Neuroscience 1 - Introduction to Neuroscience

Question 1

What is the PNS divided into?

Answer 1

1. Somatic PNS - control motor and sensory function.

2. Autonomic Nervous System - controls organs. Sympathetic and parasympathetic arms.

Question 2

What is the direction of information flow in afferent axons?

Answer 2

Towards the CNS.

Question 3

What is the direction of information flow in efferent axons?

Answer 3

Away from the CNS.

Question 4

What are interneurons?

Answer 4

CNS neurones that synapse with other CNS neurones within brain + spinal cord.

Question 5

How are axons packaged into nerves?

Answer 5

1. Afferent and Efferent axons are bundled into fascicles and are surrounded by perineurium.
2. The whole nerve is in a epineurium capsule.
3. Some axons are myelinated and others are not.

Question 6

Which axons are able to regenerate?

Answer 6

Axons in the PNS can regenerate after injury.

Question 7

Which axons are unable regenerate over long distances?

Answer 7

Axons in the CNS are unable to regenerate.

Question 8

What does white matter and grey matter consist of?

Answer 8

White matter - Ascending and descending axon tracts to and from the brain.
Grey matter - Neural cell bodies.

Question 9

What is the difference between ventral and dorsal roots?

Answer 9

ventral roots face the front of the body and conduct motor information whereas dorsal face the back and conduct sensory information.

Question 10

What do the dorsal and ventral roots emerge from?

Answer 10

The spinal cord, they are part of the PNS.

Question 11

Give an example of neurone that is unmyelinated

Answer 11

Nociceptive neurones.

Question 12

Why can’t these neurons regenerate over long distances?

Answer 12

1. There are inhibitory molecules in the CNS but not in the PNS.
2. Absence of guidance cues that stimulate growth during development.
3. Some loss of intrinsic axon growth capabilities by the neurons