Posterior Triangle of the Neck

Question 1

Define the anterior, posterior and inferior borders of the posterior triangle (aka posterior cervical triangle of the neck) of the neck.

Answer 1

Anterior: SCM
Posterior: Trapezius
Inferior: Clavicle

Question 2

Name floor muscles of the posterior triangle. What fascia covers them?

Answer 2

Splenius, levator scapulae, scalenes. Covered by prevertebral fascia.

Question 3

Location of the third part of the subclavian artery:

Answer 3

lateral side of anterior scalene muscle.

Question 4

transverse cervical a. branches from:

Answer 4

thyrocervical trunk

Question 5

Suprascapular a. branches from:

Answer 5

tyrocervical trunk

Question 6

occipital a. branches from:

Answer 6

external carotid

Question 7

Veins in the posterior triangle

Answer 7

external jugular v and subclavian v

Question 8

Describe the pressure point of the subclavian a.

Answer 8

The artery is in contact with the 1st rib as it passes posterior to the anterior scalene muscle; consequently, compression of the subclavian artery against this rib can control bleeding in the upper limb.

Question 9

Describe the pathway of the Accessory n. (CN XI) through the posterior triangle.

Answer 9

Most important structure of posterior triangle. Lies in space deep to the investing layer, but superficial to the prevertebral layer of deep cervical fascia. Nerve basically bisects the occipital triangle as it makes its way between the SCM and the trapezius muscles.

Question 10

Name the motor functions of the Accessory n. (CN XI) through posterior triangle.

Answer 10

Trapezius and SCM

Question 11

What does cranial root of XI do?

Answer 11

branchial motor, via cranial root delivered to CN X to muscles of pharynx, palate, larynx, one tongue muscle

Question 12

What does spinal root of XI do?

Answer 12

Somatic motor, via spinal root to trapezius and sternocleidomastoid

Question 13

What is the nerve point of the neck?

Answer 13

Cutaneous branches of the cervical plexus emerge around the middle of the posterior border of the SCM, often called the nerve point of the neck (Fig. 8.8 ), and supply the skin of the neck, superolateral thoracic wall, and scalp between the auricle and the external occipital protuberance

Moore, Keith L.; Agur, Anne M; Dalley, Arthur F. (2013-02-04). Clinically Oriented Anatomy (Kindle Locations 25267-25269). Lippincott Williams & Wilkins. Kindle Edition.

Question 14

What nerves are located in posterior triangle of the neck?

Answer 14

Trunks of brachial plexu, cervical plexus, phrenic n. and accessory n. (CN XI)

Question 15

What makes up the root of the cervical plexus?

Answer 15

C1-C4

Question 16

Identify nerves that come from the cervical plexus.

Answer 16

lesser occipital n. (C2)
great auricular n. (C2, C3)
transverse cervical n. (C2, C3)
Supraclavicular nn. (C3, C4)
Phrenic n. (C3- C5)

Ansa cervicalis

Question 17

Name trunks of the brachial plexus?

Answer 17

Superior (C5,6), Middle (C7), Inferior(C8,T1)

Question 18

Where does the suprascapular nerve arise from?

What muscles does it supply?

Answer 18

The suprascapular nerve, which arises from the superior trunk of the brachial plexus (not cervical plexus), runs laterally across the lateral cervical region to supply the supraspinatus and infraspinatus muscles on the posterior aspect of the scapula. It also sends articular branches to the glenohumeral joint.

Moore, Keith L.; Agur, Anne M; Dalley, Arthur F. (2013-02-04). Clinically Oriented Anatomy (Kindle Locations 25236-25239). Lippincott Williams & Wilkins. Kindle Edition.

Question 19

Identify the phrenic nerve.

Answer 19

The phrenic nerves originate chiefly from the C4 nerve but receive contributions from the C3 and C5 nerves (Figs. 8.10 and 8.13A ). forms at the superior part of the lateral border of the anterior scalene muscle at the level of the superior border of the thyroid cartilage.

The phrenic nerve descends obliquely with the IJV across the anterior scalene, deep to the prevertebral layer of deep cervical fascia and the transverse cervical and suprascapular arteries.

Question 20

Name SCM orgins, insertions, innervations, actions.

Answer 20

Superior attachment: lateral surface of mastoid process of temporal bone and lateral half of superior nuchal line

Inferior attachment:
Sternal head: anterior surface of manubrium
Clavicular head: superior surface of medial third of clavicle

Innervations: CN XI (motor)
C2 and C3 (pain and proprioception)

Actions: laterally flexes neck, rotates face, can flex neck and extend neck

Question 21

Name Playtsma orgins, insertions, innervations, actions.

Answer 21

Superior Attachment: inferior border of mandible, skin, and subcutaneous tissues of lower face

Inferior Attachment: fascia covering superior parts of pectorialis major and deltoid muscles

Innervation: cervical branch of facial nerve (CN VII)

Actions: draws corners of mouth inferiorly and widens it as in expression of sadness and fright, draws skin of neck superiorly when teeth are clenched

Question 22

Name muscles that lie deep to the posterior triangle of the neck:

Answer 22

splenius capitis
scalenus medius
scalenus anterior
scalenus posterior
levator scapulae

know innervations, actions, and attachments…. too