TBL24 - Root of the Neck

Question 1

What side of the superior thoracic aperture is the root of the neck held?

Answer 1

The root of the neck is the cervical side of the superior thoracic aperture

Question 2

Where does the phrenic nerve course inferiorly? What do the subclavian artery and roots of the brachial plexus traverse?

Answer 2

1) The phrenic nerve courses inferiorly along the surface of the anterior scalene muscle
2) The subclavian artery and roots of the brachial plexus traverse the interscalene triangle

Question 3

What artery does the vertebral artery arise from? Where does the vertebral artery ascend in when approaching the skull?

Answer 3

1) The vertebral artery arises from subclavian artery

2) It ascends toward the skull in the transverse foramina of the cervical vertebra

Question 4

Where does the short thyrocervical trunk arise lateral to? Locate the inferior thyroid artery ascending from the trunk toward the thyroid gland.

Answer 4

The short thyrocervical trunk arises lateral to the origin of the vertebral artery

Question 5

Observe the superior, middle, and inferior cervical sympathetic ganglia of the sympathetic trunk. What forms the stellate ganglion?

Answer 5

The inferior ganglion often joins the 1st thoracic ganglion to form the stellate ganglion

Question 6

Why do cervical sympathetic ganglia not receive white communicating rami?

Answer 6

1) The sympathetic trunks receive no white rami communicantes in the neck (recall that white rami associated with cervical spinal nerves)
2) These ganglia receive presynaptic fibers conveyed to the trunk by the superior thoracic spinal nerves and their associated white rami communicantes, which then ascend through the sympathetic trunk to the ganglia

Question 7

How do postsynaptic sympathetic fibers from the cervical ganglia reach the cervical spinal nerves, the thoracic viscera, the viscera of the neck, and the intracranial cavity?

Answer 7

1) After synapsing with the postsynaptic neuron in the cervical sympathetic ganglia, postsynaptic neurons send fibers to the:
a) Cervical spinal nerves via gray rami communicantes
b) Thoracic viscera via cardiopulmonary splanchnic nerves
c) Head and viscera of the neck via cephalic arterial branches (rami)
2) The latter fibers accompany arteries as sympathetic periarterial nerve plexuses, especially the vertebral and internal and external carotid arteries

Question 8

Why do ipsilateral vasodilation and anhydrosis in the face and neck occur after unilateral sympathetic trunk injury?

Answer 8

A lesion of a cervical sympathetic trunk in the neck results in a sympathetic disturbance called Horner syndrome, which is characterized by vasodilation and absence of sweating on the face and neck (anhydrosis), caused by lack of a sympathetic (vasoconstrictive) nerve supply to the blood vessels and sweat glands