L5 Biopotentials

Question 1

What are the 4 types of ion channels?

Answer 1

-Leakage ( nongated channels )
-Ligand gated channels
-Voltage gated channels
-Mechanically gated ion channels

Question 2

Resting membrane potential is a ___________ across the resting cell membrane.

Answer 2

constant potential difference

Question 3

What are the properties of resting membrane potential?

Answer 3

1. It is constant and stable
2. Negative inside compared to the outside
3. Different in different cells

Question 4

What are the genesis of resting membrane potential?

Answer 4

1. Permeability of the membrane Na+ and K+
2. Action of sodium-potassium pump
3. Negatively charged proteins in the ICF

Question 4

Excitability refers to an ability of a _____ to recieve _____ and _______ to that stimuli.

Answer 4

tissue
stimuli
respond

Question 5

Action potential is the _________ which occur in the ______ following ____.

Answer 5

brief sequence of changes
membrane potential
excitation

Question 6

What are the phases of action potential?

Answer 6

Stimulus artifact
Latent period
Depolarization
Repolarization
Hyperpolarization

Question 7

Stimulus artifact is when there is a _________ of the base line where the _______ is applied. This is due to the ______ from the stimulating site.

Answer 7

brief irregular deflection
point of stimulus
current leakage

Question 8

Latent period is the _____ for the ____ to travel from the site of ____ to the _____ electrode.

Answer 8

time taken
impulse
stimulation
recording

Question 9

Depolarization is the ______ of voltage gated ____channels.

Answer 9

opening
Na+

Question 10

Explain what happens during depolarization?

Answer 10

-when membrane potential exceeds the threshold limit, the voltage gated Na+ channels open
-results in massive influx of Na+
-potential overshoot and reach spike potential
-Na+ gated channels close.

Question 11

Repolarization is the _____ of voltage gated ____ channels.

Answer 11

opening
K+

Question 12

Explain what happens during repolarization?

Answer 12

-opening of voltage gated K+ channels
-results in efflux of K+
-causes a net transfer of positive charge out of the cell
-as it approaches towards resting state, it becomes slow.

Question 13

Hyperpolarization is when the membrane potential reaches _______, most of the K+ gate channels are ____ but some are ___.
As a result, the potential becomes more _____. After all of the K+ gated channels are closed, some ______ become ___ to restore the RMP.

Answer 13

resting state
closed
open
Na+/K+
active

Question 14

What are the properties of action potential?

Answer 14

Threshold stimulus
All or None Law
Refractory period
Conduction
Accommodation

Question 15

Threshold stimulus is the ______ quantity of _______ required to intiate _____.

Answer 15

minimum
stimulus
action potential

Question 16

Rheobase is the _____ ______ stimulus which when applied for a prolonged time will produce ____.

Answer 16

minimum voltage
action potential

Question 17

Utilization time is the ______ ______ that a current _____ to rheobase must act to induce ______.

Answer 17

minimum time
equal
action potential

Question 18

Chronaxie is the _____ ____ for which a stimulus ______ the _____ value has to be applied in order to start an ______.

Answer 18

minimum duration
twice
rheobase
action potential

Question 19

Refractory period is the period of ____ during which a ____ can not ______ another ____.

Answer 19

time
neuron
generate
action potential

Question 20

Absolute refractory period is when even a ____ stimulus will ____ generate another action potential

Answer 20

very strong
not

Question 21

Relative refractory period is when a _____ stimulus can initiates another action potential.

Answer 21

suprathreshold

Question 22

Conduction is where action potential is conducted as a _________. It is _____ in nature.

Answer 22

wave of depolarization
self propagating

Question 23

Accommodation is when the stimulus is applied constantly for a ____duration, the site of the application of stimulus ____ to produce _______.

Answer 23

prolonged
fails
action potential

Question 24

What are the 2 types of non propagated potentials?

Answer 24

Catelectrotonic potentials
-cathodal end evokes depolarizing response
Anelectronic potentials
-anodal end evokes depolarizing response

Question 25

Excitatory postsynaptic potentials ( EPSPs) is when the opening of ion channels leads to _______ which makes action potential ____ likely.

Answer 25

depolarization
more

Question 26

In EPSPs, inside the post-synaptic cell becomes less _____ and there are ___ and ____ channels outside of the cell.

Answer 26

negative
Na+
Ca2+

Question 27

Inhibitory postsynaptic potentials (IPSPs) is when the opening of ion channels which leads to ______ makes an action potential ___ likely.

Answer 27

hyperpolarization
less

Question 28

In IPSPs, inside of the post-synaptic cell becomes ____ negative and ___ goes out of the cell while ___ ( if already depolarized ) goes into the cell.

Answer 28

more
K+
Cl-