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

7. Define death in physiological terms. We know that when thehuman heart stops beating, it can be started again artificially.And, the subject lives. If the heart does not restart, the O2supply is cut off, the brain \"dies,\" but what does lack of O2cause? Take your answer as far down (reductionistically) as youcan.

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

9. A vampire bat survives on mammalian blood. Most cells inblood 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 anomnivorous mammal such as you.