Excretory System

excretory system; removes excess, unnecessary or dangerous materials from an organism to help maintain homeostasis. It is responsible for the elimination of the waste products of metabolism as well as other liquid and gaseous wastes.

OrganFunction LiverFilters the blood, glycogen storage, decomposition of red blood cells, plasma protein synthesis, hormone production, detoxification and bile production. LungsFilters the blood gasses removes Carbon Dioxide and gains oxygen. SkinGets rid of water, salts and urea KidneyRegulates electrolytes, blood pressure and filters out wastes like urea and ammonium. They also reabsorb water, glucose, and amino acids. The kidneys also produce hormones.

The Nephrons of the Kidney Function: purification and filtration of the blood. About one million nephrons are in the cortex of each kidney, renal corpuscle renal tubule

Glomerulus and Bowman’s Capsule The Glomerulus: A ball of capillaries, the main filter located within the Bowman's capsule Ultra-filtration: Blood from the renal artery is forced into the glomerulus under high pressure. Most of the liquid is forced out of the glomerulus into the Bowman'scapsule. This does not work properly in people who have very low blood pressure.

Proximal Convoluted Tube Proximal means "near to" and convoluted means "coiled up" so this is the coiled up tube near to the Bowman's capsule. Glucose is re-absorbed from the ultra-filtrate and put back into the blood. If the glucose was not absorbed it would end up in your urine. This happens in people who are suffering from diabetes.

Loop of Henle Water is reabsorbed Kidney cells in this region spend all their time pumping sodium ions This makes the medulla very salty; you could say that this is a region of very low water concentration Remember the definition of osmosis

Collecting Duct Collecting ducts run through the medulla and are surrounded by loops of Henlé The liquid in the collecting ducts (ultra- filtrate) is turned into urine as water and salts are removed

Distal Convoluted Tubule Distal means "distant" so it is at the other end of the nephron from the Bowman's capsule This is where most of the salts in the ultra- filtrate are re- absorbed.

Urinary System