• neck, shoulder, & arm ___
• ___
• impaired ___ to the extremeties

Answer 15

brachial plexus nerves
subclavian vessels

first rib
clavicle

• pain
• numbness
• circulation

Question 16

thoracic outlet syndrome (tos):

brachial plexus trunks & subclavian vessels are subject to compression or irritation as they course through passageways from the base of the neck to the axilla (3)

Answer 16

interscalene triangle (most important)
costoclavicular triangle
subcoracoid space

Question 17

thoracic outlet syndrome (tos):
interscalene triangle:
muscles:

anterior: ___
posterior: ___
inferior: ___

Answer 17

anterior scalene

middle scalene

medial border of first rib

Question 18

thoracic outlet syndrome (tos):
costoclavicular triangle:
bones:

anterior: ___

postero-medial: ___

postero-lateral: ___

Answer 18

middle third of clavicle

first rib

upper border of scapula

Question 19

thoracic outlet syndrome (tos):
subcoracoid space:

beneath the ___ process

just deep to the ___ muscle

Answer 19

coracoid process

pectoralis minor muscle

Question 20

thoracic outlet syndrome (tos):

___ symptoms occur in 95% of cases

C8 & T1 nerve roots most commonly involved producing ___ & ___ along the ___ nerve distribution

Answer 20

neurologic symptoms

pain
paresthesia
ulnar nerve

Question 21

axillary artery:

direct continuation of the ___ artery

extends from the (medial/lateral) border of the ___ rib to the (superior/inferior) border of the ___ muscle

Answer 21

subclavian artery

lateral border of the first rib
inferior border of the teres major muscle

Question 22

axillary artery:

divided into three parts by the ___ muscle:

• first part: (above/below) the muscle
• second part: (in front of/behind) the muscle
• third part: (above/below) the muslce

by convention, the medial, lateral, & posterior cords of the ___ plexus are amed according to their relationship to the ___ segment of the axillary artery

Answer 22

pectoralis minor muscle

• above
• behind
• below

brachial plexus
middle segment

Question 23

branches of the axillary artery:

first part (1)

second part (2)

third part (3)

Answer 23

superior (supreme) thoracic artery

thoracoacromial trunk
lateral thoracic artery

subscapular artery
anterior & posterior circumflex humeral arteries

Question 24

branches of the axillary artery:
first part:
superior (supreme) thoracic artery:

helps supply the ___ & the ___ muscle

Answer 24

first two intercostal spaces

serratus anterior muscle

Question 25

branches of the axillary artery:
second part:
thoracoacromial trunk:

arises beneath the ___ muscle

passes above the upper border of the ___ muscle

pierces the ___ fascia

gives off regional branches

Answer 25

pectoralis minor muscle

pectoralis minor

clavipectoral fascia

Question 26

branches of the axillary artery:
second part:
lateral thoracic artery:

arises beneath the ___ muscle

passes below the ___ muscle running along the (medial/lateral) side of the ___

Answer 26

pectoralis minor m

pectoralis minor m
lateral
thorax

Question 27

branches of the axillary artery:
second part:
lateral thoracic artery:

formerly called the ___ artery b/c it’s a chief source of blood supply to the breast

also supplies:

• ___ m’s
• ___ m
• contents of the ___

Answer 27

external mammary artery

pectoral m’s
seratus anterior m
axilla

Question 28

branches of the axillary artery:
third part:
subscapular artery:

passes (upward/downward) & (forward/backward)

divides into two main trunks (2)

Answer 28

downwrad
backward

circumflex scapular artery
thoracodorsal artery

Question 29

branches of the axillary artery:
third part:
subscapular artery:
circumflex scapular artery:

passes around the (medial/lateral) border of the ___

b/n the ___ & ___ m in the ___ space

Answer 29

lateral border
scapula

scapula
teres major m
triangular space

Question 30

branches of the axillary artery:
third part:
thoracodorsal artery:

passes (upward/downward) along the ___

joined by the ___ n

both supply the ___ m

Answer 30

downward
axilla

thoracodorsal n

latissimus dorsi m

Question 31

branches of the axillary artery:
third part:
anterior & posterior circumflex humeral arteries:

posterior circumflex humeral artery is (smaller/larger)

they pass around the surgical neck of the ___ & anastomose w/ ___

posterior circumflex runs in the ___ space w/ the ___ n

Answer 31

larger

humerus
anastomose

quadrangular space
axillary n

Question 32

axillary vein:

direct continuation of the ___ vein as it crosses the lower border of the ___ muscle

tributaries (3)

Answer 32

basilic vein
teres major muscle

venae comitantes of the brachial artery
cephalic vein
tributaries corresponding to the branches of the axillary artery