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 21, 2026

A massive study of more than 460,000 Americans found that ultra-processed foods were not associated with increased colorectal cancer risk overall, challenging a widely held assumption. While ...
Scientists have uncovered an unexpected danger lurking inside cells: too much RNA can damage the structures responsible for producing energy. A new study found that excess RNA, including the normally essential messenger RNA (mRNA), can directly ...
A new study tracking 13 astronauts suggests that the human heart may be surprisingly well equipped for a journey to Mars, especially with regular exercise during spaceflight. Researchers found that astronauts' hearts adapted to months of ...
Scientists have turned blood cells from an 80-year-old into neural stem cells with a molecular age of less than 20, effectively reversing more than 60 years of cellular aging in the laboratory. The ...
A new Penn State study suggests that just four minutes of daily strength training can significantly improve mobility and physical function in older adults. After 12 weeks, participants showed meaningful gains in balance, leg strength, and their ...
A study by DZNE finds that healthy eating is associated with slower biological aging—and that there is more than one way to eat healthily. The researchers examined ten dietary patterns considered healthy, including the Mediterranean, Nordic, ...
Scientists have uncovered a surprising reason why statins, the widely prescribed cholesterol-lowering drugs that help prevent heart attacks and strokes, can sometimes cause muscle pain, weakness, and even severe muscle damage. Using advanced imaging ...
Scientists have discovered a natural compound that targets dangerous C. difficile bacteria without wiping out the gut's beneficial microbes. Successful early tests suggest it could lead to a gentler, ...
The aging brain may be undergoing a remarkable transformation rather than simply losing its abilities, shifting its focus from remembering details to understanding the bigger picture. Scientists suggest this change could be an evolutionary ...
Scientists have found a promising way to protect the brain from Alzheimer’s-related damage by blocking immune cells that contribute to the destruction of neurons. In mice, the treatment preserved ...
A surprising clinical trial suggests that taking vitamin C daily could improve survival in people with precancerous blood disorders and early-stage blood cancers. Patients receiving the supplement had fewer adverse events and showed a promising ...
Researchers discovered that recurring arthritis triggered by cancer immunotherapy may be driven by immune cells that remember previous attacks and return in a more aggressive state. The findings could pave the way for treatments that prevent painful ...

Latest Headlines

updated 12:56 pm ET