2013 physiology midterm

Question 1

What causes the repolarization of a nerve cell?
A) K+ exit 
B) N+ exit 
C) N + entry 
D) K+ entry

Answer 1

A) K+ exit

Question 2

The plateau phase in the cardiac action potential is due to which of the following factors?
A. Na inward current
B. K outward diffusion
C. Ca inward and K outward diffusion
D. Ca outward and K inward diffusion

Answer 2

C. Ca inward and K outward diffusion

Question 3

In general, which subject has the highest percentage of body water?

a. A 20-year-old male
b. A 20-year-old female
c. A 40-year- old male
d. A 40-year-old female
e. A 70-year-old female

Answer 3

a. A 20-year-old male

Question 4

How does the reduction in the energy cause intracellular edema?

a) Opening water channel
b) Opening Na+ channel
c) Increase facilitated diffusion of glucose into the cell
d) Na /k ATPase activity decrease

Answer 4

d) Na /k ATPase activity decrease

Question 5

A large nerve cell show resting membrane potential of -90mv what is responsible for the majority of this membrane potential?

a) K gradient
b) Cl gradient
c) Ca gradient
d) Na gradient

Answer 5

a) K gradient

Question 6

What is an important characteristic of facilitated diffusion?
A- carrier-mediated
B- against concentration gradient

Answer 6

A- carrier-mediated

Question 7

[Solution X: 250 ml of 0.9% NaCl + 500 ml of 3% NaCl]
According to Van hoffs, what is the osmotic pressure of a solution X with a semipermeable membrane, having pure water on the other side?

Answer 7

no answer

Question 8

What is the function of Clarithn?

a. Endocytosis of vesicles
b. Cytoskeleton
c. Regulation of cell membrane

Answer 8

a. Endocytosis of vesicles

Question 9

Which solution is hypotonic? (MW NaCl=58.5, glucose=180)
A. 1 liter 0.9% NaCl
B. 1 liter 0.9% NaCl + 100 ml water 
C. 200 g of glucose in 500 ml water 
D. 50 g of glucose in 500 ml water 
E. 0.9% NaCl in 200 ml + 5 g NaCl

Answer 9

B. 1 liter 0.9% NaCl + 100 ml water

Question 10

Substance passes from interspace to extracellular compartment by:
A- Gated channels
B - Endocytosis 
C - Transcytosis 
D - Exocytosis
E - Pinocytosis

Answer 10

C - Transcytosis

Question 11

What causes extracellular edema?
A. Decreased in capillary hydrostatic pressure
B. Decreased in tissue collid osmotic pressure
C. Decreased in plasma collid osmotic pressure
D. Increase in lymph flow

Answer 11

C. Decreased in plasma collid osmotic pressure

Question 12

If H+ peptide depends on Na/H Exchanger which depend on Na/Ka ATpase. Which type is for transporting The peptide?

a. primary active transport
b. secondary active transport
c. tertiary active transport

Answer 12

c. tertiary active transport

Question 13

If blood pressure decreases and baroreceptors sense this change and transmit signal to cardiovascular center in the brain, which sends signals to heart to decrease the heart rate... Which role in homeostatic mechanism does the heart play?
A -effector
B -integrating center 
C -afferent  pathway 
D -efferent pathway 
E -sensor

Answer 13

A -effector

Question 14

Opening of which channel increases heart rate?
A) Fast sodium channels
B) Slow calcium voltage-gated ion channels
C) Acetylcholine regulated potassium channels

Answer 14

B) Slow calcium voltage-gated ion channels