Action Potentials Part 1

Question 1

neurons

Answer 1

cells that receive and transmit electrochemical information

Question 2

dendrites, cell body, axon

Answer 2

info comes into neurons on dendrites

axons transmit info to other neurons

Question 3

neurons communicate by sending

Answer 3

graded potentials
action potentials
synaptic transmission

Question 4

graded potentials

Answer 4

dendrites and down cell body
electrical
short distance signals
series of depolarizations 
initiate action potentials

Question 5

action potentials

Answer 5

down axon
electrical
long distance signals
series of depolarizations and depolarizations

Question 6

synaptic transmission

Answer 6

across synapse

chemical

Question 7

synaptic transmission

Answer 7

signal gets to axon terminal
neurotransmitters released across synapse and attach to receptors on dendrite
chemical signal
excitatory or inhibitory messages

Question 8

electrical signals by neurons

Answer 8

neurons communicate with signals
electrical signals are sent when
1. anything changes membrane permeability to ions
2. anything alters ion concentrations on either side of the membrane

Question 9

all or none phenomenon

Answer 9

action potential happens completely down the axon to the axon terminal or not at all

Question 10

excitatory, inhibitory, both

Answer 10

excite = build toward action potential
inhibit = inhibit action potential
equal amount of both = nothing

Question 11

mixed messages

Answer 11

receiving neurons receive multiple messages from other neurons
if more excitatory than inhibitory reach axon hillock, action potential fired

Question 12

at rest

Answer 12

neuron cell membrane polarized
outside positive, na+
inside negative, k+

Question 13

2 reasons for resting potential

Answer 13

1. differential permeability of plasma membrane to na+ and k+ ions
   ~na+ hard to go in but k+ leak channels easier to go out
   ~more positive outside
2. operation of sodium potassium pump
   ~2 k+ in, 3 na+ out
   ~maintains diffusion gradient

Question 14

stages of action potential

Answer 14

resting potential, threshold, depolarization, depolarization, restoration of resting potential