HUMAN ORGANS OF

EXCRETION

LUNGSExcrete

carbon

dioxide and

water

These are the

wastes of

cellular

respiration

LIVER Removes toxic

substances from

the blood

Disposes of

Hemoglobin – old

RBC’s are broken

down in the liver

and hemoglobin

is released

LIVER

Disposal of

nitrogenous wastes

Breaks down excess

amino acids (from

protein digestion)

Forms the toxic

waste urea.

Urea is transported

to the kidneys by the

blood

SKIN

The excretory structures of the skin are the sweat glands

The sweat glands are in contact with capillaries

Water, salt and

some urea diffuse

from the blood into

the sweat gland

and are excreted as

perspiration

Perspiration acts to

regulate body

temperature by

removing excess

heat

URINARY SYSTEM

Includes:

kidneys,

ureters,

urinary

bladder

urethra

URINARY SYSTEM

The kidneys (2) are

bean shaped

organs ,

approximately

10 cm long and

are located

below the

diaphragm near

the back

Kidneys have 2 main

functions:

1. Remove wastes

of cellular

metabolism form

the blood

2. They regulate the

amount of water

in the body.

Blood vessels carry

blood to the

kidneys, where

wastes and other

dissolved

substances are

removed from the

blood

The wastes are

excreted from the

body and the useful

substances are

reabsorbed

Kidney Structure

Kidneys consist of

microscopic

structures called

NEPHRONS.

Nephrons filter the

blood and clean out

WASTES

The kidneys form URINE

Urine contains:

water

salt

urea

URETERS

Tubes that

carry urine

from the

kidney to the

bladder

URINARY BLADDER

Stores

urine

URETHRATube that

carries urine

from the

bladder to

the outside

of the body

LIVER Disposal of

nitrogenous wastes

Breaks down excess

amino acids (from

protein digestion)

Forms the toxic

waste urea.

Urea is

transported to the

kidneys by the

blood

Malfunctions

Kidney Diseases:

Include various conditions in which the

kidneys are unable to properly excrete

nitrogenous wastes

MALFUNCTIONS Kidney stones:

Substances crystalize out of the urine in the

urinary tract or in the kidney

Some pass out in the urine on their own

Some can be shattered with lasers or sound

waves

Some are surgically removed

Treatments

Dialysis – can some

times be used to treat

various kidney

diseases

Kidney transplants

are also successful