The video tutorial explains that hair is primarily composed of keratin, a protein also found in skin, nails, and various animal parts. It describes the three layers of hair: the dome, crust, and medulla. Additionally, it highlights how hair growth varies with seasons due to changes in blood flow to the scalp, increasing in summer and decreasing in winter.

What is the primary protein that makes up human hair?

• Collagen

• Myosin

• Keratin

• Elastin

Where else in the human body is keratin found besides hair?

• Skin and nails

• Bones and teeth

• Blood and lymph

• Muscles and tendons

Which layer of hair is known as the medulla?

• Middle layer

• Outer layer

• Inner layer

• Surface layer

Why does hair grow faster in summer than in winter?

• Increased sunlight exposure

• Higher humidity levels

• Greater blood flow to the scalp

• More vitamin D production

During winter, where is blood flow redirected in the body?

• To the skin

• To the internal organs

• To the extremities

• To the hair follicles