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

December 15, 2025

Researchers discovered a hidden molecular “switch” that herpes viruses rely on to invade cells. By combining AI, simulations, and lab experiments, they identified and altered a single amino acid that shut down viral entry. What once might have ...
Researchers tracking over 63,000 adults found that high-quality, minimally processed plant foods significantly reduce cardiovascular risk. But when those plant foods are ultra-processed, the advantage disappears—and can even backfire. Some ...
New research shows that your brain’s “true age” can shift dramatically depending on how you live, with optimism, restorative sleep, stress management, and strong social support acting like powerful anti-aging tools. Using advanced MRI-based ...
Natural killer cells act as the immune system’s rapid-response team, but the stress of anxiety and insomnia may be quietly thinning their ranks. A study of young women in Saudi Arabia found that both conditions were linked to significantly fewer ...
Scientists have discovered that key compounds from cannabis—CBD and THC—show surprisingly strong effects against ovarian cancer cells. Used together, they slow cell growth, reduce colony formation, and may even block the cancer’s ability to ...
Back pain is wrapped in persistent myths, but many are far from the truth. From misconceptions about heavy lifting and bed rest to confusion over posture, exercise, and surgery, Dr. Meghan Murphy breaks down what really causes pain and what actually ...
SereNeuro Therapeutics revealed promising results for SN101, a first-in-class iPSC-derived therapy designed to treat chronic osteoarthritis pain while protecting joint tissue. Instead of blocking ...
Researchers discovered that tanning beds cause widespread, mutation-laden DNA damage across almost all skin, explaining the sharply increased melanoma risk. Single-cell genomic analysis revealed dangerous mutations even in sun-protected regions. ...
Scientists are uncovering a new possibility behind long COVID’s stubborn symptoms: hidden infections that awaken or emerge alongside SARS-CoV-2. Evidence is mounting that viruses like Epstein-Barr and even latent tuberculosis may flare up when ...
Scientists found that certain molecules made by gut bacteria travel to the liver and help control how the body uses energy. These molecules change depending on diet, genetics, and shifts in the microbiome. Some even improved insulin response in ...
Senescent “zombie” cells are linked to aging and multiple diseases, but spotting them in living tissue has been notoriously difficult. Researchers at Mayo Clinic have now taken an inventive leap by using aptamers—tiny, shape-shifting DNA ...
Forskolin, a plant-derived compound, shows surprising potential against one of the most aggressive forms of leukemia. Researchers discovered that it not only stops cancer cells from growing but also makes them far more vulnerable to chemotherapy by ...

Latest Headlines

updated 12:56 pm ET