Perspectives and Challenges of Hair Analysis
December 2023
in “
Royal Society of Chemistry eBooks
”
hair anatomy hair biology hair growth hair characteristics hair types hair composition proteins keratin hair shaft cuticle cortex medulla hair follicle hair elasticity hair strength melanin hair color hair follicle cycle hair bulb dermal papilla anagen phase hair production hair follicle development hair growth phases hair cycling melanogenesis anagen catagen telogen exogen kenogen hair structure hair growth cycle hair color pigment hair strength proteins
TLDR Hair is a complex organ, and understanding its detailed structure and growth phases is crucial for analyzing substances within it.
The document provides an extensive examination of human hair, detailing its anatomy, biology, and the factors affecting its growth and characteristics. It classifies hair into eight types based on physical attributes and discusses the composition of hair, primarily proteins and keratin, which contribute to its mechanical properties. The structure of the hair shaft, including the cuticle, cortex, and medulla, and the hair follicle, with its various compartments, are described in relation to hair elasticity and strength. The document also explores the role of melanin in hair color and the cyclical changes of the hair follicle's lower part, particularly the bulb and dermal papilla, which are essential for hair production and the anagen phase. Additionally, the document covers the hair follicle's development, growth phases, and the factors influencing hair cycling and melanogenesis, including the transition through anagen, catagen, telogen, exogen, and kenogen phases. It concludes by highlighting the complexity of hair as an organ and the necessity of considering these complexities when interpreting xenobiotic concentrations in hair.
