Category hair

Definition Commonly known as baldness, alopecia indicates a condition characterized by progressive hair loss, both in terms of quantity (number of hairs) and qualitative (reduction of thickness and elasticity of the hair). The most widespread form is androgenetic alopecia, a typically male hereditary condition, strongly influenced by hormonal variation; among other forms, alopecia areata and aldecia due to thyridism are also mentioned

Definition Tinea capitis, also known as ringworm of the hair, is a highly contagious fungal infection affecting the scalp, in which skin flaking is associated with erythema and temporary hair loss. Tinea capitis is typical of pediatric children. The tinea capitis of the child results in the tinea barbae in the adult: this infection involves the skin surface in which the beard grows

Alopecia : from the Greek "alopex" = fox, a term used to emphasize the similarity with this animal, which loses hair twice in a year. There are two main types of alopecia, the telogenic and the androgenic. The first involves, usually in a short time, a limited or generalized fall of the hair, in response to a strong physical or psychological stress

Sex hormones and GH heavily influence the growth of our hair. In particular, their evolution from short-haired hair with a terminal hair is regulated by the somatotropic hormone (GH), while involution depends on the activity of the androgenic hormones. In humans, the hair of the vertex and frontal areas in particular is more sensitive to the action of androgens, while in women this sensitivity is more widespread

The growth of these structures is not continuous, but dependent on evolutionary and involutionary cycles, which follow one after the other. Each cycle consists of three phases, called, respectively: anagen (real growth that determines the lengthening) catagen (involution, growth block) and telogen (resting phase, in which the hair falls)

The hair follicle is an epidermal formation, sunk in the dermis, consisting of the hair and its sheaths. The formation of hair follicles is very early, so much so that they begin to appear around the second month of gestation. These follicles will continue to form throughout the pregnancy; at the time of birth the child will have all the equipment of follicles of which he has been genetically endowed and from this moment onwards no others will be formed

What is that 5-alpha reductase is the name of an enzyme responsible for converting testosterone into dihydrotestosterone. The latter is the body's most powerful androgenic hormone and its activity is 4-5 times higher than that of testosterone. As anticipated, it is produced thanks to the action of the 5-alpha reductase enzyme which makes the double bond between carbon 4 and carbon simple 5

Some curiosities The hair is exclusive to the skin of mammals. They can be divided into two categories: terminal hair and fleece hair. The terminal ones are larger, more rigid and pigmented. The hair of the fleece, on the other hand, is shorter, softer and thinner, practically invisible given the lack of pigmentation

A great deal of scientific work has shown the negative influence of tobacco smoke on the health of the entire body. A figure among all reminds us that for every week of smoking (20 cigarettes a day starting from 25 years of age) a day of life is lost on average. The negative effects of smoking are also felt in the hair and scalp

Without disturbing science, even with the naked eye we see how there are people with fine hair (which tends to break) and others with thick hair (which often tend to be frizzy and bristly too). The thickness of the hair, understood as the diameter of the hair shaft, therefore has wide intra and interindividual variations