Attitudes towards different hair, such as hairstyles and hair removal, vary widely across different cultures and historical periods, but it is often used to indicate a person’s personal beliefs or social position, such as their age, sex, or religion.[1]
A beard is the collection of hair that grows on the chin and cheeks of humans and some non-human animals. In humans, usually only pubescent or adult males are able to grow beards. From an evolutionary viewpoint the beard is a part of the broader category of androgenic hair. It is a vestigial trait from a time when humans had hair on their face and entire body like the hair on gorillas. The evolutionary loss of hair is pronounced in some populations such as indigenous Americans and some east Asian populations, who have less facial hair, whereas people of European or South Asian ancestry and the Ainu have more facial hair. Women with hirsutism, a hormonal condition of increased hairiness, may develop a beard.
Attitudes towards different hair, such as hairstyles and hair removal, vary widely across different cultures and historical periods, but it is often used to indicate a person’s personal beliefs or social position, such as their age, sex, or religion.[1]
Attitudes towards different hair, such as hairstyles and hair removal, vary widely across different cultures and historical periods, but it is often used to indicate a person’s personal beliefs or social position, such as their age, sex, or religion.[1]
Attitudes towards different hair, such as hairstyles and hair removal, vary widely across different cultures and historical periods, but it is often used to indicate a person’s personal beliefs or social position, such as their age, sex, or religion.[1]
Attitudes towards different hair, such as hairstyles and hair removal, vary widely across different cultures and historical periods, but it is often used to indicate a person’s personal beliefs or social position, such as their age, sex, or religion.[1]
Attitudes towards different hair, such as hairstyles and hair removal, vary widely across different cultures and historical periods, but it is often used to indicate a person’s personal beliefs or social position, such as their age, sex, or religion.[1]
Attitudes towards different hair, such as hairstyles and hair removal, vary widely across different cultures and historical periods, but it is often used to indicate a person’s personal beliefs or social position, such as their age, sex, or religion.[1]
A hair follicle is a mammalianskinorgan that produces hair. Hair production occurs in phases, including growth (anagen), cessation (catagen), and rest (telogen) phases. Stem cells are responsible for hair production. The shape of the hair follicle has an effect on the hair shape and texture of the individual’s hair.
Follicles are composed of epidermal cells and are made up of the bulb which is innervated and the papilla which is responsible for accessing the blood supply.
A hair follicle is a mammalianskinorgan that produces hair. Hair production occurs in phases, including growth (anagen), cessation (catagen), and rest (telogen) phases. Stem cells are responsible for hair production. The shape of the hair follicle has an effect on the hair shape and texture of the individual’s hair.
Follicles are composed of epidermal cells and are made up of the bulb which is innervated and the papilla which is responsible for accessing the blood supply.
A beard is the collection of hair that grows on the chin and cheeks of humans and some non-human animals. In humans, usually only pubescent or adult males are able to grow beards. From an evolutionary viewpoint the beard is a part of the broader category of androgenic hair. It is a vestigial trait from a time when humans had hair on their face and entire body like the hair on gorillas. The evolutionary loss of hair is pronounced in some populations such as indigenous Americans and some east Asian populations, who have less facial hair, whereas people of European or South Asian ancestry and the Ainu have more facial hair. Women with hirsutism, a hormonal condition of increased hairiness, may develop a beard.
A beard is the collection of hair that grows on the chin and cheeks of humans and some non-human animals. In humans, usually only pubescent or adult males are able to grow beards. From an evolutionary viewpoint the beard is a part of the broader category of androgenic hair. It is a vestigial trait from a time when humans had hair on their face and entire body like the hair on gorillas. The evolutionary loss of hair is pronounced in some populations such as indigenous Americans and some east Asian populations, who have less facial hair, whereas people of European or South Asian ancestry and the Ainu have more facial hair. Women with hirsutism, a hormonal condition of increased hairiness, may develop a beard.
The pupil is a hole located in the center of the iris of the eye that allows light to strike the retina.[1] It appears black because light rays entering the pupil are either absorbed by the tissuesinside the eye directly, or absorbed after diffuse reflections within the eye that mostly miss exiting the narrow pupil.
In humans the pupil is round, but other species, such as some cats, have vertical slit pupils, goats have horizontally oriented pupils, and some catfish have annular types.[2] In optical terms, the anatomical pupil is the eye’s aperture and the iris is the aperture stop. The image of the pupil as seen from outside the eye is the entrance pupil, which does not exactly correspond to the location and size of the physical pupil because it is magnified by the cornea. On the inner edge lies a prominent structure, the collarette, marking the junction of the embryonic pupillary membrane covering the embryonic pupil.
Eyes are the organs of vision. They detect light and convert it into electro-chemical impulses in neurons. In higher organisms, the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in molluscs, chordates and arthropods.
Eyes are the organs of vision. They detect light and convert it into electro-chemical impulses in neurons. In higher organisms, the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in molluscs, chordates and arthropods.
Eyes are the organs of vision. They detect light and convert it into electro-chemical impulses in neurons. In higher organisms, the eye is a complex optical system which collects light from the surrounding environment, regulates its intensity through a diaphragm, focuses it through an adjustable assembly of lenses to form an image, converts this image into a set of electrical signals, and transmits these signals to the brain through complex neural pathways that connect the eye via the optic nerve to the visual cortex and other areas of the brain. Eyes with resolving power have come in ten fundamentally different forms, and 96% of animal species possess a complex optical system. Image-resolving eyes are present in molluscs, chordates and arthropods.
