New! Sign up for our free email newsletter.
Reference Terms
from Wikipedia, the free encyclopedia

Excretory system

The excretory system is the system of an organism's body that performs the function of excretion, the bodily process of discharging wastes. The Excretory system is responsible for the elimination of wastes produced by homeostasis. There are several parts of the body that are involved in this process, such as sweat glands, the liver, the lungs and the kidney system.

Every human has two kidneys. Each kidney is made up of three sections: the renal cortex, the renal medulla and the renal pelvis. The blood arrives at the kidney via the renal artery, which splits into many afferent arterioles. These arterioles go to the Bowman's Capsules of nephrons, where the wastes are taken out of the blood by pressure filtration. Peritubular capillaries also surround the nephron so substances can be taken in and out of the blood. The renal cortex is the outer layer of the kidney and the medulla is the inner layer of the kidney. The renal pelvis takes urine away from the kidney via the ureter. Both of the ureters lead the urine into the body's only urinary bladder, which expands and sends nerve impulses when full. From there, urine is expelled through the urethra and out of the body.

Related Stories
 


Health & Medicine News

October 6, 2026

Colorectal cancer in young people is often diagnosed at an advanced stage, with researchers finding most patients age 21 or younger already had Stage III or IV disease. Because symptoms like rectal bleeding, weight loss, abdominal pain, and bowel ...
Scientists have found a surprising way to regrow damaged knee cartilage by blocking a protein that becomes more abundant with age. In old mice, the treatment restored naturally lost cartilage and ...
Couples who exercise together report better communication, healthier conflict resolution, and lower marital stress than those who work out alone. Even something as simple as taking a walk together may create valuable opportunities to talk, listen, ...
New mothers paired with patient navigators were much more likely to receive postpartum care, depression screening, preventive testing, and ongoing primary care. By helping with barriers such as transportation, childcare, scheduling, and confusing ...
In a small study, sleeping near the scent of Hinoki root essential oil was linked to fewer nighttime awakenings, better morning alertness, and brain-wave changes associated with smoother sleep onset. The findings suggest an overlooked forestry ...
A ketogenic diet increased small-intestinal tumors in cancer-prone mice while reducing tumors in the colon, revealing a strikingly different response within neighboring parts of the gut. Researchers traced the increased risk not to ketones, but to ...
Scientists found that prolonged fasting triggers major changes throughout the body, but many of the most interesting effects only appeared after about three days without food. The results suggest fasting may influence health in ways that go beyond ...
A new nanoparticle therapy reduced lung tumors in mice while also targeting cachexia, the severe muscle wasting that can accompany cancer. By delivering follistatin mRNA directly to tumors, the ...
Scientists have discovered a human gene with a remarkable double life: it appears to play an important role in brain cells while still retaining the ability to jump around the genome. Called BC200, the gene evolved millions of years ago from a ...
Cancer immunotherapy can lose its punch when tumor-fighting T cells become exhausted, but researchers may have found a way to keep them going longer. Scientists at Memorial Sloan Kettering Cancer Center identified a signaling molecule called MEK ...
Scientists have discovered that E-cadherin, a protein best known as the “glue” holding cells and tissues together, has a surprising second job: helping epithelial cells swallow nearby dead cells. Using live zebrafish and mouse embryos, ...
Researchers found that just 20 minutes of comfortable walking can rapidly stimulate the gut. Within one to two minutes after exercise, bowel sounds became stronger, more frequent, and lasted longer, ...

Latest Headlines

updated 12:56 pm ET