Week 3

Question 1

Functions of the nervous system

Answer 1

Gather sensory input to monitor changes occurring inside and outside the body, process and interpret sensory input, Cause a response, if appropriate (motor output – control of effectors)

“higher functions” in the brain: memory, learning, emotion, and intelligence.

Question 2

Structure of nervous system

Answer 2

Central Nervous System (CNS)
- Brain and spinal cord
- integration, ‘command center’

Peripheral Nervous System (PNS)
- outside of the CNS
- cranial and spinal nerves
- carry info to/from CNS

Question 3

Nervous tissue: cell types

Answer 3

• highly cellular (very little extra-cellular space)\

Two main cell types:
- Neuroglia (supporting cells)
- Neurons (excitable nerve cells that transmit signals)

Question 4

4 types of neuroglial cells in the CNS

Answer 4

Astrocytes:
- maintain blood brain barrier
- controlling the levels of neurotransmitters around synapses

Microglia:
- brains immune cells
- removes dead cells and pathogens by phagocytosis

Ependymal:
- line spinal cord & ventricles off the brain
- involved in producing cerebrospinal fluid (CSF)

Oligodendrocytes:
- myelinated CNS axons, provide structural framework

Question 5

2 types of neuroglial cells in the PNS

Answer 5

Satellite cells:
- Surround neuron cell bodies in PNS and regulate environment

Schwann cells:
- Aka neurilemmocytes
- Form myelin sheaths around larger nerve fibers of the PNS
(Also surround unmyelinated axons in PNS)
- Play a role in nerve regeneration

Answer 6

Afferent neurons:
- Sensory neurons (carry info from PNS to the CNS)
- Most are unipolar

Interneurons (aka association neurons): Most Neurons
- In CNS
- Function: integration!
- Most are multipolar

Efferent neurons:
- Motor neurons (carry info from CNS to the effector, typically muscle tissue)
- Most are multipolar
- Most have cell body in CNS, often clustered
- Many dendrites (short), one long axon