EXCRETORY SYSTEM

Excretory System – removes excess water, H 2 O, urea, carbon dioxide, CO 2, and other wastes from our blood. Kidneys – filter out excess water and urea Lungs – filter out carbon dioxide, CO 2, from the blood. Skin – excretes water, as sweat, which contains some trace chemical wastes, including urea.

I. T HE K IDNEYS Every drop of blood in your body is filtered by your kidneys more than 300 times per day! Kidneys eliminate urea, minerals and excess water. Kidneys regulate the amount of water we need to maintain in our bodies.

Kidneys – filter wastes and excess water from the blood. Ureters – tubes that take urine from the kidney to the urinary bladder. Urinary Bladder – a sack that stores urine. Urethra – small tube that leads urine out of the body.

HUMAN EXCRETORY SYSTEM waste and what its removed by carbon dioxide- lungs water - skin, kidney, lungs salts - skin, kidney ammonia - liver urea - kidney

THE EXCRETORY SYSTEM The excretory system helps to remove body waste safely. The kidneys act like filters.

KIDNEYS The two kidneys are located near the spine in the middle of the back. They are protected by lower ribs and covered by layers of fat.

KIDNEYS Without the kidneys, it would not take long before the body’s system would be poisoned by its own waste. It is possible to function with only one kidney.

HUMAN EXCRETORY SYSTEM consists of the kidneys, ureters, urinary bladder, urethra and renal circuit (renal arteries and renal veins) kidney includes an outer cortex, middle medulla and the nephrons nephrons include a capsule and a looping tubule that joins others to form the collecting ducts, making up the pyramids which empty into the calyces - lead into the renal pelvis

PRIMARY ORGANS OF EXCRETION

KIDNEY Learn the parts Functions of the kidneys 1. excrete toxins and nitrogenous wastes 2. regulate chemical levels in blood 3. maintain water balance 4. helps regulate blood pressure (renin)

LABEL THE PARTS ON A MODEL

CROSS SECTION OF HUMAN KIDNEY

STRUCTURES

OTHER ORGANS ureters - long narrow tubes with expanded upper end (renal pelvis) located inside each kidney. Function is to drain the renal pelvis to urinary bladder urinary bladder- elastic muscular organ capable of great expansion. Function si storage of urine and voiding urethra – passage of urine from bladder to outside of body. Passage of semen from male body

URINE Waste drains out of the kidneys in the form of urine. Urine is about 95% water and 5% urea (protein from protein breakdown). Fresh urine has no bacteria in it. It is quite clean (probably cleaner than your hands).