Hair: Difference between revisions

Latest revision as of 21:02, 23 February 2025

Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals. The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and fine vellus hair.

Structure[edit]

The structure of hair can be broken down into three parts: the cuticle, the cortex, and the medulla.

Cuticle[edit]

The cuticle is the outermost part of the hair shaft. It is formed from dead cells, overlapping in layers, which form scales that give the hair shaft strength and protect the inner structure of the hair.

Cortex[edit]

The cortex contains the keratin bundles in cell structures that remain roughly rod-like. This part of the hair contains the most melanin, giving the hair its color.

Medulla[edit]

The medulla is the innermost part of the hair shaft. This nearly invisible part of the hair exists in different forms in different hair types and could be absent entirely in some hair.

Growth[edit]

Hair growth begins inside the hair follicle. The only "living" portion of the hair is found in the follicle. The hair that is visible is the hair shaft, which exhibits no biochemical activity and is considered "dead".

Function[edit]

Hair has a number of functions: it can serve to protect the skull, it can help control the body temperature, and it can help to evaporate perspiration.

Hair disorders[edit]

There are many types of hair disorders, including alopecia, hirsutism, and telogen effluvium.

See also[edit]

This article is a medical stub. You can help WikiMD by expanding it!
Most recent articles Ongoing trials	Wikipedia

   This article is a medical stub. You can help WikiMD by expanding it!

Gray945
Human hair and Merino wool fibre
506 Hair
Hair follicle of feline - Microscopic view
Gray944
Hair Autofluorescence
Brown hair
Hair follicle cycling
Blond long-haired young lady woman
Marianne Ernst, Long hair model
Natural Afro - hair type 4c - model Gwyneth Ellis
Curlsbaby

@@ Line 41: / Line 41: @@
 [[Category:Skin]]
 {{dictionary-stub1}}
+<gallery>
+File:Gray945.png|Gray945
+File:CSIRO_ScienceImage_8115_Human_hair_and_Merino_wool_fibre.jpg|Human hair and Merino wool fibre
+File:506_Hair.jpg|506 Hair
+File:Hair_follicle_of_feline_-_Microscopic_view_2.jpg|Hair follicle of feline - Microscopic view
+File:Gray944.png|Gray944
+File:Hair_Autofluorescence.jpg|Hair Autofluorescence
+File:Brown_hair.jpg|Brown hair
+File:Hair-follicle_cycling.ogv|Hair follicle cycling
+File:Blond_long-haired_young_lady_woman.jpg|Blond long-haired young lady woman
+File:Marianne_Ernst,_Long_hair_model.jpg|Marianne Ernst, Long hair model
+File:Natural_Afro_-_hair_type_4c-_model_Gwyneth_Ellis.jpg|Natural Afro - hair type 4c - model Gwyneth Ellis
+File:Curlsbaby.jpg|Curlsbaby
+</gallery>