Chapter 32, Problem 12A

Summary Introduction

To explain:

It doesn’t hurt when a person has a haircut.

Introduction:

To define mammal hair is considered as a specific character of them. Hair is made up of keratin protein and it also contains melanin pigment. Hair is also considered as a part of the integumentary system.

Explanation of Solution

Hair develops from epithelial cells. Hair cells grow from hair follicles which are the narrow cavities inside a dermis. Cells present at the base of hair follicles divide and push cells away from the follicle which results in the growth of hair. Sebaceous or oil glands are associated with the hair follicles. Skin and hair are lubricated by sebaceous glands. Cells that are divided and are pushed away from follicles become dead and didn’t have any nerve endings which can send stimulus to the brain that’s why it doesn’t hurt when a person has a haircut.

Conclusion

Hair has dead cells and doesn’t have any nerve ending which can send stimulus to the brain that’s why it doesn’t hurt when a person has a haircut.