Intracellular signaling pathways within target cells are organized such that

Drinking a liter of water will cause the osmolarity of blood plasma to

Which photoreceptor cells function in dim light?

A comparison of the two major body fluid compartments reveals that

Compared to young adults, the elderly usually have ______ levels of circulating growth hormone and _____ levels of circulating sex hormones.

 This figure shows a frontal section of the kidney. Which number(s) indicate a renal papilla?

Parathyroid hormone functions to raise blood calcium levels.

Which is the layer of the serous membrane that directly covers the surface of internal organs?

Glucagon and insulin work _________ on blood glucose levels.

Aldosterone release can be triggered by the presence of the blood-borne messenger angiotensin II or by low levels of sodium, and so its secretion regulation is said to be