At the end of the bronchioles are little air sacs called alveoli. the alveoli are connected to the network of blood vessels, which are connected to veins and arteries. The air in the alveoli diffuses into the blood in these vessels. this process is called . A. How urine exits the body

B. How air enters the body through airways

C. How air gets into the blood from the bronchial tubes

D. How carbon dioxide leaves the body

The kidney filters potentially toxic substances in the blood, and thus “clears” the blood of those substances. this clearance function is dependent upon and proportional to the diffusion gradient of the substance across filtering capillaries, i.e. if the concentration of the substance is doubled, twice as much will be cleared from each ml of blood that is filtered. suppose that the body produces a constant amount of a substance x per unit of time. the kidneys eliminate substance x at a rate directly proportional to the concentration of the substance and the volume of blood cleared each minute (c): elimination = c × [x], where [x] is the steady-state concentration of substance x. imagine an individual with an initial concentration of x equal to [x]0 who develops kidney disease. her baseline clearance c0 drops to one half of the original (½c0). what is the new steady state concentration of x? (for simplicity, assume that substance x is 100% filtered by the kidney).

Which component in a graph indicates an independent factor? a. y-axis b. x-axis c. scale

What substance is the most acidic. lemon juice. tomato juice. sodium hydroxide. water