Chapter 5: The Integumentary System Flashcards
Epidermis
Superficial, thinner portion of skin, composed of epithelial tissue.
Dermis
Deeper thickness connective tissue. Contains collagen and elastic fibers.
Subcutaneous Layer
Or hypodermis
Deep to the dermis not part of the skin. Composed of areolar and adipose tissue.
Lamellated Corpuscles
Contains nerve endings that are sensitive to pressure.
Keratin
Protein produced by keratinocytes
Lamellar Granules
Releases water repellent sealant that decreases water entry and loss.
inhibits the entry of foreign materials.
Melanin
Yellow-red or brown black pigment that contributes to skin color and absorbs ultra violet light.
Synthesized by amino acid: tyrosine
Found in: penis, nipples, face and limbs
Keratinocytes
90% of cells in skin
Produces protein: keratin and Lamellar granules
Melanocytes
8% of skin cells
Developed from the ectoderm of a developing embryo
Produces pigment: melanin
Intraepidermal Macrophages
Arise from red bone marrow
Migrate to epidermis
Easily damaged by uv light
Destroys pathogens
Tactile Epithelial Cells
Least numerous of epithelial cells
Located deepest to the dermis, contact with tactile disc
Epidermal Strata
From deepest to superficial layer
- Stratum Basale
- Stratum Spinosum
- Strata Granulosum
- Strata Lucidum
- Strata Corneum
Strata Basale
Deepest layer. Composed of cubodial or columnar keratinocytes
Contains scattered keratin and intermediate filaments
Site of cell divsion
Stratum Spinosum
Rows of many sided keratinocytes with bundles of keratin
Contains melanocytes and intraepidermal macrophages
Stratum Granulosum
Rows of flattened keratinocytes, organelles begin to degenerate
Contains keratonyalin protein and lamellar granules
Keratonyalin Protein
Converts keratin into keration
Stratum Lucidum
Present only in thick skin
Rows of clear, flat, dead keratinocytes with large amounts of keratin
Stratum Corneum
Top Layer
Rows of dead flat keratinocytes. Contain mostly keratin.
Mechanical stress would increase this layer.
Dermis
Second, deepest part to skin
Contains collagen, elastic fibers
Papillary region
1/5 thickness of dermis layer. Not attached to SC layer
Dermal Papilae
Increase surface area of dermis. Project into under surface of epidermis.
Contains: capillary loop (blood vessels), corpuscles of touch (free nerve endings)
Reticular Region
Attached to SC layer
Contains:
Bundles of thick collagen fibers, scattered fibroblast, wandering cells
Collagen and Elastic Fibers
Produces strength (extensibility) and stretch (elasticity)