11.2- Introduction nto Microbial Threats

Question 1

What are the three types of barriers in first line defense?

Answer 1

Mechanical
Physical
Chemical

Question 2

What do mechanical barriers do?

Give examples

Answer 2

They rinse, flush, or trap pathogens to limit their spread within the body.
I.E. Tears, urine, saliva in the mouth, ear wax, mucociliary escalator

Question 3

What do chemical barriers do?

Give examples

Answer 3

These may directly attach invaders or establish environments that limit pathogen survival.
I.E. Lysozyme- found in tears and moucus membranes.
Hydrochloric acid in the stomach
Antimicrobial Peptides (AMPs)

Question 4

What do AMPs do?

What makes them?

Answer 4

Proteins that destroy a wide variety of viruses, bacteria, parasites, and fungi.
Made by leukocytes, skin and mucous membrane cells.

Question 5

Define defensins.

Answer 5

Mamalian AMPs that kill invaders by inserting themselves into target cell membranes.

Question 6

What do physical barriers do?

Give Examples

Answer 6

Structures that physically block pathogen entry.

I.E. Epithelial Cells that line every body cavity and every entrance.