The Epidermis

Topic 3 Lesson 1 NurseHub

Epidermis

Protecting the body from the outside as the outermost layer, keeping your skin hydrated, producing new skin cells, and determining your skin color.

Dermis

The middle layer of skin, contains collagen, blood vessels, glands, hair follicles, and nerve endings support and protect the skin and deeper layers, assist in thermoregulation, and aid in sensation.

Hypodermis (Subcutaneous)

The innermost layer of skin, storing energy, connecting the dermis layer of your skin to your muscles and bones, insulating your body, and protecting your body from harm.

Stratum Corneum

the most superficial layer of the epidermis. It consists of cells that have been hardened with keratin.

Stratum Lucidum

an additional layer that is found only in the palms of the hands and soles of the feet. It provides an added thickness to these layers.

Stratum Granulosum

contains cells that have lost their nuclei. These cells remain active and secrete keratin. The cells contain granules in their cytoplasm that harbor keratin.

Stratum Spinosum

contains cells called prickle cells. These cells have small radiating processes that connect with other cells. Keratin is synthesized in this layer.

Stratum Basale

contains epidermal stem cells. This is the deepest layer of the epidermis. It consists of one layer of cells that divide and begin their migration to the superficial layers.

Basement Membrane

a critical interface between the epidermis and dermis. 

Dermal Papillae

specialized structures within the dermis, the second layer of skin, and are crucial for hair follicle formation, growth, and hair cycle control.

Melanocytes

located in the deepest layer of the epidermis. They respond to ultraviolet radiation by producing more melanin pigment which turns skin a darker color.

Lamellar Granules

Are formed in the Stratum Spinosum in keratinocytes and disperse in the stratum granulosum to secrete lipids and other proteins into the intercellular space. 

Keratinocyte

produce keratin, which provides structural support and strength to the skin, hair, and nails. found in the epidermis, specifically in the stratum basale (basal layer) and stratum spinosum. 

Merkel Cell

respond to mechanical stimuli like touch.