Excretory System

‘POISON’ Removal System

Function:

1. Get rid of waste

2. Get rid of useless by-products excreted by cell

3. Get rid of harmful chemical build-up

4. Maintain HOMEOSTASIS

FOUR WASTES

1. Carbon dioxide (lungs)

2. Sweat (skin)

3. Urine (kidneys)

4. Excrement also known as POOP (large intestines)

(tears, ear wax, snot, gas)

(vomit and pus when sick or have an infection)

Role of Lungs:

Maintain level of carbon dioxide and oxygen in blood by EXCRETING carbon dioxide

Role of Skin:

1. Sweat helps body temperature stay the same

2. Sweat is excreted through sweat glands

3. Sweat glands contain salt and water (the salt helps evaporate the water to keep the body cool)

4. Sweat glands located all over body

Role of LIVER:

1. Regulates storage of glycogen, drug detoxification, breaks down, production of blood plasma components

2. Secretes bile which breaks down fat

3. Bile is a greenish/brownish substance made of water, salts, cholesterol) which is stored in gall bladder and secreted into small intestines

4. Changes ammonia from breakdown of amino acids (poisonous gas) to urea (mix of sugar and waste)

5. Stores glucose, fatty acids, vitamins, and minerals

Role of LARGE INTESTINES:

1. Removes solid waste from body

2. Collects water from waste which is absorbed back into the body

Role of KIDNEYS:

1. Removes liquid waste

2. Blood deposits used and unwanted water, minerals, and urea (from liver) into kidneys

3. Kidneys filter these wastes to form urine.

Your kidneys produce 1.5 liters of urine a day!

Urinary System Anatomy

Kidney Anatomy

-In each kidney, there are one million tiny structures called nephrons.

-The nephron is the basic unit of the kidney

- function of nephron is to regulate the concentration of water and salts by filtering the blood, reabsorbing what is needed, and excreting the rest as urine.

What is urine?

-yellowish fluid stored in the bladder and discharged through the urethra

-Made of water, salt, nitrogen compounds such as urea, and other waste substances removed from the blood by the kidneys

Maintaining Homeostasis

• ADH antidiuretic hormone

• Promotes water retention

• More water is reabsorbed into the blood

Concentrated Urine Dilute Urine