Human chorionic gonadotropic (hCG) and human placental latogen (hPL) are peptide hormones produced and excreted by placental trophoblastic cells during pregnancy.
On highways, traffic snakes grow if cars are eaten faster than excreted, and they shrink if excreted faster than eaten, dying when the last car accelerates away before the next car must stop.
Now normally, the difference in the electrolyte concentration inside and outside the cell wouldn't pose a problem, because your kidneys flush out any excess water; however, the kidneys can only excrete fluid at a certain rate.
Space is big — remember, folks, that's why we call it “space” — and getting here is a huge pain in the butt… or whatever aliens use to excrete waste matter.
Another example is Fanconi syndrome, which is where the proximal convoluted tubule essentially loses its capacity to reabsorb a variety of solutes - including phosphate - once again letting it get excreted in the urine.
We also talked about the anatomy of storing and excreting urine — from the ureters to the urethra — and we went over the nervous system's role in controlling the act of urination.
These pumps drive potassium from the blood into the cells and from there it flows down its concentration gradient into the tubule to be excreted as urine.
Also, some individuals have a genetic predisposition to overproduction of uric acid while others with chronic kidney disease may be unable to excrete the uric acid.
But if you use different types of assisted reproductive technology that make your ovaries excrete more eggs, you might get pregnant with triplets or quadruplets.
Perhaps the key to understanding this object is that this toad excretes a hallucinogenic substance, and Central Americans believed that it represented an earth goddess.