Medullary Index and Hair Structure

The video tutorial explores the structure of hair, focusing on the cortex and medulla. It explains how the cortex gives hair its shape and color through melanin, and discusses the role of cortical fusi in hair strength. The medulla is described as a hollow structure that provides insulation, with various types and patterns that can be used to identify species. The concept of medullary index is introduced as a method to differentiate between human and animal hair.

What is the primary function of the hair cortex?

• To give hair its shape and color

• To provide insulation

• To protect the hair from damage

• To connect hair to the scalp

Which type of melanin is responsible for darker hair colors?

• Pheomelanin

• Carotene

• Xanthophyll

• Eumelanin

What are cortical fusi?

• Types of melanin

• Air spaces in the cortex

• Pigment granules

• Hair follicles

What is the primary role of the medulla in hair?

• To offer strength

• To provide color

• To attach to the scalp

• To insulate

How does the medulla contribute to insulation?

• By reflecting sunlight

• By trapping air within its hollow structure

• By absorbing moisture

• By being solid and dense

Which medulla type appears as a continuous line without breaks?

• Intermittent

• Fragmented

• Continuous

• Stacked

What pattern does a uniserial medulla resemble?

• A zigzag pattern

• A series of circles

• A single ladder

• A solid line

What does the medullary index help determine?

• The age of the hair

• The color of the hair

• The species origin of the hair

• The length of the hair

How is the medullary index calculated?

• Length of the hair divided by width of the medulla

• Diameter of the medulla divided by diameter of the hair

• Diameter of the hair divided by diameter of the medulla

• Width of the medulla divided by length of the hair

What is the typical medullary index for human hair?

• Greater than one half

• Less than one third

• Equal to one

• Greater than two thirds