Autonomic Nervous System

Question 1

What is the autonomic system divided into?

Answer 1

Sympathetic

Parasympathetic

Question 2

In the ANS, where do sensory neurones enter the spinal cord? Where do they have their cell body?

Answer 2

Dorsal horn

Dorsal root ganglion

Question 3

Which part of the brain regulates the autonomic NS?

Answer 3

Hypothalamus

Medulla oblongata

Question 4

What are the 2 efferent neurones found in the ANS?

Answer 4

Preganglionic - leaving ventral horn

Postganglionic - from ganglia to target tissue

Question 5

What is the parasympathetic nervous system also called? Where do the preganglionic neurones exit the spinal cord?

Answer 5

Thoracolumbar system

T1-L3

Question 6

What is the ratio of pre to post ganglionic fibres in the sympathetic nervous system?

Answer 6

1: 20

Question 7

What is the ratio of pre to post ganglionic fibres in the parasympathetic nervous system

Answer 7

1:2

Question 8

The parasympathetic system is also called the what? Where do the motor nerves emerge?

Answer 8

Craniosacral system

Cranial nerves 3, 5, 9, 10 and sacral segments

Question 9

Which nerve carries the majority of parasympathetic activity?

Answer 9

Vagus

Question 10

What does the parasympathetic nervous system control?

Answer 10

Heart rate, motility of GI tract and exocrine secretions

Question 11

In the parasympathetic nerounes, what do the preganglionic neurones release and what does it bind to? What about the post ganglionic neurones?

Answer 11

Acetylcholine - nicotinic receptors

Acetylcholine - muscarinic receptors

Question 12

In the sympathetic neurones, what do the pre ganglionic release and where do they bind? What do the post ganglionic?

Answer 12

Acetylcholine

Noradrenaline

Question 13

In the sympathetic nervous system, neurotransmitter is released into the blood by what?

Answer 13

Adrenal medulla

Question 14

Describe the differences between the autonomic and somatic nervous system

Answer 14

ANS: involuntary, excitatory or inhibitory, 2 motor neurones, glands/smooth muscle/cardiac, can function without nerve supply
SNS: voluntary, excitatory only, 1 motor neurone, skeletal muscle, cannot function without NMJ

Question 15

What are the 4 fibre types of neurons?

Answer 15

A - large, fast, myelinated - touch/pressure
A delta - type of A fibre but small, less myelination, pain
B - medium size and speed, preganglionic neurones
C - small and slow, unmyelinated motor neurones