They serve the body as a natural filter of the blood, and remove water-soluble wastes which are diverted to the bladder. In producing urine, the kidneys excrete nitrogenous wastes such as urea and ammonium. They are also responsible for the reabsorption of water, glucose, and amino acids. The kidneys also produce hormones including calcitriol and erythropoietin.
Definition of skeg. 1  1 : the stern of the keel of a ship near the sternpost; especially : the part connecting the keel with the bottom of the rudderpost in a single-screw ship. 2  2 : a fin situated on the rear bottom of a surfboard that is used for steering and stability.
On the other hand many people think that the skeg is used to make a kayak track in a straight line. Once again, while essentially true, its actual function is to âtrimâ the boat when wave and wind conditions begin to adversely affect the boats handling.