A hairy business

Let your hair down: 10 amazing facts about human hair

Image: Ali Pazani

The human body is incredible, from its mechanics to its ability to heal and adapt to multiple environments and situations. Hair, as part of our body, is no exception to this complexity and wonder. Let’s take a look at 10 amazing facts about our hair that you may not know!

Image: Ian Talmacs

The word hair is used to describe two separate and distinct components: the follicle and the shaft. The follicle—what we commonly refer to as the root—is a living organ located in the dermis of the scalp. It’s responsible not only for growing hair but also for helping regenerate skin after a wound.

On the other hand, the shaft—often referred to as the strand—is a filament composed of layers of keratin, the same protein that makes up our nails. Unlike the follicle, the hair shaft is technically dead because it consists of dead cells.

Image: Joyful Bird

Each hair strand is composed of three layers. The innermost layer is the medulla, and even scientists are still uncertain about its exact function. Surrounding the medulla is the cortex, which absorbs water and provides strength to the strand. The cortex also contains melanin, the pigment that determines hair color, and its shape plays a major role in whether hair is straight or curly. The outermost layer is the cuticle, which serves primarily to protect the hair shaft.

Image: Tyler McRobert

Hair color is primarily influenced by several genes, including MC1R, which plays a key role in melanin production. However, not everyone produces the same type or amount of melanin. Higher amounts of melanin result in black hair, while varying levels and types of melanin—along with genetic variations—produce brown, blond, and other shades.

Red hair, the rarest natural color, is caused by a mutation in the MC1R gene and is inherited in a recessive pattern. This means a person must inherit two copies of the mutated gene (one from each parent) to have red hair, though many people carry the gene without expressing the trait.

Image: William Warby

Growing at a rate of about 0.2 to 0.5 inches per month, hair is the second-fastest growing tissue in the human body—surpassed only by bone marrow. This rate is influenced by factors such as genetics and ethnic background. Other variables, such as age, lifestyle, or health, can also have an impact on our hair growth and density.

Image: Sohan Rahat

We usually think of cats or dogs when it comes to shedding, but humans also shed hair regularly. After all, hair is a trait shared by all mammals. The average person sheds between 50 and 100 strands of hair per day, though this number can increase in response to stressors such as illness, hormonal changes, or emotional stress. Once the stress subsides and the body readjusts, the excess shedding typically stops.

Image: Joseph Chan

Commonly associated with aging, grey hair isn’t a color in itself but rather the result of a loss of pigment. As part of the natural aging process, melanin production in the hair follicle gradually decreases and eventually stops, causing strands to appear grey or white.

Genetics and ethnic background play a major role in determining when and how the greying process begins. Some people are even genetically predisposed to start greying at a very young age.

Image: Jaroslav Devia

Hair texture is commonly associated with ethnic background, but that’s not the only factor involved. Texture is primarily determined by genetics, and while genetics are closely tied to ancestry, all hair textures can be found across different populations.

Scientists believe that hair texture—specifically curl pattern and volume—is a result of the shape of the shaft. A round shaft typically produces straight hair, while flatter or more oval-shaped shafts tend to create curls and waves.

Image: Amritanshu Sikdar

Depending on the structure of your hair cuticle, your hair may be more or less water-repellent. Hair shafts with a more porous cuticle absorb water easily but also lose moisture quickly. In contrast, shafts with a tighter-packed cuticle struggle to get wet and are slow to dry.

Image: Sonja Langford

Hair doesn’t grow continuously or all at once—each strand follows a cycle with distinct phases. First comes the growing phase, which varies depending on the type of hair (for example, facial hair grows faster and for a shorter period than scalp hair). Eventually, growth slows down, and the strand detaches from the root.

After this, the hair enters a resting phase, during which it remains in place until it is naturally shed. At any given time, we have hairs in all stages of this cycle, which is why we regularly shed hair without going bald.

Image: Hans Reniers

Like any other part of the body, hair contains DNA and genetic material, which means a person can be genetically identified from a single strand, provided it includes the root. But hair holds even more information. The analysis of a hair strand can reveal substances that were present in a person’s bloodstream over time, including vitamins, minerals, medications, alcohol, and other substances.

