Epidermis layers and Skin (Thick & Thin)

Thick skin

All 5 epidermal strata (deep-superficial) occur in the thick skin. It houses sweat glands but has no hair follicles or sebaceous (oil) glands

Tactile Cells

Also called markel cells. Sensitive to touch

Order of Epidermis layers from deepest to superficial

Basale Layer, Stratum Spinosum, Stratum Granulosum, Stratum Lucidum, Stratum Corneum,

Epidermal Dendric cells (PART OF STRATUM SPINOSUM)

Cells that help fight infection in the epidermis

Stratum Granulosum

Consists 3-5 layers of keratinocytes. The process of KERATINIZATION begin

Stratum Lucidum Layer

Consists of 2-3 layers of keratinocytes. Found ONLY in thick skin within the palms of hands and soles of the feet.

Where is thin skin found?

Covers most of the body.

What is the name of keratin found in the epidermal cells?

Cytokeratins. Their structure in theses cells gives skin its strength and makes the epidermis almost waterproof

Keratinocytes (cell that occupies the basale layer)

Dominated by large keratinocyte stem cells which divide to generate new cells that replace dead keratinocyte cells shed from surface. Name is derived fro synthesis of keratin

What type of keratinocytes are in the Stratum Lucidum Layer?

Flattened keratinocytes that are filled with the translucent protein ELEIDIN.

What are some structures of thin skin

Hair follicles, sebaceous glands, and sweat glands

Desmosomes function (part of the stratum spinosum layer)

Keep keratinocytes tightly bound

A keratinized epithelium contains large amount of what?

Keratin

What does Anucleate mean?

Lacking a nucleus

Thin skin

Lacks the stratum lucidum layer so it only has 4 specific layers in the epidermis.

Melanin is transferred through what ?

Melanosomes.

Stratum Corneum Layer

Most superficial layer. Consists of 20-30 layers of dead keratinized cells. The dead keratinized cells are ANUCLEATE and are tightly packed together.

Where is thick skin found?

Palms of the hands and soles of the feet

What is keratin?

Protein that strengthens the epidermis

Melanocytes (cell that occupies the basale layer)

Scattered among the keratinocytes of the stratum basale. Produce and store the pigment MELANIN in response to ultraviolet light exposure

Stratum Spinosum Layer

Several layers of keratinocytes. The non dividing keratinocytes in the stratum spinosum attach to their neighbors by many membrane junctions called DESMOSOMES.

Basale Layer

Single layer of cuboidal to low columnar cells. There are 3 types of cells that occupy the basale layer

Melanin pigments helps in doing what ?

The pigment accumulates around the nucleus of the keratinocytes and shields nuclear DNA from ultralight radiation

What is Keratinization?

When the keratinocytes fill up with the protein keratin and in so doing, cause both cells nucleus and organelles to disintegrate and the cell dies.