2017 physiology midterm

Question 1

Which ion channels open as a result to activation of post synaptic glycine receptors?

a. Calcium
b. Chlorine
c. Potassium
d. Sodium

Answer 1

b. Chlorine

Question 2

What best defines a steroid hormone receptor?

a. It forms a heterodimer with retinoid X receptor
b. It recruits co-repressors when steroid is bound to it
c. When in an inactive state, it’s bound to heat shock proteins
d. It’s located only in the nucleus

Answer 2

c. When in an inactive state, it’s bound to heat shock proteins

Question 3

Binding of which proteins initiates exocytosis (docking)?

a. T-snare and v-snare
b. NSF and COP1
c. Clatherin and t-snare
d. NSF and v-snare

Answer 3

a. T-snare and v-snare

Question 4

What is the equilibrium potential of Cl- if the concentration inside the cell is 9mM and outside is 90mM?

a. -61mv
b. 61mv
c. -114mv
d. 114mv

Answer 4

a. -61mv

Question 5

According to sterling law of capillary exchange with tissue, there is a near equilibrium between inward and outward forces with 0.33mmHg causing slight outward filtration of plasma into tissue. Which factor is preventing swelling of tissue?

a. Plasma proteins cross capillary wall to counter act the force
b. Tissue colloid osmotic pressure works against this force
c. Excess fluid removed by lymphatics
d. This force is insignificant, the tissue can tolerate it

Answer 5

c. Excess fluid removed by lymphatics

Question 6

ATP was hydrolyzed on a carrier protein and this energy was used by the carrier to transport a molecule into the cell?

a. Facilitated transport
b. Primary active transport
c. Secondary active transport
d. Tertiary active transport

Answer 6

c. Secondary active transport

Question 7

What is a characteristic of a cell at rest?

a. Higher permeability to K+
b. Higher permeability to Na+
c. Permeability to Na+ and K+ is equal
d. No permeability to Na+ and K+

Answer 7

a. Higher permeability to K+

Question 8

In a liver disease, the liver has reduced its ability to produce proteins. The consequence of this will be tissue edema?

a. Capillary hydrostatic pressure
b. Plasma colloid osmotic pressure
c. Tissue colloid osmotic pressure
d. Interstitial fluid pressure

Answer 8

b. Plasma colloid osmotic pressure

Question 9

What happens with strong stimulus?

a. Action potential amplitude increases
b. Action potential duration increases
c. Gradient potential amplitude increases
d. Gradient potential duration increases

Answer 9

c. Gradient potential amplitude increases

Question 10

A cell produces a single long molecule that acts within the cell that synthesized it using intracellular receptors?

a. Autocrine
b. Paracrine
c. Intracrine
d. Neurocrine

Answer 10

c. Intracrine

Question 11

What is a saltatory condition?

a. An action potential that jumps back and forth along a neuron
b. An action potential that jumps from one node of Ranvier to the next
c. An action potential that jumps from one neuron to the next
d. An action potential that jumps from an axon to a dendrite

Answer 11

b. An action potential that jumps from one node of ranvier to the next

Question 12

What best describes chemical synapse?

a. Faster than electrical synapse
b. Gap junctions
c. Binding of agonist activates ligand binding ion channels
d. Channel conformational change in response of action potential

Answer 12

c. Binding of agonist activates ligand binding ion channels

Question 13

Poor circulation to a tissue causes a reduction in cells’ energy. This results in intracellular water retention (intracellular edema). What may cause this?

a. Decrease in Na/K ATPase
b. Opening of water channels
c. Opening of Na channels
d. Water entering the cell by pinocytosis

Answer 13

a. Decrease in Na/K ATPase

Question 14

What best describes hydrophilic receptors?

a. They bind to receptors in the cytosol
b. The best example for it is steroid receptors
c. They bind to extracellular membrane receptors to generate second messenger cascade
d. They only have receptors in the nucleus

Answer 14

c. They bind to extracellular membrane receptors to generate second messenger cascade

Question 15

1L of water added to 500 ml of 0.9% of NaCl. What is the new concentration?

a. 0.2%
b. 0.3%
c. 0.6%
d. 0.8%

Answer 15

b. 0.3%

Question 16

What is the final concentration after combining these 2 containers: 250 ml 2% NaCl & 500 ml 0.9%?

a. 2.1%
b. 2.7%
c. 1.2%
d. 1.7%

Answer 16

c. 1.2%

Question 17

What is the osmotic pressure of  0.45% NaCl when placed is semipermeable membrane having pure water?
(MW: NaCl = 58.5)
a.	2969
b.	5544
c.	5314
d.	6290

Answer 17

a. 2969

Question 18

What factor contributes to maintaining a negative resting membrane potential?

a. Anions trapped outside the cell
b. Cations trapped inside the cell
c. Sodium-potassium pump
d. Voltage-gated sodium channels

Answer 18

c. Sodium-potassium pump

Question 19

An enzyme is produced by gastric gland, which is activated by HCl has an auto-activation function, in which it activates it’s inactive forms. What is this process?

a. Positive feedback
b. Negative feedback
c. Paracrine communication
d. Autocrine communication

Answer 19

a. Positive feedback

Question 20

What is the configuration for an activated voltage-gated sodium channel?

a. Activation channel open, inactivation channel open
b. Activation channel open, inactivation channel closed
c. Activation channel closed, inactivation channel open
d. Activation channel closed, inactivation channel closed

Answer 20

a. Activation channel open, inactivation channel open