Anatomy Quiz 3, Chapter 5: Integumentary System (Know It All Version)

Integumentary System

Hair, skin, nails, glands

Epidermis

-Superficial layer of stratified squamous epithelial tissue

-Protection & reduces water loss

Dermis

-Deep layer of connective tissue

-Structural Strength

Subcutaneous Tissue

-Not part of the skin

-Loose connective tissue that connects skin to underlying structures

Keratinocytes

-Most cells

-Produces Keratin for strength

Melanocytes

-Contributes to skin color

-Same number of them in all people

Langerhans Cells

Part of immune system

Merkel Cells

-Detect light touch

-Superficial pressure

Keratinization

-As cells extend outward through the layers they fill with keratin, they die

-Serves as a layer that resists abrasion & forms permeability layer

Stratum Basale

-Deepest portion of epidermis

-Single layer of cuboidal/columnar cells

-High mitotic activity

Length for keratinocytes to undergo mitosis

Every 19 days

What desmosomes do for keratinocytes

Hold together and provide structural strength

Amount of time to move from stratum basale to surface

40-56 days

Stratum Spinosum

-8-10 layers of many-sided cells (flatten as they are pushed upward)

-Contain new desmosomes

-Lipid-filled lamellar bodies

Additional keratin fibers

Stratum Granulosum

-2-5 layers of flattened, diamond-shaped cells

-Contains granules of keratohyalin cells

In Stratum Granulosum Layers…

-Nucleus and other organelles degenerate and cell dies

-Keratin fibers and keratohyalin granules do not regenerate

Stratum Lucidum

-Thin, clear zones of dead keratinocytes

-Indistinct boundaries

-Found only in palms of hands and soles of feet

Stratum Corneum

-Most superficial

-Consists of 25+ dead, overlapping squamous cells

-Joined by desmosomes called cornified cells

Cell remnants of Stratum Corneum Have…

-A soft protein envelop of keratin

-A mixture of keratin fibers

-Keratohyalin

Strata Layers: Deep to Superficial

5. Stratum Corneum

4. Stratum Lucidum

3. Stratum Granulosum

2. Stratum Spinosum

1. Stratum Basale

Thick Skin

-Superficial

-Epidermis

-All 5 strata

-Found in. areas subject to pressure & friction (palms, soles, fingertips)

Thin Skin

-Deep

-4 strata; no stratum lucidum

-more flexible

-covers the rest of body

-hair grows here

Melanin

-Provides protection against UV light

-Group of chemicals derived from aminos & tyrosine

-Colored brown-black, may be yellowish or reddish

Melanocytes

-Processes extend between keratinocytes

-Deposit melanosomes (pigment of melanin)

Albinism

-Deficiency or absence of pigment

-Production determined by genetics, hormones, and exposure to light