How does the excretory system work

The regulation process of body fluids and salt levels is also called osmoregulation. The kidneys act as a filter. Eventually all of the blood in your body passes through the kidneys and they are able to do their filtering magic. The kidneys pull harmful molecules out of your bloodstream and leave the ones that are good for you. The kidneys are also key players in the hydration water levels for your body. Let's say you are in the desert and you haven't been drinking much water.

Chemical signals are sent to your kidneys to reabsorb as much water as possible. The result is less urine creation and your body loses less water.

A normal day has you creating about one and a half liters of fluid. Interacting with Other Systems The excretory system is a close partner with both the circulatory and endocrine system. The circulatory system connection is obvious. Blood that circulates through the body passes through one of the two kidneys. Urea, uric acid, and water are removed from the blood and most of the water is put back into the system. Urea is carried in the bloodstream to the kidneys, where it is removed along with water and other wastes in the form of urine.

Other important functions of the kidneys include blood pressure regulation and the production of erythropoietin, which controls red blood cell production in the bone marrow. Kidneys also regulate the acid-base balance and conserve fluids. Two kidneys. This pair of purplish-brown organs is located below the ribs toward the middle of the back. Their function is to:. The kidneys remove urea from the blood through tiny filtering units called nephrons. Each nephron consists of a ball formed of small blood capillaries, called a glomerulus, and a small tube called a renal tubule.

Urea, together with water and other waste substances, forms the urine as it passes through the nephrons and down the renal tubules of the kidney. Two ureters. These narrow tubes carry urine from the kidneys to the bladder.

Muscles in the ureter walls continually tighten and relax forcing urine downward, away from the kidneys. The liver and intestines excrete bile pigments that result from the destruction of hemoglobin. The major task of excretion still belongs to the urinary system. If it fails the other organs cannot take over and compensate adequately. The urinary system maintains an appropriate fluid volume by regulating the amount of water that is excreted in the urine.