Phys 1 Flashcards
Approximately what percentage of CO2 is carried as bicarbonate? A. 5% B. 25% C. 30% D. 70%
D. 70%
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
A. Dorsal respiratory center
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
C. Va= 0 , but perfusion >0
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
C. Renal excretion of bicarbonate ion
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
D. -5
Of the following ions, which is the most [] in the extracellular environment? A. Sodium B. Chloride C. Potassium D. Calcium
A. Sodium
Saltatory conduction is characteristic of which part of a typical neuron? A. Dendrite B. Nerve cell body C. Axon hillock D. Axon
D. Axon
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
A. A Band
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
C. Cells are mononucleated
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
A. SA nodes
Which of the following is the direction of bipolar lead III? A. 0 degrees B. 60 degrees C. 90 degrees D. 120 degrees
D. 120
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
C. Veins
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
B. 5 L/min
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%
B. 60%
Approximately what percentage of total cardiac output is received by the kidneys? A. 15% B. 22% C. 34% D. 47%
B. 22%