2/13 Derm Cell Biology Flashcards
What are the 2 main layers of the skin and what are the components of each?
(out -> in)
Epidermis (corneum, granulosum, spinosum, basalis)
Dermis (papillary, reticular)
What are the functions of keratinocytes?
- Principal cell of the epidermis
- Filaments made of keratin
- Attached by desmosomes (spines)
4 layers
- stratum basalis - anchors epidermis to dermis via connection through the basement membrane
- stratum spinosum
- stratum granulosum
- stratum corneum - forms a barrier to prevent water and temperature loss as well as infestation
What is the difference btwn Bullous Pemphigoid and Pemphigus Vulgaris?
Bullous pemphigoid “blister” SUBEPIDERMAL, autoantibodies are directed against basement membrane; tends to attract a lot of eosinophils (mxn unclear!)
Pemphigus vulgaris “blister” SUPRABASILAR - autoantibodies are directed against some part of the epidermis (compare to Bullous pemphigoid)
What is the function of melanocytes?
What is a key feature of these cells?
- produces melanin (located above the nucleus - protects DNA from UV damage)
- Intermixed with the kertainocytes
- Stains with S-100 protein
What are the functions of Langerhans cells?
What is a key feature of these cells?
- Primary antigen-presenting cell of the skin (dendritic cells)
- Contain Birbeck granules (tennis brackets)
What is the function of lymphocytes?
What is a key feature of these cells?
- Round, dark staining nucleus with a narrow rim of cytoplasm
- T and B subsets present in many inflammatory dermatoses
What is the function of Eosinophils?
What is a key feature of these cells?
- Stain red (granules contain hydrolytic enzymes stain strongly eosinophilic)
- Bilobed nucleus
- Involved in hypersensitivity reactions and parasitic infections
What is the function of neutrophils?
What are the key features of this cell?
What is Sweet’s Syndrome?
- Multilobed nucleus
- Inflammatory and phagocytic
- Infections
Sweet’s syndrome (Neutrophilic dermatosis is a paraneoplastic syndrome of leukemia or lymphoma; rule out infection by staining because this is a STERILE specimen (won’t find any bacteria or fungi under the microscope)
What is the function of mast cells?
What are the key features of this?
What is mastocytosis?
- Mediate allergies
- Mast cell degranulation can lead to anaphylaxis
Mastocytosis - fried egg look (centered nuclei) neoplastic proliferation of mast cells
What is the function of histiocytes?
What are the key features of this?
- Bone marrow-derived cells
- Mononuclear phagocytes
- Aggregates of activated macrophages are referred to as granulomas
What are the 3 types of glands?
- Apocrine: anogenital, breasts, eyelids, axillae areas
- Eccrine: palms & soles
- Sebaceous: face, areola, genital mucosa
What is the functions of endothelial cells?
What are the key features of this cell type?
- Weibel-palade body (rod-shaped)
- Antigen presentation (just like langerhans)
- Interact with adhesion molecules
- Permeability of vessels
What are the major nerves types of the skin? What do they innervate?
- Meissner’s and pacinian corpuscles
- Sensory and autonomic nerves
- Innervate vessels, glands, follicles
what’s a weibel-palade body? function? found in what cell type?
storage granules found in endothelial cells
released when the endothelium is activated
they release vWF and P selectin –> pro-coagulant
what are birbeck granules? what shape? what cells are they found in?
what’s their role?
tennis-racket shaped, found in langerhans cells (which are the antigen-presenting cells in skin).
unknown role!
