Chapter 3: Hair Analysis

Label a diagram of human skin by matching each structure to its best description.

• Shaft that emerges above the skin surface

• Hair

• Tubular sheath surrounding the root of the hair

• Epidermis

• Layer of skin beneath the outer layer containing glands and follicles

• Dermis

• Small blood vessels within the skin

• Capillaries

• Outermost layer of skin

• Hair follicle

Which of the following are functions of hair? Select all that apply.

• Protection from the sun and dirt

• Regulation of body temperature

• Detection of movement by nerves in the follicle

• Camouflage for some animals

• Increase in blood glucose levels

Match each part of hair to its description.

• Thick middle layer containing pigment

• Medulla

• Central core that may be hollow or filled

• Cuticle

• Outermost protective layer composed of scales

• Cortex

Match the parts of a wooden pencil to the analogous structures in hair.

• Medulla of the hair

• Paint on the pencil

• Cuticle of the hair

• Wood of the pencil

• Cortex of the hair

• Lead of the pencil

Tags

NGSS.MS-LS4-2

Match each type of hair medulla to its description.

• Missing central core

• Interrupted

• No gaps or breaks

• Solid

• Repeating gaps in a pattern

• Fragmented

• Irregular gaps

• Continuous

• Fills most of the hair’s diameter

• Absent

Match each hair cuticle formation to its description or typical example.

• Petal-like scales; common in cats

• Coronal

• Flattened, overlapping scales; common in humans

• Spinous

• Crown-like scales; bats and small rodents

• Imbricate

Match each body hair type to its typical characteristics.

• Very coarse; triangular cross-section; thick medulla

• Pubic hair

• Coarse and wiry; wider medulla

• Head hair

• Uniform pigment; long and soft; often circular cross-section

• Beard hair

Which statements correctly describe differences among hair from various ethnic groups? Select all that apply.

• Asian hair tends to be straight and coarse with a round cross-section.

• Caucasian hair is typically straight or wavy with an oval cross-section.

• African hair is usually curly or coiled with a flat or elliptical cross-section.

• Pigment distribution in the cortex is identical across all ethnic groups.

• Color differences relate to variations in melanin concentration.

Tags

NGSS.HS-LS3-2

What is the correct formula for the medullary index of hair?

• Width of the entire hair divided by the width of the medulla

• Width of the medulla divided by the width of the entire hair

• Diameter of the cortex divided by the total hair diameter

• Number of medulla fragments divided by hair length

Which statements accurately compare human hair with other animal hair? Select all that apply.

• Humans typically have a small medullary index, while many animals have a large one.

• Human cuticles are usually imbricate; animal cuticles can vary by species.

• Animal medullae are often patterned or thick; human medullae are typically thin or fragmented.

• Human medullae are usually solid along the entire diameter of the shaft.

• All animals share the same cuticle type.