Excretory System’s Function

1) Briefly Describe the Steps of Urine Formation.

The process of urine formation can be divided into the following steps:

• Filtration by the nephrons
• Reabsorption by the nephrons
• Secretion by the nephrons

2) Why Do We Feel the Urge To Pee?

• The urinary bladder is a balloon-like organ that stores urine inside it temporarily.
• When it fills with urine, it expands and increases the pressure on the bladder muscles.
• When the bladder exceeds its limit of storing urine, the urge to urinate is triggered.

3) What Kind of Wastes Are Eliminated by the Kidneys?

• Mainly toxins from the blood are eliminated, such as ammonia, urea and uric acid.
• Excess salt and sugar are eliminated to maintain proper water and salt balance inside the body.
• The kidneys also eliminate drugs taken in the form of medicines.

4) Why Are Nephrons Called the Structural and Functional Units of the Kidney?

• The nephrons are called the structural units of the kidney because many nephrons combine to form a kidney.
• Each nephron is specialised for the key steps of blood purification, i.e. filtration, reabsorption and secretion, hence called the functional unit.

5) What Is the Path of Excretion of Urine Through the Excretory System?

The path of urine through the excretory system is-