2012 physiology midterm

Question 1

A Subject has total body solutes of 18000 mOsmoles and osmolarity of 300 mOsm/L What’s the osmolarity (mOsm/L) after equilibrium if we infuse 1L of 500 mOsm/L solute intravenously?

a. 320.3
b. 303.2
c. 298.4
d. 280.1
e. 275.5

Answer 1

b. 303.2

Question 2

A molecule is transported along its gradient across the membrane using protein. In this process of being transported, the molecule binds to protein & change its structure. What is the mechanism of transport?

a. Diffusion of gated channel
b. Diffusion of open channel
c. Facilitated Diffusion
d. Primary active transport
e. Secondary active transport

Answer 2

c. Facilitated Diffusion

Question 3

In the stomach lumen, pepsinogen is secreted as an inactive enzyme, if it’s activated in acidic medium and the activated enzyme activates more inactivate pepsinogen.
What mechanism best describes this process?
a. Negative Feedback
b. Positive Feedback
c. Paracrine process
d. Autocrine process
e. Homeostasis

Answer 3

b. Positive Feedback

Question 4

When this parameter increases, the rate of diffusion will decrease across the membrane. Which of the following is the parameter?
Pressure
a. Molecular weight of solutes 
b. Concentration of Solutes 
c. Temperature

Answer 4

a. Molecular weight of solutes

Question 5

How are neurotransmitters released into the chemical synapse?

a. Exocystosis
b. Endocytosis
c. diffusion

Answer 5

a. Exocystosis

Question 6

Concentration of Na Outside the Cell = 9 mM & Inside = 90 mM. What is the membrane potential (mV) if All Channels are open?

Answer 6

-61mV

Question 7

Opening of which channels maintain negative transmembrane electrical potential during cell ischemia?

a. Purinergic channels
b. Nicotinic channels
c. Acetylcholine K Channels
d. ATP channels
e. Slow Na channels

Answer 7

a. Purinergic channels

Question 8

What’s the major function of Smooth ER?

a. Lipids production
b. Making Ribosomes
c. Exocytosis
d. Degradation

Answer 8

a. Lipids production

Question 9

What’s the mechanism of cAMP (response binding protein)?

a. inhibit cAMP
b. 2nd messenger

Answer 9

b. 2nd messenger

Question 10

What’s the osmolarity (mOsm/L) of 4.5% NaCl?

a. 770
b. 1540
c. 2080
d. 3000
e. 3050

Answer 10

b. 1540

Question 11

According to hav’s Noff law, What’s the osmotic pressure (mmHg) of the solution in the prev. Q (osmolarity=1540)?

Answer 11

1540 X 19.3 = 29722

Question 12

Na inside= 10 Na outside= 130
Cl inside= 6 Cl outside= 118
K inside= 140 K outside= 4
What’s the membrane potential when equal amounts of Na & Cl channels are open?
a. 1.6
b. -1.6
c. -5.8
d. 5.8
e. -17.2

Answer 12

a. 1.6

Question 13

Na inside= 10 Na outside= 130
Cl inside= 6 Cl outside= 118
K inside= 140 K outside= 4
If all channels where open, what will be the Membrane Potential (mV)?
a. 1.6
b. -1.6
c. -5.8
d. 5.8
e. -17.2

Answer 13

e. -17.2

Question 14

To what extent does the electrical membrane potential contribute to Na ion influx at the end of the depolarized state of the action potential?

a. 0%
b. 10-50%
c. 50-90%
d. 100%

Answer 14

a. 0%

Question 15

What does stabilize hormone receptor?

Answer 15

Heat shock proteins (HSP)

Question 16

100g put in oven & evaporates. 90g of this substance is left after evaporation. What’s the kind of this substance?

a. Connection
b. Cardiac
c. Liver
d. Muscle
e. Adipose

Answer 16

e. Adipose

Question 17

Why is the concentration of Na is higher in plasma than in ISF

Answer 17

Because o–ve protein inside the plasma attracts Na+

Question 18

How does an extracellular protein enter the cell?

a. transcytosis
b. receptor-mediated endocytosis
c. receptor-mediated exocytosis

Answer 18

b. receptor-mediated endocytosis