1. The Excretory
System

2. The Excretory System
is a passive biological system that
removes excess, unnecessary materials
from an organism.
Excretion is the removal of metabolic
wastes from the body, including toxic
chemicals, excess water, carbon dioxide
and salts.

3. Functions:
1. Metabolic and toxic wastes removal
2. Collect water and filter body fluids
3. Helps maintain Homeostasis (stable
internal state of the body)
4. Eradicates harmful chemical build-
ups

4. Metabolic Wastes
Waste A by product of :
carbon dioxide Cellular respiration
salts Neutralization
urea Protein metabolism,
Deamination
water Dehydration
synthesis and
respiration

5. Excretory Organs
 Lungs
 Liver
 Skin
 Urinary system

6. Lungs
A pair of cone-shaped, porous and
spongy, located in the chest that are
composed of bronchioles, alveoli,
blood vessels, lymphatic, nerves and
elastic connective tissues.
As an excretory organ, it releases
carbon dioxide and some water vapor
as a waste product through
respiration.

7. The Lungs

8. Liver
Function is for deamination
A process by which some
proteins & other nitrogenous
compounds are broken down
in the liver.
As a result, urea is formed.

9. The Liver

10. Skin
Secretes sweat
which is a mixture
of three metabolic
wastes: water, salts,
& urea through the
sweat glands.
Two types:
-Eccrine
-Apocrine

11. Urinary System
 A group of organs in the body
concerned with filtering out excess
fluid and other substances from the
bloodstream.
 Urination or Micturition is the act by
which urine (combination of salt,
water, and urea), is expelled from the
urinary bladder

12. Functions
 Excretion of urine
 Maintains an appropriate fluid volume
 Regulates the concentrations of
various electrolytes in the body fluids
 Maintains normal pH of the blood

13. Components of the Urinary
System
 Kidneys
 Ureters
 Urinary Bladder
 Urethra

14. Kidneys
 A pair of bean shaped, reddish brown organs
about the size of your fist.
 Measures 10-12cm in length, 5-7cm wide, and 2-
5cm thick.
 Site of urine manufacture
Functions:
 filter blood ,
 process the filtrate to form urine,
 produce hormones and enzymes that regulate
blood pressure and red blood cell production
 regulate blood pH.

15. 3 Major Regions
 Renal Cortex
- The outer layer with lots and lots of
nephrons
- The filtering layer
 Renal Medulla
- Middle layer
- The Collecting layer
- Contains the Renal Pyramids
 Renal Pelvis
- Center of the kidney
- The Draining Layer
- Connects with the ureters

16. Kidney

17. Nephrons
 The basic structural and functional unit of the
kidney
 Comes from the Greek word (nephros)
meaning kidney.
 A long tubule with a series of associated
blood vessels
 Chief function is to regulate water and soluble
substances
 Each kidney has more than 1,000,000 of
them
 Each nephron is made of a cup shaped
portion called Bowman’s capsule, tubules
and a network of capillaries.

18. Nephro

19. How is urine formed ?
Three major processes are involved in the
formation of urine:
 filtration -filters the blood to produce a
filtrate
 reabsorption - selectively reabsorbs
needed water and essential solutes from
the filtrate
 secretion - moves substances into the
filtrate for removal as part of the urine

20. Ureters
 Two tubes that drain urine from
the kidneys to the bladder
 Each is a muscular tube about
10 inches (25 cm) in length and
3mm in diameter.

21. Urinary Bladder
 The urinary bladder is the
organ that collects urine
excreted by the kidneys prior to
disposal by urination.
 It is a hollow muscular, and
distensible (or elastic) organ,
and sits on the pelvic floor.
 can hold approximately 17 to
18 ounces (500 to 530 ml) of
urine.

22. Urethra
 A tube which connects the
urinary bladder to the outside
of the body
 The function of the urethra is to
remove urine from the body
through urination
 It measures about 1.5 inches
(3.8 cm) in a woman but up to
8 inches (20 cm) in a man.
 The urethral sphincter is a
collective name for the muscles
used to control the flow of urine
from the urinary bladder.

23. Common Diseases
of the Excretory
System

24. Kidney Stones
(Nephrolithiasis)
 Hard masses that form in the urinary tract
from crystals that have separated from the
urine.
 Causes:
 Dietary factors
 Recurrent UT
• Symptoms:
 Extreme Pain
 Cramping in the back and lower abdomen
 Nausea
 Vomiting

25. Kidney Stones

26. Urinary Tract Infection (UTI)
 A bacterial infection that affects part of the urinary tract.
 Causes:
◦ Bacteria from the bowel that live on the skin near the
rectum or in the vagina.
◦ Sexual Intercourse
◦ Waiting too long to urinate
• Symptoms:
• Painful urination
• Frequent urination or urge to urinate (or both)
• Fever
• Flank Pain

27. Acne(Acne vulgaris)
 Kind of skin disorder that occurs when
the oil glands in the skin are, such as
affected by bacteria.
 Causes:
◦ Hormone changes
Most acne form on the face, neck, back,
chest, and shoulders.

28. Athlete’s foot (Tinea pedis)
 Fungal infection of the skin.
 Occurs between the toes
 Caused by fungi in the
genus Trichophyton
 Symptoms:
 Various degree of itching of burning
 Blister and cracked skin

29. Athlete’s foot

30. Bladder Cancer
 A type of malignancy arising from
epithelial lining of the urinary bladder
 Causes:
 Smoking
 Chemical exposures
 Improper Diet
 Symptoms:
 Blood in the urine
 Frequent urination
 Feeling the need to urinate without results

31. Thank You !!!
XD