Reference Terms
from Wikipedia, the free encyclopedia
White blood cell
White blood cells (also called leukocytes or immune cells) are cells which form a component of the blood. They help to defend the body against infectious disease and foreign materials as part of the immune system. There are normally between 4x109 and 11x109 white blood cells in a litre of healthy adult blood - about 7,000 to 25,000 white blood cells per drop. In conditions such as leukaemia this may rise to as many as 50,000 white blood cells in a single drop of blood. As well as in the blood, white cells are also found in large numbers in the lymphatic system, the spleen, and in other body tissues.
Related Stories
1
2
Health & Medicine News
July 8, 2026
July 8, 2026 Scientists have discovered that creatine may strengthen one of the immune system's most important cancer-fighting pathways by energizing dendritic cells that activate killer T cells. The promising results could eventually help make immunotherapy ...
July 8, 2026 Intermittent fasting helped people lose as much weight as calorie restriction, but without the same feeling of constantly controlling their food intake. Researchers say that difference could make ...
July 8, 2026 A new once-daily weight-loss pill called orforglipron delivered better weight loss and blood sugar improvements than the leading oral semaglutide in a major clinical trial. The tablet could offer a more convenient alternative to injectable drugs ...
July 7, 2026 Scientists at the University of Illinois Chicago have turned an unlikely source into a potential new weapon against cancer: bacteria that naturally live inside tumors. They developed a peptide called aurB, inspired by a bacterial protein, that ...
July 7, 2026 Almost half of the takeaway meals tested contained more salt than advertised, with some dishes delivering nearly twice the recommended daily limit in a single serving. Surprisingly, classic fish and chips ranked among the lowest-salt options, while ...
July 7, 2026 Scientists have identified a molecular switch that may help explain how colorectal cancer becomes deadly. When levels of a gene-regulating factor called GATA6 drop, cancer cells can shed their normal identity and transform into highly adaptable, ...
July 6, 2026 Researchers have uncovered a molecular “switch” that helps explain why exercise keeps aging muscles healthy. By reducing levels of a gene called DEAF1, physical activity allows older muscles to clear out damage, repair themselves, and maintain ...
July 6, 2026 Scientists have finally solved a nearly 30-year-old mystery surrounding two unusual molecules found in rye pollen that once showed an intriguing ability to help animals fight tumors. By determining ...
July 6, 2026 Scientists are calling for a lunar quarantine facility where samples from Mars, the Moon, and beyond would be examined before being brought to Earth. They warn that even a tiny alien microorganism ...
July 6, 2026 A new study suggests that apoB, a blood test that measures harmful cholesterol particles, is better than standard LDL cholesterol testing for deciding who needs more intensive treatment. Researchers found it could prevent more heart attacks and ...
July 6, 2026 A large study found that pregnant women are exposed to dozens of common chemicals, many of which were associated with earlier births and lower birth weights. Researchers also discovered that some ...
July 5, 2026 Researchers discovered an “Achilles’ heel” shared by E. coli, Shigella, and other diarrhea-causing bacteria: enzymes they use to breach the gut’s protective mucus layer. By targeting this common vulnerability, scientists may be able to ...
Latest Headlines
updated 12:56 pm ET
July 7, 2026 A new study suggests human hair grows in a way scientists never expected. Researchers found that hair is pulled upward by coordinated cell movements inside the follicle rather than simply being ...
July 5, 2026 Researchers have identified a previously overlooked mechanism of brain cell death that appears to play a major role in Alzheimer's disease and frontotemporal dementia. The finding could lead to new ...
July 5, 2026 Quantum mechanics has journeyed from a strange and controversial idea to the foundation of some of humanity’s most advanced technologies. Now researchers are pushing its boundaries even further, ...
July 5, 2026 Researchers have identified the brain circuitry that links deep sleep with the release of growth hormone, revealing how the two regulate each other. ...
July 5, 2026 Some cancer cells evade treatment by entering a dormant state triggered by stress hormones. ETH Zurich scientists have created a light-controlled molecular switch that selectively destroys the ...
July 4, 2026 Some people live past 100 with remarkable health, and researchers may have uncovered one reason why. A new study found that centenarians have a unique chemical "fingerprint" in their blood that sets ...
July 4, 2026 A UCLA study has identified a hidden Achilles' heel in aggressive small cell cancers that have resisted new treatments for decades. Scientists found that tumors lacking the RB gene become critically ...
July 4, 2026 A new intranasal DNA vaccine may give the immune system an extra weapon against tuberculosis by targeting bacteria that can hide from antibiotics. In animal studies, it helped clear infections ...
July 3, 2026 Using alcohol to cope with stress when young may permanently alter the brain, making it harder to adapt to challenges and increasing the risk of returning to drinking later in life. Researchers also ...
July 3, 2026 Some brains appear to fight back against Alzheimer's by helping immature brain cells survive damage instead of succumbing to it. Understanding this natural resilience could point researchers toward ...