Excretory system

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The excretory system is the system of an organism's body that performs the function of excretion, the bodily process of discharging wastes.

Majestic180 21:07, 10 December 2006 (UTC)== ==

- Kidneys
- Nephron
- Urine
Intestines
- Feces
Lung
- Carbon dioxide
Skin
- Sweat
Liver
Malphigian tubule system (Arthropod excretory system)

- Menses

The Excretory system is responsible for the elimination of wastes produced by homeostasis. There are several parts of the body that are involved in this process,such as sweat glands,the liver,the lungs and the kidney system. Since we are focusing on the formation of urine within the kidneys, we will simply overviewing the kidney's role in excretion.

Every human has two kidneys.Each kidney is made up of three sections:the renal cortex,the renal medulla and the renal pelvis.The blood arrives at the kidney via the renal artery,which splits into many afferent arterioles.These arterioles go to the Bowman's Capsules of nephrons,where the wastes are taken out of the blood by pressure filtration.Peritubular capillaries also surround the nephron so substances can be taken in and out of the blood.

The renal cortex is the outer layer of the kidney and the medulla is the inner layer of the kidney.The renal pelvis takes urine away from the kidney via the ureter.Both of the ureters lead the urine into the body's only urinary bladder,which expands and sends nerve impulses when full.From there, urine is expelled through the urethra and out of the body.

The Human Excretory System The urinary system is made-up of the kidneys, ureters, bladder, and urethra. The nephron, an evolutionary modification of the nephridium, is the kidney's functional unit. Waste is filtered from the blood and collected as urine in each kidney. Urine leaves the kidneys by ureters, and collects in the bladder. The bladder can distend to store urine that eventually leaves through the urethra.