The structural and functional unit of the kidney is called a nephron. It consists of two main parts viz. the glomerulus and the tubular system. The glomerulus is composed of Bowman’s capsule and a tuft of leaky blood vessels encapsulated by the Bowman’s capsule.
Glomerulus capsule is a tuft of capillaries that are found inside the capsule of Bowman. Bowman’s capsule is a sac-like organ that is present at the nephron’s tabular end, encapsulating glomerulus in it.
The primary purpose of the glomerulus is filtration. The leaky vessels filter into the glomerulus almost all the water, electrolytes, small proteins, nutrients such as sugar etc and excretory products such as urea etc.