Excretion  Excretion is the process of removing metabolic waste.  Types of Cells: Podocytes, Endothelial, and Mesangial (all found in enthrones)  Organs: Lungs, Kidneys, and Skin  Tissues: Exocrine Glandular Tissue- Produces secretions such as sweat and mucus

Importance  The Excretory System is important because it removes waste from the body that can be dangerous  As a whole, it helps maintain homeostasis within other organisms and is responsible for removing waste products of metabolism

Epidermis  The epidermis is the outer surface layer of cells of a plant or animal

Roles of Organs  Kidneys- primary excretory organs of the body. They also play an important role in maintaining homeostasis of body fluid.  Lungs:- primary site of carbon dioxide excretion. The lungs carry out detoxification. This changes the harmful substances so that they are not poisonous.  Skin- helps kidneys control the salt composition of the blood. Waste and other substances are excreted through perspiration.

Roles (cont.)

Kidneys  Kidneys are the main organs of the urinary system and regulates the chemical composition of the body and the excretion of water dissolving waste.

Kidneys (cont.)  The structure of the kidney has three main parts: The renal cortex The renal medulla The renal pelvis

Urine and Urea  Muscular contractions of the bladder force urine out of the body through a tube called the urethra.  Urea is a nitrogenous product made by the liver.

Nephron  Urine is made in structures called nephron, which are tiny tubes in the kidney.  Bowman’s capsule: retains cells and large molecules and passes wastes dissolved in water through the nephron  Inside each Bowman’s capsule a network of capillaries called glomerous is formed  Nutrients travel through the nephron and are absorbed in the bloodstream

Circulatory System  The circulatory is made up of the cardiovascular system and lymphatic system  Systematic circulation is the movement of blood between the heart and rest of the body. It supplies blood to the kidneys where wastes are filtered and removed.

Peristalsis  Peristalsis is the series of muscular contractions through the digestive tract

Bile  Bile is a bitter-tasting dark green fluid.  It helps the digestion of lipids in the small intestine  It is produced in the liver of most vertebrates

Duodenum  Duodenum is the first section of the small intestine  It is responsible for the breakdown of food in the small intestine with help from enzymes  It also regulates the rate of emptying the stomach using the hormonal pathways

Kidney Disorder  Alcoholism- destroys the balance of ions and water in the body by altering the filtering ability of the kidney.

Additional Information  The liver produces 6,500 ounces of bile in the average persons lifetime  The vein that leads to your kidney is the longest in the body  Kidneys also produce vitamin D which promotes strong bones and keeps blood pressure at a healthy level

Bibliography  /systems/system%20research/excretory/ex cretory.htm /systems/system%20research/excretory/ex cretory.htm  biology/human-body-the-excretory-system/ biology/human-body-the-excretory-system/  facts.com/excretory-system.html facts.com/excretory-system.html  atomy-of-urinary-system.asp atomy-of-urinary-system.asp  tion.html tion.html