Excretion by definition is passive and deals with metabolic wastes as filtered by the kidneys. Though the sweat may contain a trace amount of metabolic wastes, sweating is an active process of secretion not excretion, specifically for temperature control and pheromone release. Therefore, its role as a part of the excretory system is minimal.


The lungs and gills of organisms constantly secrete gaseous wastes from the bloodstream as a regular part of respiration.


The primary organs in the excretory system of vertebrates. The kidneys are placed on either side of the spinal column near the lower back. They are primarily responsible for filtering blood by removing nitrogenous wastes from metabolism, salts & other excess minerals and excess water.


Organisms eliminate solid, semisolid or liquid waste material (feces) from the digestive tract via the anus during the process of defecation. Waves of muscular contraction known as peristalsis in the walls of the colon move fecal matter through the digestive tract towards the rectum. Undigested food may also be expelled this way; this process is called egestion.


In human anatomy, the ureters are muscular ducts that propel urine from the kidneys to the urinary bladder..

Urinary bladder

The urinary bladder is the organ that collects urine excreted by the kidneys prior to disposal by urination. Urine enters the bladder via the ureters and exits via the urethra.


The urethra is a tube which connects the urinary bladder to the outside of the body. The urethra has an excretory function in both sexes to pass urine to the outside, and also a reproductive function in the male, as a passage for semen during sexual activity.

<Go Back<