Neurons, Glia, and Brain Tissue Flashcards Preview

MS2 - Nervous System > Neurons, Glia, and Brain Tissue > Flashcards

Flashcards in Neurons, Glia, and Brain Tissue Deck (30):
1

In general, white matter is _________ to gray matter in the cortex. In the spinal cord, however, it is opposite: ___________.

deep; gray matter is on the inside

2

Tracts, peduncles, and fasciculi are all examples of ______ matter.

white matter

3

Nuclei are an example of _________ matter.

gray

4

Once stimuli pass from dendrites to the cell body, the _________ regulates whether the signal will continue down the axon.

axon hillock

5

What stain selects for RNA?

Nissl

6

Why do neurons need to make a lot of protein?

They are large cells, requiring extensive cytoskeletons to transport proteins to the periphery of axons and dendrites.

7

Which kind of neuron (peripheral or central) can regrow damaged axons?

Peripheral (CNS axons can regrow – demonstrated in vitro – but they are prevented from doing so by astrocytes)

8

Stacks of rough endoplasmic reticulum are called ___________.

Nissl bodies

9

Necrosis due to damaged axons is called ___________.

chromatolysis (loss of coloring)

10

What are myelin cells in the CNS called?

Oligodendrocytes or oligodendroglia

11

What are myelin cells in the PNS called?

Schwann cells

12

Embryologically, the nervous system comes from _____-derm.

ecto-

13

The microglia are the __________ of the brain.

macrophages

14

Why does ATP activate microglia?

ATP outside cells is a sign of lysis

15

What are the three types of supportive cells in the CNS?

Astrocytes
Oligodendrocytes
Microglia

16

Astrocytes provide what function in the CNS?

They fill in the spaces between cells.

17

What is the most common neurotransmitter?

Glutamate

18

What cell type is responsible for maintaining the blood-brain barrier?

Astrocytes (by instructing endothelial cells to form tight junctional complexes preventing leakage of plasma into extracellular space)

19

List the functions of astrocytes.

- Neurotransmitter clearance
- Neuronal support
- Blood-brain barrier
- Local control of blood flow

20

What is the cellular difference between white and gray matter?

White matter is myelinated.

21

The white matter can be thought of as merely the ______________.

cables connecting the processing areas of the brain

22

Cell bodies all live in ________ matter.

gray

23

Most pathways are named using a __________ system.

"from-to" (so the corticospinal tract connects the motor system in the cortex to the spin)

24

In terms of action potentials, how do dendrites and cell bodies differ from axons?

Dendrites and cell bodies are generally passive – meaning the electrical signal decreases with distance – while axons have voltage-sensitive channels that propagate an action potential.

25

In general, axons greater than ________ are myelinated.

1 micron

26

Recent research has indicated that __________ dysfunction may be a source of chronic pain.

microglia

27

Unlike oligodendrocytes, which can myelinate _________ cell(s), Schwann cells can myelinate ________ cell(s).

many; only one

28

___________ envelop all blood vessels in the central nervous system.

Astrocytes

29

What two sites in the brain do not have the blood-brain barrier?

The circumventricular organs: caudal medulla and the hypothalamus

30

By what two mechanisms do neurons communicate to the blood vessels that they need more oxygen?

They generate NO (which itself causes vasodilation); and the increased in glutamate uptake by astrocytes leads to activation of a phospholipase that produces EET; EET leads to hyperpolarization of the arteriolar membrane and thus vasodilation.

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