The excretory system removes waste from the body through various organs like the skin, liver, lungs, large intestine and kidneys. The objectives of the presentation are to define the excretory system, describe the anatomy and physiology of excretory organs like the kidneys and nephrons, and explain the functions of the kidneys and other parts of the urinary tract.

2. OBJECTIVES
By the end of the presentation students will be able to;
• Define Excretory System.
• Enlist organs associated with excretory system
• Describe Anatomy and physiology of excretory organs.

3. CONTI…
• Discuss functions of kidneys. Draw and label parts
of nephron
• Name different parts of excretory system. Draw and
label urinary tract.
• Describe short notes : Urethra, Urinary bladder

4. EXCRETORY SYSTEM
Definition:
The excretory system is the system of an organism's
body that performs the function of excretion, the bodily
process of discharging wastes. There are several parts
of the body that are involved in this process, such as
sweat glands, the liver, the lungs and the kidney
system. Every human has two kidneys.

5. EXCRETORY ORGANS
 Skin
 Liver
 Large intestine
 Lungs
 Kidneys

6. ACCESSARY EXCRETORY ORGANS
SKIN
 The skin performs its excretory function via the sweat
glands.
 These glands produce sweat that contains salt, excess
oils, water, and other unnecessary substances which
are then excreted out of the body through small pores.

8. CONTI…
LIVER
 The liver plays a vital part in keeping the body clean.
Harmful poisons and chemicals that are either produced in
the body or consumed are broken down and detoxified by
the liver.
 For example, a bi-product of the metabolic process within
the body is ammonia and the liver processes this into
urea, a less harmful substance which continues to be
filtered and excreted by the kidneys as urine.

10. CONTI…
Large Intestine
 The undigested substances are transferred to the large
intestine which essentially serves as a storage organ for the
excretory products.
 The descending, ascending and transverse colons also
facilitate the absorption of leftover vitamins, water and salt.
 The distal straight section (known as the rectum) is used for
the storage of waste products (faeces) before they are
excreted from the body via the anal canal with the help of
internal and external sphincters.

12. CONTI…
LUNGS
 The lungs are very important excretory organs as they
expel carbon dioxide from the body via exhalation. The
lungs use cells known as alveoli to remove the carbon
dioxide from our blood.
 Otherwise, the carbon dioxide would accumulate and
have a detrimental effect to our body.

14. PRIMARY EXCRETORY ORGANS
Kidneys
 Kidneys are bean-shaped organs of a reddish brown
colour that are found in the sides of the vertebral column.
 Once the body has extracted what it needs from food and
drink, it sends the wastes to the kidneys.
 The kidneys filter the wastes, including urea, salt and
excess water, which are flushed out of the body as urine.

16. LABEL?

17. PRIMARY EXCRETORY ORGANS
Nephron
 Functional unit of the kidney, the structure that actually
produces urine in the process of removing waste and
excess substances from the blood.
 There are about 1,000,000 nephrons in each human
kidney.

19. PRIMARY EXCRETORY ORGANS
Urinary Bladder
 The waste fluid that is created in the liver and collected in
the kidney is transferred into the urinary bladder where it
is temporarily stored until the individual urinates.
 The urinary bladder provides a short-term solution for
storing urine in the body until it is ultimately discharged.

20. SHORT NOTES
Urethra
The tube through which urine leaves the body. It
empties urine from the bladder.