Nasal hair or nose hair is the hair in the nostril. Adult human noses have hairs, which serve as a crude air filter to stop foreign particles from entering the nasal cavity, as well as to help collect moisture. Nasal hair is different from the cilia of the ciliated lining of the nasal cavity. These cilia are microtubule-based structures that are found in the respiratory tract, involved in the mucociliary clearance mechanism.
Ear hair is the terminal hair arising from follicular cartilage inside the external auditory meatus in humans. In its broader sense, ear hair may also include the fine vellus hair covering much of the ear, particularly at the prominent parts of the anterior ear, or even the abnormal hair growth as seen in hypertrichosis and hirsutism. Medical research on the function of ear hair is currently very scarce.
Hair growth within the ear canal is often observed to increase in older men, together with increased growth of nasal hair. Visible hair that protrudes from the ear canal is sometimes trimmed for cosmetic reasons. Excessive hair growth within or on the ear is known medically as auricular hypertrichosis. Some men, particularly in the male population of India, have coarse hair growth along the lower portion of the helix, a condition referred to as "having hairy pinnae" (hypertrichosis lanuginosa acquisita).
Hair removal is the deliberate removal of body hair or head hair. This process is also known as epilation or depilation.
Hair is a common feature of the human body, exhibiting considerable variation in thickness and length across different populations. Hair becomes more visible during and after puberty. Additionally, men typically exhibit thicker and more conspicuous body hair than women.Both males and females have visible body hair on the head, eyebrows, eyelashes, armpits, genital area, arms, and legs. Males and some females may also have thicker hair growth on their face, abdomen, back, buttocks, anus, areola, chest, nostrils, and ears. Hair does not generally grow on the lips, back of the ear, the underside of the hands or feet, or on certain areas of the genitalia.
The human nose is the first organ of the respiratory system. It is also the principal organ in the olfactory system. The shape of the nose is determined by the nasal bones and the nasal cartilages, including the nasal septum, which separates the nostrils and divides the nasal cavity into two.
The nose has an important function in breathing. The nasal mucosa lining the nasal cavity and the paranasal sinuses carries out the necessary conditioning of inhaled air by warming and moistening it. Nasal conchae, shell-like bones in the walls of the cavities, play a major part in this process. Filtering of the air by nasal hair in the nostrils prevents large particles from entering the lungs. Sneezing is a reflex to expel unwanted particles from the nose that irritate the mucosal lining. Sneezing can transmit infections, because aerosols are created in which the droplets can harbour pathogens.