Skin, Nails, Hair Flashcards
Anagen Phase
Growth phase of hair
Catagen Phase
Regression phase of hair bulb.
Telogen Phase
Resting phase of hair. Remaining hair is called club. Will be pushed out when anagen phase starts again.
Telogen Effluvium
Too many follicles enter telogen phase. Results in hair shedding. This is a reversible condition.
Anagen Effluvium
Hair loss due to something damaging growing cells.
Androgenetic Alopecia
Hair loss triggered by androgens. Hair follicules become miniaturized.
Alopecia Areata
Autoimmune destruction of hair follicles and hair loss. Lymphocytes surround hair bulb. Patches of hair loss
Eccrine Glands
Sweat glands that release to surface. Help cool down body and releases urea too. Glands surrounded by myoepithelia cells to help push sweat up.
Appocrine glands
Releases proteinaceous material at upper part of hair follicle. Glands surrounded by myoepithelial cells. Don’t secret until puberty. Found in axilla (armpit), areola, and circumanal (around anus) region.
Sebaceous glands
Release lipid called Sebum to upper part of hair follicle. Becomes more active after puberty.
Free nerve endings respond to
Respond to temperature and pain. Enter epidermis from dermis.
Pacinian Corpuscles respond to
Respond to pressure stimuli. Located deep in dermis.
Meissner’s corpuscles
Located in dermal paillae. Numerous around fingertips, soles of feet, lips, and genitalic area. Composed of coiled nerve endings surrounded by modified Schwann cells. Light touch and vibration.
Merkel cells
Light touch. End in epidermis.
Stratum Basale
Melanocytes which make melanin which get eaten by keratinocytes. Collagen VII secreted by keratinocytes here. These attach cell integrins of cells to dermis via laminin (?)
Stratum Spinosum
Cells from basal layer migrate up and become prickle cells. Lots of desmosomes. Reinforced internally by bundles of keratin filaments called tonobrils. Vitamin D is made here. Langherans cells here act as antigen presenting molecules.
Stratum Granulosum
Keratin cells called keratohyalin cells produce profilaggrin which become flaggrin.
- Proflaggrin cross-links keratin filaments for reinforcement in corneocytes.
- Flaggrin acts as a moisturizer and acidifies stratum corneum to prevent colonization by pathogens.
- Lamellar bodies secret lipid and act as mortar for cornified layer. Has waterproofing qualities.
Stratum Corneum
Dead cells. Squamous. Attached by desmosomes.
