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Flashcards in 9.15 Notes Deck (33):
1

Radial glia

Helps neurons go where they're supposed to go during development

2

Three types of macroglia

Astrocytes, Schwann cells, ogliodendrocyte

3

Astrocytes

Star-shaped macroglia; very involved in stopping neurotransmission from occurring; places part of their cell (end feet) on a capillary; sends neurotransmitters to the blood; makes up the blood-brain barrier

4

Schwann cells

Macroglia located in the PNS; makes up myelin

5

Oligodendrocyte

Macroglia located in the CNS; relatively small; makes up myelin

6

Parkinson's disease

Death of neurons that produce dopamine

7

Blood-brain barrier

Semi permeable barrier between the blood and brain; allows some materials to cross, that prevents others; somethings can cross with help

8

Things that can cross the blood-brain barrier easily

Oxygen and carbon dioxide

9

Things that can cross the blood-brain barrier with active transportation

Glucose

10

Fat-soluble molecules

Can pass into the blood brain barrier her, but this has negative effects; acts directly on the brain; nicotine, alcohol, heroin, and barbiturates

11

Where is the blood-brain barrier particularly weak?

In the circumventricular organs; Pituitary gland (needs to be able to monitor the blood for hormone levels) and area postrema (the vomiting center; Can monitor the blood for toxins)

12

Neuron membrane

Semi permeable; made of a lipid bilayer and protein molecules that are embedded in the lipid bilayer

13

When a neuron is at rest, is the inside more negative or positive than the outside?

Negative

14

Electrical gradient

The difference in the electrical charge between the inside and outside of the cell

15

At rest, where are each of the molecules?

Inside: Na+, CL+, and negatively-charged proteins
Outside: K+

16

K+

Potassium ion

17

Na+

Sodium ion

18

CL-

Chloride ion

19

Ca++

Calcium ion

20

Concentration gradient

Absolute number of ions; difference of the ions on the inside versus outside

21

Sodium-potassium pump

Enzyme that actively forces 3 sodium ions outside of the cell and pulls in 2 potassium ions; uses 1 ATP

22

Action potential

An explosion of electrical energy caused by a depolarizing current

23

Depolarize

To become more positive; to move towards zero

24

Threshold

-55 millivolts; based on the all-or-none principle; determined by whether the neuron fires or not; the action potential does not change

25

Hyperpolarization

The cell is now more negative after firing than it was at rest; sodium-potassium pump fixes this

26

Propagation of action potential

The movement of the firing down the axon

27

Nodes of Ranvier

The junctions between myelin; where the action potential occurs

28

Salutatory conjunction

The jumping of the action potential from node to node, which makes the action potential move faster in myelinated neurons

29

Refractory period

When a neuron can no longer fire again after it was fired; can be either absolute or relative

30

Absolutely refractory period

Sodium channels are closed; no action potential can occur whatsoever

31

Relative refractory period

Potassium channels are still open; a lot more sodium has to come in, so a stimulus would have to be very strong for firing to occur

32

Otto Lowei

Electrically stimulated a frogs heart to beat very quickly; took fluid from the heart and put it in another frog's heart, which started beating faster; prove that there's a chemical part of communication

33

Microglia

Highly involved in caring for neurons; remove dead neurons and waste; involve the neurotransmission; involved in the uptake of neurotransmitters