PHGY 210 – MAMMALIAN PHYSIOLOGY II MIDTERM
Monday, February 28, 2005
MCGILL STUDENT NO.:
PROGRAM and YEAR:
1. The 9 digit McGill STUDENT NUMBER (ID) and CHECK BITS (the two first
letters of your last name as indicated on your ID) will be used for identification
purposes in this test. Please place your McGill ID number on this test paper and also
in the spaces marked "Student No." on your Answer Sheet.
IMPORTANT: Below the words "Student Number" and "Check Bits", FILL
IN THE APPROPRIATE CIRCLES.
2. DO NOT FOLD or BEND the Answer Sheet.
3. Use a No. 2 or HB black pencil to fill in the appropriate circle on the IBM answer
sheet. ALL ERASURES MUST BE COMPLETE.
4. ANSWER ALL 30 QUESTIONS. Marks are not deducted for wrong answers.
5. The time allocated for the exam is 1 hour and 30 minutes. 6. LEAVE THE ANSWER SHEET AND THE ENTIRE EXAMINATION PAPER
as directed at the end of the exam. You may NOT take any part of the examination
paper with you.
7. The results of this examination may be submitted to statistical testing designed to
UNCOVER POSSIBLE CHEATING.
8. Scientific calculators are permitted (NO WORD MEMORY).
NOTE: The Department of Physiology will not tolerate any academic offenses with
regard to cheating. Students are FORBIDDEN to converse with any person, other than
an INVIGILATOR, during the course of the exam. If you are seen speaking with
another student, your examination and answer sheet WILL BE IMMEDIATELY
COLLECTED BY THE INVIGILATOR.
TYPE A: Choose the ONE that is BEST in each case and darken the
appropriate circle on the answer sheet.
1. What component of the cardiac conduction system distributes electrical signals
through the papillary muscles directly?
a) The atrio-ventricular node.
b) The atrio-ventricular bundle.
c) The sino-atrial node.
d) The bundle of His.
e) The Purkinje system.
2. The velocity of blood flow is the lowest in
a) the systemic arteries.
b) the pulmonary artery.
c) the pulmonary veins.
d) the vena cava.
e) the capillaries.
3. The main pacemaker cells of the heart are located in
a) the atrio-ventricular node.
b) the Hensen’s node.
c) the bundle of His. d) the Purkinje system.
e) the sino-atrial node.
4. The PR interval of the electrocardiogram corresponds to the time taken for
activation to travel through
a) the atria and the atrioventricular node.
b) the Purkinje fibers.
c) the bundle of His and the bundle branches.
d) the sino-atrial node.
e) all the above structures.
(For the above question, both (a) and (e) were accepted as correct
5. Which of the following is TRUE about the stroke volume response to
moderate submaximal dynamic exercise?
a) Stroke volume increases primarily due to an increase in end-diastolic
b) Stroke volume increases due to an increase in heart rate. c) Stroke volume increases due to an increase in total peripheral
d) Stroke volume increases due to an increase in systolic pressure.
e) Stroke volume increases due to an increase in end-systolic volume.
6. In a patient with advanced pulmonary fibrosis,
a) the rate of oxygen diffusion through the alveolar-capillary membrane
b) the recoil pressure of the lungs is increased.
c) the airway resistance is increased.
d) the functional residual capacity (FRC) is larger than in a healthy
e) the alveolar ventilation-perfusion ratio is increased.
7. Under normal circumstances, alveolar ventilation
a) increases when the body metabolic rate increases .
b) increases when PO in 2he arterial blood is above 80 mmHg.
c) increases during CO poisoning.
d) decreases after both vagus nerves are cut.
e) is equal to the minute ventilation. 8. In a climber at high altitude, where air PO i2 about 60 mmHg,
a) minute ventilation increases.
b) the rate of O d2ffusion increases.
c) the pH of the arterial blood remains normal.
d) the O c2ntent in the arterial blood remains normal.
e) None of the above statements is true.
9. During rest, at the functional residual capacity,
a) the lung volume is about 50% of the total lung capacity.
b) the alveolar pressure exceeds atmospheric pressure.
c) the recoil pressure of the chest exceeds atmospheric pressure.
d) all respiratory muscles are relaxed.
e) all pulmonary vagal receptors are firing.
10. Which of the following conditions may lead to a decrease in the arterial
a) A decrease in the alveolar ventilation.
b) Breathe holding. c) Breathing a mixture of air with increased CO concentration.
d) A decrease in the body metabolism while ventilation remains normal.
e) A decrease in the lung diffusion capacity.
11. In newborn babies, increased activity of pulmonary vagal slowly
a) a rapid and shallow respiration.
b) a prolongation of expiration.
c) an increase in minute ventilation.
d) an increase in the functional residual capacity.
e) an increase in the physiological dead space.
12. The conducting airways,
a) contribute to gas exchange.
b) are filled up with dry air at the end of inspiration.
c) are innervated by vagal non-myelinated fibres.
d) contribute to the total body defence mechanisms against infections.
e) include the respiratory airways down to the alveolar sacs. 13. In a healthy individual at rest, at the end of a normal inspiration,
a) all respiratory muscles are contracting.
b) the alveolar pressure is greater than atmosphe