Skin - Final Exam Study Cards

Front 1

What is the average transit time from the basilar layer to the granular layer of the skin?

Back 1

Two weeks

Front 2

What is the average transit time from the basilar layer to the top of the corneal layer of the skin?

Back 2

Four weeks/one month

Front 3

What structures make up the roads for the "superhighway of the cell?"

Back 3

Microtubules

Front 4

Name the keratin protein subtypes for the following cell layers:
a) Basilar
b) Spinous
c) Granular

Back 4

a) K5, K14
b) K1, K10
c) K2a

Front 5

Which of the following has both extra- and intracellular components: Desmogleins, Plakoglobulins, Desmoplakins, Desmocollins

Back 5

Desmogleins and Desmocollins have both extra- and intracellular components

Front 6

Which is responsible for the brown/black pigmentation of the skin: pheomelanin or eumelanin?

Back 6

Eumelanin is an insoluble, mostly brown/black pigment of the skin. Pheomelanin is a red/yellow pigment found in large quantities in people with "fire red" hair.

Front 7

What four locations can you find mature melanocytes?

Back 7

1) epidermis and hair bulbs of the skin
2) uveal tract of the eye
3) the cochlea, and vestibular labyrinth of the ear
4) leptomeninges of the brain.

Front 8

What line of melanocytes does NOT come from the neural crest cells?

Back 8

The melanocytes of the retina, which come from the optic cup.

Front 9

What enzyme is the rate-limiting step in the production of melanin?

Back 9

Tyrosinase, a copper-dependent enzyme at the top of the melanin synthesis pathway.

Front 10

What is the pathogenesis of Waardenburg Syndrome?

Back 10

Abnormal melanocyte migration, resulting in hypopigmentation and deafness.

Front 11

How do melanocytes distribute their melanosome organelles to the surrounding Epidermal Melanin Unit?

Back 11

By using their long, slender dendritic arms.

Front 12

What cell type contains the majority of melanin in the skin?

Back 12

Keratinocytes.

Front 13

What receptor favors activation of the eumelanin pathway?

Back 13

Binding of MSH (from the POMC precursor) to MCR-1. The AGOUTI gene product antagonizes the eumelanin pathway, promoting pheomelanogenesis.

Front 14

Describe the pathogenesis of Dermal Melanocytosis (Mongolian Spots)

Back 14

Arrest of melanocyte migration in the dermis.

Front 15

What causes Piebaldism? What does it look like?

Back 15

Problems with activation of the C-Kit gene leads to a lack of melanocyte proliferation. Many have a white forelock of hair and patches of persistent hypopigmentation.

Front 16

How do patients with pan-hypopituitaryism present? What is their skin color?

Back 16

Low MSH and ACTH production leads to a chalky-white appearance

Front 17

How do patients with Addison's present? What is their skin color?

Back 17

Primary adrenal insufficiency leads to high levels POMC expression, resulting in excess MSH and hyper-pigmentation.

Front 18

What common acquired condition leaves patches of hypo-pigmentation?

Back 18

The auto-immune disease Vitiligo

Front 19

Name two exogenous skin pigments

Back 19

1) Argyria - from the consumption of colloidal silver
2) Tattoos
3) Minocycline - from the consumption of tetracycline antibiotics.

Front 20

What are the four functions of a basement membrane?

Back 20

Adhesion of the epithelium
Supply Polarity to the tissue
Barrier functions
Signal Transduction between epithelium and underlying connective tissue

Front 21

Mechanobullous Disorders

Back 21

Epidermolysis Bullosa

Front 22

What are the three classes of Epidermolysis Bullosa disorders?

Back 22

1) EB Simplex: fragile skin just above the BMZ, within basal keratinocytes
2) Junctional EB: fragile within the BMZ
3) Dystrophic EB: fragile just below the BMZ, at the superficial dermis

Front 23

What two proteins are commonly mutated in EB Simplex?

Back 23

Those produced by basal keratinocytes - Keratins 5 and 14

Front 24

What cellular structure is most likely to be involved in cases of Junctional EB?

