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

September 4, 2026

A substance found in edible sea squirts appeared to reverse several signs of aging in older mice. Plasmalogen supplements improved memory and learning, strengthened connections between brain cells, reduced inflammation, and even helped the mice grow ...
UCLA researchers have discovered two powerful influences that help guide how the human brain forms before birth. Radial glia, stem cells responsible for producing much of the cerebral cortex, change their behavior depending on how they process ...
Duke researchers developed an injectable scaffold that helped stroke-damaged brains grow new blood vessels, support nerve regrowth, and recover movement in mice. The treatment appears to work partly by recruiting the body’s own immune cells, ...
Scientists discovered that more than 500 species of vesper bats possess two separate sets of antibody genes, an immune arrangement never before found in mammals. The surprising system could help explain how bats tolerate so many viruses without ...
Aging may be partly fueled by immune cells losing their ability to clear away damaged, inflammation-promoting cells. Blocking a single receptor restored that cleanup process in mice, reducing inflammation and helping their organs, muscles, and ...
Some of the attention patterns that make ADHD challenging may also help spark creativity by allowing the brain to explore more ideas and unexpected connections. Researchers think creative activities could potentially channel this “defocused ...
Sitting for long, uninterrupted stretches may carry greater health risks than sitting the same amount of time in shorter bouts. Researchers found that each extra hour of prolonged sedentary behavior was associated with a 9% higher risk of cancer ...
“Broken heart syndrome” can mimic a heart attack so closely that patients often need invasive testing to tell the difference. Researchers have now developed the BioTAK score, which combines ...
Brain changes associated with Alzheimer’s may begin at least seven years before amyloid plaques become detectable with current PET scans. Researchers uncovered the signal by tracking healthy older adults with repeated brain imaging over nearly 20 ...
Following nearly 10,000 older women for 10 years, researchers found that tea drinking was associated with slightly higher hip bone density. Moderate coffee consumption did not appear harmful, but drinking more than five cups a day was linked to ...
Where you live in early adulthood may quietly shape your heart health for decades. Researchers found that adverse neighborhood conditions were linked to a higher risk of coronary artery calcification in midlife, an early warning sign of ...
Obesity appears to leave a molecular imprint on key immune cells that may persist for 5 to 10 years after weight loss. This long-lasting “obesity memory” could help explain why some obesity-related health risks remain elevated even after body ...

Latest Headlines

updated 12:56 pm ET