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

April 24, 2026

A newly confirmed mass grave in ancient Jordan offers chilling insight into one of history’s first pandemics. Hundreds of plague victims were buried within days, revealing how the Plague of Justinian devastated entire communities. The findings ...
A rare group of adults over 80, known as SuperAgers, are rewriting what we thought was possible for the aging brain. With memory abilities comparable to people decades younger, their brains either resist or withstand the damage typically linked to ...
Scientists have identified two specific types of brain cells that behave differently in people with depression, offering a clearer picture of what is happening inside the brain. By analyzing donated brain tissue with advanced genetic tools, the ...
A new minimally invasive procedure may help people keep weight off after stopping popular drugs like Ozempic and semaglutide—something most patients struggle with. In a clinical trial, those who underwent a technique called duodenal mucosal ...
A new virus-fighting plastic film could transform everyday surfaces into invisible defenders against disease. Instead of relying on chemicals, this flexible material is covered in microscopic pillars that physically stretch viruses until they burst, ...
Scientists at UC Irvine have found a way to potentially reverse age-related vision loss by targeting the ELOVL2 “aging gene” and restoring vital fatty acids in the retina. Their experiments in mice show that supplementing with specific ...
A newly discovered virus hiding inside a common gut bacterium could help explain one of medicine’s long-standing mysteries: why a microbe found in both healthy people and cancer patients is linked to colorectal cancer. The research suggests that ...
A routine blood marker tied to inflammation may reveal Alzheimer’s risk years in advance. Scientists found that higher neutrophil levels—part of the body’s first immune response—were linked to a greater chance of developing dementia. The ...
Scientists have discovered that combining two existing drugs can dramatically reduce liver fat linked to a common and often silent disease. The treatment not only improved liver health in animal models but also showed potential to lower ...
A key protein, HOXD13, helps melanoma tumors grow and evade the immune system by boosting blood supply and blocking cancer-fighting T cells. Disabling it shrinks tumors and reopens the door for the ...
Cancer cells are known for their “glutamine addiction,” but many can escape this weakness by switching to alternative fuels. Researchers found that vitamin B7 acts like a metabolic “license,” enabling this escape route through a key enzyme. ...
A trio of common amino acids may hold the key to unlocking far more powerful gene therapies. Researchers found that adding them to lipid nanoparticles can boost mRNA delivery up to 20-fold and push CRISPR editing efficiency close to 90%. The trick ...

Latest Headlines

updated 12:56 pm ET