Back 24

The Hemidesmosome. HDs allow basal keratinocytes to adhere to the lamina lucida of the basement membrane.

Front 25

What three hemidesmosome proteins are modified in cases of JEB?

Back 25

1) Plectin
2) a6b4 Integrin - also associated with plyloric atresia
3) Bullous Pemphigoid Antigen 2 - a.k.a. TXVII Collagen.

Front 26

What type of blistering problem is this? What are the light and dark arrows pointing to?

Back 26

Epidermolysis bullosa simplex
Dark Arrow: cleft in lower basal keratinocytes
Light Arrow: clumps of abnormal keratin

Front 27

What non-hemidesmosome protein mutation can cause JEB?

Back 27

The most severe types of JEB are caused by mutations in Laminin 5, an anchoring protein found in the lamina lucida.

Front 28

What gene is always found to be mutated in cases of Dystrophic EB?

Back 28

Type VII Collagen is always mutated in cases of Dystrophic EB.

Front 29

Which is a transmembrane protein - Integrin or Laminin?

Back 29

Integrin is a transmembrane protein. Mature Laminin proteins are found in the extracellular matrix.

Front 30

Which Laminin protein subtypes are found within the skin's BMZ?

Back 30

Laminins 1, 5, 6 and 7 are found in the BMZ.

Front 31

What's the pathophys behind Bullous Pemphigoid?

Back 31

BP patients have autoantibodies to both BPAg1 and BPAg2/TVII Collagen.

Front 32

What are the disease characteristics of BP?

Back 32

Bullous pemphigoid afflicts mostly older individuals (7th & 8th decade). Bullae are found on the extremities, groin and axilla.

Front 33

What Immunobullous disorder attacks Laminin 5?

Back 33

Cicatricial Pemphigoid. Typically scars the eyelids and conjunctiva, esophagus and trachea.

Front 34

Define direct and indirect immunoflourescence.

Back 34

Direct IF is a histologic technique using anti-IgG ABs to stain a patient's tissue specimen.

Indirect IF analyzes a patient's sera for the presence of autoimmune ABs.

Front 35

Explain the phenotype of Dysmorphic EB based on the molecular basis of disease.

Back 35

Unlike non- or lightly-scaring epidermal syndromes, Dysmorphic EB involves fibrous scar formation in the dermis.

Front 36

What are the three primary sub-types of Pemphigus?

Back 36

1) pemphigus vulgaris - Desmoglein 3
2) pemphigus foliaceus - Desmoglein 1
3) paraneoplastic pemphigus.

Front 37

What is the underlying pathogenesis of Pemphigus Vulgaris?

Back 37

Auto-antibody attack of keratinocyte desmosomes, leading to intra-epidermal blistering.

Front 38

Why are PV blisters rarely found intact?

Back 38

The disunion of keratinocytes in the epithelium leads to a friable, fragile blister roof. Lesions are usually seen as erosions.

Front 39

Why are bullous pemphigoid blisters usually found intact?

Back 39

BP attacks BMZ proteins BPAg1 & 2, found in the lamina lucida. Blister roofs are more durable.

Front 40

What proteins are targeted in the following immunobullous disorders:
1) Pemphigus vulgaris
2) Pemphigus foliaceus

Back 40

1) Pemphigus vulgaris- Desmoglein 3
2) Pemphigus foliaceus- Desmoglein 1

Front 41

What are the three most common collagen types in the skin?

Back 41

Type I - 80%
Type III - 10-15%
Type V - 4%

Front 42

Type I Collagen supplies

Back 42

Type I Collagen supplies tissue strength

Front 43

Type III Collagen supplies

Back 43

Type III Collagen supplies tissue compliance

Front 44

Type IV Collagen is associated with

Back 44

Type IV Collagen is associated with basement membranes, and is made by epithelial and endothelial cells

Front 45

What's gone wrong in Ehlers-Danlos syndrome diseases?

Back 45

Ehlers-Danlos Syndrome is a group of collagen synthesis defective diseases.

