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
1
2
Health & Medicine News
September 3, 2026
Sep. 3, 2026 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 ...
Sep. 3, 2026 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 ...
Sep. 2, 2026 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 ...
Sep. 2, 2026 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 ...
Sep. 2, 2026 “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 ...
Sep. 2, 2026 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 ...
Sep. 2, 2026 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 ...
Sep. 1, 2026 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 ...
Sep. 1, 2026 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 ...
Sep. 1, 2026 Mindfulness, gratitude, and optimism training may improve blood pressure, inflammation, and other heart-health measures within just eight to 12 weeks. The strongest programs paired daily practice with regular reinforcement, suggesting that improving ...
Sep. 1, 2026 A study of people over 90 found that dementia risk remains strongly shaped by sex, race and genetics, with women and black participants facing notably higher risks. Intriguingly, some people stayed cognitively healthy despite carrying major risk ...
Sep. 1, 2026 A once-nightly pill cut breathing interruptions by about 44% in a major phase 3 sleep apnea trial, while improving oxygen levels and disease severity. By strengthening the muscles that keep the airway open during sleep, AD109 could offer a new ...
Latest Headlines
updated 12:56 pm ET
Aug. 31, 2026 Scientists discovered that human microglia, immune cells that help shape developing brain circuits, can take four to eight years to mature instead of just weeks as they do in mice. The unusually slow ...
Aug. 31, 2026 Researchers discovered a possible way cancer cells hide from the immune system: they build a thick, sugar-rich coating around themselves. High blood sugar can strengthen this protective shield under ...
Aug. 31, 2026 Two widely used zero-calorie sweeteners, sucralose and stevia, may have effects that linger far longer than the sweet taste itself. In mice, researchers found that both sweeteners altered the gut ...
Aug. 31, 2026 Scientists have created an injectable gel that can remain inside arthritic joints for weeks, slowly releasing medication while also improving lubrication. The approach could make it easier to deliver ...
Aug. 31, 2026 A simple waist measurement may be nearly as effective as more complicated methods for detecting unhealthy levels of body fat. Researchers also found that BMI alone missed many people with obesity, ...
Aug. 31, 2026 Alcohol-related liver disease may trap damaged liver cells in a regenerative limbo, preventing the organ from rebuilding itself even after drinking stops. Researchers linked the problem to ...
Aug. 30, 2026 Omega-3 and low-dose aspirin matched the effectiveness of antibiotics in a year-long study of patients with severe gum disease, with both approaches helping about 58% reach the treatment goal. The ...
Aug. 30, 2026 Adults aged 40 and older performed about 12% faster on a test of executive function after using a HEPA air purifier at home for one month. The findings suggest that cleaner indoor air could offer a ...
Aug. 30, 2026 Researchers have produced a form of Spirulina containing biologically active vitamin B12 at levels comparable to beef. By carefully controlling the light used to grow the algae, they overcame a major ...
Aug. 29, 2026 CAR T-cell therapy dramatically reduced disease activity in six people with severe rheumatoid arthritis that had resisted other treatments, with three achieving medication-free remission. The ...