Another name for the form and structure of something is its ______________.
In a 24hour period, the average person sheds ____ hairs from the scalp alone.
Label the parts of the hair shaft pictured here.
A _________________ is the organ out of which a hair shaft grows.
Why is analyzing hair useful for drugs and poisons?
Match the following descriptions of the parts of a hair shaft.
_____ cortex a. spongy interior core of hair that gives it flexibility; appears as a canal in the middle of
_____ cuticle b. middle layer of the hair shaft that provides strength; comprises most of the hair mass
_____ medulla c. tough, clear outside covering of the hair shaft
What is unique about the cuticle of human hair?
Identify the origin of the hair shafts pictured here.
_____ Human hair
Why does human hair have a characteristic odor when it burns?
The protein of which hair is made is __________________.
Label the longitudinal diagram of the hair shaft below.
_____ Cortical fusi
_____ Pigment granules
_____ Cuticle scales
Pigment that makes hair black, brown, red or yellow is found in the ___________________.
Distinguish the medulla patterns in the diagram below.
_____ Continuous (human)
_____ Continuous (animal)
The medulla is normally invisible, except in the hair of which people groups?
What hair shapes are generally found among these people groups?
Whites, Mexicans, and Middle Eastern peoples:
Asians and Native American peoples:
Head hair, on average grows ________ cm per month.
Put the threes stages of growth of hair into chronological order (telogen, catagen, anagen).
The stage of hair growth that lasts up to five years is the ______________ phase.
Hairs found on a hair brush are normally from the __________________ phase.
Match the hair end description with a condition that would explain it.
____ Squared off at the tip A. mature human hair
____ Rounded at the base B. use of harsh chemicals, or overuse of a blow dryer
____ Tapers to a point C. recently cut
____ Frayed or split ends D. uncut for a period of time
List three reasons how a pencil can be a useful analogy for a hair shaft.