Cranial nerve definitions

Question 1

Efferent?

Answer 1

Carries information from brain to the periphery

Question 2

Afferent?

Answer 2

Carries information from the periphery to the brain

Question 3

Mixed?

Answer 3

Carries information both ways (brain to periphery and vice versa)

Question 4

Special?

Answer 4

Carries information from/to the special senses (vision, smell, taste, hearing and balance)

Question 5

General?

Answer 5

Carries information from/to any other part of the body, except special senses.

Question 6

Somatic?

Answer 6

Carries information to/from the skin or skeletal muscles

Question 7

Visceral?

Answer 7

Carries information to/from internal organs.

Question 8

Ganglion?

Answer 8

a ganglion is a cluster of nerve cells, also known as neurons, located outside the central nervous system (the brain and spinal cord).

Ganglia are a part of the peripheral nervous system (PNS) and serve as relay points for transmitting signals between different parts of the body and the central nervous system.

They can be parasympathetic (autonomic) or sensory.

Question 9

What is the cranial nerve nuclei?

Answer 9

• The cranial nerve nuclei are aggregate of cells (collection of cell bodies).
• Attached to these cell bodies are fibres called cranial nerves (= bundles of axons).
• These nuclei are either sensory or motor but never both (NB whereas the cranial nerves can be both).

Question 10

What is the sympathetic nervous system (SNS)?

Answer 10

• This is responsible for the bodys “fight or flight” response.
• Prepares body for stressful situations by increasing heart rate, dilating airways, and reducing blood flow to vital organs,

Question 11

What is the parasympathetic nervous system?

Answer 11

• Often referred to as the “rest and digest” system.
• Helps body relax and conserve energy, slowing the heart rate, promoting digestion, and enhancing body function during periods of rest.

Question 12

What is sympathetic and parasympathetic ganglia?

Answer 12

• In the PNS, ganglia are located near or within the target organs. When Parasympathetic nerve signal reach these ganglia, it typically synapses with another neuron before reaching the target organ, allowing for a specific and localised control over bodilt functions.
• Sympathetic ganglia are clusters of neurons which exist outside of the spinal cord. When sympathetic nerve signals reach these ganglia, they often travel to different ganglia before reaching the target organ. This allows for widespread and coordinated responses in the body.