THE EXCRETORY SYSTEM

What Stuff Is Pair of kidneys ◦ Retroperitoneal Pair of ureters Urinary bladder Urethra

Where Stuff Is

The Kidney The Kidney Cortex Medulla Calyx Pelvis Ureter Hilum Papilla Pyramid Column

Functions of Excretory System Regulate body fluids ◦ Volume, pH, composition Remove metabolic wastes from blood Control rate of RBC formation Regulate blood pressure Regulate absorption of calcium

Body Needs The body has certain needs if it is to stay alive: It needs food, water and oxygen, among other things. Three body systems work together to gather these requirements and get them to the right places (the respiratory, digestive & circulatory system). As a result of these systems working together to keep the body alive and functioning properly, they also produce a lot of waste as a by-product.

Body Waste What is body waste? Any material that the body cannot use. Hidden throughout your body are dangerous poisons that must be removed in order for it to survive. These wastes are toxic to the organism if allowed to accumulate inside the body or blood. It will lead to sickness and death. This body waste must be found, collected and then removed from the body by the excretory system.

The Job The job of the excretory system is to get rid of body waste and to maintain water balance (it keeps the amount of water in the body fairly constant). Body waste that the body must get rid of: Carbon dioxide, solid waste (indigestible food), water, ammonia (cell waste), inorganic salts and heat.

Unlike other organ systems, the excretory system involves a few different organ systems, spread throughout the body, working together to do its job. Excretory System Integumentary System (skin) Removes sweat Urinary System Removes urine Respiratory System Removes carbon dioxide (CO2) Digestive System Removes solid waste (feces)

Excreting Waste Through 4 Systems Integumentary System: Also known as the skin, this system removes excess salt, water, and other waste in the body as sweat, through the pores of the skin. At the same time, this process helps to cool off the body and to maintain a healthy body temperature. Digestive System: Materials that the body does not take in as nutrients is eliminated as solid waste (feces). Urinary System: Removes waste from the blood that has been converted to urine (see next slide) Respiratory System: Carbon dioxide, a cell waste, is exited out of the body by the lungs.

Pee is made Urine is created by your kidneys. Your kidneys process waste from your blood. Essentially, the blood is filtered through the kidney where wastes and water, minerals, salts, sugars, etc are removed. Some of the sugars and such are reabsorbed back into your blood. What’s left in the kidney after filtration of the blood; the toxins, salts, urea, ammonia, excess water, etc becomes urine.

Skin Your Integumentary System uses sweat glands in the skin to get rid of body waste. In these glands, excess water, salt and a small amount of waste build up. These substances leave your body through the skin as sweat. This process helps your body cool down.

Kidneys The kidneys are the body’s filtration system. They clean out your blood of body waste and make sure that your blood is just the right combination -- not too thin or too thick, not too salty, or overloaded with excess vitamins and minerals or wastes made in your body. The kidneys work as they do because they contain millions of very small filters called “nephrons”. The entire blood supply passes through the kidneys once every minutes for a total of about 60 times a day.

Liver Liver is the largest gland in the human body and one of the most complex of all human organs. The liver serves as the body's main chemical factory and one of its major storehouses of food. It lies in the upper right part of the abdomen, directly under the diaphragm and above the stomach and intestines. The liver performs many essential functions. One of its most important tasks is to help the body digest food. The liver also stores food. the liver filters poisons and wastes from the blood.

Lungs The lungs are a pair of organs which are a part of the respiratory system, but they also function in the excretory system. When the diaphragm contracts, it pulls air into the lungs. The oxygen in the air is absorbed and transported to the cells through the bloodstream. When the cells in the body receive and use the oxygen, as a part of the process of cellular respiration, carbon dioxide is created as a waste. This is transported by the bloodstream back to the lungs so that the carbon dioxide is released into the air in the lungs. When the diaphragm relaxes and forces the air out of the body system, the carbon dioxide is also transported out of the body system. This system is repeated many times so that oxygen continues to be provided for the body and, as it is used and wastes are created.

Diseases Nephritis is a disease affecting the kidneys. It’s an inflammation on the glomeruli, due to a number of possible causes, including things like strep throat. Symptoms include bloody urine, scant urine output, and sweeling/puffliness. Nephrosis is characterized by the excretion of an abnormally large amount of protein (causing “foamy” urine) and generalized edema (water retention/swelling) throughout the whole body, especially noted as “puffy” eyelids.

Kidney Stones Kidney stones can form when urine contains too much of certain substances. These substances can create small crystals that become stones. The biggest risk factor for kidney stones is dehydration. Kidney stones may not produce symptoms until they begin to move down the tubes (ureters) through which urine empties into the bladder. When this happens, the stones can block the flow of urine out of the kidneys. This causes swelling of the kidney or kidneys, causing pain. The pain is usually severe. Kidney stones are common. A person who has had kidney stones often gets them again in the future. Kidney stones often occur in premature infants. Some types of stones tend to run in families. Certain kinds of stones can occur with bowel disease, ileal bypass for obesity, or renal tubule defects.

Kidney Stones (cont.) There are different types of kidney stones. The exact cause depends on the type of stone. ◦ Calcium stones are most common. They occur more often in men than in women, and usually appear between ages They are likely to come back. Calcium can combine with other substances, such as oxalate (the most common substance), phosphate, or carbonate to form the stone. Oxalate is present in certain foods. Diseases of the small intestine increase the risk of forming calcium oxalate stones. ◦ Cystine stones can form in people who have cystinuria. This disorder runs in families and affects both men and women. ◦ Struvite stones are mostly found in women who have a urinary tract infection These stones can grow very large and can block the kidney, ureter, or bladder. ◦ Uric acid stones are more common in men than in women. They can occur with gout or chemotherapy.

PEACE!!!!