Chapter 5, Problem 1CYU

While walking baretoot in a barn, Jeremy stepped on a rusty nail that penetrated the epidermis on the sole of his foot. Name the layers the nail pierced from the superficial skin surface to the junction with the dermis.

Summary Introduction

To review:

The name of the layers present between the superficial skin surface and the dermis of the skin of foot of Jeremy, when pierced by the nail on walking barefoot.

Introduction:

The thick skin of palms, fingertips, and soles of the feet consists the epidermis, which is divided into five different layers which are named as follows: stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum from deep to superficial. Each of these strata have different properties.

Explanation of Solution

The five layers present between the superficial skin surface and the dermis are as follows:

Stratum basale: As the name indicates this is the basal layer or the deepest epidermal layer which is in contact with dermis. It is mainly characterized by the presence of single row of stem cells, which are continuously undergo cell division, so consists of the youngest keratinocytes. One of the daughter cell is pushed into the upper epidermal layer to form mature keratinocyte. The other daughter cell continue the division to form new keratinocytes.

Stratum Spinosum: this is a multilayer tissue, in which cells consists of intermediate filaments. The keratinocytes of this layer have a spiny appearance, so also known as prickle cells. Melanin granules and dendritic cells are found most abundantlyin this epidermal layer.

Stratum Granulosum: This is four to six cell layers thick where the process of keratinization starts. Keratinization is the process of accumulation of keratin in the cell, and the nuclei and organelles starts degeneration. This layer is specific for the accumulation of two types of granules. Keratohyaline granules helps in the formation of keratin and lamellar granules helps in providing the water resistant.

Stratum Lucidum: This is a layer consists of two or three rows of flat and dead keratinocytes with indistinct boundaries. In this layer or in stratum corneum above, the sticky substanceof the keratohyaline granules attaches with thekeratin filaments in the cells.

Stratum corneum: This is the outermost layer of the epidermis which consists of dead cells known as corneocytes. Around 15–20 layers of flattened cells with no nuclei and cell organelles are present in this layer.

Conclusion

Thus it is concluded that stratum basale, stratum spinosum, stratum granulosum, stratum lucidum, and stratum corneum from deep to superficial, are the name of the layers present between the superficial skin surface and the dermis of the skin of foot of Jeremy, when pierced by the nail on walking barefoot.