A&P Chapter 5

stratum lucidum

"clear layer" below the stratum corneum and above the stratum granulosum layer; only found in thick skin; the cells are flattened, densely packed, largely without organelles, and filled with keratin.

what are the 5 layers of epidermis (thick skin)

1. stratum corneum 2. stratum lucidum (extra layer found in thick skin) 3. stratum granulosum 4. stratum spinosum 5. stratum basale

Ecrine sweat glands

aka merocrine sweat glands; discharge their secretions directly onto the skin; adult integumentary contains 2-5 million of these glands.

sebaceous glands

aka oil glands, holocrine glands that discharge an oily lipid (sebum) secretion into hair follicles.

thin skin

contains 4 layers of keratinocytes, covers most of the body surface

stratum basale

deepest layer of epidermis; attachment to the basement membrane; contains basal cells (stem cells), melanocytes, and tactile cells (Merkel cells).

3rd degree burn

destroy the epidermis, dermis, extending into the subcutaneous layer. despite swelling these burns are less painful than 2nd degree- because sensory nerves are destroyed. these burns cannot repair themselves.

2nd degree burn

entire epidermis and some of dermis is damaged. blistering, pain, and swelling occur.

apocrine sweat glands

found in the armpits (axillary region), around the nipples, and in the pubic region they produce a cloudy and odorous secretion; and rely on merocrine secretion.

thick skin

has 5 layers of keratinocytes, found on the palms of the hands and soles of the feet

stratum spinosum (spiny layer)

layer superficial to stratum basale; contains 8-10 layers of keratinocytes bound together by desmosomes; cells look like pin cushions.

basal cell carcinoma

most common, less severe type of skin cancer. caused by stratum basal cells that proliferate and slowly invade dermis and hypodermis.

melanoma cancer

most dangerous type. comes from Melanocyte cells

1st degree burn

only epidermis is damaged, skin reddens and can be painful (this type includes most sunburns); the redness is a sign called erythema.

stratum corneum

outermost layer for both thin and thick skin; water resistant layer but not water proof; contains 15-30 layers of keratinized cells.

squamous cell carcinoma

second mot common type of skin cancer; can metastasize. involves keratinocytes of stratum spinosum.

Which layer of the epidermis is only found in thick skin?

stratum lucidum

stratum granulosum

superficial to the stratum spinosum; consists of 3-5 layers of keratinocytes derived from stratum spinous.