electrical signals

Question 1

characterized by temporary change in RMP, strength of it depends on size of stimulus

Answer 1

graded potential

Question 2

stimularion of a neuron reaches a threshold that triggers active transport of ions known as an ___ ____

Answer 2

action potential

Question 3

RMP: actively move ions against gradient; atp dependent

Answer 3

pumps

Question 4

RMP: exchange ions

Answer 4

exchanger

Question 5

RMP: ions to diffuse down concentration gradients when open

Answer 5

channels

Question 6

two major classes of channels

Answer 6

leakage and gated

Question 7

always open; more K+ than Na+ channels
(influx of Na+, efflux of K+)

Answer 7

leakage channels

Question 8

open/closed based on environment

Answer 8

gated channels

Question 9

types of gated channels

Answer 9

voltage, ligand, signal, mechanical

Question 10

more K+ inside and Na+ outside, does what?

Answer 10

sets resting membrane potential

Question 11

RMP results primarily from what three processes

Answer 11

1. diffusion of ions down their conc. gradients (k+ leakage channels)
2. selective permeability of plasma membrane (3 Na+ out, 2 K+ in)
3. attraction of cations to anions

Question 12

gated channel that requires a signal and occurs in cell bodies and dendrites

Answer 12

ligand gated

Question 13

gated channel that requires change in RMP at the initial segment, axon hillock, axon

Answer 13

voltage gated

Question 14

gated channel that is activated by mechanical change and is somatosensory

Answer 14

mechanically gated

Question 15

the magnitude of graded potential can or cannot vary

Answer 15

can

Question 16

this potential spreads passively and is short loved

Answer 16

graded

Question 17

ligand gated channels can be ____ tropic or ___ tropic and are activated by extracellular ligand

Answer 17

iono or metabo

Question 18

signal at same time but at different synaptic sites

Answer 18

spatial summation

Question 19

signal at time back to back on same synapse

Answer 19

temporal summation

Question 20

an action potential is started through what type of channel

Answer 20

voltage gated

Question 22

what potential does not decay with distance and magnitude stays the same

Answer 22

action

Question 23

ap is spread by

Answer 23

simple diffusion

Question 24

action potential requires both ___ and ___ current flow

Answer 24

active and passive

Question 25

all voltage gated channels open at _____

Answer 25

threshold

Question 26

what ion in action potential has faster reaction time

Answer 26

Na+

Question 27

at ___ mV Na closes and K opens

Answer 27

+35

Question 28

if there was no myelin the axons would be poor conductors and signals would die out why?

Answer 28

current "leaks" out across axon membrane

Question 29

what is the action potential location

Answer 29

axon hillock, axon

Question 30

what is the graded potential location

Answer 30

dendrites, cell body

Question 31

membrane change in graded potential is either what or what

Answer 31

depolarization (excitatory) or hyperpolarization (inhibitory)

Question 32

unmyelinated axons; depolarization/repolarization step-wise and must move down entire membrane

Answer 32

continuous conduction

Question 33

node, internode in myelinated fibers, AP passes down nodes, saves ATP (faster)

Answer 33

saltatory

Question 34

anesthetics: prolongs inactivation of voltage-sensitive Na+ channel (cannot start another action potential): lidocaine

Answer 34

local

Question 35

ketamine is similiar size to magnesium block in NMDA channel and blocks flow

Answer 35

intravenous anesthetics