11 Autonomic Innervation of Head and Neck Structures

Question 1

In general terms, what are the target tissues for the autonomic nervous system?

Answer 1

Question 2

Which structures in the head and neck receive sympathetic impulses and which receive parasympathetics?

Answer 2

• Sympathetic- fight or flight
  
  • Smooth muscle of
    
    • Blood vessels
    • Eye lid (tarsal muscle)
    • Iris (dilator pupilllae)
• Parasympathetic -rest and digest
  
  • Smooth muscle of
    
    • Iris (sphincter pupillae)
    • Ciliary body (control thickness of lens)
    • Respiratory and GI tracts
  • Lacrimal glands
  • Salivary and mucosal glands
    *

Question 3

How are parasympathetic and sympathetic outflow described in terms of location?

Answer 3

PS: Craniosacral outflow

SS: Throracolumbar outflow

Question 4

At what spinal level segment do all the sympathetics destined for the head and neck come out at?

Answer 4

T1/T2

Question 5

What are the top 3 ganglia of the sympathetic chain called?

Answer 5

Cervical ganglion (found in the neck)

(superior middle and inferior)

Question 6

Use this diagram to describe the route of the sympathetic outflow to the head and neck

Answer 6

Imagine sympathetic plexus wrapped around carotid artery and branches

Question 7

Give a possible cause of Horner’s syndrome. What is it and how does it present?

Answer 7

• Damage to sympathetics to the face
• Causes:
  
  • Stroke
  • Tumour in apex of lung and common carotid artery and its branches

Symptoms:

1. Partial ptosis
   
   1. Levator palpebrae muscle- has 2 parts skeletal and smooth muscle
      
      1. Smooth muscle= superior tarsal- sympathetic innervation
2. Miosis
   
   1. Unopposed parasympathetics
      
      1. Constricted pupil

Question 8

Use as revision: Summary of sympathetic innervation to head and neck structures

Answer 8

Question 9

Which cranial nerves carry parasympathetics (4)?

Answer 9

• CN III Oculomotor
• CN VII Facial
• CN IX Glossopharyngeal
• CN X Vagus

Question 10

Fill in the missing gap in the diagram showing the parasympathetic innervation to the head and neck:

Answer 10

Question 11

Which nerves pass through each of these foramen?

Answer 11

Question 12

Name the parasympathetic nuclei associated with cranial nerve III.

Answer 12

Edinger Westphal

Question 13

Name the 4 parasympathetic ganglia for the head and neck:

Answer 13

Question 14

This diagram shows the path of the cranial nerve III (oculomotor). Where on this diagram are is the Edinger Westphal nucleus and the Cilliary ganglion?

Answer 14

Question 15

What path do the parasympathetics supplying the:

• Ciliary muscles (alter shape of lens)
• Sphincter pupillae muscles (constrictor of pupil)

take?

Answer 15

Brianstem-CN III- ciliary ganglion- small branches from CN Va–>

• Ciliary muscles (alter shape of lens)
• Sphincter pupillae muscles (constrictor of pupil)

Question 16

When a light is shined in one eye (left/right) then the pupils in both eyes should constrict (pupillary light reflex). Explain why this is.

Answer 16

Question 17

Which 2 branches of the facial nerve CN VII carry all of the parasympathetics associated with the facial nerve and where do they arise?

Answer 17

Question 18

What are the 2 parasympathetic ganglia associated with the facial nerve?

Answer 18

Question 19

Talk through the following scematic to show the parasympathetic outflow associated with the facial nerve. Why is it important to know this?

Answer 19

If patient presents with facial nerve palsy- ask about probelms with saliva etc as can use this to determine where damage to facial nerve is

Question 20

Use as revision: Summary of parasympathetic innervation to head and neck structures

Answer 20

Question 21

Describe the course taken by the parasympathetic nerve associated with CN IX (glossopharyngeal).

Answer 21

Question 22

Describe the course taken by the parasympathetics associated with the vagus nerve (CN X).

Answer 22