Structure and Function of Skin Flashcards
skin layers
- Stratus Corneum
- Epidermis
- Dermis
- Subcutaneous Fat
- Muscle
cornification
Filaggrin associates with keratin filaments resulting in dense packing of keratin filaments
cells of the epidermis
- Keratinocytes
–Melanocytes
–Merkel Cell
–Langerhans Cells
What does the dermis contain?
- collagen (gives bulk)
- elastin (gives recoil)
- ground substance
- vasculature
- adnexa:
- Sebaceous glands
–Eccrine glands
–Apocrine glands
–Fibroblasts, Endothelial cells
* note: glands actually epidermal appendages therefore outlined by epidermis though they push into dermis
keratinocytes
- 90-95% of all epidermal cells
- Differentiate as they grow up the epidermal layers
- Cycle takes 28 days
- Heterodimeric rod
Melanocytes
* Derived from neural crest cells
•Can be found in leptomeninges, uvea, retina, cochlea, vestibular labyrinth
•Most dense in face and genitalia
•Respond to MSH (melanin stimulating hormone)
•The density is the SAME in all races
(about one melanocyte for 10 keratinocytes)
Pheomelanin
(laminated, round melanosomes) in red and blonde hair
Eumelanin
(dark, oval melanosomes) in black hair
Merkel cells
Associated with neurites and contribute to sense of touch and mechanoreception
Langerhans cells
immunosurveillance of the skin
Bone marrow derived cells
•About 5% of cells in stratum spinosum
•Antigen presenting cells of skin –> interact with T cells via MHC Class II (HLA-DR)
•Produce large amounts of IL-1
•Can be infected by HIV
•Adhere to keratinocytes via E-Cadherin
desmosomes
mediate cell-cell adhesion
Composed of: Cadherins, desmocalmin, desmoyokin, band 6 protein, plakophillin
•Cadherins are calcium dependent adhesion molecules: Desmogleins and Desmocollins
etiology of pemphigus foliaceus
antigenic target desmoglein 1 (get a superficial blister)
pemphigus vulgaris
antigenic target Dsfg 3
What can we use to tell if the prob is from antibody?
immunofluoesence
Bullous pemphigoid
Antigenic target BPAg2:
