3. Functions:
It eliminates nonsolid wastes from the body
It regulates body fluids
It filters the blood supply to remove salts and other
body wastes
It controls rate of RBC formation
It regulates blood pressure
It regulates absorption of calcium
The Excretory System
5. Lungs – exhale carbon dioxide and water vapor
Skin – Sweat glands in skin release excess water and
salts
Liver – removes hazardous chemicals from the blood.
(Detoxification of blood)
Some proteins and other nitrogenous
compounds are broken down in the
liver forming a compound called urea
Major Organs
6. KIDNEYS
The two kidneys are located near the spine in
the middle of the back.
They are protected by lower ribs and covered
by layers of fat.
The kidneys are fist-sized, bean-shaped
structures
It is possible to function with only one kidney.
Major Parts:
7. KIDNEYS
At any given time, 20 % of blood is in the
kidneys.
The body’s entire volume of blood is filtered
every 45 minutes.
If one ceases to work, the other increases in size
to handle the workload.
Without the kidneys, it would not take long
before the body’s system would be poisoned by
its own waste.
Major Parts:
8. Two Layers:
Cortex (Outer Region)
Medulla (Inner region)
Nephron – filtering units
They clean and rebalance the blood to
produce urine.
There are approximately 1 million nephrons
in each kidney
Renal Artery
Renal Vein
Parts of the Kidney
9. Functions
It filters blood in order to remove cellular waste
products from the body.
It helps to maintain homeostasis by filtering the
blood.
It helps to maintain electrolyte, pH, and fluid
balances
10. URINE
Waste drains out of the kidneys in the form of urine.
Urine is about 95% water and 5% urea (protein from
protein breakdown).
Fresh urine has no bacteria in it. It is quite clean
(probably cleaner than our hands).
Waste Products
12. Urea – a nitrogenous waste produced in the
liver from the breakdown of protein. It is the
main component of urine
Uric acid – usually produced from breakdown
of DNA or RNA
Creatinine – waste product of muscle action.
Waste Products
16. Parts of the Kidney
The principal
function of the
loop of Henle is
the recovery of
water and
sodium
chloride from
the urine.
This is how the
body’s water is
conserved and
how
Homeostasis is
maintained
18. Ureters – are tubes that carry urine from the pelvis
of the kidneys to the urinary bladder.
Urinary Bladder – temporarily stores urine until it
is released from the body.
Urethra – is the tube that carries urine from the
urinary bladder to the outside of the body.
The outer end of the urethra is controlled by a
circular muscle called a sphincter.
Other Parts of the Urinary System
19. Digestive System
When you eat, the food you eat gets
processed by your digestive system. The solid
waste come out the anus, while the excretory
system processes the liquid waste and releases it.
Circulatory System
The excretory system pays close attention to
the circulatory system to maintain liquid levels
balanced, and keep all liquids in the body free of
toxics.
Excretory System in Relation with other Systems
20. Nervous System
It also works with the nervous system
because when the bladder is filled with urine, it
sends the nervous system a message that it is time
to go the bathroom.
Endocrine System
The Endocrine system has adrenal glands
that have chemical substances that allow the
kidney to control body fluid levels in the body
Excretory System in Relation with other Systems
21. Musculoskeletal System
It protects the organs in order for these to
function well. They work in concert with the
urinary system to regulate the release of urine.
The bladder is a muscle that can expand and
contract as necessary to accommodate or expel
urine.
Excretory System in Relation with other Systems
22. Kidney
Stones
Definition: These are smaller sized deposits of calcium and can be seen in the
nephrons. The stones could also increase or go down to urinary tract causing extreme
pain. The stone may also get infected causing further set of complications
Causes: The main cause is change/increase in salt and mineral levels and that of other
substances in urine. This may later on cause coagulation and increase size of stones.
The other reason can be heredity.
Symptoms:
•Vomiting or nausea
•Painful urination
•Frequent urination
•Fever or chills
•Bloody or smelly urine
•Sharp pain of the back or the side
Treatments: Reduced size of stones tends to pass out of body without requiring any
surgery. The treatment may consist of just taking lot of fluids so that the stones are
washed down. In such cases, the fluid is collected for 24 hours continuously and
examined in laboratory for presence of small stones. Painkillers may also be used for
alleviation of pains for the patient.
23. Cystitis Definition: The inflammation of the bladder is known as cystitis. The bladder is the
storage place for the urine until it is discharged by voluntary action of body. The urge to
urinate is not an automatic action and hence bladder always has some quantity of urine.
The bladder is the place where bacteria can grow easily leading to inflammation of
bladder.
Causes: It may be due to reaction of some of medicines, bacterial infection, using catheter
for long time in case of some diseases, undetected underlying diseases, and a result of
radiation therapy.
Symptoms:
•Pain or difficulty when urinating
•Foul-smelling urine
•Pain or soreness of abdomen
•Cloudy urine
•Blood in urine
Treatments: Cystitis is normally treated with antibiotics for bacteria. The removal of
contributing causes can also form part of treatment.
