Cells of the Brain and their Function

Question 1

What does myelin do?

Answer 1

• decreases metabolic energy requirements
• decreases capacitance load of axon
• increases conduction speed of APs (saltatory conduction)

Question 2

What are the thee neuron types? (shape)

Answer 2

bipolar, pseudounipolar, multipolar

Question 3

Describe a bipolar neuron

Answer 3

single axon and single dendrite emerging form opposite ends of the soma; ex: retinal ganglion cell

Question 4

Describe a pseudo-unipolar neuron

Answer 4

dendrite and axon emerging from the same process; ex: DRG

Question 5

describe a multipolar neuron

Answer 5

more than two dendrites;
Golgi I - neurons with long axons
Golgi II (granule neurons) - neurons with short, locally projecting axons; spinal motor neuron, pyramidal neuron, purkinje cell

Question 6

What are four functional components that all neurons have in common?

Answer 6

1. input component
2. integrative component
3. conductive component (axon))
4. output component (secretory function)

Question 7

Some functions of dendrites and soma?

Answer 7

receive and integrate synaptic inputs, propogate these inputs to inital segment (of axons where AP is initiated)

Question 8

Axons vs Dendrites (number)

Answer 8

neurons have single axon, can have multiple dendrites

Question 9

Axons vs Dendrites (ribosomes)

Answer 9

axons have none, dendrites have both rough ER and cytoplasmic polysomes

Question 10

Where are the branches of axons and dendrites located with respect to cell body?

Answer 10

Axonal branches are distal teo cell body and dendrites branch extensively near the cell body

Question 11

Oligodendrocytes vs Schwann cells

Answer 11

both make myelin, but oligo is in CNS and schwann in PNS

Question 12

Function of microglia

Answer 12

scavengers and remove debris after injury, disease or neuronal death. Act as resident macrophages

Question 13

Function of radial glia

Answer 13

guide migrating neurons and direct outgrowht of axons, modulate synaptic properties

Question 14

Function of astrocytes

Answer 14

participate in formation of maintenance of blood-brain-barrier (BBB), also have signals that act both presynaptically and postsynaptically to regulate synaptic transmission, also function to buffer K concentrations in the CNS

Question 15

4 types of microglia

Answer 15

amoeboid - present during development and phagocytose debris
ramified- common morphology of resting micoglia
activated - phagocytic AND ANTIGEN PRESENTING
gitter cells - micoglia that are full of debris (unable to phagocytose any more material)

Question 16

Which type of glial cell can strip synapses off?

Answer 16

microglia

Question 17

Which glial cell can release cytotoxic substances?

Answer 17

microglia

Question 18

Which glial cell is involved in making Nodes of Ranvier?

Answer 18

oligodendrocytes