Excretion

1
Excretion
2
Excretion

• What is excretion?
• Excretion is the removal of wastes made in the
  body

Source adapted from www.juniorscience.ie
3
Products of excretion

• 1.Carbon dioxide made from respiration in cells
  
• 2. Water made from respiration in cells
• 3.Urea - is produced from excess protein in
  the liver

4
Organs of excretion
5
Excretion in the lungs

• Carbon dioxide and some of the water is excreted
  by the lungs

Source www.juniorscience.ie
6
2. Excretion in the skin

• Water, salt and a tiny amount of urea are
  excreted as sweat through the pores of the skin

Source adapted from www.juniorscience.ie
7
Structure of the Urinary System
kidney
ureter
bladder
urethra
Source www.juniorscience.ie
8
Functions of the Urinary System
Source adapted from www.juniorscience.ie
9
Filtration in the kidneys how urine is formed
water
2 urea, some salts and water are removed from
bloodstream by filtration in the kidneys and form
urine
salt
urea
1 blood containing water, salts and urea enters
the kidney in the renal artery
3 Useful
materials such as water leave the kidneys through
the renal vein and are reabsorbed back into the
bloodstream
4 the urine
leaves the kidney in the ureter and goes to the
bladder
Source adapted from www.juniorscience.ie
10
Urine is then stored in the bladder before being
released from the body
urethra
Source www.juniorscience.ie
11
Virtual Dissection of Excretory System

• http//www.whitman.edu/biology/vpd/excretory.html

12
Excretory Quizzes

• http//www.kidshealth.org/misc/how_the_body_works/
  urinary_quiz.html
• http//www.whitman.edu/biology/vpd/excquiz.html