The removal of cellular wastes (liquids and gases)

It does NOT involve solid wastes

Excretion is…..

Carbon dioxide – aerobic respiration

Water – aerobic respiration Urea – nitrogen waste that is a

result of the break down of amino acids

Mineral Salts – breakdown of compounds in the cell

Wastes need to be excreted because….. Harmful to the cells Disrupts homeostasis

What role does blood play in excretion?

Cell Wastes Plasma Excretory Organs Removal from the body

Skin Lungs (2) Liver Kidneys (2) Urinary System

Epidermis (thin top layer)

Dermis (contains blood vessels, bones, and muscle)

Sweat glands and Sebaceous glands (oil) to moisturize skin

Perspiration (ie: Sweat)– nitrogen wastes (urea), salts, and water leave the skin through pores to regulate body temperature.

Excrete carbon dioxide and water vapor as a waste product of respiration

      

Largest internal organ

Produces urea by breaking down excess amino acids

Removes poisons (alcohol) from the blood

Stores excess sugars

Kidneys Ureter Urinary bladder Urethra

New York Times Article – January 2008 Kidney Thefts Shock India

Fighting drowsiness, he fumbled beneath the unfamiliar folds of a green medical gown and traced his fingers over a bandage attached with surgical tape. An armed guard by the door told him that his kidney had been removed. Mr. Mohammed was the last of about 500 Indians whose kidneys were removed by a team of doctors running an illegal transplant operation, supplying kidneys to rich Indians and foreigners, police officials said.

Made up of millions of nephrons – subunit of the kidneys that actually does the filtering

Filter wastes from the blood and makes urine

8. Kidneys

Urea – nitrogen wastes that result from the break down of proteins

Mineral Salts – result from the break down of compounds in the cell

Excess water

Some water Vitamins Blood cells Proteins Glucose

Wastes Kept in blood

Kidneys include: 1. Renal Artery- supplies (dirty)

blood to kidneys 2. Renal Vein- filtered (clean) blood

leaves kidney 3. Renal Cortex 4. Renal Medulla 5. Renal Pelvis

Tube that connects the kidneys to the urinary bladder.

Transports urine (urea and water)

9 and 6. Ureter

Sac-like organ that stores urine

10. Urinary Bladder

Tube that is connected to the urinary bladder

Where urine leaves the body

11. Urethra

FYI… 7. Adrenal Gland Releases adrenaline

The Nephron 1. Bowman’s capsule– acts as a filter 3. Renal artery 4. Glomerulus- Brings blood to kidneys 5. Capillary network 6. Renal vein 8. Loop of Henle- where water is reabsorbed 10. Collection tubule- where more salts are

reabsorbed 9. Collecting Duct- liquid in duct is turned

into urine when water and salt are removed

Kidney stones Gout Kidney Failure Bacterial Infections

Collection of solid material that may block the kidney, ureters, bladder

Results from a diet too high in protein

Uric acid build up in the bones and joints Uric Acid is

solid crystals within liquid waste.

Kidney Failure Total shut down of both kidneys

Treated with a Dialysis machine

Bacterial Infections Urinary tract and bladder

infections Common in infants and elderly Common in females

Treated with antibiotics