Introduction to Dermatology and Epidermis Flashcards
List the layers of dermis from outside to inside.
Epidermis, papillary dermis, reticular dermis, and subcutaneous fat.
What are the layers of tissue within the epidermis?
Stratum corneum, stratum granulosum, stratum spinosum, and stratum basalis
List and describe some of the functions of the skin.
Barrier (to physical things, light, and pathogens), vitamin D synthesis, water retention, thermoregulation, and sensation
What is Fitzpatrick I?
Never tans; always burns
What are the two types of melanin?
Eumelanin (black/brown) and pheomelanin (yellow/red-brown)
How are dark and light skin types different?
In darker skin, melanosomes are larger and distributed throughout the cytoplasm, while in lighter skin melanosomes are smaller and usually near the nucleus
Albinism is due to a ________.
defect in the tyrosinase gene involved in melanin production
Explain the pathology of vitiligo.
Vitiligo is an autoimmune disorder in which the body attacks melanocytes, resulting in acquired depigmentation.
Vitamin D can come from _____.
the diet or from UVB and 7-dehydrocholesterol (in the skin)
What connects the epidermis to the dermis?
Hemidesmosomes (defects of which can cause bullous pemphigoid)
The genetic defect in recessive dystrophic epidermolysis bullosa is ________.
defect in collagen VII
The genetic defect in junctional epidermolysis bullosa is ______.
mutations in laminin V
Stratum spinosum cells are held together with __________.
desmosomes (which is why they appear spiny)
There are two main disorders of stratum spinosum desmosomes: ________.
pemphigus vulgaris (acquired autoimmune) and epidermolysis bullosa simplex (genetic)
The stratum lucidum is found deep to _______.
thick skin (between the corneum and granulosum strata)
The medical term for “red all over” is ______.
erythroderma
Which is denser, papillary or reticular dermis?
reticular (it is also deeper)
How do melanocytes transport melanin, and to what cells?
Through dendrites, to keratinocytes
What are dendritic cells in the skin called?
Langerhans cells
Explain the difference between eccrine and apocrine glands?
Apocrine glands are specialized and are found in the pubic, axillary, and perianal regions, while eccrine glands are sweat glands and are found everywhere except the lips, under the nail beds, and on the glans of the penis and the clitoris.
The peripheral parts of the extremities and fingers is called the ____ region.
acral
Describe the pathophysiology of pemphigus vulgaris.
Autoimmune disorder in which antibodies attack the desmosomes that adhere stratum spinosum cells, leading to intraepithelial blisters.
In which layer of the epidermis does water retention occur, and how?
Filaggrin breaks down in the stratum cornea and retains water.
What are flat lesions called?
Macules, and patches when they are larger than 1.0 cm
