Feeling pain, hunger, thirst, sleepiness, and being aware of our thoughts and emotions are all examples of Internal stimuli.
It affects the layers of the earth the ozone layer which protects us from the sun can't protect very good. Which increases the tempature here on earth.
Parietal cells within the stomach lining secrete hydrochloric acid that lowers the pH of the stomach. A low pH (1.5 to 2) activates pepsin. Acetylcholine, gastrin, and histamine stimulate the proton pump in parietal cells to release hydrogen ions and decrease pH.
<span>Relative concentration of water in a hypnotic solution is high</span><span />
