Real-time tracking of individual hair cells has revealed that hairs don't actually get pushed out from the root—instead, hair cells are tugged upward by surrounding tissues that act like tiny motors.

Humans may have as many as 100,000 to 150,000 individual hairs on our scalps, growing at a rate of roughly 1 centimeter per month.

Rodent research suggests goose bumps may play a role in hair growth—raising questions about if this knowledge could be used to reactive sympathetic nerves in hair follicles to boost hair growth in people.

We're typically born with all the hair follicles we'll ever have, just as women are born with all their eggs.

Telogen effluvium is a common, temporary type of hair loss that can be triggered by severe stress, illness, or other body changes like childbirth—it pushes as much as 70% of hair into its resting phase, causing hair to fall out. (Paywall may apply.)

In 1909, a top public health official in America wrote in an academic journal that baldness was caused almost exclusively by snug-fitting hats.

Hair loss after childbirth happens because pregnancy hormones paused the normal hair shedding process during pregnancy, so the hair loss is actually your hair cycle 'catching up' with its normal process several months postpartum.

The anatomy of our hair follicles explains goose bumps

The arrector pili muscle contracts when we're cold or scared, causing hairs to stand up and the skin to form the bumps known as goose bumps. This reaction is typically involuntary.

Male pattern baldness is not solely inherited from the maternal side; its causes are still under investigation, but scientists think the genetic component of this type of hair loss involves multiple genes.

Despite lacking a traditional nervous system, plants have specialized cells that help detect gravity, enabling them to identify which way is down to grow roots and which way is up to push shoots toward the surface.

A man’s genes can predict his hairline

There’s actually some truth to the idea that you should look at your mother’s father. But genetic research tells us that the full picture is somewhat more complicated. An interesting read on how to use genetics to figure out if you'll go bald (with illustrations).

See what loud noises do to inner ear hair cells

This animation illustrates how louder music can affect inner ear hair cells. Damage to these cells is generally considered permanent. Hearing protection like ear plugs can reduce the level of sound entering into the ear and help protect those cells.

It's been about 30 years since a new hair loss drug was approved in the US, and women currently have no approved pills for hair loss.

Humanity's reduced body hair slows down wound healing

Cuts to human skin take twice as long to heal compared to chimps and other mammals. Scientists argue this is due to the reduced number of hair follicles on human bodies. Hair follicles contain stem cells which help repair skin cells faster, so as humanity shed its hair over time, so to speak, it also slowed its wound healing.

40% of women will have noticeable hair loss by age 50.

Cleopatra purportedly recommended grinding up fly heads and rubbing them on areas experiencing hair loss as a treatment.

A fascinating look at why cucumber tendrils coil in opposite directions

The tendrils of cucumber plants coil when they hit a surface, creating a distinct telephone-cord look. Charles Darwin wrote about the mystery in the 1850s, though it wasn't until the 21st century that scientists figured out just how mysterious the coil is: its tendrils coil in opposite directions.

Stress contributes to gray hair because when the body experiences stress, the sympathetic nervous system releases specific hormones that influence pigment-producing cells.

The three smallest bones in the human body—the malleus, incus, and stapes—amplify the vibrations of sound waves by almost 20 times to help enable hearing.

Scalp cooling caps may help prevent hair loss during chemotherapy by temporarily reducing blood flow to the scalp, thereby reducing the amount of chemotherapy that reaches hair follicles.

Explore how cells respond to signals from their environment

In "Dropping Signals," users can drag stimuli, such as hormones and light, into various cellular environments to observe cellular responses. These include changing their shape, enabling the transport of chemicals into or out of the cell via the cell membrane, or dividing to compensate for surrounding damaged cells.

Male pattern baldness accounts for more than 95% of hair loss in men and is characterized by thinning hair, hair loss, and a receding hairline.

Cells cannot grow forever due to escalating inefficiency in transporting chemicals

As cells get larger, their volume grows much faster than the surface area through which nutrients and waste products pass, creating a bottleneck that eventually causes cells to die. This forces nearly all organisms visible to the naked eye to comprise enormous numbers of smaller cells, such as the approximately 30 trillion found in the average adult human.

