Dermis and Subcutaneous Tissue

Question 1

Dermis is derived from__

Function

Answer 1

derived from mesoderm

Functions: Structure and flexibility, vascular support, immunologic protection, nerve sensation

Contains adnexal structures

The dermis has papillary dermis and reticular dermis

Question 2

Extracellular matrix

Answer 2

Supports cells of the dermis, regulates cell functions

Components: collagen, elastic fibers and extracellular matrix

Question 3

Collagen

Answer 3

main component of the dermis (20% of overall skin volume, 75% of the dry weight of the skin)

Produced by dermal fibroblasts

12 of 28 collagen types are in the skin

Very strong and stretches very little
type one: most abundant (90%)
Collagen 3: increased levels during ebryogenesis, infancy, wound healing
Basment membrane has 4, 7, and 17

Question 4

Elastic fibers

Answer 4

Give skin elasticity and structure (microfibrils/fibrillin) and elastin

Question 5

Extrafibrillar Matrix, aka ground substance

Answer 5

composition: Water, electrolytes, plasma proteins, proteoglycans (structure- protein core, glycosaminoglycans/long chain polysaccharides/dermatan sulfate), link protein, hyaluronic acid
function- binds large amounts of water

Question 6

fibroblasts

Answer 6

derived from mesoderm, synthesize ECM components:
collagen, elastic fibers, ground substance

RER translation, ER and golgi modification, intracellularlyy via procollagen, extracellular becomes cleaved into collagen fibril

Question 7

Marfan syndrome

Answer 7

Autosomal dominant, mutation in FIBRILLIN, variable expression

Long arms and fingers, stria, short torso

Question 8

Ehlers Danlos syndrome

Answer 8

Group of inherited connective tissue, abnormalitlies of COLLAGEN structure, production, processing, assembly

Variable inheritance and clinical features based on mutation

Question 9

Morphea

Answer 9

Autoimmune disease, causes sclerosis (thickening of collagen)

Causes plaques, limb and joint complications, neurologic involvment

Question 10

Systemic sclerosis

Answer 10

(morphea all over)

Autoimmune disease, middle-aged women, widespread sclerosis

Clinical feature: sclerosis of the skin (microstomia, sclerodactyly), Raynauds phenomenon (white->blue->red finger tips), telangiectasia, arthritis, internal organ incolvement (pulmonary fibrosis, renal crisis, esophageal dysmotility)

Question 11

Wound healing

Answer 11

Injury–>hemostasis–>inflammation–>proliferation–>maturation

Question 12

Hemostasis

Answer 12

reflexive vasoconstriction, coagulation through platelet activation, formation oof fibrin plug

Question 13

Inflammation

Answer 13

hours to 3 days
Vasodilation, increased vascular permeability
Leukocyte recruitment

Question 14

proliferation

Answer 14

4-12 days
Angiogenesis by endothelial cells

Collagen, elastin, and matrix synthesis by fibroblasts

Re-epithelialization through keritinocyte migration from edges

Question 15

Maturation

Answer 15

12 days to 2 years, inflammatory cells cleared, fibroblast apoptosis, blood vessels maturation, collagen maturation

Question 16

Subcutaneous fat

Answer 16

derived from mesoderm

Functions:energy storage, insulation shock absorption

Question 17

Erythema nodosum

Answer 17

Reactive panniculitis (inflammatory fat), streptococcal pharyngitis, oral contraceptives, inflammatory bowel disease, malignancy

Young women
Tender red nodules on the shins