Question

6. Lungless salamanders live in moist habitats and can die if their skin dries out. Yet, some species cannotlive in water as adults and will drown if fully immersed. Why might this occur (consider the functional disadvantage of lungs in underwater) ?   Why must their skin remain moist?

7. Define death in physiological terms. We know that when the human heart stops beating, it can be started again artificially. And, the subject lives. If the heart does not restart, the O2 supply is cut off, the brain "dies," but what does lack of O2 cause? Take your answer as far down (reductionistically) as you can.

8. You have designed a new drug (Provasoshut®️) that acts as an agonist of alpha-adrenergic receptors. In most of the systems you have studied (e.g. capillary beds of the digestive system, liver, and adipose), Provasoshut®️ causes vasoconstriction that lasts for at least 15 minutes. However, when you tried the drug on the capillary beds of the contracting muscle of the frog leg prep in your physiology lab, the vasoconstriction lasted only 20 seconds! What is the best explanation for the short-lived action of Provasoshut®️ in this preparation?

9. A vampire bat survives on mammalian blood. Most cells in blood are erythrocytes filled mostly with water and hemoglobin. Most of plasma is water and its most abundant solute is albumin. Predict how the urine of a vampire bat would differ compared to an omnivorous mammal such as you.

Answer 1

6. Lungless salamenders are salamenders that doesn't have lungs or gills and they breathe by absorbing oxygen through their moist skin(cutaneous respiration) and mucous membrane in the mouth and throat . Because of this, their skin should remain moist all the times to absorb oxygen and will die if their skin becomes dried out.

Gills must be present to breathe underwater but lungless adult salamenderssalamenders don't have gills.The oxygen is absorbed through nose into the mouth by muscles of the throat. Because of this type of breathing, some species cannot live underwater and over a long period of time ,they get drown in the water .