Cosmetology

Structure of the Skin

The Epidermis

The outermost and thinnest layer of the skin and made up of five layers.

Layers of the Epidermis

1. stratum corneum: outer layer of the epidermis
2. stratum lucidum: the clear transparent layer under the stratum corneum
3. stratum granulosum: layer of the epidermis that is composed of cells that look like granules and are filled with keratin.
4. stratum spinosum: the spiny layer just above the stratum germinativum. process of skin shedding begins.
5. stratum germinativum: also known as the basal cell layer; the deepest layer of the epidermis. produces new skin cells and is responsible for growth.

The Dermis

The underlying or inner layer of the skin. Also known as derma, corium, cutis, or true skin. The dermis is comprised of two layers.

Layers of the Dermis

1. Papillary Layer: layer of the dermis, directly underneath the epidermis. This layer contains (endings of) capillaries, lymph vessels and sensory neurons. It has a loose network of connective tissue, this characteristic separates it from the reticular layer underneath
2. Reticular layer: The lower, reticular layer, is thicker and made of thick collagen fibers that are arranged in parallel to the surface of the skin. The reticular layer is denser than the papillary dermis, and it strengthens the skin, providing structure and elasticity.

The Subcutaneous Tissue

Also known as the hypodermis or superficial fascia, its the Fatty tissue found just below the dermis

Nerves of the Skin

Motor nerve fibers: Fibers of the motor nerves that are distributed to the arrector pili muscles attached to hair follicles.  Motor nerves carry impulses from the brain to the muscles.

Sensory nerve fibers: Fibers of the sensory nerves that react to heat, cold, touch, pressure, and pain. these sensory receptors send messages to the brain.

Secretory Nerve fibers: fibers of the secretory nerve that are distributed to the sudoriferous glands and sebaceous glands. secretory nerves, which are part of the autonomic nervous system, regulate the excertion of perspiration from sweat glands and control flow of sebum to the surface of the skin.

Fluids of the skin

Blood: delievers nutrients and oxygen to the skin and takes away cellular waste products and carbon dioxide

Lymph vessels: the clear fluids of the body that bathe the skin cells, remove toxins and cellular waste and have immune functions that help protect the skin and body against disease.