FOM 6.2.3

Question 1

What are each of these on the histological slide?

Answer 1

Epidermis

Dermis

Hypodermis

Question 2

What are the cell types in the epidermis?

Answer 2

Keratinocytes - epidermal skin cells

Merkel cells - tactile receptors

Langerhans cells - macrophages

Melanocytes - derived from neural crest cells

Question 3

What are each of these cell layers?

Answer 3

Top to bottom

Stratum corneum, lucidium, granulosum, spinosum, and basale

Question 4

What is the underlying etiology of psoriasis?

Answer 4

Infiltrating immune cells synthesize and release cytokines that signa; proliferation and thus lead to a reduced length of cell cycle. Turnover is reduced to three to four days.

Question 5

Answer the following

Answer 5

D - Cytokines from infiltrating lymphocytes

Question 6

What is filaggrin?

Answer 6

It induces the aggregation of keratins

Question 7

What is are lamellar bodies?

Answer 7

The place where lipids form

Question 8

The formation of the water barrier is cause by what?

Answer 8

Question 9

What is lamellar ichthyosis caused by?

Answer 9

A mutation in the TGM 1 gene which leads to a defective transglutaminase protein.

Question 10

What would you find in dermatitis herpetiformis?

Answer 10

Autoantibodies to transglutaminase, a gluten intolerance and IgA deposits

Question 11

What is a melanocyte?

Answer 11

It originates from the neural crest and it creates melanosome that travel to the nearby keratinocyte.

Question 12

What is a langerhans cell?

Answer 12

It is a peripheral dendritic cell that presents antigens to the immune complex.

Question 13

What is a merkel cell?

Answer 13

These are tactile mechanoreceptors that associate with the basal lamina. It has a short axon

Question 14

What is the target antigen of pemphigus vulgaris?

Answer 14

The target antigen for pemphigus vulgaris is desmoglein (DSG) 3

Question 15

Pemphigus foliacues has autoantibodies to what?

Answer 15

DSG1

Question 16

Moving from the base to surface what is happening to the level of DSG3? DSG1?

Answer 16

The levels of Dsg3 is decreasing moving from base to top

The levels of Dsg1 is increasing from the base to the top

Question 17

What are the two types of pemphigus vulgaris?

Answer 17

Musous membrane dominant - anti DSG-3

Mucocutanous - anti-DSG 1 and DSG 3

Question 18

What is the levels of Dsg1 in the mucous membrane?

Answer 18

It is almost non existant

Question 19

This histological slide is indicative of what disease?

Answer 19

This is pemphigus vulgaris. The mucosal epithelial damage is more severe owing to a lack of compensation by the weakly expressed DSG-1.

Question 20

Mucocutaneous pemphigus vulgaris has autoantibodies against what?

Answer 20

It has autoantibodies for Dsg1 and Dsg3

Question 21

What is this a picture of

Answer 21

Pemphigus foliaceus anti-DSG1 antibodies produce blister formation in the upper epidermis, because the remaining DSG3 can maintain cell–cell adhesion in the lower epidermis; there are no blister formations on the mucous membranes, because the remaining DSG3 can completely maintain cell–cell adhesion of the mucosal epithelium

Question 22

What are the main characterics to know about the hair follicle?

Answer 22

The external root sheath is continuous with the stratum basale

The internal root sheath surrounds the hair shaft

Depmal papilae are a reservoir of stem cells

Question 23

What are the three “gen” terms associated with hair growth and what do they mean?

Answer 23

Anagen - growth phase

Catagen - intermediate/regression

Telogen - rest/shedding

Question 24

What is the type of secretion that sebaceous glands go through?

Answer 24

Holocrine secretion

Question 25

What are the two types of secretion sweat glads do?

Answer 25

There are two general types, eccrine and apocrine. Eccrine (merocrine) sweat glands are long tubular extensions from the epidermis which coil into a ball-shaped mass in the dermis or hypodermis. Apocrine glands are in the axilla, perianal and pubic areas, scrotum, labia majora and around the nipples. They lie in the subcutaneous tissue and their ducts terminate in hair follicles.

Question 26

What is the meissner and pacinian corpuscle?

Answer 26

Meissner - tactile receptor Paninian - sensitive to pressure

Question 27

Compare first and second intention healing

Answer 27

First intention healing involves clotting, neutrophils, monocytes, macrophages, and fibroblasts and vascular endothelial cells Second intention - fibroblasts are myofibroblasts

Question 28

What are the two types of mechanisms for tissue repair in the skin?

Answer 28

Mechanisms of tissue repair: regeneration and scar formation. Following mild injury, which damages the epithelium but not the underlying tissue, resolution occurs by regeneration, but after more severe injury with damage to the connective tissue, repair is by scar formation

Question 29

What is the basis of skin grafting?

Answer 29

Take a piece of skin for somewhere else, put a bunch of little tiny holes in it and put it somewhere else. It can also depend on the thickness of tissue needed. Thick skin vs thin skin.

Question 30

What is the importance of the stratum basale?

Answer 30

It is the source of the stem cells after injury to the skin