Phys 1

Question 1

Approximately what percentage of CO2 is carried as bicarbonate?
A. 5%
B. 25%
C. 30%
D. 70%

Answer 1

D. 70%

Question 2

Which center is primarily responsible for establishing the ramp signal during normal breathing?
A. Dorsal respiratory center
B. Pneumotaxic center
C. Ventral respiratory center
D. Carotid body

Answer 2

A. Dorsal respiratory center

Question 3

The Va/Q ratio is zero (0) under which if the following conditions?
A. Va = infinity, but Q = 0
B. Va = infinity but Q =1
C. Va= 0, but perfusion >0
D. Va > 0, but Q = 0

Answer 3

C. Va= 0 , but perfusion >0

Question 4

Respiratory alkalosis due to a decrease in CO2 [] caused by hyperventilation is compensated for by which of the following mechanisms?
A. Increased ventilation rate
B. Decreased ventilation rate
C. Renal excretion of bicarbonate ion
D. Renal addition of new bicarbonate ion to extracellular fluid

Answer 4

C. Renal excretion of bicarbonate ion

Question 5

Two dogs are used in a study to test the effects of a drug that causes hypertension as a possible side effect. In one of the dogs the baroreceptor feedback system has been inactivated. In the dog with the intact feedback system the arterial pressure increases from 100 to 110. In the inactivated control system animal, the pressure increases from 100 to 160. What is the effectiveness with which the baroreceptor system controls increase in blood pressure?
A. -1
B. -2
C. -4
D. -5

Answer 5

D. -5

Question 6

Of the following ions, which is the most [] in the extracellular environment?
A. Sodium
B. Chloride
C. Potassium
D. Calcium

Answer 6

A. Sodium

Question 7

Saltatory conduction is characteristic of which part of a typical neuron?
A. Dendrite
B. Nerve cell body
C. Axon hillock
D. Axon

Answer 7

D. Axon

Question 8

Which of the following sarcomeric bands does not undergo a change in length during contraction of skeletal muscle?
A. A band
B. H band
C. I band
D. J band

Answer 8

A. A Band

Question 9

Which of the following characteristics would be true of cardiac muscle cells but not skeletal muscle cells?
A. Cells have the sarcomeric banded pattern
B. Cells utilize T tubules
C. Cells are mononucleated
D. Cells utilize ryanodine channels

Answer 9

C. Cells are mononucleated

Question 10

Phase4 of the cardiac muscle action potential is the resting phase. Which of the following cardiac tissues will depolarize fastest during this phase and eventually reach threshold?
A. SA node
B. AV node
C. Purkinje fibers
D. Ventricular myocytes

Answer 10

A. SA nodes

Question 11

Which of the following is the direction of bipolar lead III?
A. 0 degrees
B. 60 degrees
C. 90 degrees
D. 120 degrees

Answer 11

D. 120

Question 12

84% of the blood volume is in the systemic circulation. Of this, 64% is in which of the following vessels?
A. Capillaries
B. Systemic arteries
C. Veins
D. Aterioles

Answer 12

C. Veins

Question 13

What is the volume of venous return when the mean systemic filling pressure is 7mm Hg, and the right atrial pressure is 0 mm Hg, and the resistance to venous return is 1.4 mm Hg/L/min?
A. 4 liters/min
B. 5 L/min
C. 9.8 L/min
D. 7 l/min

Answer 13

B. 5 L/min

Question 14

If the end diastolic volume is 120 ml, and the end systolic volume is 50 ml, what is the approximate value of the ejection fraction?
A. 42%
B. 60%
C. 214%
D. 240%

Answer 14

B. 60%

Question 15

Approximately what percentage of total cardiac output is received by the kidneys?
A. 15%
B. 22%
C. 34%
D. 47%

Answer 15

B. 22%

Question 16

Which of the following, in liters.day, represents the GFR in the average adult human?
A. 3
B. 125
C. 180
D. 360

Answer 16

C. 180

Question 17

Aldosterone is an important regulator of sodium reabsorption and potassium secretion; one of its main targets is?
A. Podocytes
B. Principal cells
C. Intercalated cells
D. Cells of macula densa

Answer 17

B. Principal cells

Question 18

Which of the following plays a major role in stimulating potassium excretion by the kidney tubules?
A. Aldosterone
B. Angiotensin II
C. Sodium ion
D. PTH

Answer 18

A. Aldosterone

Question 19

Vital capacity does not include which of the following volumes?
A. Inspiratory reserve
B. Expiratory reserve
C. Residual
D. Tidal

Answer 19

C. Residual

Question 20

Baroreceptors are a type of stretch receptor located in the arterial walls of the carotid system. They sense an increase in arterial pressure. Which of the folllowing statements might best describe the purpose of these receptors?
A. They acts a part of a positive feedback system that results in blood vessel dilation and an increase in heart pumping capacity
B. They act as part of a negative feedback system that results in blood vessel dilation and a decrease in heart pumping capacity
C. They act as part of a positive feedback system that results in blood vessel constriction and decrease heart pumping capacity
D. Negative feedback system, blood vessel constriction, increase heart pumping capacity

