Exam 44: Gas Exchange and Circulation

What is the QRS complex in an ECG tracing?

A rabbit taken from a meadow near sea level and moved to a meadow high on a mountainside would have some trouble breathing.Why?

Which of the four muscular chambers of the human heart directly propels blood into the pulmonary circulation?

Fick's law of diffusion describes the factors that influence the diffusion of respiratory gases across biological membranes like gills and lungs.Diffusion rate = k × A × (P₂ - P₁)/D.Natural selection is least likely to act upon which variable in Fick's law?

Which of the following events would be predicted by the Bohr shift effect as the amount of carbon dioxide released from your tissues into the blood capillaries increases?

You prop open the gill covers of a fish,tie a string around its tail,and tow it backward through the water.This action forces water to flow in the back of the gill covers,from back to front over the gills,and out through the fish's mouth.What effect would this backward movement have on gas exchange?

In what way does hemoglobin act as a buffer against changes in blood pH?

When you are jogging,your muscles are using more oxygen and releasing more carbon dioxide into the blood than when you are at home on the couch.Which of the following would occur during your jog?

Which of the following mechanisms are used to regulate blood pressure in the closed circulatory system of vertebrates?

Baroreceptors sensing a rapid increase in blood pressure will likely result in _____.

When the sea lamprey (Petromyzon marinus),a marine jawless fish,was moved in the ballast of ships from the Atlantic to the Great Lakes (a freshwater environment)the fish could more easily obtain oxygen from freshwater than it could in its native marine habitat.Why is this the case?

Baroreceptors are specialized pressure-sensing nerve cells that are important in circulatory homeostasis.Where are these nerve cells located in humans?

If other factors are equal,which of the following environments would have the highest level of dissolved oxygen?

Use the following information when answering the corresponding question(s). Lymph hearts are pumping structures that drive lymph through the lymphatic system,returning it to the circulatory system at the large veins entering the heart.Researchers examined rate and strength of pumping of lymph hearts in two species of amphibians,a toad (Bufo marinus)and a frog (Rana catesbiana).During hemorrhage or dehydration,the volume of blood in the circulatory system falls.A hormone,arginine vasotocin (AVT),is released in these situations.The researchers examined the effect of AVT on lymph heart function.They found that AVT increased pressure at the lymph heart but did not affect the rate of lymph heart pumping.They also examined the effect of atrial natriuretic peptide (ANP),a hormone that is released when blood volume is higher than normal.(E.A.DeGrauw and S.S.Hillman.2004.General function and endocrine control of the posterior lymph hearts in Bufo marinus and Rana catesbiana.Physiological and Biochemical Zoology 77(4):594-600. ) -Refer to the paragraph on lymph hearts.If atrial natriuretic peptide (ANP)has an effect on the lymph hearts,what effect would logically be predicted?

What adaptations are observed in trachea and lungs to reduce water loss?

If you were to design a countercurrent exchange respiratory system in fish,which of the following would not be expected?

Why is it more difficult to obtain enough oxygen via respiration from water than from air?

Use the following information when answering the corresponding question(s). Lymph hearts are pumping structures that drive lymph through the lymphatic system,returning it to the circulatory system at the large veins entering the heart.Researchers examined rate and strength of pumping of lymph hearts in two species of amphibians,a toad (Bufo marinus)and a frog (Rana catesbiana).During hemorrhage or dehydration,the volume of blood in the circulatory system falls.A hormone,arginine vasotocin (AVT),is released in these situations.The researchers examined the effect of AVT on lymph heart function.They found that AVT increased pressure at the lymph heart but did not affect the rate of lymph heart pumping.They also examined the effect of atrial natriuretic peptide (ANP),a hormone that is released when blood volume is higher than normal.(E.A.DeGrauw and S.S.Hillman.2004.General function and endocrine control of the posterior lymph hearts in Bufo marinus and Rana catesbiana.Physiological and Biochemical Zoology 77(4):594-600. ) -Refer to the paragraph on lymph hearts.What effect would increasing lymph heart pressure have?

Carbonic anhydrase inhibitors cause less movement of carbonic acid toward CO₂ production and are used as a prophylactic treatment of altitude sickness.Altitude sickness occurs when a hiker ascends to altitudes where the density of oxygen is low.How does this decrease the symptoms of high altitude sickness?

Atria contract _____.