The Urinary System

4. Any of a group of compounds with varying hormone-like effects.
5. The minor component in a solution.
6. Excrete (waste matter).
8. The outermost layer of the wall of a blood vessel.
11. An organelle found in large numbers in most cells.
13. Waste is eliminated from an organism. In vertebrates this is primarily carried out by the lungs, kidneys, and skin.
14. Periods of weakness.
16. The removal of an amino group from a molecule.
17. A region of the forebrain below the thalamus.

1. Involuntary or unconscious.
2. A process by which molecules of a solvent tend to pass through a membrane from a less concentrated solution into a more concentrated one.
3. A biological process that results in stable equilibrium.
4. Consisting of closely packed cells which appear to be arranged in layers.
7. A muscle which forms a layer of the wall of the bladder.
9. Relating to or denoting an apex.
10. Relating to the equilibrium of liquids and the pressure exerted by liquid at rest.
12. A cuplike cavity or structure.
15. pH is a measure of how acidic or alkaline a substance is, as determined by the number of free hydrogen ions in the substance.