(E1) 4 - Posterior Triangle

Question 1

What are the boundaries of the posterior triangle

Answer 1

Posterior boder - SCM
Anterior Border - Trapezius
Base - Clavicle Middle 1/3
Apex - Behind the Ear

Question 2

What are the 2 subdivisions of the posterior triangle divided by?

Answer 2

Inferior belly of the omohyoid (don’t need to know the names)

Question 3

What makes up the roof of the posterior triangle?

Answer 3

Skin, superficial fascia, platysma, investing layer of deep cervical fascia

Question 4

What layer of fascia covers the muscles that make up the floor of the posterior triangle?

Answer 4

Muscles covered by pre-vertebral layer of the deep cervical fascia

Question 5

What are the 2 types of cervical fasica?

Answer 5

Superficial and deep

Question 6

What is embedded in the superficial fascia?

Answer 6

Fat
Muscles of facial expression
Nerves and Vessels

Question 7

What are the 3 layers of deep fascia?

Answer 7

• Superficial layer of deep/investing fascia
• Middle layer of deep/pretracheal (muscular and visceral)
• Deep layer of cervical fascia/pevertebral and alar

Question 8

______ represents a condensation of all 3 deep fascial layers.

Answer 8

Carotid sheath

Question 9

What is the name of the area in the neck where a lot of nerves are exiting?

Answer 9

Erb’s Point

Question 10

What muscles make up the floor of the posterior triangle?

Answer 10

• Semispinalis capitus (apex)
• Splenius capitus
• Levator Scapulae
• Posterior, Middle, and Anterior Scalene

Question 11

What innervates SCM?

Answer 11

CN XI

Question 12

What innervates Trapezius?

Answer 12

CN XI

Question 13

What innervates the deep back muscles? (semispinalis capitus and splenius capitus)

Answer 13

Dorsal Rami

Question 14

What is the function of semispinalis capitus?

Answer 14

Bilateral Flex - Extend
Unilateral - Turn head to the opposite side

Question 15

What is the function of splenius capitus?

Answer 15

Bilateral Flex - Extend
Unilateral - Turn head same side

Question 16

What innervates the muscles found in the floor of the neck? (scalenes, levator scapulae)

Answer 16

Ventral Rami

Question 17

Anterior and middle scalene attach to the ____ rib

Answer 17

1st

Question 18

Posterior scalene attaches to the ____ rib

Answer 18

2nd

Question 19

__________ attaches between the 3rd part of the subclavian artery and subclavian vein

Answer 19

Anterior scalene

Question 20

What ventral rami innervates anterior scalene?

Answer 20

C3-C8

Question 21

What is the action of the scalene muscles?

Answer 21

Elevate the rib

Question 22

What ventral rami innervate posterior/middle scalene?

Answer 22

C3-C8

Question 23

What ventral rami innervates levator scapulae?

Answer 23

C5 - Dorsal Scapular Nerve

Question 24

What is the action of levator scapulae?

Answer 24

Elevates the scapula

Question 25

What cutaneous nerves make up the cervical plexus (include the rami)?

Answer 25

Question 26

What are the branches that make up ansa cervicalis?

Answer 26

C1, C2, and C3 ALL MOTOR

Question 27

What are the sensory nerves of the cervical plexus?

Answer 27

C2-C4

Question 28

What nerve travels with the Hypoglossal nerve?

Answer 28

C1

Question 29

What are the branches of C1?

Answer 29

Nerve to thyrohyoid Geniohyoid

Question 30

What does the ansa cervicalis supply?

Answer 30

C1-C3 1 Loop - 2 Roots Motor to the strap muscles

Question 31

What does the accessory nerve innervate?

Answer 31

Innervates SCM and Trapezius - Superficial so prone to injury

Question 32

What nerve lies on the anterior scalene?

Answer 32

Phrenic Nerve (C3-5)

Question 33

What nerves comes off the belly of the middle scalene? (include the rami)

Answer 33

Dorsal Scapular (C5) (goes back) Long Thoracic Nerve (C5-7) (goes down)

Question 34

What nerve is found coming off the top of the brachial plexus?

Answer 34

Suprascapular Nerve (C5,6)

Question 35

What does the phrenic nerve innervate?

Answer 35

The diaphragm

Question 36

What does the dorsal scapular nerve innervate?

Answer 36

Levator scapulae and Rhomboids

Question 37

What does suprascapular nerve innervate?

Answer 37

Supraspinatus and Infraspinatus

Question 38

What arteries are found in the posterior triangle?

Answer 38

- subclavian (3rd part) - occipital (varies) - transverse cervical (thyrocervical trunk) - suprascapular (thyrocervical trunk) - dorsal scapular (variable)

Question 39

Describe the location of the 3rd part of the subclavian artery

Answer 39

Question 40

What are the veins found in the posterior triangle?

Answer 40

Question 41

What does the external jugular vein receive blood from?

Answer 41

Posterior Auricular and Posterior branch of the retromandibular veins