Intro to Cells

Question 1

Define

Glia cells

Answer 1

support cells of CNS
- non-neuronal components of NS (can’t transmit info)

Question 2

Define

neuron

Answer 2

functional unit of the NS

Question 3

Why are brain tumors technically not CNS tumors?

Answer 3

not made of neurons, made of glial cells or meninges

Question 4

10-50x more glia cells/neurons in CNS

Answer 4

glia>neurons

Question 5

where are microglia located?

Answer 5

CNS

Question 6

3 categories of macroglia

Answer 6

oligodendrocytes/schwann cells, astrocytes, ependymal/choroidal cells

Question 7

where are oligodendrocytes located?

Answer 7

CNS

Question 8

where are schwann cells located?

Answer 8

PNS

Question 9

location

astrocytes

Answer 9

CNS

Question 10

location

ependymal/choroidal cells

Answer 10

CNS

Question 11

Define

microglia

Answer 11

mononuclear phagocytes derived from macrophages, that respond to injury, infection or disease

immune cells of CNS

Question 12

immune cells of the CNS

Answer 12

microglia

Question 13

microglia express a range of ____

Answer 13

antigens

Question 14

what activates microglia

Answer 14

infections and diseases (MS, AIDS-related dementia, parkinson’s, alzheimer’s)

active in all autoimmune diseases

Question 15

what are the 2 types of myelin-producing cells?

Answer 15

oligodendrocytes (CNS); schwann cells (PNS)

Question 16

Define

oligodendrocytes

Answer 16

envelop ~15 axonal internodes where they produce and support myelin sheaths in the CNS

Question 17

what are axonal internodes?

Answer 17

spaces between nodes of ranvier

Question 18

define

schwann cells

Answer 18

envelop 1 internode and produce & support myelin sheath

Question 19

what type of cell is associated with the ability of the PNS to regenerate after injury?

Answer 19

schwann cells

Question 20

schwann cells envelop ____ internode(s)

Answer 20

1

Question 21

oligodendrocytes envelop ____ internode(s)

Answer 21

about 15

Question 22

ependymal cells line the ____

Answer 22

ventricles

Question 23

choroidal cells line the ____

Answer 23

choroid plexus

choroidal arteries

Question 24

define

ventricles

Answer 24

cavities in the CNS filled with cerebrospinal fluid

Question 25

define

choroid plexus

Answer 25

collection of vessels within the ventricles that secrete CSF

Question 26

where is the majority of CSF located

Answer 26

choroid plexus

Question 27

functions

astrocytes

Answer 27

• influence embryonic growth/retraction of neurites (synapses)
• regulate chemical contents in extracellular space (restrict spread of NT; regulate [] of potassium)
• possess NT receptors
• extend end feet on CNS neurons to form glial limiting membranes to regulate nutrient passage
• form end feet on CNS capillaries creating BBB

Question 28

define

glial limiting membrane

Answer 28

astrocytes laid in a way to drain lymph from CNS (glymphatics) during sleep and empty into veins

Question 29

describe

regulation of chemical contents in extracellular space by astrocytes

Answer 29

restrict spread of NT:
- prevent NT engaging with receptors
- astrocytes have NT receptors to take up extra NT in CNS

Question 30

define

blood-brain barrier

Answer 30

tight junction between end feet of astrocytes and CNS capillaries

Question 31

function

blood-brain barrier

Answer 31

• allows small, highly lipid soluble substances to enter CNS
• prohibits large, complex substances
• selectively transports substances such as glucose, electrolytes and aa

Question 32

where do astrocyte end feet extend to?

Answer 32

CNS neurons (glial limiting membranes) and capillaries (BBB)

Question 33

components of neuronal soma

Answer 33

• nucleus
• rough ER (Nissl bodies)
• smooth ER
• mitochondria
• cytoskeleton (microtubules, microfilaments, intermediate/neurofilaments)

Question 34

function of microtubules in cytoskeleton of neuronal soma

Answer 34

wall structure and transport of molecules

Question 35

function of microfilaments in cytoskeleton of neuronal soma

Answer 35

make proteins

Question 36

cytoskeleton components

Answer 36

• microtubules
• microfilaments
• intermediate/neurofilaments

Question 37

define

neurite

Answer 37

processes coming out of cell body

Question 38

components of neurites

Answer 38

dendrites & axons

Question 39

where does axoplasmic transport occur?

Answer 39

axon

Question 40

define

anterograde axoplasmic transport

Answer 40

transport of synaptic vessicle from cell body to axon terminal

Question 41

define

retrograde axoplasmic transport

Answer 41

transport of empty vessicle from axon terminal to soma to be refilled

Question 42

where does the axon begin?

Answer 42

at the axon hillock

Question 43

how can the axon be differentiated from the soma?

Answer 43

no RER in axon - no Nissl bodies (appear black when dyed)

Question 44

bouton

Answer 44

axon terminal/presynaptic terminal contains synaptic vessicles

Question 45

location

myelin sheaths

Answer 45

envelop axon at internodal spaces

Question 46

define

nodes of ranvier

Answer 46

unmyelinated points on axon where an AP procedes from node to node (saltatory conduction)

Question 47

define

saltatory conduction

Answer 47

AP procedes from node to node

jumps between myelin sheaths

Question 48

battery effect/conduction

Answer 48

occurs on unmyelinated neurons

Question 49

4 functional components of neurons

Answer 49

1. input
2. trigger (integrative)
3. conductile
4. output

Question 50

define

input component

Answer 50

• area that receives information to be propagated
• produces graded local signal based on stimulus intensity or amount of NT released

Question 51

receptor potential

Answer 51

stimulus intensity

Question 52

synaptic potential

Answer 52

amount of NT released