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.
Gullet. 1. (Science: anatomy) The tube by which food and drink are carried from the pharynx to the stomach; the oesophagus. 2. Something shaped like the food passage, or performing similar functions; as: a channel for water. (Science: engineering) a preparatory cut or channel in excavations, of sufficient width for the passage of earth wagons.