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Mar 17, 2024 · The hair shaft is the visible, nongrowing portion of a hair protruding from the skin. This part of the hair is not anchored to the hair follicle. The hair shaft has three layers: a central medulla, a keratinised cortex and an outer layer, known as the cuticle, which is highly keratinised and forms the thin hard cuticle on the outside of the hair.
- Medical Content
- 29 min
This video explores the structure and growth of nails and hair, integral parts of the integumentary system. It delves into the role of the epidermis and dermis in nail and hair formation, the function of keratin, and the intriguing role of the arrector pili muscle in creating goosebumps.Created by Raja Narayan. Questions Tips & Thanks.
- Fashion Statement
- What Is hair?
- Structure of Hair
- Characteristics of Hair
- Functions of Hair
- Hair in Human Evolution
- Social and Cultural Significance of Hair
This colourful hairstyle makes quite a fashion statement. Many people spend a lot of time and money on their hair, even if they don’t have an exceptional hairstyle like this one. Besides its display value, hair actually has important physiological functions.
is a filament that grows from a in the of the skin. It consists mainly of tightly packed, keratin-filled cells called . The human body is covered with hair follicles, with the exception of a few areas, including the mucous membranes, lips, palms of the hands, and soles of the feet.
The part of the hair located within the follicle is called the .The root is the only living part of the hair. The part of the hair that is visible above the surface of the skin is the hair shaft. The shaft of the hair has no biochemical activity and is considered dead.
Two visible characteristics of hair are its colour and texture. In adult males, the extent of balding is another visible characteristic. All three characteristics are genetically controlled.
In humans, one function of head hair is to provide insulation and help the head retain heat. Head hair also protects the skin on the head from damage by . The function of hair in other locations on the body is debated. One idea is that body hair helps keep us warm in cold weather. When the body is too cold, muscles contract and cause hairs to stand...
Among mammals, humans are nearly unique in having undergone significant loss of body hair during their evolution. Humans are also unlike most other mammals in having curly hair as one variation in hair texture. Even non-human primates (see Figure 10.5.7) all have straight hair. This suggests that curly hair evolved at some point during human evolut...
Hair has great social significance for human beings. Body hair is an indicator of biological sex, because hair distribution is . Adult males are generally hairier than adult females, and facial hair in particular is a notable secondary male sex characteristic. Hair may also be an indicator of age. White hair is a sign of older age in both males and...
- Christine Miller
- 2020
People also ask
What is a hair shaft?
How long does a hair shaft grow?
How many layers are in the hair shaft?
What are the 3 zones of a hair shaft?
The answer is there are three layers in the hair shaft; the medulla, cortex and cuticle. The medulla is the deepest layer of hair seen only in thick hairs. The cortex is the central layer of the hair shaft, giving strength, shine, colour and texture to your hair. The cuticle is the thin, colourless outermost layer of the hair shaft which ...
A hair shaft consists of dead, keratin-filled cells that overlap each other like the shingles on a roof (see Figure below ). Like roof shingles, the overlapping cells help shed water from the hair. Shaft of Human Hair. This shaft of hair is magnified to show its overlapping cells. Hair helps to insulate and protect the body.
The hair shaft is composed of three concentric layers, namely the outer cuticle, middle cortex, and inner medulla. They differ from each other in the types of keratin filaments they possess. Cells in the hair matrix surrounding the dermal papilla are responsible for hair growth.
The hair shaft is the part of the hair not anchored to the follicle, and much of this is exposed at the skin’s surface. The rest of the hair, which is anchored in the follicle, lies below the surface of the skin and is referred to as the hair root .
