TEACHERS NAME SAIDA MOHAMED SUBJECT BIOLOGY CLASS FORM

TEACHER’S NAME: SAIDA MOHAMED SUBJECT: BIOLOGY CLASS : FORM III TOPIC: EXCRETION SUB TOPIC : EXCRETION IN HUMANS

EXCRETION IN HUMANS Think pair share……. In group of five work on the following: 1. What are excretory organs in humans ? ( GROUP 1, 3, 5, ) 2. Describe urinary system in humans and its adaptive features (GROUP 7, 4, 6, ) 3. Explain the process of urine formation. (GROUP 2, 3, 7)

The table below summarizes excretory products in humans and the organs:

MAIN EXCRETORY ORGANS IN HUMANS • The main excretory organs in humans includes Lungs , kidney , skin and liver. I. LUNGS • The lungs excretes carbon dioxide (a waste products from cell respiration) Carbon dioxide is transported from the cells to the lungs and removed out through exhalation.

II. SKIN • Is the outer covering of the body. • It regulates temperature • The sweat glands produces sweat. • Sebaceous glands excretes fats such as sterol and waxes.

III. LIVER • The RBCs are destroyed in the liver. • The worn out hemoglobin are destroyed in in liver and converted into bile. • The bile is stored in the gall bladder and periodically released in the duodenum. • The bile is removed out the body with feaces.

THE HUMAN EXCRETORY ORGANS WITH EXAMPLES

IN YOUR GROUPS STUDY AND LABEL THE FOLLOWING DIAGRAM OF URINARY SYSTEM

THE HUMAN URINARY SYSTEM

THE HUMAN URINARY SYSTEM • The urinary system is a system concerned with production, storage and removal of urine. • In humans, it is made up of the two kidneys, ureters, blood vessels that join them, urinary bladder and urethra.

• Each kidney is connected to a urinary bladder by a tube called the ureter. • As urine is formed, it passes through the ureter to the urinary bladder where it is stored temporarily. • Below the bladder is a tube called urethra.

• Bladder is surrounded by a ring of muscles called sphincter muscles. • The urethra is a canal that carries urine from the bladder and expels it outside the body. • The urethra passes urine when sphincter muscles relax