Neuron and resting potential

Question 1

parts of a neuron and description

Answer 1

1. dendrites - many branched aspects
2. body (soma) - genetic and metabolic center of the cell
3. axon - fiber for transmission
4. terminals - chemicals come out

Question 2

2 types of transmission in nerve and where

Answer 2

1. electrical - dendrite, body, axon

2. chemical - terminal

Question 3

direction of transfer in nerve

Answer 3

unidirecitonal from dendrites to terminal

Question 4

3 types of neurons and descriptions

Answer 4

1. multipolar - numerous dendrites, single axon
2. bipolar - two processes arise from body - one to dendrites, one to terminal
3. pseudounipolar - single process arises from body and splits into the two directions

Question 5

2 processes of pseudounipolar

Answer 5

1. periperhal - joins peripheral nerve

2. central - goes to CNS

Question 6

where are different neurons located

Answer 6

1. multipolar- most common - interneurons and motor
2. bipolar - special senses
3. pseudounipolar - somatic and visceral sensory neurons

Question 7

what is electrical communication within a cell

Answer 7

transmembrane potential

Question 8

what is general voltage

Answer 8

-70 to ECF

Question 9

what is graded potential and where does it occur

Answer 9

• amplitude based on strength of stimulation

- dendrites and cell bodies

Question 10

what is fixed amplitude and where

Answer 10

• fixed amplitudes, stength based on frequency

- in axon

Question 11

how do dendrite increase surface area

Answer 11

increase in spines

Question 12

what does cytoplasm contain

Answer 12

cytoskeletal proteins, mitochondria, ER, ribosomes

Question 13

what is stim. from sensory neurons and what does it produce

Answer 13

response to stim. generates receptor potentials

Question 14

what is stim in non-sensory neurons and what is generated

Answer 14

response from NT binding - causes synaptic potential

Question 15

what demarcates the beginning of an axon

Answer 15

spike initiations zone

Question 16

where is spike initiation zone in various neurons (2)

Answer 16

1. multipolar neurons - axon hillock next to cell body

2. pseudounipolar - where the dendrites coalesce

Question 17

where are ribosomes located and what is the significance of this

Answer 17

not in axon - means they cannot produce their own proteins and must be transported from cell body

Question 18

what is name of terminal branching of axons

Answer 18

axon collaterals

Question 19

what is bidirectional axon transport called

Answer 19

axonal transport

Question 20

what is direction of anteriograde transport

Answer 20

body to terminal

Question 21

what are 2 types of anterior transport

Answer 21

1. fast - 400mm/day

2. slow - 50mm/day

Question 22

what does fast transport move

Answer 22

membrane bound substances, mitochondria, macromolecules

Question 23

what directs fast transport

Answer 23

kinesin - ATP microtubules

Question 24

what does slow transport move

Answer 24

diffusion of cytosolic and cytoskeletal proteins

Question 25

what does retrograde transport move (3)

Answer 25

1. old garbage - endosomes and mitochondria
2. NGF during development
3. can move viruses etc - bad

Question 26

what is movement source of retrograde

Answer 26

dynein

Question 27

what are 2 conditions for an ion to move through channel

Answer 27

1. external force must induce - electrochemical gradient (electric+concentration)
2. channel must be permiable

Question 28

what are 2 types of channels

Answer 28

1. nongated - always open

2. gated - only open in certain conditions

Question 29

3 types of gated ion channels

Answer 29

1. voltage gated
2. ligand gated
3. mechanically gated -

Question 30

what ions are greater in and out of cells

Answer 30

out - Na, Cl, Ca

in - A and K

Question 31

what is leak channel

Answer 31

allows slow leak of K out of cell so ICF is -ve

Question 32

what 3 ways can a charge become more postive

Answer 32

1. more Na conductance
2. more Ca conductance
3. Less K conductance

Question 33

what 1 way may the charge become more -ve

Answer 33

K conductance increased - causes hyperpolarization