Autonomics of the Head and Neck

Question 1

Where along the spinal chord are the preganglionic fibers of the sympathetic nervous system found?

What rami enter the sypatheric trunk?

What rami leave the sympathetic trunk?

Answer 1

T1-L2

White rami go to the sympathetic trunk

grey rami exit the sympathetic trunk

1. to spinal nerve & follows out into periphery
2. rise up sympathetic trunk to higher level, then synapse (like to superior cervical ganglion) & making our way to plexuses

Question 2

What are sympathetic fibers doing on the following structures:

Internal carotid

External carotid

inferior thyroid artery

vertebral artery

Answer 2

• Internal carotid
  
  • vasoconstriction of its branches
  • dilator of the pupil
  • superior tarsal muscle
• External carotid
  
  • somatic to skin
  • visceral to glands
• inferior thyroid artery
  
  • visceral to lower larynx, hypopharynx, oesophagus
• vertebral artery
  
  • vasoconstriction of its branches only

Question 3

What two nerves merge to form the nerve to the pterygoid canal?

Answer 3

deep petrosal and greater petrosal

Question 4

Check out this sympathetic innervation of the head

Question 5

How does the superior cervical ganglion send axons into the head?

Answer 5

post ganglionic cells are sent on the surface of arteries

Question 6

Sympathetic innervation to the head is sent to the blood vessels and what two tissues?

Answer 6

superior tarsal muscle and dilator pupillae

Question 7

Where are the preganglionic parasympathetic cell bodies that innervate the head and neck located?

Answer 7

nuclei in the brainstem and intermediate gray matter at s2-s4 spinal cord levels

Question 8

What is the parasympathetic ganglion where synapsing occurs to provide innervation to the lacrimal gland and the nasal mucous gland?

Answer 8

pterygopalatine ganglion

Question 9

Do only parasympathetic fibers exist in parasympathetic ganglion?

Answer 9

no, sensory and sympathetic fibers can pass through (ciliary ganglion for example)