Chapter 6, Problem 1TYR

Cells of the ________ are keratinized and dead.

1. a. papillary layer
2. b. stratum spinosum
3. c. stratum basale
4. d. stratum corneum
5. e. stratum granulosum

Summary Introduction

Introduction:

The main type of cells which make up the epidermis are Markel cells, keratinocytes, with melanocytes and Langerhans cells. The subdivision of layers of the skin is strata carneum, strata lucidum, stratum granulosum, and stratum spinosum and stratum basale.

Answer to Problem 1TYR

Correct answer: Option (d) stratum carneum.

Explanation of Solution

Rationale: This is the topmost layer, consists of dead cells that shed periodically and is progressively replaced by cells formed from the basal layer.

Option (a). Papillary layer. It is the upper most layer of the dermis. It intertwines with the rete ridges of the epidermis and is composed of fine and loosely arranged collagen fibres.

Option (b). Stratum spinosum. It is a layer of the epidermis found between the stratum granulosum and stratum basale.

Option(c).Stratum basale. It also contains melanocytes, cells that produce melanin, the pigment primarily responsible for giving skin its colour.

Option (e). Stratum granulosum. It is a thin layer of cells in the epidermis.

Conclusion

Stratum carneum is the top layer of the skin and it protects the living cells beneath it by providing a tough barrier between the environment and the lower layers of the skin.