Science of Skin Flashcards
Atopic dermatitis: What is the defect?
Defect in fillagrin (protein that retains water in granulosa layer).
What helps skin insulate body?
Hair and fat
What helps skin accelerate heat loss?
Sweat and dense superficial microvasculature
Raynaud phenomenon: Describe.
Chronic episodic attacks of digital ischemia provoked by exposure to cold.
(Sudden dilation rather than restriction).
What are four phases of cutaneous wound repair?
Coagulation, inflammatory phase, proliferative-migratory phase (tissue formation), and remodeling phase.
HIV associated lipoatrophy causes what?
Loss of fat throughout face.
Atrophy of buccal fat pads can be particular concern to patients since it gives appearance of facial wasting and can have impact on self esteem.
What are three layers of skin?
Epidermis, dermis, subcutis
Epidermis is composed of what cell primarily?
Keratinocytes
Dermis is composed of what mainly?
Fibroblasts, collagen, elastic fibers.
What is the subcutis comprised of?
Fat
Aka panniculus or hypodermis
Four layers of epidermis?
Stratum corneum, stratum granulosum, stratum spinosum, stratum basale.
How long does it take cell to move from stratum basale to stratum coreneum?
2 weeks then two weeks to shed (28 day cycle)
What makes spinous layer have a “spiny” appearance?
Desmosomal junctions which hold keratinocytes together
What is important function of granular cell layer?
Lipids produced by keratinocytes in granular cell layer and secreted into extracellular space between keratinocyte forms a water barrier that keeps water in skin.
In the startum corneum what are the bricks and what are the mortar?
Bricks: Flattened keratinocytes filled with keratin and filaggrin.
Mortar: Lipid mixture which surrounds keratinocytes and provides the water barrier.
