9.15 Notes

Question 1

Radial glia

Answer 1

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

Question 2

Three types of macroglia

Answer 2

Astrocytes, Schwann cells, ogliodendrocyte

Question 3

Astrocytes

Answer 3

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

Question 4

Schwann cells

Answer 4

Macroglia located in the PNS; makes up myelin

Question 5

Oligodendrocyte

Answer 5

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

Question 6

Parkinson’s disease

Answer 6

Death of neurons that produce dopamine

Question 7

Blood-brain barrier

Answer 7

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

Question 8

Things that can cross the blood-brain barrier easily

Answer 8

Oxygen and carbon dioxide

Question 9

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

Answer 9

Glucose

Question 10

Fat-soluble molecules

Answer 10

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

Question 11

Where is the blood-brain barrier particularly weak?

Answer 11

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)

Question 12

Neuron membrane

Answer 12

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

Question 13

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

Answer 13

Negative

Question 14

Electrical gradient

Answer 14

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

Question 15

At rest, where are each of the molecules?

Answer 15

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

Question 16

K+

Answer 16

Potassium ion

Question 17

Na+

Answer 17

Sodium ion

Question 18

CL-

Answer 18

Chloride ion

Question 19

Ca++

Answer 19

Calcium ion

Question 20

Concentration gradient

Answer 20

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

Question 21

Sodium-potassium pump

Answer 21

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

Question 22

Action potential

Answer 22

An explosion of electrical energy caused by a depolarizing current

Question 23

Depolarize

Answer 23

To become more positive; to move towards zero

Question 24

Threshold

Answer 24

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

Question 25

Hyperpolarization

Answer 25

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

Question 26

Propagation of action potential

Answer 26

The movement of the firing down the axon

Question 27

Nodes of Ranvier

Answer 27

The junctions between myelin; where the action potential occurs

Question 28

Salutatory conjunction

Answer 28

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

Question 29

Refractory period

Answer 29

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

Question 30

Absolutely refractory period

Answer 30

Sodium channels are closed; no action potential can occur whatsoever

Question 31

Relative refractory period

Answer 31

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

Question 32

Otto Lowei

Answer 32

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

Question 33

Microglia

Answer 33

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