Last minute review for EXAM 2 of Biology 1442, per student request.

Questions requested by students for further review of material on S.I. practice exam.

Question# 10 on (mini exam 40,41)

10) A mouse uses ______ energy per kilogram of body weight compared to an elephant, therefore in smaller animals the rate of energy use per cell is _______ than that in larger animals.

                A)less, more

                B) less, greater

                C) less, less

                D) more, less

                E) more, greater


 the correct answer is E.
smaller organisms use more energy per kilogram of body weight unlike larger organisms.
Hence, smaller organisms use greater energy per individual cell than larger organisms.

Reasons being because they have less cells to perform the same metabolic duties a
larger organism performs.  For example, not all your cells are directly involved in digestion. Right?
You have specialized organs (ex stomach, liver, etc) that perform that action.

A smaller or single celled organism has just one cell (or a few) that perform all their actions (reproduction,
digestion, etc) so the cellular metabolic energy usage and production will be higher than that of a larger
organism.

Hope that works, let me know
if I can help some more.

Question # 27 (from S.I. Exam review)

27) Ventricular tachycardia (v tach) is a dangerous condition of elevated heart rate, about 200 beats per minute.  Which of the following best explains why v tach is such a deathly condition if normal rhythm is not quickly restored?

                A) The heart fills with blood during systole, so faster heart beat means less time there is for blood to enter the heart.  A faster heart beat means diminishing returns in terms of amount of blood supplied to the body.

                B) Damage to the SA node comes with aging, hence the v tach condition can only be found in the older population.

                C) During period of rest or exercise the autonomic nervous system controls heart rate.  Hence a v tach syndrome is due to a nervous disorder.

                D) The v tach condition is evidence of cardiac input disorder.

                E) The heart fills with blood during diastole, so faster heart beat means less time there is for blood to enter the heart.  A heart with v tach cannot properly fill with blood and paradoxically stops pumping blood.

the correct answer is E.

Why is A not correct? Faster heart beat means diminishing returns in terms of blood....that is all correct, except that blood does not enter the heart during systole.

Question # 35 from S.I. Exam 2 review

35) A sphygmomanometers measure the gauge pressure in the systemic circulation, which is the pressure above atmospheric pressure (760 mmHg at sea level).  At what component of the circulatory circuit would one expect to detect the largest drop in blood pressure?

                A) Arteries

                B) Veins

                C) Venules

                D) Capillaries

                E) Arterioles

The correct answer is E.
If you can recall blood pressure is highest in
arteries right.  And it is lowest in the capillaries.
Hence that high blood pressure leaving the aorta
undergoes its largest drop when it reaches the arterioles,
so that by the time it gets to the capillaries, its blood
pressure is lowest, allowing for exchange of substances.

Thanks

Questions # 26 - 32 (from S.I. practice exam)

The mechanism of Antimicrobial burst.

Usually, since an antimicrobial burst is an
innate ability, it is triggered in anticipation
of infection.  When the epithelial cells of
the skin are damaged during a sporting
event by bruises, or something of that
nature. 

It's triggered similar to how the blood clot
mechanism works.  Usually spontaneous when
blood pressure seems to drop around a
particular superficial vein/vessel.

Hope this helped.

Questions #8, 22, 39 & 43 from S.I. exam 2 review

8. which of the following have influence on metabolic rate.
E. all of the above

22. HIV pt. w/o T-lymphocytes, would be most susceptible to A. Viral infections
or
B. to bacterial infections? I remember Pneumonia and TB (viral and bacterial)?
A, viral infections. T-cells are vital for protection against viral infections, while B cells which are much larger and cannot cross the cell membrane generally fight bacterial infections.

39. osmotic pressure on venous side of capillary beds drops below hydrostatic pressure-
C. the pH of the interstitial fluids increase????
B, fluids will tend to accumulate.
Osmotic pressure higher than hydrostatic pressure on the venous side is what allows for substances to diffuse across blood plasma into interstitial fluids. Whenever osmotic pressure drops lower than hydrostatic pressure at the venous end of capillary beds, fluids don't diffuse enough across and tends to coagulate blood returning to the heart. Clinically diagnosed as pulmonary thromboembolism.

43. Compared with the interstitial fluid that bathes active muscle cells, blood reaching these cells in arteries has a
B. higher PCO2?
A, higher PO2 (partial pressure of oxygen). Muscles part of systemic system, so arteries taken blood to these muscles has a higher partial pressure of oxygen versus Carbon dioxide.