Neural Conduction

Question 1

the diff between internal and external charge of a neuron

Answer 1

membrane potential

Question 2

how to measure membrane potentia?

Answer 2

microelectrode

One tip inside and other in the extracelluar fluid

Question 3

inside charge of neuron is

Answer 3

-70mV

Question 4

Na+ is

Answer 4

Sodium

Question 5

Potassium is

Answer 5

K+

Question 6

At rest there is are more ___outside and more ___ inside

Answer 6

Na+

K+

Question 7

what creates pressure for Na+ to enter a neuron?

Answer 7

the electrostatic pressure from the Resting Membrane Potential due opposite charges attracting

AND

random motion

Question 8

What is the function of the sodium/potassium pump?

Answer 8

Maintains membrane potential

Question 9

what is the ratio of action for the Sodium Potassium pump?

Answer 9

3 Na+ out

2 K+ In

Question 10

input from another cells results in

Answer 10

Post-synaptic potentials

Question 11

What are the two possible effects when NTs bind to Post-syn-receptors?

Answer 11

Depolarize (excitatory PSP)

Hyperpolarize (inhibitory PSP)

Question 12

all post-syn-potentials are

Answer 12

graded potentials

Amplitudes are proportional to the signals that elicit them

Question 13

what amplitude is the Threshold of Excitation?

Answer 13

about 65mV

Question 14

Action potentials are

Answer 14

all or nothing

Question 15

Explain Spatial summation of an EPSP or IPSP

Answer 15

two simultaneous EPSP or IPSP will produce a greater -one

simultaneous IPSP and EPSP will cancel each other out

Question 16

Explain temporal summation of EPSP and IPSP

Answer 16

Rapid succession of IP or EP can add up to a bigger one

PSP’s can outlast and superimpose on the next one.

Question 17

Tremor at rest is a symptom of

Answer 17

Parkinson’s

Question 18

A neuron is rest is said to be

Answer 18

polarized

Question 19

What are the two factors that pressure Na+ ions to enter resting neurons?

Answer 19

random motion

electrostatic pressure

Question 20

at rest, neurons have more _____ outside than inside

Answer 20

Na+

Question 21

Rising phase of AP?

Answer 21

Na+ channels open and ions rush in

K+ channels open and K+ ions leave

Once MP is depolarized, the Na+ channels close

Question 22

Repolarization Phase of AP

Answer 22

K+ channels stay open and ions keep leaving until -70mV is achieved.

Question 23

Hyperpolarization Phase of AP

Answer 23

K+ channels stay open and the MP gets to -90mV

Question 24

how long is the refractory period of an AP and what can’t happen?

Answer 24

1-2ms

Absolute refractory
Can’t fire again

Question 25

Relative refractory?

Answer 25

a neuron can fire again, but stim needs to be higher than normal.

Question 26

Transmission in myelinated axons is

Answer 26

saltatory conduction

Question 27

neurons are about ___ apart

Answer 27

20 nanometers

Question 28

3 types of ion transporters

Answer 28

Pumps (in and out) (atp energy)

Co-transporters (use energy from diffusion)

Exchangers (energy from diffusion)

Question 29

most ion channels are of two types….

Answer 29

Voltage (open close due to changes in polarization)

Lingand (open due to binding of NT or Neuromodulator to receptor associated with the channel)