Describe the Human Kidney

The kidneys are the main filtration system for the body. Without kidneys, higher order organisms such as humans would not be able to filter waste from the blood and excrete from the body. The kidneys take waste product from metabolism and send beneficial elements such as water and electrolytes back to the blood, and remove harmful elements such as nitrogen in the form of urea.

Location

• The human body has two kidneys located on the lower back lateral to the spine. They are bean-shaped organs and are connected to the ureters, which take the waste product and send it to the bladder.

Filtration Overview

• Normal, healthy human kidneys filter approximately 200 quarts of blood every day. The filtration process removes about 2 quarts of urea daily.

Main Parts

• The main filtration of the blood happens in the nephron. Kidneys have about 1 million nephron that contain the glomerulus. The glomerulus are the parts of the kidney that filter the blood and return beneficial elements back to the body.

Hormone Release

• In addition to filtration, kidneys also release three hormones--erythropoietin (bone marrow stimulation), renin (blood pressure regulation) and calcitriol (the active form of vitamin D).

Terminology

• Medical researchers and practitioners use the term "renal function." The term "renal" and "kidney" are synonymous. Renal function is used to describe the efficiency of the kidneys to filter waste.