Pen to screen

From A to B: 10 movies centered around the world of writers and words

Image: Rafaela Biazi

A script may be constructed in words, but it is not a book. At least not in the common sense of the term. That is why it can sometimes be hard to translate a great book into a great movie. Likewise, expressing onscreen the struggles of writing is never an easy task. A few notable exceptions exist, where the passion, the work, the loneliness, and the hardships endured by those who immerse themselves in the world of prose and poetry, are vividly depicted. The following ten are movies that manage to successfully translate those same things. If you haven’t seen any of these, we encourage you to do so: The experience will be a rewarding and inspiring one.

Image: Alex Batchelor

The movie that brought a whole new fame level to the Latin phrase Carpe Diem (seize the day), Dead Poets Society was a blockbuster that no one saw coming when it came out in 1989.

Starred by Robin Williams as an English teacher who inspires his students through teaching poetry at a fictional elite boarding school, Dead Poets Society received many accolades, including Academy Awards for Best Picture and Best Director. It remains a classic to this day.

Image: Fabian Mardi

A movie based on a book about a writer who is kidnapped by a fan and forced to rewrite one of his books, Misery is a quintessential Stephen King story. The psychological thriller film starred James Caan and Kathy Bates and was released in 1990 to highly positive reviews and box office success.

Misery manages to capture the deep anxiety and horror of a person who realizes that he is utterly helpless and in the hands of a disturbed individual, far away from society. Stephen King himself has stated that Misery is one of his top ten favorite film adaptations.

Image: CK Hicks

Capote is a movie sometimes more remembered for the actor who played the starring role (and did a fantastic, Academy Award-winning job), Philip Seymour Hoffman, than for the movie itself. But it actually is a great film.

This biographical drama is about Truman Capote, the American novelist, and follows the events during the writing of Capote's 1965 nonfiction book In Cold Blood. The film became a box office success and received acclaim from critics.

Image: Rachel Martin

Every story about a recluse writer is probably going to be compared to the real-life story of J.D. Salinger and this is not the exception. Finding Forrester is a 2000 American drama film in which, a teenager is invited to attend a prestigious private high school. By chance, Jamal befriends a reclusive writer, William Forrester, through whom he refines his writing talent.

The writer is played by Sean Connery, who later acknowledged that the inspiration for his role was indeed Salinger.

Image: David Lusvardi

As delirious as this movie is, it is a brilliant representation of the actual book and its writing style. Fear and Loathing in Las Vegas was released in 1998 and is based on Hunter S. Thompson's novel of the same name.

The film, starring Johnny Depp and Benicio del Toro as Raoul Duke and Dr. Gonzo respectively, details the duo's journey through Las Vegas as their initial journalistic intentions devolve into an exploration of the city under the influence of psychoactive substances.

Image: jules a.

Presented as a semi-autobiography of American poet and author Charles Bukowski during the time he spent drinking heavily in Los Angeles, Barfly is a 1987 black comedy that starred Mickey Rourke and Faye Dunaway.

The movie was scripted by Bukowski himself, who later published a longer version of the script as a novel, called Hollywood.

Image: Ruth Durbin

The previously mentioned Charles Bukowski was a big fan of John Fante, the man who wrote the book on which Ask the Dust is based. This romantic drama film was almost entirely shot in South Africa, even though it portrays Los Angeles.

The movie and the book depict the life of John Fante’s alter ego, Arturo Bandini, as a young struggling writer living in motels and trying to get his works published.

Image: Mitchell Lawler

Inspired by the life and works of the Marquis de Sade, Quills is a fiction film based on the final years of the Marquis's incarceration in the insane asylum at Charenton. The movie starred Geoffrey Rush as de Sade and Kate Winslet as laundress Madeleine "Maddie" LeClerc.

In the film, the Marquis continues to write prolifically even when all writing equipment is taken from him, resorting to using his bed sheets and his own blood as ink.

Image: Jakob Owens

Another film about a young writer trying to make it in Los Angeles, Barton Fink was released in 1991 with John Turturro in the title role. The Coen brothers' movie was written when they were experiencing writer’s block during the production of another script.

Barton Fink depicts the writing process, labor conditions in creative industries, and the relationship between intellectuals and regular people. The main characters are supposedly based on writers Clifford Odets and William Faulkner.

Image: Nathan DeFiesta

The last entry on our list is a 2002 comedy-drama film based on director Charlie Kaufman’s struggles to adapt Susan Orlean's 1998 nonfiction book The Orchid Thief while suffering from writer's block.

The movie featured Nicholas Cage, Meryl Streep, and Chris Cooper in the leading roles and received widespread acclaim for their performances as well as for the direction, screenplay, and humor.