lecture 3- neurophysiology

Question 1

three types of neuronal signals

Answer 1

resting potentias
graded potentials
action potentials

Question 2

two types of graded potentials

Answer 2

receptor

synaptic

Question 3

what factors play a role in neuronal signaling

Answer 3

concentration gradients
membrane permeability
electrical charge of ions

Question 4

two types of ion transporters

Answer 4

ATPase pump

ion exchange pump

Question 5

ion exchange pumps use ATP as an energy source. T/F?

Answer 5

false- use an electrochemical Na+ gradient

Question 6

a receptor potential results from

Answer 6

external stimuli

Question 7

a synaptic potential results from

Answer 7

activation from a pre-synaptic neuron

Question 8

role of astrocytes

Answer 8

mop up excess potassium

Question 9

what happens with too much K+ in extracellular membrane

Answer 9

cell will keep firing AP constantly

a common feature of seizures

Question 10

what happens if Na+ channels are blocked

Answer 10

takes longer for the stimulus intensity to increase –> takes longer to reach threshold

Question 11

what happens in K+ channels are blocked

Answer 11

cell remains +, cell can’t repolarize, can’t fire a new AP

Question 12

in relative refractory period, does the cell need more or less input to reach threshold vs a RMP cell

Answer 12

need more because cell is lower than RMP so, needs more input to reach threshold

Question 13

where is the spike zone (“axon hillock”) of sensory neurons

Answer 13

near the sensory nerve ending (vs. near cell body)

Question 14

the more depolarization the higher the ___ of AP is

Answer 14

frequency

Question 15

bigger neuron = larger axon diameter = (a) less or more? resistance to flow = current will flow (b) faster or slower?

Answer 15

(a) less

(b) faster