Question

Write a short note on kidneys and its functions. (5 marks)

Answer 1

The kidneys are two bean-shaped organs, each about the size of a fist. They are located just below the rib cage, one on each side of the spine. Kidneys filter blood and produces urine composed of wastes and extra fluid. The urine flows from the kidneys to the bladder through two thin tubes of muscle called ureters, one on each side of the bladder. The bladder stores urine. The muscles of the bladder wall remain relaxed while the bladder fills with urine. As the bladder fills to capacity, signals sent to the brain tell a person to find a toilet soon. When the bladder empties, urine flows out of the body through a tube called the urethra, located at the bottom of the bladder. (2 marks)

Kidney's function:
The urinary system depends on proper kidney structure and function. Some of these core actions include:
1. Excretes waste: The kidneys get rid of toxins, urea, and excess salts. Urea is a nitrogen-based waste product of cell metabolism that is produced in the liver and transported by the blood to the kidneys. (1 mark)
2. Maintains water balance: The kidneys help maintain water and electrolyte balance in the body. They react to changes in the water level, which may increase or decrease throughout the day. (0.5 mark)
3. Regulates acid levels: Acids are products of metabolism. The kidneys help maintain proper acid-base balance to keep the body health (0.5 mark)
4. Regulates red blood cells: The kidneys produce erythropoietin, a hormone that stimulates your bone marrow to produce more red blood cells when the body does not get enough oxygen. (0.5 mark)
5. Regulates blood pressure: The kidneys help regulate blood pressure by producing angiotensin, a substance that constricts blood vessels and signals the body to retain water and sodium when blood pressure is low. (0.5 mark)