Excretory System

Excretory SystemExcretory System

ExcretionExcretion

Excretion is the Excretion is the removal of wastesremoval of wastes

Wastes from:Wastes from: Cellular respirationCellular respiration Digestion of foodDigestion of food Cellular activitiesCellular activities

SkinSkin

Your skin is very Your skin is very important to the important to the excretory system.excretory system.

Excretes excessExcretes excess WaterWater UreaUrea HeatHeat

What is Urea?What is Urea? A common metabolic A common metabolic

cellular waste product is cellular waste product is ammonia. ammonia.

It can raise the pH of It can raise the pH of blood.blood.

The human body can The human body can combine ammonia and combine ammonia and excess CO2 to make excess CO2 to make Urea.Urea.

Urea is very soluble in Urea is very soluble in water, making it an easy water, making it an easy way to excrete excess way to excrete excess nitrogennitrogen

Lungs?Lungs?

The lungs are an The lungs are an important organ of important organ of the excretory the excretory systemsystem

But what wastes But what wastes do they get rid of?do they get rid of?

Carbon DioxideCarbon Dioxide

Carbon Dioxide is Carbon Dioxide is a waste product of a waste product of cellular respirationcellular respiration

It makes the blood It makes the blood acidicacidic

Our body needs to Our body needs to get rid of itget rid of it

DiffusionDiffusion

We have no special We have no special process for CO2 process for CO2 removalremoval

Rely on simple Rely on simple diffusiondiffusion

AlveoliAlveoli High to low High to low

concentrationconcentration LungsLungs

LiverLiver

Liver is Liver is responsible for responsible for detoxification of detoxification of the bodythe body

It converts It converts ammonia to ureaammonia to urea

CirrhosisCirrhosis

Scarring of the Scarring of the liverliver

Usually caused by Usually caused by alcoholismalcoholism

Large IntestinesLarge Intestines

Removal of water Removal of water from solid wastesfrom solid wastes

Excretion of solid Excretion of solid wasteswastes

The act of The act of defecation is not defecation is not considered a part considered a part of excretory of excretory systemsystem

KidneysKidneys

Kidneys are the Kidneys are the most important most important organ of the organ of the excretory systemexcretory system

Regulate pH of the Regulate pH of the bloodblood

Remove excess Remove excess water, and urea to water, and urea to create urinecreate urine

Urinary SystemUrinary System

Kidneys feed Kidneys feed UreterUreter

Ureter connects to Ureter connects to BladderBladder

Bladder stores Bladder stores urineurine

Excreted through Excreted through UrethraUrethra

Excretion and Excretion and HomeostasisHomeostasis

Excretion is essentially a process of Excretion is essentially a process of maintaining homeostasismaintaining homeostasis To maintain a constant internal To maintain a constant internal

environment all metabolic wastes need environment all metabolic wastes need to be removedto be removed