EXCITABLE TISSUE

Question 1

potassium

Answer 1

• cation positive charges leaves negative
• concentration gradient forced potassium out of the cell
• the electrical gradient keeps potassium in (NaKATPase pump)
• efflux out of the cell is the normal conduction of K
• passive
• not energy dependent no ATP needed
• resting membrane potential is very sensitive to changes in the EXTRACELLULAR K+
• gives CARDIAC problems

Question 2

Na K ATPase

Answer 2

• needs energy

Question 3

membrane conductance

Answer 3

• ungated channels
• voltage gated channels
• ligand gated channels

Question 4

ungated channels

Answer 4

• concentration

Question 5

voltage gated channels

Answer 5

• positive (+) and negative (-) charges
• Cl-
• Na K +

Question 6

ligand gated

Answer 6

• protein transporter channel

Question 7

cell is

Answer 7

• NEGATIVE

- sodium and potassium is POSITIVE

Question 8

-70 mV

Answer 8

• keeps the potassium IN

Question 9

membrane potential

Answer 9

• -70 and - 90mV

Question 10

resting membrane potential

Answer 10

- INSIDE THE CELL -90mV more negative hyper polarization 
low Cl-
high K +
low Na +
- OUTSIDE THE CELL
high Cl-
low K+
high Na+

Question 11

depolarization

Answer 11

• normally intracellular charge is NEGATIVE
• rapid influx of sodium INTO the cell
• fast
• increase K extracellularly influx
• cell BECOMES more POSITIVE

Question 12

repolarization

Answer 12

• based on the pump

Question 13

hyperpolarization

Answer 13

• potassium LEAVING the cell

- making THE CELL more NEGATIVE -70mV

Question 14

rhabdomyolysis
tumor lysis
hemolysis

Answer 14

• K levels in the blood is INCREASED
• INFLUX of the cell due to sudden increase in K
• depolarized the cell
• causing arrhythmia

Question 15

seizure most common cause of death

Answer 15

• hyperkalemia depolarizing the cell then death occurs

Question 16

sodium

Answer 16

• is higher extracellularly
• not involved in resting membrane potential
• CNS problems

Question 17

pumping Na+ out of the cell

Answer 17

• K pump into the cell (active, energy)

- K diffusion

Question 18

POTASSIUM brings the cell

Answer 18

• into EQUILIBRIUM