Anatomy of the Skin

What is the primary function of the stratum corneum?

What is the term for the process of cell hardening in the stratum corneum?

How often is the entire stratum corneum replaced?

What type of fibers are found in the deeper layer of skin?

What is the purpose of desmosomes in the stratum corneum?

What is the function of the hypodermics?

What is the term for the shedding of cells from the stratum corneum?

What is the number of cell layers typically found in the stratum corneum?

What is the primary function of the stratum lucidum?

Which layer of the epidermis is characterized by a grainy appearance?

What is the primary component of the stratum lucidum cells?

What process occurs in the accessory structures of hair and nails?

What is the function of the glycolipid released by keratinocytes in the stratum spinosum?

What is the result of the nuclei and cell organelles disintegrating in the stratum granulosum?

What is the location of the stratum lucidum?

What is the characteristic of keratinocytes in the stratum spinosum?

The Integumentary System

The skin and its accessory structures make up the integumentary system, which provides overall protection to the body.
The skin is composed of multiple layers of cells and tissues held together by connective tissue.

Structure of the Skin

The skin consists of two main layers: epidermis and dermis, and a closely associated layer: hypodermics.
The epidermis is the most superficial layer, attached to the deeper dermis.
Accessory structures, such as hair, glands, and nails, are found associated with the skin.

Layers of the Epidermis

Stratum Corneum

The stratum corneum is the most superficial layer of the epidermis, exposed to the outside environment.
This layer is composed of 15-30 layers of dead, keratinized cells that help prevent microbial penetration and dehydration of underlying tissues.
Cells in this layer are shed periodically and replaced by cells from the stratum granulosum.

Stratum Lucidum

The stratum lucidum is a smooth, translucent layer found only in thick skin of palms, soles, and digits.
This layer is composed of dead, flattened keratinocytes packed with eleidin, a clear protein rich in lipids.
Eleidin provides a barrier to water and gives the layer its transparent appearance.

Stratum Granulosum

The stratum granulosum has a grainy appearance due to changes in keratinocytes as they are pushed from the stratum spinosum.
Cells in this layer become flatter, their cell membranes thicken, and they generate large amounts of keratin and keratohyalin.
These proteins make up the bulk of the keratinocyte mass in the stratum granulosum and give the layer its grainy appearance.

Stratum Spinosum

The stratum spinosum is where keratin synthesis begins, and keratinocytes release a water-repelling glycolipid that helps prevent water loss from the body.

Learn about the structure and functions of the skin and its accessory structures, making up the integumentary system. This quiz covers the layers of cells and tissues that provide overall protection to the body.