Lecture 4: Posterior triangle of neck

Question 1

superficial cervical Fascia?

Answer 1

Superficial fascia - contains fatty tissue together with platysma (A thin sheet of skeletal muscle that originates from the superficial fascia of the thorax and runs upwards to the mandible - innervated by facial nerve VII)

Question 2

Deep cervical fascia?

Answer 2

1. Investing layer surrounds the neck and encloses peripheral muscles around the neck (eg. trapezius, sternocleidomastoid, strap muscles)
2. Pretracheal layer encloses the thyroid, larnxy/trachea and pharynx/oesophagus
3. Prevertebral layer encompasses the vertebral column and the paravertebral muscles (divides into 2 layers when goes over anterior vertebral body)
4. Carotid sheath surrounds the internal carotid a, internal jugular v and the vagus nerve getting contributions from the other 3.

Question 3

Boundaries of the posterior triangle?

Answer 3

Posterior boarder of SCM

Anterior boarder of Trapezius

Superior boarder of clavicle

The apex of the triangle is the back of the skull on the superior nuchal line

The roof is formed by the investing layer of the deep fascia and superficial structures of this (skin, a bit of platysma)

The floor is formed by the prevertebral fascia

Question 4

Neves in the posterior triangle

Answer 4

Nerves run within the investing layer or just deep to the investing fascia.

The major one in CN XI - surface markings are incorrect and damage results in loss of trap muscle control (very annoying) - usually 2cm above the greater auricular nerve but in a deeper plane

All the other nerves are sensory nerves from erbs point perforating the investing fascia at some point.

Small parts of the brachial plexus can be seen between the middle and anterior scalene.

Question 5

Arteries in the posterior triangle?

Answer 5

They are all at the base of the triangle

Transverse cervical and also the Suprascapular artery both come off the thyrocervical trunk

Question 6

Muscles deep the the prevertebral fascia?

Answer 6

Most superior

Splenius capitis

levator capitus

Posterior, middle, anterior scalene

+ inferior belly of the omohyoid muscle

Question 7

Lymphatics of the head and neck?

Answer 7

Divided into superficial and deep

Superficial nodes go around the head and consist of the submental, submandibular, occipital, mastoid, and parotid

Occipital and mastoid drain back to the superficial cervical lymph nodes and then to the deep.

But the parotid, submandinular and submental drain to the deep cervical lymph nodes

Question 8

Spinal accessory nerve path?

Answer 8

Innervates SCM ant Trapezius and is commonly damaged in cervical lymph node biopsy.

It leaves the jugular foramen and travels in the carotid sheath before perforating this sheath and traveling into the posterior traingle.