Reference Terms
from Wikipedia, the free encyclopedia
Hair
Hair is a filamentous outgrowth of the skin found only in mammals. The speed of hair growth is roughly 11 cm/yr. The average human head has about 100,000 hair follicles. Older people tend to develop grey hair because the pigment in the hair is lost and the hair becomes colourless. Grey hair is considered to be a characteristic of normal aging. The age at which this occurs varies from person to person, but in general nearly everyone 75 years or older has grey hair, and in general men tend to become grey at younger ages than women.
For more information, see the following related content on ScienceDaily:
Related Stories
1
2
Oct. 16, 2024 Prenatal human skin atlas and organoid will accelerate research into congenital diseases and lead to clinical applications for regenerative ...
Jan. 30, 2024 The composition of microbiota found in the gut influences how susceptible mice are to respiratory virus infections and the severity of these ...
Apr. 9, 2025 Rsearchers have developed the first wearable device for measuring gases emitted from and absorbed by the skin. By analyzing these gases, the device offers an entirely new way to assess skin health, ...
Nov. 2, 2023 In a new study, scientists show that their synthetic melanin, mimicking the natural melanin in human skin, can be applied topically to injured skin, where it accelerates wound healing. These effects ...
Aug. 7, 2024 Babies born very early had stronger neurodevelopmental performance at 1 year if they received more skin-to-skin care as newborns, a study ...
Nov. 15, 2023 Scientists have 3D-printed hair follicles in human skin tissue cultured in the lab. This marks the first time researchers have used the technology to generate hair follicles, which play an important ...
Dec. 26, 2025 Vitamin C doesn’t just belong in skincare products—it works even better when you eat it. Scientists discovered that vitamin C from food travels through the bloodstream into every layer of the ...
Nov. 7, 2025 Rockefeller scientists uncovered how hair follicle stem cells can switch from growing hair to repairing skin when nutrients run low. The key lies in serine, an amino acid that activates a stress ...
Nov. 20, 2024 The skin microbiome plays a key role in skin health and disease. While imbalances in skin microbiome composition are linked to disease, studying it has been challenging due to limited methods for ...
Jan. 1, 2025 Researchers have traced a cellular route Ebola virus (EBOV) uses to traverse the inner and outer layers of skin and emerge onto the skin's surface. The study identifies new cell types within the ...
Health & Medicine News
February 17, 2026
Feb. 17, 2026 Researchers investigating crops grown in soil contaminated by the 2015 mining disaster in Brazil discovered that toxic metals are moving from the earth into edible plants. Bananas, cassava, and cocoa were found to absorb elements like lead and ...
Feb. 17, 2026 An Ice Age double burial in Italy has yielded a stunning genetic revelation. DNA from a mother and daughter who lived over 12,000 years ago shows that the younger had a rare inherited growth disorder, confirmed through mutations in a key bone-growth ...
Feb. 17, 2026 Researchers have identified two brain receptors that help the brain clear away amyloid beta, a hallmark of Alzheimer’s disease. By stimulating these receptors in mice, scientists increased levels of a natural amyloid-breaking enzyme, reduced ...
Feb. 17, 2026 A mysterious RNA found in breast cancer led scientists to uncover an entire hidden class of cancer-specific RNAs across dozens of tumor types. These molecules form unique molecular signatures that identify cancer type and subtype with remarkable ...
Feb. 17, 2026 A decades-long study of nearly 200,000 adults challenges the low-carb versus low-fat debate. Both eating patterns were tied to lower heart disease risk when they emphasized whole grains, plant-based foods, and healthy fats. Versions filled with ...
Feb. 16, 2026 As cash transfer programs expand across the United States, critics often warn that giving people money could spark reckless behavior, leading to injuries or even deaths. But a sweeping 11-year analysis of Alaska’s long-running Permanent Fund ...
Feb. 16, 2026 A new light-based sensor can spot incredibly tiny amounts of cancer biomarkers in blood, raising the possibility of earlier and simpler cancer detection. The technology merges DNA nanotechnology, CRISPR, and quantum dots to generate a clear signal ...
Feb. 16, 2026 A parasite that may already be hiding in your brain has a shocking survival trick: it can infect the very immune cells sent to destroy it. Yet most people never get sick, and new research from UVA ...
Feb. 16, 2026 Researchers have built a realistic human mini spinal cord in the lab and used it to simulate traumatic injury. The model reproduced key damage seen in real spinal cord injuries, including inflammation and scar formation. After treatment with fast ...
Feb. 16, 2026 A sweeping review of global research suggests that exercise—especially aerobic activities like running, swimming, and dancing—can be one of the most powerful ways to ease depression and anxiety. ...
Feb. 16, 2026 Researchers have uncovered the enzyme behind chromothripsis, a chaotic chromosome-shattering event seen in about one in four cancers. The enzyme, N4BP2, breaks apart DNA trapped in tiny cellular structures, unleashing a burst of genetic changes that ...
Feb. 15, 2026 A major new study suggests that eating the Nordic way could help you live significantly longer—while also helping the planet. Researchers from Aarhus University found that people who closely followed the 2023 Nordic dietary guidelines had a 23% ...
Latest Headlines
updated 12:56 pm ET
Feb. 16, 2026 For years, compulsive behaviors have been viewed as bad habits stuck on autopilot. But new research in rats found the opposite: inflammation in a key decision-making brain region actually made ...
Feb. 15, 2026 Researchers tracked more than 400 toddlers to see whether mRNA COVID-19 vaccination during or just before pregnancy was linked to autism or ...
Feb. 15, 2026 Scientists have created the most detailed maps yet of how genes control one another inside the brains of people with Alzheimer’s disease. Using a powerful new AI-based system called SIGNET, the ...
Feb. 15, 2026 A simple shift in your evening routine may give your heart a measurable boost. In a new study, adults who stopped eating and dimmed the lights three hours before bed and extended their overnight fast ...
Feb. 15, 2026 Scientists have uncovered a hidden partnership between pancreatic cancer and the nervous system. Support cells in the pancreas lure nerve fibers, which then release signals that accelerate early ...
Feb. 15, 2026 A massive review of 23 randomized trials found that statins do not cause the vast majority of side effects listed on their labels. Memory problems, depression, sleep issues, weight gain, and many ...
Feb. 14, 2026 Scientists at Michigan State University have uncovered the molecular “switch” that powers sperm for their final, high-speed dash toward an egg. By tracking how sperm use glucose as fuel, the team ...
Feb. 14, 2026 Scientists are launching an ambitious global effort to map the “human exposome” — the lifelong mix of environmental and chemical exposures that drive most diseases. Backed by new partnerships ...
Feb. 14, 2026 A global study has uncovered a mysterious group of gut bacteria that shows up again and again in healthy people. Known as CAG-170, these microbes were found at lower levels in people with a range of ...
Feb. 13, 2026 Fish oil’s cancer-fighting reputation may hinge on a little-known gene. Researchers discovered that omega-3s like EPA and DHA help curb colorectal cancer only when the enzyme ALOX15 is present. ...
- Brain Inflammation May Drive OCD
- No Autism Link to COVID Vaccine in Pregnancy
- AI Maps Gene Networks in Alzheimer’s
- Stop Eating 3 Hours Before Bed for Heart Health
- Nerves Actively Fuel Pancreatic Cancer
- Most Statin Side Effects Not Proven
- Male Birth Control Breakthrough
- Mapping the Hidden Causes of Disease
- Hidden Gut Bacterium Linked to Good Health
- Fish Oil Supplements Could Backfire