Select the correct answer from each drop-down menu. The heart is a muscular organ that pumps blood. Blood that contains waste materials is brought to the heart by blood vessels. This blood enters the and then moves down. The presence of the prevents the backflow of blood inside the heart

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 ocean is on the eastern coast of north and south america? arctic ocean indian ocean pacific ocean atlantic ocean

Vessels draining the myocardium of the heart, open primarily ,into which chamber?