Trichology

First quarter, 2nd lesson chapter

Anatomy

Study of organs and systems of the body

Physiology

Study of the functions that organs and systems perform

Cells

Basic units of living matter (life)

Tissue

Groups of cells of the same kind

Organs

• Separate body structures that perform specific functions

• Composed of 2 or more different tissues

Body Systems

Group of body structures and/or organs that, together, perform functions for the body

Matter

Anything that occupies space and has weight

pH

Numerical measurement that indicates the acidity or alkalinity of a water-based substance

Alkaline

More negative hydroxide ions

Acidic

More positive hydrogen ions than negative hydroxide ions

Peptide Bond (End Bond)

• Link amino acids end to end to form a chain

• Backbone of all protein molecules

Polypeptide Bond

• Connects amino acids in a chain to form hair protein.

• Creates the hair’s main structural framework.

• Strong bond that holds the hair’s shape and strength.

Hydrogen Bond

• A weak bond formed by opposite charges

• Easily broken by heat or water.

• Gives hair about 35% of its strength due to the large number of these bonds.

Disulfide Bond

• Formed when sulfur atoms in hair join together.

• Most important bond to a salon professional

• Can be broken or rebuilt by chemicals, causing permanent changes to hair.

Salt Bond

• Formed by the attraction between opposite charges in amino acids.

• Can be broken by changes in pH.

• Makes up about 35% of the hair’s resistance to change.

Keratinization

Process of cells changing shape, drying out and forming keratin protein

Medulla

Central core of hair shaft

Melanin

The natural pigment that gives hair, skin, and eyes their color

Anagen

• Active growing

• Attached root sheath

Catagen

• Transitional

• Cell division stops

Telogen

• Resting

• No attached root sheath

Trichology

Technical name for the study of hair

Hair Bulb

The rounded bottom part of a follicle where the hair starts growing

Hair fiber

Portion of hair that extends above skins surface

Hair Root

Portion of hair inside the hair follicle under the skin’s surface

Cortex

Second layer with unique protein structures

Cuticle

Outer covering of the hair shaft

Acid Mantle

Protects cuticle of hair fiber and maintains the natural pH of hair and skin

Porosity

Ability of the hair to absorb moisture, liquids or chemicals

Texture

Degree of coarseness or fineness in the hair fiber

Elasticity

Ability of hair to stretch and return to its original shape without breaking

External Parasites

Tiny organisms like lice or mites that live on the skin or scalp and feed on the host.

Alopecia

A condition that causes hair loss from the scalp or body.

Spilt Ends

Brittle Hair, small cracks in the cuticle deepen into the cortex

Noduels

Trichorrhexis Nodosa, lumps or swelling along hair shaft

Grayness

Canities, grayness or whiteness of hair, congenital or acquired

Dandruff

Pityriasis, chronic, excessive flaking, itchiness, tightness, and irritation

Greasy or Waxy Dandruff

Pityriasis Steatoides, oily flakes combined with sebum, stick to scalp in clusters, yellowish