Front 46

On average, how long does scalp hair grow in a month?

Back 46

Scalp hair grows at approx. 1cm/month

Front 47

How fast do fingernails grow?

Back 47

Fingernails grow approx. 3mm/month

Front 48

In what phase does hair actively grow: anagen, telogen, or catagen?

Back 48

Hair actively grows in the anagenic phase.

Front 49

What are the four types of hair shafts?

Back 49

1) Terminal - thickest (scalp, eyebrows)
2) Vellus - most hair on the body
3) Intermediate - between terminal and velus
4) Lanugo - hair formed in utero, i.e. first hair

Front 50

What cytokines are associated with a TH-2 response?

Back 50

IL-4, IL-5 and IL-10 are associated with a TH-2 response.

Front 51

What cytokines are associated with a TH-1 response?

Back 51

IL-2 and IFN-gamma are associated with a TH-1 response.

Front 52

What are the circulating mediators of the innate immune system?

Back 52

Complement, IL-1, TNF-alpha, INF-gamma and chemoattractants all function in the innate immune response.

Front 53

Atopic dermatitis is associated with which immune response?

Back 53

Atopic dermatitis, a.k.a. eczema or irritant dermatitis, is a TH-2/humoral response.

Front 54

With what skin infection is atopic dermatitis commonly associated?

Back 54

Staphylococcus aureus

Front 55

What immune response is associated with Allergic Contact Dermatitis?

Back 55

ACD follows a cytotoxic T-cell, or TH-1, path. Initially Langerhan's Cells mediate the response.

Front 56

What causes telangiectasia?

Back 56

Dilation and congestion/hyperemia of the superficial vascular plexus

Front 57

What are the two causes of scaling of the skin?

Back 57

Hyperorthokeratosis - retention of the granular cell layer and cornified cell layer

Hyperparakeratosis - thinning or absence of the granular layer, cornified layer retain nuclei

Front 58

What cytoskeletal structure is at issue with Epidermolysis bullosa simplex and Bullous congenital ichthyosiform erythroderma/epidermolytic hyperkeratosis?

Back 58

They both involve problems with Keratin/Intermediate Filaments.

Front 59

What extracellular molecule is associated Bullous pemphigoid?

Back 59

Type XVII Collagen, or BPAg2

Front 60

Are the Epidermolysis Bullosa disorders typically acquired or congenital?

Back 60

Typically congenital

Front 61

What are the common Pemphigoid disorders?

Back 61

1) Bullous pemphigoid - geriatric, extremities, BPAg1 & 2
2) Pemphigoid Gestationis - Pregnancy, BPAg2
3) Cicatricial Pemphigoid - Laminin 5

Front 62

EB Simplex

Back 62

Epidermolysis Bullosa Simplex:
1) Fragile skin at keratinocytes
2) Mutations in K5 & 14

Front 63

What is characteristic of Junctional EB?

Back 63

1) Fragile WITHIN basement membrane
2) Affected proteins: plectin & BPAg1, A6B4 integrin, Laminin 5

Front 64

Acanthosis

Back 64

Thickening of the spinous layer. Found in warts, molluscum, and psoriasis

Front 65

What is one of the molecular etiologies of psoriasis?

Back 65

Abnormal Keratin type switching. Should be to from K1 & 10, in psoriasis mistakenly switched to K6 & 16

Front 66

Bullous congenital ichthyosiform erythroderma (BCIE)

Back 66

1) Histo: clumping of keratin and keratohyalin in suprabasilar keratinocytes.
2) Caused by genetic defect in keratins K1, K10, K2e

(Disase aka epidermolytic kyperkeratosis (EHK))

Front 67

What disease is caused by a mutation in the keratinocyte enzyme transglutaminase?

Back 67

Nonbullous congenital ichthyosiform erythroderma (NCIE)
1) Thick scale & erythema
2) Defects in cornified cell layer

(Disease aka Lamellar ichthyosis)

Front 68

What skin disease is caused by a deficiency in steroid sulfatase?