Answer 20

B. Negative feedback, blood vessels dilation, decrease heart pumping

Question 21

The Na/K ATPase pump is an example of which kind of transport?
A. Diffusion
B. Primary active transport
C. Secondary active transport
D. Facilitated diffusion

Answer 21

B. Primary

Question 22

Which of the following types of neurons would transmit an action potential the fastest?
A. smaller diameter, non-myelinated
B. Small diameter, myelinated
C. Large diameter, myelinated
D. Large, non-myelinated

Answer 22

C. Large, myelinated

Question 23

Dihydropyridine (DHP) channels are part of which of the following structures?
A. Sarcoplasmic reticulum
B. Plasmalemma
C. T tubules
D. Z discs

Answer 23

C. T tubules

Question 24

Which of the following represents the first thing that happens after Ach binds to the ligand gated channels on the sarcolemma?
A. An action potential is created on the sarcolemma
B. DHP channels allow entry of Ca ions
C. An end plate potential is created on the muscle fiber
D. Ryanodingaling channels allow Ca to escape into the myoplasm

Answer 24

C. An end plate potential is created on the muscle fiber

Question 25

``` The cardiac muscle fast action potential occurs in the atria, ventricles,and conduction system. It is typically divided into 5 phases, numbered from 0 to 4. The resting potential of -85 mV is characteristic of which of the following phases? A. Phase 0 B. Phase 1 C. 2 D. 3 E. 4 ```

Answer 25

E. Phase 4

Question 26

``` In a typical (average) individual, arterial pressure drops by how much from the time it leaves the left ventricle until it reaches the venous system? A. 35mm Hg B. 40 mm Hg C. 80 mm Hg D. 120 mm Hg ```

Answer 26

D. 120

Question 27

``` A systemic vein is about 8 times as distensible as its corresponding artery and has a volume about 3 times as great. How would its compliance compare to that of a corresponding artery? A. 8 times as compliant B. 3 times as compliant C. 24 times as compliant D. 2.6 times as compliant ```

Answer 27

C. 24 times 3 x 8 = 24

Question 28

``` The mean circulatory filling pressure is 0 under which of the following conditions? A. Blood volume is 5 L B. Blood volume is 4 L C. Blood volume is 6.5 L D. Blood volume is 5.5 L ```

Answer 28

B. Blood volume is 4L

Question 29

GFR is determined by the net filtration pressure and the glomerular capillary filtration coefficient. Which of the following factors has the greatest effect on increasing GFR? A. Glomerular capillary colloid osmotic pressure B. Bowman’s capsule hydrostatic pressure C. Bowman’s capsule colloid osmotic pressure D. Glomerular hydrostatic pressure

Answer 29

D. Glomerular hydrostatic pressure

Question 30

``` About 2/3 of filtered electrolytes are reabsorbed in which of the following parts of the kidney tubule? A. Proximal convoluted tubule B. Thin descending loop of Henle C. Thick ascending loop of Henle D. Distal convoluted tubule ```

Answer 30

A. Proximal convoluted tubule

Question 31

``` Which of the following cells plays a major role in the secretion of potassium? A. Intercalated cells B. Principal cells C. Chief cells D. Podocytes ```

Answer 31

B. Principal cells

Question 32

``` Which of the following buffer systems is most important in buffering renal tubular fluid? A. Phosphate buffer system B. Carbonate buffer system C. Bicarbonate buffer system D. Hemoglobin buffer system ```

Answer 32

A. Phosphate buffer system

Question 33

``` The pressure difference between pleural pressure and alveolar pressure is referred to as A. Atmospheric pressure B. Compliance C. Thoracic pressure D. Transpulmonary pressure ```

Answer 33

D. Transpulmonary pressure

Question 34

Humidification of air in the alveoli has which of the following effects on the partial pressures of nitrogen and oxygen in the alveoli? A. It increases partial pressure of each of the other gasses B. It decreases partial pressure of each of the other gasses C. It has no effect on the partial pressures of each of the other gasses D. It increases partial pressure of oxygen but decreases partial pressure of nitrogen in alveolar air

Answer 34

B. Decreases partial pressures

Question 35

``` If arterial blood carries 19.4 ml of oxygen per deciliter, and returning venous blood carries 14.4 ml of oxygen per deciliter, the utilization coefficient is approximately? A. 25% B. 40% C. 50% D. 75% ```

Answer 35

A. 25%

Question 36

``` The rate and depth of breathing is mainly controlled through which of the following brain centers? A. Dorsal respiratory group B. Pneumotaxic center C. Ventral respiratory center D. Carotid body ```

Answer 36

B. Pneumotaxic center