Mechanism of Excretion

Topic Content:

A nephron or the kidney tubule, as discussed in our SS2 2nd Term Course , is the functional unit of the kidney, responsible for filtering blood and forming urine.

There are about one million nephrons in each kidney, each of which performs essential tasks to maintain the body’s homeostasisHomeostasis is the process by which a living organism or system maintains a stable internal environment despite external changes. This balance is crucial for the proper functioning of biological systems. Homeostasis... More, including regulating blood volume and pressure, electrolyteAn electrolyte is a substance that dissociates in water into charged particles called ions. Positively charged ions are called cations. Negatively charged ions are called anions. Simply, an electrolyte is a... More balance, and waste excretion.

The kidneys perform the function of excretion in two phases:

(i) Ultrafiltration
(ii) Selective reabsorption

1. Ultrafiltration:

Blood containing excretory substances flows into the glomerulus from the