Artificial goose bumps could theoretically be used for information storage

Inspired by how fine hairs stand on the skin with goose bumps, researchers have recently created artificial skin that raises artificial goose bumps when exposed to a laser. This type of precise, localized, and controllable system could potentially fuel later development of programmable machines that could be used for information storage.

If hearing is damaged, the brain may amplify remaining sounds, perhaps causing tinnitus

Recent mouse brain and ear imaging revealed that the creature compensates for hearing loss by sending signals to the cochlea in the inner ear. This triggers nerve fibers in the inner ear to increase volume and become more sensitive. Learning about these boosted-sensitivity messages from the brain to the cochlea—if they're similar in humans—might help explain tinnitus and fuel experimental approaches to turn down that sensitivity.

While most cells possess DNA, red blood cells destroy their nuclei to maximize the amount of oxygen they carry and more easily alter their shape to fit through narrow blood capillaries.

The halting of human bone growth helps manage heat produced from metabolism

While fish, amphibians and reptiles get bigger throughout their lives until they die, their slower metabolisms allow their bodies to regulate the resulting smaller temperature increases. In humans, hormones triggered during puberty harden growth plates, ending bone lengthening.

Henrietta Lacks' tumor cells became the first recognized 'immortal' cell line about 75 years ago, but researchers are still investigating the specific mechanisms that enabled the cells to continuously grow and divide in the laboratory.

A Venus flytrap's hairs convert sensory touch into electrical signals

A stretch-activated ion channel called DmMSL10 acts as an amplifier, converting grazing contact into a strong impulse that the plant uses to react and close its jaw. To distinguish prey from raindrops or other stimuli, the jaw only closes when the hairs are touched twice in quick succession.

No medical evidence suggests collagen drinks or supplements will improve your hair

Marketing claims that collagen supplements or drinks will make your hair shiny, thick, and improve hair growth are not backed by scientific evidence.

Plant hormones and growth regulators guide growth stages and responses in plants

Plants naturally produce hormones like auxin and gibberellins, while humans apply synthetic or extracted growth regulators to control plant development. These substances influence processes like flowering, root growth, dormancy, and ripening—even in very small doses.

'Hair' helped redefine Broadway theater

"Hair" rewrote the rule book, bringing politics, race, and, yes, nudity to Broadway. Plenty was going on backstage, too, with the young, revolutionary cast embracing the countercultural life they portrayed onstage.

Scientists using gene therapy recently managed to regenerate retinal cells in the lab—a breakthrough for mammals that could potentially lead to future treatments for human retinal diseases.

Watch how DNA is packaged to a 10,000th of its original size in a cell

In humans, the 2-meter (6.56-foot) molecule wraps around spool-like proteins called histones, forming beads—nucleosomes—that fold up into fibers. These fibers—chromatin—form loops through folding that compress into larger fibers, which tightly coil together to form a chromosome.

Some animals may anchor their brain cells to specific landmarks to determine direction

In a study of bats exploring a new area, specific sets of "head direction cells" were seen becoming active based on bats' orientation when moving, and this activity became more coordinated over time. Researchers suspect, like humans, bats and other animals establish this sense of direction based on movement relative to known points of interest.

So-called 'recession blondes and brunettes' skip hair appointments to save money

One hairstyle trend is seen as a recession indicator: people letting their hair grow darker roots instead of frequently splurging on expensive blonde highlights.

Recent research found that the brain doesn't seem to massively rewire following amputation—upending earlier beliefs about the cause of phantom limb pain.

One of the leading theories behind muscle movement

According to the Sliding Filament Theory, skeletal muscle contraction is made possible by sarcomeres, which are made of bundles of myosin and actin proteins inside muscle cells. Myosin pulls itself along actin to contract a muscle, shortening the muscle and its cells and enabling physical movement. It then releases its grasp on actin so it can start the process over again if so commanded.

The secret lives of cells

Cutting-edge microscopy has revealed previously unseen interactions of biological molecules within their cellular environment, enabling scientists to observe and analyze the molecules in a holistic view. This podcast explains the minute advancements made over the last few decades in observing cells, revealing how scientists have come and what the future holds for the field.