Posterior triangle of neck, axilla + brachial plexus

Question 1

What are the superior boundaries of the neck?

Answer 1

mandible and posterior skull

Question 2

what is the inferior boundary of the neck?

Answer 2

thorax and shoulders

Question 3

what are the boundaries of the posterior triangle?

Answer 3

-INFERIOR BOARDER: Middle 1/3 of the clavicle
-POSTERIOR BORARDER: trapezius
-ANTERIOR BOARDER: sternocleidomastoid (SCM)

Question 4

What forms the roof of the posterior triangle?

Answer 4

skin, superficial fascia, platysma

Question 5

What nerves run through the posterior triangle?

Answer 5

● Cutaneous nerves of cervical plexus
● Accessory nerve
● Phrenic nerve
● Brachial plexus rami and trunks

Question 6

What forms the cervical plexus?

Answer 6

ventral rami of C1-C4 (cutaneous and muscular branches)

Question 6

What vessels run through the posterior triangle of the neck?

Answer 6

● External jugular vein
● Subclavian vein
● Subclavian artery

Question 7

which cutaneous branches are in the cervical plexus?

Answer 7

● Lesser occipital nerve
● Greater auricular nerve
● Transverse cervical nerve
● Supraclavicular nerves

Question 8

How can you test for a spinal accessory nerve injury?

Answer 8

ask patient to preform “idk motion” (raise shoulders and shake head from side to side)

Question 9

What muscles are innervated by the spinal accessory nerve?

Answer 9

trapezius and SCM

Question 10

what nerve innervates the diaphragm and what are its spinal levels?

Answer 10

Phrenic nerve
C3,4,5 (keeps the man alive, C4 is major innervation)

Question 11

If a patient presents with pain in epigastric region and shoulder region what might you suspect happened?

Answer 11

damage to the C4 nerve (if stomach acid escapes the stomach it can reach the phrenic nerve, causing it to not function properly, causing issues to the dermatome and myotomes of C4)

Question 12

what are the boundaries oft he scalene interval/triangle?

Answer 12

● Anteriorly: anterior scalene muscle
● Posteriorly: middle and posterior scalene muscles
● Inferiorly: first rib

Question 13

C5-T1 are __ ___ NOT _____ of spinal nerves. However, they are the _____of the brachial plexus

Answer 13

ventral rami, roots, roots

Question 13

what lays on top of the anterior scalene?

Answer 13

phrenic nerve

Question 14

what is the most proximal pulse point for evaluating arterial sufficiency in the upper limb

Answer 14

subclavian artery

Question 15

where can you palpate the subclavian artery?

Answer 15

The subclavian pulse can be evaluated by palpating downward posterior to the clavicle to compress the artery against the
first rib

Question 16

After the subclavian artery passes what it becomes what?

Answer 16

first rib, axillary artery

Question 17

what is scalene interval syndrome or thoracic outlet syndrome?

Answer 17

something narrows the scalene interval compressing subclavian artery and/or inferior trunk of brachial plexus

Question 18

What makes up the apex of the axilla region

Answer 18

clavicle, upper boarder of scapula, 1st rib

Question 19

What makes up the base of the axilla region?

Answer 19

skin and fascia of armpit

Question 20

What makes up the anterior wall of the axilla region?

Answer 20

pec major, minor and clavicle

Question 20

What makes up the posterior wall of the axilla region?

Answer 20

teres major, latissimus dorsi, subscapularis, scapula

Question 21

What makes up the medial wall of the axilla region?

Answer 21

upper portion of thoracic wall, serratus anterior

Question 22

What are the contents of the axilla?

Answer 22

● Axillary artery and its
branches
● Axillary vein and its
tributaries
● Brachial Plexus
● Axillary lymph nodes

Question 22

What makes up the lateral wall of the axilla region?

Answer 22

intertubercular sulcus of humerus

Question 23

When does the axillary change its name again and what does it become?

Answer 23

Axillary artery changes name to brachial artery at lower border of teres major

Question 23

What comes off the first part of the axillary artery?

Answer 23

superior thoracic artery

Question 24

What is in the second part of the axillary artery?

Answer 24

the thoracoacromial trunk and the lateral thoracic artery

Question 25

The third part of the axillary artery gives rise to :

Answer 25

-the subscapular a.
-anterior and posterior circumflex humeral arteries

Question 26

where does the axillary vein start? What are its contributes?

Answer 26

the lower border of teres major by joining together of the brachial veins and the basilic vein

Question 27

What is the function of the musculocutaneous nerve?

Answer 27

Motor: muscles in anterior compartment of arm
Sensory: skin of lateral forearm

Question 28

Where does musculocutaneous originate? What is its spinal segment?

Answer 28

lateral cord
C5-7

Question 29

what is the function of the median nerve?

Answer 29

Motor: all muscles in anterior forearm, three thenar muscles
Sensory: skin over palmar surface of three and one half digits, lateral side of palm and middle wrist (look at the image)

Question 30

What is the function of the ulnar nerve?

Answer 30

Motor: all intrinsic muscles of hand, flexor carpi ulnaris flexor digitorum of profundus
Sensory: palmar surface medial one and half digets (look at picture)

Question 30

where does the median nerve originate? what are its spinal segments?

Answer 30

medial and lateral cords
C5-T1

Question 31

What is the function of the axillary nerve?

Answer 31

Motor: deltoid and teres minor
Sensory: skin over upper and lateral forearm

Question 32

what is the function of the radial nerve?

Answer 32

Motor: all muscles of posterior compartment of arm and forearm
Sensory: skin on posterior arm and forearm, lower lateral surface of arm, dorsal lateral surface of hand