Chapter 5, Problem 1RAC

If a splinter penetrates the skin of the palm of the hand to the second epidermal layer from the surface, the last layer damaged is the
a. stratum granulosum. d. stratum
b. stratum basale.     e. stratum spinosum.
c. stratum corneum.

Summary Introduction

Introduction:

The skin is comprised of 2 major tissue layers, the epidermis and the dermis. The epidermis is the superficial skin layer, comprising stratified epithelial squamous tissue. The multiple cell layers of the epidermis protects against the potential damage from abrasion on the skin's surface.

Answer to Problem 1RAC

The correct answer is option (d) stratum lucidum.

Explanation of Solution

Explanation/justification for the correct answer:

Option (d) stratum lucidum. The stratum lucidum in the epidermis is a thin, transparent layer of dead skin cells named for its translucent appearance under a microscope. It is easily noticeable by light microscopy only in regions of thick skin found on the hands ' palms and feet's soles. So, the correct answer is option (d).

Explanation for incorrect answer:

Option (a) stratum granulosum. A thin layer of cells in the epidermis is the stratum granulosum (or granular layer). Keratinocytes that migrate from the underlying stratum spinosum are known in this layer as granular cells. So, this is an incorrect option.

Option (b) stratum basale. The stratum basale is the deepest layer of the five layers of the epidermis, which cover the outside of the skin in mammals and is sometimes called as the stratum germinativum. So, this is an incorrect option.

Option (c) stratum corneum. Stratum corneum is the peripheral layer of the skin, comprising of keratinized cells. The stratum corneum, or the skin boundary, goes about as our first line of resistance against the outer condition. It is a compact layer of cells and lipids that has two basic capacities: it shields our bodies from microorganisms, UV harm and other assaults; and avoids natural moisture from escaping, to keep skin hydrated. So, this is an incorrect option.

Option (e) stratum spinosum. Stratum spinosum is a superficial stratum basale which consists of 8 to10 layers of multi-sided cells. As the cells in this stratum are pushed to the ground, they flattened; desmosomes break apart and fresh desmosomes form. So this is an incorrect option.

Conclusion

If a splinter penetrates the skin of the palm of the hand to the second epidermal layer from the surface, the last layer damaged is the stratum lucidum. Hence, the correct answer is option (d) small intestine.