The Excretory System
1. The excretory system plays an important role in homeostasis.
2. The primary organs of the excretory system are kidneys.
The human kidney
1. The kidneys filter blood and form urine which exits the body through the ureters, urinary bladder and urethra.
2. Urine is fluid which consists of water, urea and other dissolved wastes.
3. The human kidney shows three distinct regions
(a) Cortex (outer light-red region)
(b) Medulla (inner dark-red region)
1. Each kidney consists of millions of microscopic tubules called nephron.
2. A nephron consists of three major parts:
(a) the glomerulus
(b) the Bowman’s capsule, and
(c) renal tubule
3. The renal tubule is made up of the
(a) proximal convoluted tubule
(b) loop of Henle
(c) distal convoluted tubule