Excretory System: ‘POISON’ Removal System

Excretory Function: Get rid of waste Get rid of useless products excreted by cell Get rid of harmful chemical build-up 4. Maintain HOMEOSTASIS

FOUR WASTES 1. Carbon dioxide (lungs) 2. Sweat (skin) 3. Urine (kidneys) Solid waste/feces (large intestines) Others: (tears, ear wax, snot, gas) (vomit and pus when sick or have an infection)

Role of Lungs: Maintain level of CO2 and O2 in blood by EXCRETING carbon dioxide

Role of Skin: Sweat helps body temperature stay the same 2. Sweat is excreted through sweat glands Sweat glands contain salt and water (the salt helps evaporate the water to keep the body cool) Sweat glands located all over body

Role of LARGE INTESTINES: Solid waste removal 2. Reabsorbed water from solid waste (feces) back into the body

Role of the LIVER: Stores glycogen, drug detoxification Secretes bile: breaks down fat 3. Amino acids are broken down into ammonia (poisonous gas). Liver changes this to urea (mix of sugar and waste)

Role of KIDNEYS: Kidneys filter wastes from blood to form urine Remove liquid waste Your kidneys produce 1.5 liters of urine a day!

Urinary System Anatomy Liver Kidney  Ureter  Bladder Urethra

Kidney Anatomy Each kidney has a million tiny structures called nephrons. Nephron= basic unit of the kidney function of nephron: filtering the blood to regulate water and salt concentration in body reabsorb what is needed excreting the rest as urine. HERE

What is urine? yellow fluid stored in the bladder & released through the urethra Made of water, salt, nitrogen compounds (urea) and other waste substances removed from the blood by the kidneys

Maintaining Homeostasis: ADH ADH= antidiuretic hormone Causes water retention Causes MORE water to be reabsorbed into the blood

Concentrated Urine: Dark Yellow Dilute Urine: Clear/light yellow