Overview of Nervous System

Question 1

3 cells of the nervous system and function of each

Answer 1

1. Neurons -Primary processors of neural signals ( neuronal cell type)
2. Neuroglia- support electrical and chemical functions of neurons ( non-neuronal cell type)
3. Vascular endothelium-provides blood supply to the brain tissue ( non-neuronal cell type)

Question 2

Difference between a apical and basal dendrite

Answer 2

Apical dendrite-extends upward from cell body

basal dendrite-extend downward from cell body

Question 3

The functional zones of a neuron

Answer 3

1. input zone-dendrites and cell body, axon hillock; gray matter, no myelin sheaths
2. conduction zone-axons; white matter, has myelin sheaths
3. output zone-synapses; axon terminals; no myelin sheaths

Question 4

Significance of Dendritic Spines

Answer 4

tiny protusion on surface dendrites=generally found on exictatory neurons; indicative of synpases with other neurons
Smooth dendrites=generally means an inhibitory neurons

Question 5

3 Classes of Neurons

Answer 5

1. Motor/Efferent
2. Sensory/Afferent
3. Interneurons-found in spinal cord, reflex arcs

Question 6

Do neurons/nerve cells make up the majority of brain tissue?

Answer 6

No, neurons are not the majority of the brain tissue.

Glia/neuroglial and vascular endothelium , non-neuronal cells, make up the majority of brain tissue

Question 7

Name the 5 main glial/neuroglial cell sub-types and their function

Answer 7

1. Oligodendrocyte/Schwann cells
2. Astrocytes
3. Microglial
4. Glial stem cell
5. Oligodendrocyte precursors

Question 8

Dormant vs. Amoeboid Microglial Cell

Answer 8

Migrate into brain during development

Dormant/ramified-non active immune response
Amoeboid/active immune response; release of cytokines

Question 9

Oligodendrocytes vs. Schwann cells

Answer 9

cells that make myelin, primarily found in white matter

present antigens to direct growth of axons during development an injury recovery

Oligodentrocytes found in CNS

Schwann cells found in CNS

Question 10

Function of Astrocytes

Answer 10

Found in grey matter ( cell body, dendrites, synapses

Involved in
synapse activity, ionic balance of ECF, scar fromation; blood-brain barrier

Question 11

Function of Glial stem cell

Answer 11

type of astrocyte, found near brain ventricles

can give rise to more stem cells, astrocytes, oligodendrocytes or neurons

exhibit somatice cell properties

Question 12

Oligodendrocyte precursors

Answer 12

move throughout white matter of brain

usu becomes an mature oligodendrocyte but can also become an astrocyte or neuron

can revert back to pluripotent state or become another cell type as long as they don’t become a fully myelinating oligodendrocyte

Question 13

What is the Blood-Brain Barrier?

Answer 13

specialized permeable barrier b/w capillary endothelium and extracellular space in brain tissue