Question | Answer |
Skin is both: | An organ and a system |
Epidermis | Derived from surface ectoderm, migrate from neural tube in circumferential bands. |
Basal Layer | Replaces the surface cells as they slough off |
Dermis | Derived from mesoderm |
Melanoblasts/melanocysts | Pigment of neural crest origin, located in basal layer. |
Sebaceoius glands | secretes the sebum |
Sweat glands | secretes the sweat |
Mammary glands | Used to be sweat glands |
Eumelanin | Brown tinted |
Pheomelanin | Red color in red color in red hair, Freckles |
Landmarks of skin | Pigmentation, Thickness, Mobility, Elasticity, Strength, Creases, Dermatoglyphs,and Blaschko's lines |
Minor Pigmented Nevi anomalies of the Skin | Mongolian spot, Cafe-au-lait spot, Freckles, Lentigines, Hamartomatous, epidermal nevi, angiofibromas |
Hamartomatous | Benign mix type of cells. Not in the right spot but close. |
Minor Vascular Nevi anomalies of the Skin | Nevus Flammeus, Port wine stain, Telangiectases, Raised. |
Deformations of the Skin | Redundant neck skin, Redundant abdominal skin, Abnormal skin creases. |
Dysplasias of the Skin | Cutis Laxa, Hyperelasticity, Ichthyosis, Epidermolysis bullosum, Hypopigmentation, Hyperpigmentation, Premature thelarche, Absence of the sweat glands. |
Malformations of the Skin | Cutis Aplasia, Focal Dermal hypoplasia, Skin Tumors - Neurofibromas, Plexiform neurofibromas, Lipomas, Xanthomas, Nevi, Shagreen Pathes, Hypopigmentation - ash-leaf spots, Piebaldism, Vitiligo, Hyperpigmentation, Poikiloderma. |
Incontinentia pigmenti: What is it and the 4 stages. | X-Linked Dominant, Lethal in males, Any female is a mosaic.
1.) Born with blisters, 2.) Develop raised lines, 3.) Settles to streaky lines, 4.) Linear hypopigmenetation. |
Hypomelanosis of Ito | Multigenic, Even male to female ratio |
Poikiloderma | Mixture of Hypo, Hyper and Normal skin color. |
Peutz-Jehger syndrome | Brown/black macules |
Hair Embryology | Begins = Week 14
Direction of hair shaft = 15-19 weeks
Lanug0 = 20 weeks to birth |
Landmarks of the Hair | Distribution, Whorls, Color, Eyebrows, Pubic/axillary hair |
Minor anomalies of the Hair | Low anterior hairline, Widow's peak, Supernumerary whorls. |
Synophrys | Cornelia De Lange |
Embryology of the Nails | Fingers separate and nails begin = Week 10
Nails to fingertip = 32-33 weeks
Toenails lage behind. |
Landmarks of the Nails | Shape, Lunula, Cuticle, Curvature, Nail angle |
Nail abnormalities | Thickened nails, Dystrophic nails |
Malformations of the Nail | Narrow, Hyperconvex, Tapered, Broad, Small, Aplastic. |