A: Histology of skin Flashcards
Identify
Stratified squamous
3 layers of skin:
Epidermis
Dermis
Hypodermis
Epidermis
- Stratified squamous epithelium
- Keratinocytes: produce keratin
- Cells are in layers
- Separated from dermis by basal membrane
- Avascular
Stratum corneum
Cells are dead: flat sacs filled with keratin
Extracellular space has glycolipid –> waterproof
Stratum granulosum
Keratohyaline granules
Cells are flatter
Organelles degenerate and the cell dies
Stratum spinosum
- Intermediate filaments of cytokeratin
- Desmosomes
Stratum basale
- High mitotic activity
- Cuboidal cells
Stratum lucidum layer
- only in thick skin
- inner part of keratin layer
- thin, clear zone
Desquamation
Cells move through deep layers, older cells on surface fall off.
Keratinization
Cells move through layers, fill with keratin and die
Surface cells resist abrasion and forms permeability layer
Psoriasis
Cells move through epidermal layers in days instead of weeks, so cells pile up on surface before having a chance to mature
White scales: keratin + immature cells
Keratinocyte cells:
Most cells, produce keratin
Melanocytes
- produces melanin
Langerhan’s cells
Increases inflammatory conditions
Merkel cell
Touch receptor
Contact dermatitis
Inflammation of skin caused by direct contact with irritating substance.
Skin rash at site of exposure,
Dermis papillary layer
- areolar CT
- Dermal papillae arranged in parallel rows
Dermis reticular layer
- Thicker
- Dense irregular CT
- Tension lines
Hypodermis
- Areolar CT and adipose CT
- Anchors skin
- Variable thickness
In which layer of the epidermis do cells contain keratohyalin granules?
stratum granulosum
Identify
Dermis, papillary layer
Identify
Thin skin
Identify
Hypodermis
Identify
Stratum granulosum
