ch 5 (skin) Flashcards
(34 cards)
What are the 4 strata of the epidermis?
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum corneum
What are the 5 layers of the epidermis?
- stratum basale
- stratum spinosum
- stratum granulosum
- stratum lucidum
- stratum corneum
fascia
the connective tissue around muscles and bones.
lamellated corpuscles
nerve endings that are sensitive to pressure.
What are the 4 principle types of cells in the epidermis?:
- keratinocytes
- melanocytes
- intraepidermal macrophages
- tactile epithelial cells
stratum basale
- composed of a single row of cuboidal or columnar keratinocytes.
- contains stem cells
- contains keratin intermediate filaments
apoptosis
an orderly, genetically programmed cell death in which the nucleus fragments before the cells die.
keratohyalin
it assembles keratin intermediate filaments into keratin (protein).
stratum lucidum
- is present ONLY in thick skin (fingertips, palms, soles)
- 4-6 layers of flattened clear, dead keratinocytes that have more keratin.
keratinization
the process of cells moving from one epidermal layer to the next, accumulating more and more keratin.
dandruff
the excessive amount of keratinized cells shed from the scalp skin.
stratum spinosum
- 8-10 rows of keratinocytes with bundles of keratin intermediate filaments
- contains projections of melanocytes and intraepidermal macrophages
what tissue is the dermis made of?
- dense irregular CT containing collagen and elastic fibers.
what are the cell types in the dermis?
- fibroblasts
- macrophages
- adipocytes
what are the two regions of the dermis?
Papillary region and reticular region
Papillary region
- consists of areolar connective tissue
- Contains collagen and elastic fibers
- dermal papillae
- contains dermal ridges that hold blood capillaries, corpuscles, and free nerve endings
Reticular region
- consists of dense irregular connective tissue
- attached to the subcutaneous layer
- Contains collagen and elastic fibers
- contains things like nerves, fat, and hair follicles
- deep to the papillary region
Extensibility
The ability to stretch
Elasticity
The ability to return to original shape after stretching
pheomelanin
yellow to red melanin pigment
eumelanin
brown to black melanin pigment
tyrosine, tyrosinase
- melanocytes synthesize melanin from the amino acid tyrosine in the presence of an enzyme called tyrosinase.
hemoglobin
oxygen-carrying pigment in red blood cells.
Anatomy of a hair
each chair is composed of columns of dead, keratinized, epidermal cells bonded together by extracellular proteins.
