Dermatopathology Flashcards
3 main layers of the skin
Epidermis
Dermis
Subcutis (hypodermis)
Sebaceous glands, arrector pili, hair follicle, and eccrine coil (sweat glands) are all located in which layer of the skin?
Dermis
Layers of the epidermis
Stratum Corneum
Stratum Granulosum
Stratum Spinosum
Stratum Basale
Layer of epidermis; made up of multiple layers of flattened keratinized, non-nucleated cells to provide a barrier against trauma and infection; regulates water loss
Stratum Corneum
Layer of epidermis; contains keratohyalin granules; forms cornified cell envelope (lipids that are produced by keratinocytes and secreted into extracellular space) which serves as a water barrier
Stratum Granulosum
Layer of epidermis; has a “spiny” appearance due to desmosomal junctions holding keratinocytes together
Stratum Spinosum
What makes the Stratum Spinosum look “spiny”
Desmosomal junctions between keratinocytes to hold them together
Layer of epidermis; source of mitotically active keratinocytes to replenish the epidermis that is shed
Stratum Basale
It takes _________ for basal cells tor reach the stratum corneum and another _______ to shed
2 weeks; 2 weeks (about 30 days)
minority cell in epidermis; staggered around the basal layer; produce pigment (melanin)
Melanocytes
minority cell in epidermis; dendritic cell that acts as antigen presenting cells of the skin; important for the induction of DELAYED-type hypersensitivity (allergic contact; poison oak)
Langerhans Cells
What intercellular junction prevent water loss and is made up of claudins and occludins?
Tight junctions
What intercellular junction attaches to actin and is made of cadherins and plakoglobin?
Adherens junctions
What intercellular junction attaches to keratin and is made of desmogleins, desmocollins, and plakoglobin?
Desmosomes
What intercellular junction serves as intercellular communication and is made of connexons?
gap junctions
What junction attaches the keratinocytes of the epidermis to the connective tissue/extracellular matrix in the dermis?
Hemidesmosomes
What disease is caused by autoantibodies against hemidesmosomes?
Bullous pemphigoid
What disease is caused by inherited defects of hemidesmosomes?
epidermolysis bullosa
What diseases are caused by autoantibodies against desmogleins of desmosomes?
Pemphigus vulgaris
Pemphigus foliaceus
Hyperkeratosis (more stratum corneum), parakeratosis (retention of nuclei in s. corneum), and acanthosis (thickening of epidermis, spinosum) are characteristics of
Psoriasis
Acanthosis can also be found in
seborrheic keratoses
Papillomatosis (undulating of epidermis) is characteristic of
Viral wart (verruca)
Hypergranulosis (thickening of s. granulosum) is characteristic of
Lichen simplex chronicus
Lichen Planus
Spongiosis (edematous fluid in intercellular space in the epidermis) is characteristic of
atopic dermatitis (eczema)
Lichenoid (band-like infiltrate of lymphocytic cells and sawtooth epidermal retes) is characteristic of
lichen planus
Acantholysis (loss of intercellular connections, desmosomes) is characteristic of
Pemphigus vulgaris
Pemphigus Foliaceus
autoimmune disease against hemidesmosomes holding Stratum Basale to the Dermis; will cause blisters and bullae
Bullous Pemphigoid
Dysplasia in the skin caused by UV exposure
Actinic Keratosis
Type of skin cancer caused by thickening of full epidermis
Squamous cell carcinoma in situ
Type of skin cancer caused by thickening of full epidermis and penetration into dermis
Invasive squamous cell carcinoma
Accumulation of keratin debris forming a dome-shaped lump or tumor
Keratoacanthoma
Most common form of skin cancer; arise from S. basal keratinocytes; basophilic
Basal Cell Carcinoma
Aka. mole; is a common benign skin lesion due to a local proliferation of pigment cells (melanocytes); normal nuclei
Nevus
a type of skin cancer that occurs when pigment producing cells called melanocytes mutate and begin to divide uncontrollably; pleomorphic nuclei
Melanoma
layer of skin; thick layer that is flexible but tough; contains blood and lymphatic vessels, nerves, sweat glands and hair follicles
Dermis
cell located in the dermis; responsible for synthesis and degradation of connective tissue; instrumental in wound healing
Fibroblast
cell located in the dermis; immune cell responsible for IMMEDIATE-type hypersensitivity (urticaria)
Mast cells
Difference between Langerhans and Mast cells (location and function)
Langerhans Cells: in epidermis, DELAYED-type hypersensitivity
Mast Cells: in dermis, IMMEDIATE-type hypersensitivity
layer of skin; fat layer that separates the dermis from the deeper underlying structures (fascia and muscle); insulates body, energy supply, cushion and protects skin
Subcutis
