Neurons

Question 1

2 types of nerves in the NS

Answer 1

1- neurons - main cells, receive and transmit so body can communicate
2- Glial cells support system of cells of NS

Question 2

Dendrites

Answer 2

Branching fibers with synaptic receptors that receive info from other neurons

Question 3

Soma

Answer 3

Cell body- metabolic stuff; nucleus, ribosomes, mitochondria- to perform metabolic stuff

Question 4

Axon

Answer 4

Thin fiber which converts a message towards another neuron

Question 5

Myelin sheath/ Schwann cell

Answer 5

Insulate axon

Question 6

Nodes of Ranvier

Answer 6

Interruptions in myelin sheath

Question 7

Nerve ending/terminal button

Answer 7

Swell at the end of the axon where chemicals are released from the neuron

Question 8

2 ways to categorize neurons

Answer 8

1- Direction
2- function

Question 9

Direction (2)

Answer 9

A) afferent - bring info into a structure (a=admit)
B) efferent - carry info outta a structure (e= exit)

Question 10

Function of sensory neurons and motor neurons

Answer 10

A) sensory neuron sensitive to stimulation and sends info from body to a body part
B) motor neuron= based on S.C. and sends info to other body parts

Question 11

SAME

Answer 11

Sensory
Afferent
Motor
Efferent

Question 12

DAVE

Answer 12

Dorsal
Afferent
Ventral
Efferent

Question 13

Answer 13

Interneuron

Question 14

Answer 14

Motor neuron

Question 15

Answer 15

Sensory neuron

Question 16

Interneuron

Answer 16

Neuron that’s all contained in 1 structure (aka intrinsic neuron)

Question 17

Astrocyte (3)

Answer 17

1. Star shape
2. Wrap around synapse- to functionally related axons so that there’s no interference and so they are super in sync
3. Dilate blood vessel to bring more nutrients into brain areas with heightened activity

Question 18

Microglia (2)

Answer 18

1. Part of immune system
2. Clean up N.S. (By remove virus and fungi, dead/damaged neurons, weak synapses)

Question 19

Oligodendrocytes (3)

Answer 19

1. Brain and spinal cord
2. Build myelin sheath
3. Supply axons with nutrients

Question 20

Schwann cells

Answer 20

1. In PNS
2. Build myelin sheath around axon
3. Supply axon with nutrients

Question 21

Radial Glia (2)

Answer 21

1. Guide migration of neurons during embryonic development
2. Most differentiate into neurons after development

Question 22

Blood brain barrier

Answer 22

1. Tight packed endothelial cells (cells that line circulatory system) that form walls of capillaries surrounding the brain. It’s more tightly packed than anywhere in the body.

Question 23

What does the BBB do?

Answer 23

1. Prevents most chemicals from crossing over into brain from rest of body

Question 24

Why do we need BBB? (3)

Answer 24

1. When a virus invades other cells in the body, the immune system destroys the cells and the cells replicate, creating new cells in that part of the body.
2. The brain doesn’t usually replaced damaged neurons
3. Therefore the brain needs extra protection from viral infections

Question 25

What can cross the BBB?

Answer 25

Small, unchanged, molecules (ex: oxygen, carbon dioxide)

Question 26

What can’t cross the BBB?

Answer 26

1. Water - brought into the brain via protein channels in the walls of the endothelial cells.
2. All other chemicals- brought into brain through active transport (transport of materials that requires energy)

Question 27

How does the BBB affect the type of nutrition the brain uses?

Answer 27

1. Most cells in body use a combo of carbs and fats for nutrition
2. Brain relies primarily on glucose (why? Cuz glucose is the only nutrient that cross the BBB)

Question 28

Nerves use _____

Answer 28

Electrical conduction

Question 29

Problem/solution/ result

Answer 29

Problem- signal would decay Bc of water and CO2 in body
Solution- axon regenerates an impulse at each point
Result- impulse travels without weakening