Question

How urine is produced and eliminated from the body?

Answer 1

Answer:

Urine is formed in the kidneys through a filtration of blood. The urine is then passed through the ureters to the bladder, where it is stored. During urination, the urine is passed from the bladder through the urethra to the outside of the body.

Answer 2

Formation of urine:

1. Ultrafiltration

2. Selective reabsorption

3. Tubular secretion

Ultrafiltration: Ultrafiltration is a process in the kidney by which urea, salt, water, and glucose, etc. is extracted from the blood. When blood passes through the top of the nephron, it enters a structure called the glomerulus which is a network of tiny capillaries. This causes the pressure to increase and fluid is forced through the "sieve-like" walls of the vessels into the Bowman's capsule. This fluid is called filtrate.

Reabsorption: Selective reabsorption is the process whereby certain molecules (e.g. ions, glucose and amino acids), after being filtered out of the capillaries along with nitrogenous waste products (i.e. urea) and water in the glomerulus, are reabsorbed from the filtrate as they are needed. This is a process called selective reabsorption.

Tubular secretion: The next step in urine formation is tubular secretion. Here, tubular cells secrete substances like hydrogen ions, potassium ions into the filtrate. By this process, the ionic, acid-base, and the balance of other body fluids are maintained. The secreted ions combine with the filtrate and form urine. The urine passes out of the nephron tubule into a collecting duct.

Then from collecting duct urine joins and moves to the ureter and stored in the urinary bladder and flushed out through the urethra...