phases of action potentials, ions, and channels make my head hurt

Question 1

in slow action potential phase 0, what ion and channel type dominate

Answer 1

i ca(L) (slow inward) calcium

Question 2

in slow action potential phase 3, what ion and channel type dominate

Answer 2

i K(dr) delayed rectifier potassium

Question 3

in slow action potential phase 4, what ion and channel type dominate

Answer 3

the mother fucking funny current
i(f) Na, K, Ca, the most important current according to Gaffin

pacemaker potential

Question 4

what controls automaticity and rhythmicity

Answer 4

SA nodal fibers

Question 5

the slow current has a slow rate of depolarization and threshold potential increases ____ permeability not ____ permeability

Answer 5

the slow current has a slow rate of depolarization and threshold potential increases Ca permeability not Na permeability

Question 6

T/F the slow action potential has a stable resting membrane potential

Answer 6

false
slow action potential has no stable resting membrane potential

Question 7

which AP is described as short, unstable plateau
fast or slow?

Answer 7

slow action potential

Question 8

rapid depolarization is what phase of slow AP?

Answer 8

phase 0

Question 9

repolarization is what phase of slow AP?

Answer 9

phase 3

Question 10

diastolic depolarization aka pacemaker potential which produces automaticity of these APs is what phase of slow AP?

Answer 10

phase 4

Question 11

Ca doesn’t affect the cardiac _______membrane potential, but it does affect cardiac ______potential

Answer 11

resting
action

Question 12

atrial action potential has a fast response like ventricle action potential, but atrial AP has an ________ ______ ______

Answer 12

atrial action potential has a fast response like ventricle action potential, but atrial AP has an attenuated plateau phase

Question 13

mean electrical axis is the net cardiac dipole during the most intense phase of ventricular depolarization.
where would it be represented in PQRST

Answer 13

peak of the R wave

Question 14

P wave 
What does it represent in the heart in regards to conduction?
What phase(s) of AP does it represent? Fast or slow?
What ion is dominate?

Answer 14

1. P wave represents atrial depolarization
2. Phase 0 rapid depolarization and 1 early repolarization of action potential
3. Fast
4. Fast Phase 0 Na fast inward
5. Fast Phase 1 K transient outward

Question 15

QRS wave

What does it represent in the heart in regards to conduction?
What phase(s) of AP does it represent? Fast or slow?
What ion is dominate?

Answer 15

1. QRS wave represents ventricle depolarization
2. Phase 0 rapid depolarization and 1 early repolarization of action potential
3. Fast
4. Fast Phase 0 Na
5. Fast Phase 1 K

Question 16

T wave

What does it represent in the heart in regards to conduction?
What phase(s) of AP does it represent? Fast or slow?
What ion is dominate?

Answer 16

1. T wave represents ventricular repolarization
2. Fast AP phase 3 final repolarization
3. delayed rectifier potassium

Question 17

ST segment

What does it represent in the heart in regards to conduction?
What phase(s) of AP does it represent? Fast or slow?
What ion is dominate?

Answer 17

1. ST represents the entire ventricular system depolarizes, isoelectric line
2. Fast phase 2 plateau
3. slow calcium

Question 18

what K channel is activated by depolarization to cause phase 3 repolarization?

Answer 18

the delayed rectifier potassium channel

Question 19

what K channel is activated by hyperpolarization, phase 4 fast AP to maintain the cell’s nernst potential to that of potassium?

Answer 19

potassium inward rectifier