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Comparative Immunology > Epithelial Barrier > Flashcards

Flashcards in Epithelial Barrier Deck (50):
0

Epithelial cells are tightly joined together by?

Adhesion molecules and right junction proteins

1

Epithelial cells have _____ morphology

Polarized

2

What are the two sides of epithelial cells and what are each exposed to?

Apical side exposed to commensal microbes and environment. Basolateral side protected from microbial exposure.

3

PRRs are concentrated on what side of the epithelial cell?

Basolateral

4

Why are PRRs concentrated on the specific side they are?

To alert the immune system if invading microbes and/or tissue damage

5

This organ is a peripheral sensory organ, involved in nutrient synthesis, thermoregulation, osmoregulation, and act as a protective barrier against environmental stressors

The skin

6

What are examples of environmental stressors?

UV radiation, chemical exposure, and microbial invaders

7

What type of fish has placoid-scales that rose out of the epidermis to protect underlying skin?

Cartilaginous fish (ex. Sharks and rays)

8

What type of fish are covered with a multilayered epidermis that is coated with mucus that contains anti microbial proteins and peptides?

Bony fish species

9

What are the cells that produce mucus called?

Goblet cells

10

What are melanophores?

Provide skin pigmentation and help sequester reactive oxygen species generate during oxidative stress in bony fish

11

What is the non-viable layer of cells on the epidermis of birds and mammals called?

The stratum corneum

12

The non-viable layer of cells on the epithelial of birds and mammals is constantly replaced by epithelial cells called?

Keratinocytes that differentiate from pluripotent stem cells

13

Unlike mammalian skin, avian skin lacks what?

Sweat glands

14

Instead of having sebaceous glands, birds have what type of glands that do what?

Uropygial glands that produce lipids to condition the feathers to repel water

15

Avian feathers and mammalian hair are both comprised of _____ produced by ______?

Keratin, keratinocytes

16

True or false - keratinocytes are immune cells

True

17

The sub-epithelial immune system of the skin is referred to as?

Skin-associated lymphoid tissue (SALT)

18

What characteristics of the stratum corneum are highly variable within and across mammalian species?

Thickness, amount of melanocytes pigmentation, and sebaceous gland secretions

19

People of what race have a thicker stratum corneum, higher lipid content, and is replaced more rapidly?

Dark race

20

What are the two benefits of people with dark skin?

More effectively retain water and more resistant to chemical and microbial exposure

21

Neural tube defect (ex. Spins bifida) is cause by?

UV-induced folio acid depletion during pregnancy

22

Offspring of people win what colour skin are more susceptible to rickets and immunodeficiency?

Dark skin

23

Rickets and immunodeficiency results from?

Insufficient vitamin D production

24

Sheep secrete a moisture barrier called?

Lanolin

25

In what mammal are sweat glands distributed all over the body?

Primates

26

What are examples of two anti microbial peptides?

Der codon and lactoferrin

27

The sweat glands of hoofed animals are concentrated where?

Scilla (armpits)

28

What are sweat gland concentrated for pigs, dogs and cats?

Footpads and snout

29

What are haptens?

Small molecular weight reactive chemicals the immune system can become sensitized to found in cosmetics, jewellery, etc

30

Repeated exposure to haptens can cause?

Cell-mediated hypersensitivity rxn that can cause allergic contact dermatitis

31

Mucus is a _________ comprised of ________ and _______

Gel gradient, mucin proteins, lipids

32

Very basically, what are the 7 important functions of mucus?

Physical barrier preventing attachment of pathogenic microbes and commensals, lubricates the epithelium, traps and removed microbes and antigens, maintains hydration, adhesive surface for commensal microbes, concentrate anti microbial proteins, facilitates removal of motile immune cells

33

What is the sub-epithelial immune system associated with the lining of the nasal, oral cavities, trachea and bronchi called?

Nasal and bronchi associated lymphoid tissues

34

The nasal and oral cavities, trachea, bronchi and bronchioles contain goblet cells as well as? Why does the latter do?

Clara cells that secrete anti microbial proteins and peptides

35

Specialized epithelial cells called ______ have also been found in the bronchi.

Microfold cells

36

What do M-cells do?

Sample antigens from the mucus and pass them along to underlying tissue macrophages and DCs for antigen presentation

37

What two parts of the respiratory system is considered a sterile environment except in cases of pneumonia?

Bronchioles and alveolar sacs

38

What are the epithelial cells making up the alveolar sacs called?

Pneumocytes

39

How are surfactant proteins produced and what do they do?

Type 2 pneumocytes replace type 1 pneumocytes which produce surfactant proteins. They reduce surface tension preventing lung collapse and haw anti microbial properties

40

Why are the two ways in which mucus is removed from the bronchioles, bronchi, an trachea?

Beating of ciliates epithelial cells and coughing

41

What is a microbiome?

Colonization of commensal microbe populations in the GIT

42

When does the microbiome develop?

Following birth

43

What is the hygiene hypothesis?

Lack of exposure to certain microbes during early life development can affect immune development and increase risk of atopic disease (ie asthma, food allergy)

44

How are atopic diseases caused?

Antibody-mediated hypersensitivity reactions (ex. IgE)

45

The small intestine epithelium is comprised of finger-like _____ and gland-like invaginated ______.

Villi and crypts

46

The gland-like structure in small intestinal epithelium contain?

Pluripotent stem cells that proliferate and differentiate into various epithelial cell types

47

What two cell types are found in the crypts of the small intestine? What does the latter do?

Goblet and panth cells which secrete anti microbial peptides

48

True or false - the large intestine is lined with villi like the small intestine

False

49

Epithelial cells lining the GIT act as innate immune cells and communicates with?

Gut-associated lymphoid tissues (GALT)