Neuron Structure

Question 0

Neuron

Answer 0

basic building blocks of the nervous system

Question 1

Neuron Doctrine

Answer 1

neurons are individual cells
dynamic polarization
connectional specificity

Question 2

3 basic parts of a typical neuron

Answer 2

Cell body/soma
Dendrites
Axon

Question 3

What is contained in the soma?

Answer 3

nucleus and cytoplasmic organelles
Nissl substance
neurofilament

Question 4

What is Nissl substance?

Answer 4

Rough ER

Question 5

Where is Nissl substance absent?

Answer 5

axon hillock

Question 6

What is the function of dendrites?

Answer 6

major receptive sites for synapses

Question 7

Dendritic trunks

Answer 7

continuations of the soma

Question 8

What are the parts of a dendrite?

Answer 8

trunks
fields
spines

Question 9

What is the function of the axon?

Answer 9

major effector site for synapses:

conducts action potenials

Question 10

What are the parts of an axon?

Answer 10

Initial segment
axolemma
axoplasm
axon collaterals

Question 11

Initial segment

Answer 11

initiation of action potentials

Question 12

axolemma

Answer 12

surface membrane of axon

Question 13

axoplasm

Answer 13

no ribosomes or RER

Question 14

Unipolar cell

Answer 14

Intervertebrate neuron

Question 15

Bipolar cell

Answer 15

bipolar cells of the retina

Question 16

Pseudo-unipolar cell

Answer 16

Ganglion cell of dorsal root

Question 17

Multipolar cells

Answer 17

Motor neuron of spinal cord
Pyramidal cells of hippocampus
Purkinje cell of cerebellum

Question 18

Golgi Type I

Answer 18

Projected neurons

Question 19

Golgi Type II

Answer 19

Interneurons

Question 20

Size and shape of the soma is related to:

Answer 20

length and number of processes

Question 21

Subcellular organelles of neurons

Answer 21

plasma membrane
mitochondria
Golgi apparatus
RER

Question 22

What is the function of lysosomes?

Answer 22

membrane turnover

Question 23

What are Lipofuscin granules?

Answer 23

Large end-stage lysosomes
normal aging
accumulated in dementia

Question 24

What is accumulated in dementia patients?

Answer 24

Lipofuscin granules

Question 25

What is the function of the cytoskeleton?

Answer 25

maintaining the shape of neurons and their processes

Question 26

What makes up the cytoskeleton?

Answer 26

Microtubules Neurofilaments Microfilament

Question 27

What is most abundant in the cytoskeleton?

Answer 27

microfilaments

Question 28

________ binds ATP and polymerize to form filamentous ________

Answer 28

G actin; F actin

Question 29

Microfilaments have a _________ (+) end, and a __________ (-) end resulting in a _______________.

Answer 29

fast-growing; slow-growing; treadmilling effect

Question 30

Cytochalasins

Answer 30

depolymerize F actin

Question 31

Phalloidin

Answer 31

stabilizes F actin

Question 32

What blocks the turnover of microfilaments and what is the result of doing such?

Answer 32

Cytochalasins and phalloidin | Threatens cell viability

Question 33

Microfilaments

Answer 33

5-8 nm diameter | polar ATPases

Question 34

Neurofilaments

Answer 34

10 nm diameter | nonpolar

Question 35

Where are neurofilaments present?

Answer 35

In cytoplasm of cell bodies, dendrites and axons

Question 36

Neurofibrils

Answer 36

aggregates visible at the light microscopic level

Question 37

Characteristic of Alzheimer's Disease

Answer 37

Neurofibrillary tangles

Question 38

Microtubles

Answer 38

20-25 nm diameter polar, GTPases made of 13 protofilaments: chains of tubulin (alpha & beta)

Question 39

Which way are the microtubules in axons pointed?

Answer 39

(+) ends are pointed away from the soma

Question 40

Which way are the microtubules in dendrites pointed?

Answer 40

proximally: mixed polarity distally: (+) end point toward the postsynaptic site (away from soma)

Question 41

Antimitotic chemo drugs

Answer 41

Taxol (stabilizes microtubules) | Colchicine (depolymerizes microtubules)

Question 42

Microtuble-associated proteins (MAPS)

Answer 42

stabilize microtubules against abnormal disassembly | mediate interaction of microtubles with other cell components

Question 43

High molecular weight MAPS

Answer 43

Kinesin | Dynein

Question 44

Low molecular weight MAPS

Answer 44

Tau proteins

Question 45

Kinesin

Answer 45

transport toward the (+) end of microtubules 2 heavy chains: bind to microtubules and ATP 2 light chains: bind to other cell components

Question 46

Dynein

Answer 46

transport toward the (-) end of microtubules 2 or 3 heavy chains variable number of light and intermediate chains

Question 47

Tau proteins

Answer 47

found in neurofibrillary tangles of Alzheimer's Disease patients

Question 48

What is the site of macromolecular and organellar synthesis?

Answer 48

soma

Question 49

What are the types of axoplasmic transport?

Answer 49

Slow axonal transport: axoplasmic flow Fast anterograde axonal transport Fast retrograde axonal transport

Question 50

Components of microtubules and neurofilaments, as well as, soluble proteins move by what kind of transport?

Answer 50

Axoplasmic flow/slow axonal transport: Slower component

Question 51

Actin and calmodulin move by what type of transport?

Answer 51

Axoplasmic flow/slow axonal transport: Faster component

Question 52

What type of transport is blocked by colchicine?

Answer 52

Fast anterograde axonal transport

Question 53

Fast anterograde transport is ____________, relies on ___________, and transports ______________.

Answer 53

ATP-dependent; microtubules and kinesin; subcellular organelles

Question 54

What type of transport relies on microtubules and cytoplasmic dyein?

Answer 54

fast retrograde axonal transport

Question 55

Fast retrograde transport is responsible for transporting what?

Answer 55

cell components for degradation, growth factors, viruses, toxins, experimental tracers

Question 56

Which type of transport is typically the fastest?

Answer 56

Fast anterograde axonal transport