Final answer:
Trichology is the study of hair and its diseases. Hair and skin are interrelated, with hair providing protection and contributing to sensory functions while growing from the skin's dermis. The hair's health can be influenced by skin conditions and genetic factors.
Step-by-step explanation:
The scientific study of hair and its diseases is known as trichology. Hair plays significant roles in the human body, including protection, regulation of body temperature, and facilitating evaporation of sweat. Hair growth occurs in cycles, with the anagen phase being the active growth phase. Dysfunctions in the hair growth cycle can lead to diseases such as alopecia, where there is a loss of all body hair. This loss can disturb body homeostasis by affecting temperature regulation and reducing protection against pathogens.
The skin and hair have a close biological relationship as hair grows from follicles located within the skin's dermis layer. They work together to offer protection to the body, where the skin acts as a barrier against harmful substances and the hair can trap and filter particulates. Each serves as the first line of defense against environmental threats.
Hair consists of keratinocytes packed with the protein keratin, which gives hair its strength. The roles played by hair include protection against UV radiation, insulation, and aiding in sense perception. Aspects such as hair color, texture, and pattern are genetically controlled, with melanin determining hair color. About diseases, the skin condition acne involves infected sebaceous glands often found near hair follicles, and genetic disorders like albinism affect melanin production impacting both skin and hair pigmentation.