Posterior Triangle, Brachial Plexus

Question 1

What is found in the superficial cervical fascia?

Answer 1

fat, cutaneous nerves, vessels, and PLATYSMA

Question 2

What fascia envelopes all structures of the neck except the platysma?

Answer 2

Investing Fascia (splits to include trapezius and sternocleidomastoid)

Question 3

What is within the carotid sheath?

Answer 3

carotid artery, internal jugular vein, vagus nerve

Question 4

What fascia surrounds the vertebral column and muscles associated with it?

Answer 4

Prevertebral fascia

Question 5

The trachea, esophagus, and thyroid gland is enveloped by the _______ fascia.

Answer 5

Pretracheal Fascia

Question 6

What are the boundaries of the posterior triangle?

Answer 6

Sternocleidomastoid (Anterior)
Trapezius (posterior)
Clavicle (inferior)
- roof = investing fascia, platysma, superficial fascia
-floor = pre vertebral fascia over scalene

Question 7

What are the branches of the subclavian artery

Answer 7

VITamin C and sometimes D

1. Vertebral A.
2. Internal Thoracic
3. Thyrocervical Trunk (SITA)
   i. Suprascapular
   ii. Inferior thyroid
   iii. Transverse cervical
   iv. Ascending cervical
4. Costacervical
   i. Deep Cervical ii. Supreme Intercostal
5. Dorsal Scapular

Question 8

Where does the brachial plexus pass between?

Answer 8

Anterior and Middle Scalene

Question 9

The phrenic nerve sits on top of which muscle?

Answer 9

Anterior Scalene

Question 10

Dorsal scapular nerve pierces which scalene?

Answer 10

Middle Scalene

Question 11

What are the muscles WITHIN the posterior triangle

Answer 11

1. Omohyoid
2. Splenius Capitis
3. Levator Scapulae
4. Scalene Muscles

Question 12

Anterior Scalene

Answer 12

O: Anterior tubercles of transverse processes of C3-C6
I: FIRST RIB
A: elevate 1st rib (inspiration), flex and laterally flex neck

Question 13

Middle Scalene

Answer 13

O: transverse processes of C1-C2, posterior tubercles of transverse processes C3-C7
I: FIRST RIB
A: elevate 1st rib (inspiration), laterally flex neck

Question 14

Posterior Scalene

Answer 14

O: posterior tubercles of transverse processes of C4-C6
I: SECOND RIB
A: elevate 2nd rib (inspiration), laterally flex neck

Question 15

Upper root damage results in ______

Answer 15

Erb’s Palsy

Question 16

Klumpke’s Palsy is due to damage of the____

Answer 16

lower root of the brachial plexus.

Question 17

3 Musketeers Assasinated 5 rats, 5 mice, and 2 unicorns

Answer 17

Musculocutaneous - C5, C6, C7 
Axillary - C5, C6
Radial - C5 to T1 
Median - C5 to T1
Ulnar - C8 & T1

Question 18

Sternocleidomastoid

Answer 18

O: Anterior and superior manubrium and superior medial third of clavicle
I: Lateral aspect of mastoid process and superior nuchal line
A: Flexes and laterally rotates cervical spine. Protracts head when acting together . Extends neck when neck already partially extended
N: Spinal accessory nerve (lateral roots C1-5)

Question 19

Platysma is innervated by which nerve?

Answer 19

Cranial Nerve 7

Question 20

The axillary artery and brachial plexus originate from:

Answer 20

between Anterior and Middle Scalene

Question 21

Spinal Accessory nerve innervates what two muscles?

Answer 21

Trapezius and Sternocleidomastoid

Question 22

Transverse cervical nerve is motor. True or False?

Answer 22

False, it is SENSORY (cutaneous) to the skin

Question 23

The external jugular vein travels over which muscle?

Answer 23

Sternocleidomastoid

Question 24

The posterior Chord of the brachial plexus contains which three nerves?

Answer 24

1. Upper Subscapular (to the subscapularis muscle)
2. Middle Subscapular – Thoracodorsal
3. Lower Subscapular (to Teres Major)

Question 25

What two triangles are formed by the omohyoid muscle?

Answer 25

1. Superior = Occipital Triangle

2. Inferior = Omaclavicular Triangle

Question 26

The suprascapular artery anastomoses with what two arteries?

Answer 26

Transverse cervicle artery and Circumflex Scapular Artery

Question 27

What nerves of the cervical plexus are motor and which are sensory?

Answer 27

Ansa cervicalus - Motor (innervates omohyoid)
& Phrenic = Motor

1. Great auricular, lesser occipital, Transverse Cervicle, and Supraclavicular = SENSORY

Question 28

Musculocutaneous nerve innervates what three muscles?

Answer 28

BBC
Brachialis
Biceps Brachii
Corachobrachialis (pierced by the nerve itself)

Question 29

The vagus nerve (CN X) travels with what two blood vessels?

Answer 29

Internal Jugular Vein

and Carotid Artery

Question 30

Outside the dura mater is ___ and inside the dura mater is ____

Answer 30

outside = Peripheral Nervous System

inside = CNS