Excretory System

Functions The job of the excretory system is to rid the

body of waste that result from metabolism. These are NOT the same wastes that result

from digestion. Also, maintaining fluid, salt, and pH levels

in the blood.

A) Structure Lungs: Rid the body

of CO2 build up.

Skin: Secretes sweat which helps to regulate fluid and salt levels of the blood.

Kidneys: Major excretory organ of the body.

A) Structure Skin: In the skin wastes

such as excess salt, urea, and water build up in the sweat glands.

When triggered they release this fluid: “sweating”.

A) Structure The kidney is connected to

the bladder. Upon filtration waste is

delivered to the bladder for storage.

A) Structure The kidney filter wastes,

water and salt from the blood.

Parts of the Kidney: Renal Cortex – outer portion Renal Medulla – inner portion Renal Pelvis – Location of

filters

B) Function Kidney: Functional

Unit called Nephrons.

B) Function Blood is delivered via the renal artery. Blood enters the nephron via glomerulus. Around the glomerulus there is a structure

called Bowman’s capsule. In the glomerulus waste diffuses into

Bowman’s capsule.

B) Function Primary form of waste is Urea – a

nitrogenous salt dissolved in water. The urea collects in a a series of structures

structure: the convoluted tubule, Loop of Henle and the collection tubule.

Glucose and water are reabsorbed: Reabsorption Waste travels to the collecting tubule

B) Function Urine is the resulting

waste product, collecting in the tubule.

This structure leads to the ureter.

The ureter empties into the bladder.

C) Disorder Infections can impair or damage kidney

function. Nephritis – swelling of the glomeruli.

Causes blood in the urine Protein in the urine Swelling

Kidney Stones are build up of solid crystals in the kidneys, Stones are passed, or removed

surgically

D) Treatments Dialysis: artificial

kidneys to detoxify the blood. Blood is passed through

a machine to clean the blood.

The blood is then returned to the body.