Exam 1

Question 1

Homeostasis

Answer 1

The dynamic mechanisms that detect and respond
to deviations in physiological variables from their
“set point” values by initiating effector responses that restore the variables to the
optimal physiological range.

Question 2

Integrating Center pathway

Answer 2

Integrating center —>
effector —->
response —–>
NEGATIVE feedback
Stimulus —->
receptor —->
integrating center

Question 3

Resting membrane potential

Answer 3

associated with leak channels

Question 4

Equilibrium potential is…

Answer 4

calculated to be used as a tool to find out why other potentials work the way they do

Question 5

K leak channel

Answer 5

driving force of resting potential

Question 6

Equilibrium potential flux

Answer 6

net 0 when the concentration gradient and electrical gradient work tandem to make the net flux 0.

Question 7

Equilibrium potential for each ion…

Answer 7

is independent of each other

Question 8

Nernst equation

Answer 8

gives equilibrium at given concentrations for an ion

Question 9

Goldman equation

Question 10

why is resting potential closer to the Eq. Pot. of K+

Answer 10

The driving force of K+ is less than Na+ (V)

Na has a much higher driving force since it is farther from resting potential, however it has much more resistance

Question 11

Amplitude of graded potentials

Answer 11

can vary and be different heights depending on stimulus. Duration of potential can be much longer with longer stimulus

Question 12

graded v action potentials

Answer 12

graded can vary in amplitude and duration unlike action. Action cannot undergo summation.

Question 13

Summation of graded potentials

Answer 13

multiple stimuli can combine the graded potentials to form a larger or smaller amplitude. They can cancel each other out. Summation can prevent the action potential from ever happening by preventing the threshold from being reached.

Question 14

Stretch gates

Answer 14

when cell stretches, opens the gate which can trigger graded or action potential.

Question 15

What does further increase in stimulus have on action potential

Answer 15

no effect, all or nothing

Question 16

what does sustained stimulus have on action potential

Answer 16

can lead to a train of action potentials

Question 17

when do action potentials occur

Answer 17

when a graded potential depolarizes the membrane past a threshold and proceeds with a very rapid high amplitude all or nothing behavior

Question 18

what follows an action potential

Answer 18

Refractory period

Question 19

when do graded potentials occur

Answer 19

when permeability is altered permitting Na+ or K+ to flow across membrane

Question 20

As an Ion lke Na+ starts to flow into a cell, what happens to the driving force?

Answer 20

The driving force

Question 21

what stops the Hodgkin Cycle

Answer 21

after inactivating, a ball and chain style structure closes the channel which stops Na+ influx.

Question 22

During Action potential, the driving force for potassium first, _____ then _______

Answer 22

increases, decreases

decreases because the voltage decreases and gets closer to potassium level (distance gets closer - less driving force)