Anagen / Catagen / Telogen
Definition
Hair growth phases. Anagen is the active growing phase (about 85 percent of scalp hairs), catagen the brief transition, telogen the resting phase (about 10 to 15 percent) ending in shedding with a club-shaped root.
Related terms
- Cortex
- The middle, and largest, layer of the hair shaft. It contains cortical cells, pigment granules (melanin), and cortical fusi (air spaces). The...
- Cuticle
- The waxy, polymer layer covering the outer surface of leaf epidermal cells. It protects against water loss and herbivory but, forensically, it...
- Follicular Tag
- Translucent sheath tissue adhering to the root of a forcibly pulled hair. Contains nucleated epithelial cells from the inner root sheath and...
- Medulla
- The central canal of the hair shaft, which may be continuous, interrupted, fragmented, or absent. Medullary pattern and the medullary index (medulla...
- Medullary Index
- The ratio of the medulla diameter to the total hair shaft diameter. In companion animal hair identification, a medullary index above 0.5...
- Natural Fibre
- Fibre of biological or mineral origin. Animal (wool, silk, cashmere, mohair, alpaca), vegetable (cotton, jute, flax, hemp, sisal, coir) or mineral (asbestos;...
- Synthetic Fibre
- Fibre manufactured from regenerated cellulose (rayon, acetate) or polymer chemistry (nylon, polyester, acrylic, polypropylene, spandex, kevlar). Identified by birefringence, FTIR and pyrolysis...
Explained in
- Hair and Fibers: Nature, Types, Structure and ExaminationHair growth phases. Anagen is the active growing phase (about 85 percent of scalp hairs), catagen the brief transition, telogen the resting phase (about 10 to...