Back 68

X-Linked recessive ichthyosis
1) Large dark scale, central attachment
2) Enzyme deficiency results in an accumulation of cholesterol sulfate
3) Can't desquamate

Front 69

What three diseases are associated with Type VII Collagen?

Back 69

Dystrophic EB (congenital) - fragile just below the BMZ
Epidermolysis Bullosa Acquisita (acquired) - assoc. with IBD, RA, MM, extensor surface erosions
Linear IgA Dermatosis (acquired) - ring-shaped, diag. with immunofluorescence

Front 70

What disorder is associated with Irritable Bowel Syndrome, Rheumatoid Arthritis and Multiple Myeloma?

Back 70

Epidermolysis Bullosa Acquisita

Front 71

What disease is associated with a mutation in Type IV collagen?

Back 71

Alport's Syndrome. No skin manifestations, but presents with glomerulosclerosis

Front 72

What elastin deficiency causes "hound dog" faces?

Back 72

Cutis Laxa

Front 73

Match the types: Lepromatous and Tuberculoid with TH1 and TH2

Back 73

Lepromatous Leprosy <-> TH2: poor outcome
Tuberculoid Leprosy <-> TH1

Front 74

What skin infection is pathomneumonic with coral-red fluorescence on Wood's lamp exam?

Back 74

The bacterial skin infection Erythrasma glows coral-red under UV light. Cause is Corynebacterium. Looks like a yeast infection.

Front 75

What clinical sign differentiates Erysipelas from generic Cellulitis?

Back 75

Erysipelas (GAS infection) presents with well demarcated erythematous borders due to its epithelial origins.

Cellulitis, a dermal infection, appears much more diffuse.

Front 76

What are the "Big Three" dermatophytes?

Back 76

Trichophyton, Epidermophyton and Microsporum - the "Tinea Three"

Front 77

What pigmenting skin infection grows well in humid climates?

Back 77

Tinea versicolor (Malassezia furfur) - Spag and meatballs on KOH. May be hypo- or hyper-pigmented.

Front 78

What wavelength of UV light causes immediate pigment changes?

Back 78

UVA exposure causes photo-oxidation of preexisting melanin.

Front 79

What is the cause of delayed tanning?

Back 79

UVB exposure is the cause of the delayed tanning response.

Front 80

Physiologically, what happens during the delayed tanning response?

Back 80

Melanocyte numbers increase, as well as melanosome synthesis and transfer.

Front 81

Spongiosis is

Back 81

an exudative collection edema fluid between keratinocytes that stretches the intracellular bridges

Front 82

What two broad-functioning cytokines trigger the innate immune response?

Back 82

Interleukin-1 (IL-1) and Tumor Necrosis Factor alpha (TNFa)

Front 83

What are the two primary cytokines responsible for a TH1 response?

Back 83

Interleukin-2 (IL-2) and Interferon-gamma (INF-g) stimulate a cytotoxic TH1 T-Cell response.

Front 84

What are the three primary cytokines of a TH2 response?

Back 84

Think flyfishing "10 and 2": TH2 response is generated by IL-10, as well as IL-4 and IL-5

Front 85

What effect does IL-12 have on undifferentiated T-Cells?

Back 85

IL-12 stimulates the production of TH1 cells, and inhibits the production of TH2 cells.

Front 86

What endothelial ligand binds T-Cell Cutaneous Lymphocyte Antigen (CLA)?

Back 86

E-selectin, expressed on dermal capillary endothelial cells, is a "homing signal" for T-Cells headed for the skin.

Front 87

What are the three stages of cancer in the Multistage Model for Photocarcinogenesis?

Back 87

Initiation: mutation of a target gene
Promotion: external forces lead to clonal expansion
Progression: further genetic damage leads to cancer

Front 88

What two tumor suppressor genes are most important in non-melanomatous skin cancer?

Back 88

p53 and PTCH (patched)

Front 89

What gene is associated with Familial Melanoma?

Back 89

CDKN2A, aka p16

Front 90

A defect in what gene is responsible for Basal Cell Nevus Syndrome?

Back 90

PTCH (patched).