The Neck

Question 1

What regions is the neck bounded by?

Answer 1

It is bounded by the base of the skull and the mandible above and by the clavicles and top of the sternum below.

Question 2

What are the 4 main components that the neck can be divided into? (they begin with V)

Answer 2

Visceral = containing the trachea and the oesophagus, contains the passageways for the larynx and pharynx

Vascular = encloses the common carotid artery, the internal jugular vein and the vagus nerve within the carotid sheath

Vertebral = contains the vertebrae and the surrounding muscles.
7 cervical vertebrae contained, muscles such as the sternocleidomastoid and trapezius muscle and postural muscles that surround the deep layers to assist in the movement of the neck

Question 3

How can the neck be flexible while also being able to hold the weight of the head?

Answer 3

By having the oddly shaped atlas and axis.
They do not have any intervertebral discs.
The weight of the skull is held within the synovial joints of the vertebrae and reinforced by numerous ligaments.

Question 4

How do cervical vertebrae differ from other vertebrae?

Answer 4

They contain the transverse foramen, the passageway for the vertebral artery.

Question 5

What is the main muscle found in the superficial layers of the neck and explain this muscle?

Answer 5

The platysma lies at level C7.
This is a flat and thin muscle which covers the entire anterior half of the neck from the mandible to the clavicles.
Main role is to tense the skin to help depress the mandible and in some facial expression.

Question 6

What are the 2 main muscles seen in the deep fascia?

Answer 6

The sternocleidomastoid muscle.

The trapezius muscle.

Question 7

What does contraction of the right sternocleidomastoid muscle do?

Answer 7

Causes the head to tilt to the right and rotate to the left.

Question 8

Where does the trapezius muscle originate from and to?

Answer 8

Comes from the occipital protuberance at the back of the head and also from the spinous process of the cervical vertebrae.
It inserts onto the lateral 1/3 of the clavicle and spine of the spacula (shoulder blades).

Question 9

Why are the cervical vertebrae less protected than the thoracic?

Answer 9

The thoracic have extra protection from their attachment to ribs.

Question 10

We divide the neck into 2 anterior and 2 posterior triangles.
How do we define what each region is bounded by and what each region contains?

Answer 10

Anterior triangle = from the sternum to the chin to underneath the mandible to the sternocleidomastoid.

Posterior triangle = from the middle 1/3 of the clavicle to the posterior border of the sternocleidomastoid and then to the anterior margin of the trapezius muscle.

Question 11

What nerve do we see in the posterior triangle of the neck?

What vein is seen?

Answer 11

The accessory nerves (cranial nerve 11).
Goes from the posterior border of the sternocleidomastoid to the anterior border of the trapezius.

The external jugular vein which passes obliquely down over the sternocleidomastoid muscle to enter the posterior triangle.

Question 12

What are the main components of the anterior triangle?

Answer 12

The muscles that attach to the hyoid bone
Carotid arteries
The vagus nerve
The elements of the respiratory and gastrointestinal system
The thyroid and parathyroid glands

Question 13

What vasculature do we see within the anterior triangle?

Answer 13

All arteries derive from the common carotid artery.
The common carotid artery arises from the brachiocephalic artery on the right side of the body coming out the aorta.
This artery enters the neck within the carotid sheath.

The interior jugular vein is the main vein of the anterior triangle.
It emerges from the base of the skull and travels in the carotid sheath.

Question 14

What is the innervation to the neck?

Answer 14

Several structures of the neck receive innervation from cranial nerves 8-12 (vestibulocochlear, glossopharyngeal, vagus, accessory, hypoglosssal).

8 cervical spine nerves which divided into anterior and posterior branches. Posterior branches supply the extensor muscles of the vertebral column except for C1 which supplies the skin of the posterior parts of the scalp and neck.

The cervical plexus (C1-C4) supplies the muscles and skin of the neck.
The cervical plexus may be divided into superficial and deep groups. The superficial supply the skin of the anterior and lateral parts of the neck and the side of the head while the deep group supplies muscles.

Question 15

What are some of the cutaneous branches of the cervical plexus?

Answer 15

• Occipital
• Great auricular
• Transverse nerve of the neck
• Supraclavicular

Question 16

What is the ansa cervicalis nerve?

Answer 16

A nerve that innervates the muscles which attach to the hyoid bone or thyroid cartilage.

Question 17

What is the brachial plexus?

Answer 17

A network of nerves that send signals from your cord to your shoulder.
The remaining anterior rami of the cervical vertebrae (C5 C6, C7, C8) as well as the first thoracic vertebrae (T1) form the branchial plexus.
This network projects towards the armpit to supply the entirety of the upper limb.

Question 18

How is lymph drained from the neck?

Answer 18

All the lymph vessels in the head and neck drain into the deep cervical lymph nodes.

The efferent vessels of the deep cervical nodes drain into the jugular trunk that ultimately lead into the venous system at the junction of the internal jugular and subclavian veins.