CHE 107 Lecture Notes - Lecture 36: Cuticle, Comparison Microscope, Pigment

• School: Pace University
• Department: Chemistry
• Course: CHE 107
• Professor: Dickerson

Document Summary

Appendage of skin that grows out of an organ known as hair follicle. Length of hair extends from root continues into shaft & terminates at tip end: root: bulb embedded in the follicle, provide necessary tools to produce hair & continue growth. There are 3 phases of hair growth: anagen, catagen, telogen. Follicular tag: when pulled from the head, some translucent tissue surrounding hair"s shaft near root may be found. By using dna analysis on follicular tag, the hair may be individualized. Cellular column running through the center of the hair. Medullary index: measures diameter of medulla relative to diameter of hair shaft. For humans, medulla generally occupies less than 1/3 diameter of shaft. May be continuous, interrupted, fragmented, or absent. Presence of medulla varies from individual to individual. Even among hairs of a given individual. Medullae also have different shapes, depending the species: cortex: middle layer containing pigment melanin, which gives hair its color.