Exam 1: Anterior Triangle of the Neck

Question 1

What makes up the boundaries of the posterior triangle?

Answer 1

SCM, clavicle, trapezius.

Question 2

What makes up the apex of the posterior triangle?

Answer 2

Junction of SCM and trapezius.

Question 3

What makes up the floor of the posterior triangle?

Answer 3

Splenius capitus, levator scapulae, posterior/middle/anterior scalene muscles.

Question 4

What makes up the roof of the posterior triangle?

Answer 4

Investing layer of cervicle fascia.

Question 5

What are the two subdivisions of the posterior triangle and what are they separated by?

Answer 5

1. Subclavian (smaller)
2. Occipital (larger).

Separated by inferior belly of omohyoid.

Question 6

Which nerves make up the cervical plexus (cutaneous nerves) that innervate the posterior triangle?

Answer 6

Spinal nerves 1-4.

1. Lesser occipital
2. Great auricular
3. Transverse cervicle
4. Supraclavicular

Question 7

Where does the subclavian artery travel?

Answer 7

Between the anterior and middle scalenes.

Question 8

What is the branching sequence for the subclavian artery?

Answer 8

Subclavian–> thyrocervical–> suprascapular–> transverse cervical.

Question 9

What are the 4 motor nerves of the posterior triangle?

Answer 9

1. 2 nerves to levator scapulae.
2. Dorsal scapular- goes to rhomboid.
3. Long thoracic- comes off nerves 5/6/7 in brachial plexus- innervates seratus anterior.
4. Phrenic nerve- pinned to anterior scalene. (3,4,5 keep you alive).

Question 10

Which two arteries pin the phrenic nerve to the anterior scalene?

Answer 10

1. Transverse cervicle

2. Suprascapular.

Question 11

Where do the roots and trunk of brachial plexus emerge from?

Answer 11

Anterior and middle scalenes.