Anatomy of the NS

Question 1

Where are most synapses found in neurones?

What is synaptic delay of each type of synapse?

Answer 1

At dendrites - axodendritic synapses.

0.5-1.5ms for chemical, 100 microseconds for electrical.

Question 2

What constitutes grey and white matter?

Answer 2

Grey matter is cell bodies/soma.

White matter is axons.

Question 3

What is the role of the brain stem?

Answer 3

Regulate vital autonomic physiological functions.

Contains cell bodies for 12 pairs of cranial nerves.

Question 4

What do the meningeal membranes do?

How do neurones exit the spinal cord?

What is the dorsal root?

Answer 4

Membranes which surround CNS in the spinal cord.

As spinal nerves through the ventral root.

Where sensory neurones enter the spinal cord.
The dorsal root ganglion contains cell bodies of sensory neurones.

Question 5

What constitues the PNS?

Answer 5

Peripheral NS includes Cranial and spinal nerves….

Sensory neurones.

Connects the CNS to the rest of body.

Question 6

What is the somatic PNS?

What is the ENS?

Answer 6

Voluntary system - voluntary motor movements.

THe ENS is within the autonomic PNS - unlike somatic PNS.

ENS is enteric NS governs GI tract functioning.

But itself is innervated by the sympa and parasympa NS