DD Derm Term and Fxns, Epidermal Struc and diseases

Question 1

Which cells are responsible for Vit D synthesis?

Answer 1

Keratinocytes in the epidermis

• also synthesizes keratin

Question 2

Which cells are involved in immunologic barriers?

Answer 2

langerhan cells

Question 3

Which types of cells are involved in pheromones and body odor?

Answer 3

apocrine glands

Question 4

Keratinocytes

Answer 4

1. forms barrier layer,
2. synthesize keratin (fibrous protein of skin),
3. synth Vit D
4. involved in proliferation,
5. differentation,
6. programmed cell death.

Question 5

What is skin color variation due to?

Answer 5

Type of melanin produced and distribution of melanosomes

-NOT due to the # of melanocytes

Question 6

Langerhans Cells:

Answer 6

□ Dendritic cells derived from bone marrow stem cell; found in small #s

□ Participate in cell-mediated immune reactions by behaving as an APC

Question 7

Layers of the dermis

Answer 7

Papillary layer (loose CT directly deep to the epidermis)

Reticular layer (deeper)

Question 8

Which dermis layer provides blood supply for the epidermis?

Answer 8

Papillary

• note: reticular layer serves as the pathway of major BVs arranged specifically to facilitate thermoregulation

Question 9

Meissner’s corpuscles
Pacinian corpuscles
- Where are they found?
- What do they do?

Answer 9

Meissner’s corpuscles

• in papillary layer
• fine/tactile sense touch (fingertips)

Pacinian corpuscles

• in reticular layer
• sense vibration, pressure, and touch (gentitals ahhh yyeeaaaa)

Question 10

cellular layers of skin

Answer 10

Chinese Ladies Give Superb Backrubs (superficial to deep)

1. Stratum corneum
2. Stratum lucidum (thick skin only)
3. Stratum granulosum
4. Stratum spinosum
5. Stratum basale

Question 11

Eumelanin

Pheomelanin

Answer 11

Eumelanin: black-brown pigment

Pheomelanin: yellow-red-brown pigment

Question 12

Three ways you can get VIt D

Answer 12

1. Sun (UVB -> skin)
2. Diet (Ergocaciferl aka Vit D2)
3. Diet (Cholecaciferol aka Vit D3)

• These are then converted to Calcidiol by the liver
• Calcidiol is then converted to Calcitriol by the kidneys

Question 13

UVB from the sun gets converted to what?

Answer 13

Cholecalciferol Vit D3

same as the one from the diet

Question 14

Hemidesmosomes

Answer 14

attach basal cells to the basal lamina of dermal epidermal junction

Question 15

Desmosomes

Answer 15

attach keratinocytes to each other

Question 16

Pemphigus Vulgaris

Answer 16

• AutoAntibodies to desmosome proteins
  
  • Epidermis attaches fine to Dermis, but connection between keratinocytes suck
  • Skin lesions are flaccid bulla.
    
    • • nikolai’s sign (skin peels off)

(that 16 year old kid had it)

Question 17

Tonofilaments

Answer 17

protein structures that insert into the cytoplasmic side of the plasma membrane of desmosomes

Question 18

Bullous Pemphigoid

Answer 18

Antibodies to the hemidesmosomes.

Epidermis does not attach to dermis.

Question 19

Basal keratinocytes

• what are they
• where are they located?

Answer 19

Stem cells of the epidermis

located in the bottom most stratum basalis (germinativum)

Question 20

How long does it take to renew the epidermis?

Answer 20

28 days

Question 21

Function of:

Stratum Basalis

Answer 21

Location of some cell attachments

Question 22

Function of:

Stratum Spinosum

Answer 22

Reinforce the cytoskeleton

note: Synthesis of involucrin and membrane coating granules occurs here

Question 23

Function of:

Stratum Granulosum

Answer 23

Contain different types of granules (ie: kertohyalin granules containing filaggrin)

Question 24

What skin layer do cells no longer have nuclei or organelles?

Answer 24

Stratum lucidum if present

Or Stratum corneum

Question 25

What skin layer is the entire cell filled with keratin?

Answer 25

Stratum corneum

Question 26

What granules contain the filaggrin precursor? What layer of skin is it in?

Answer 26

Keratohyalin granules contain the filaggrin precursor.

- In Granulosum

Question 27

What layer does shedding of dead corneocytes occur? What is that called?

Answer 27

Stratum corneum is where Desquamification occurs.

Question 28

Filaggrin is mutated in what two skin disorders?

Answer 28

Atopic dermatitis

Ichthyosis