External Barriers Against Infection

Question 1

what are the 3 levels of immune defence against pathogens

Answer 1

physical barriers and preformed chemicals to prevent entry
innate immune system which is broad-acting and acts early
adaptive immune system that develops to mount a specific defence

Question 2

commensal bacteria can usually…

Answer 2

outcompete invading pathogens for essential nutrients

Question 3

what is the site of adaptive immunity ready to work at epithelial barrier in the gut called?

Answer 3

peyer’s patches
(type of secondary lymphoid organ)

Question 4

what is the normal function of epithelial barriers in the airway

Answer 4

low permeability
exclude pathogens and allergens from tissue
intercellular junctions adhere the epithelial cells to each other and to the cytoskeleton of the cell
secretion of mucus by goblet cells

Question 5

what filaments make up the cytoskeleton of the cell (epithelium)

Answer 5

actin and intermediate filaments

Question 6

what do actin filaments hold in place?

Answer 6

Claudins
JAMs
Occludin