Innate Immunity Flashcards
Chapter 15
Define Species resistance
Properties that protect an organism from infection by pathogens of other different organisms
Define Innate Immunity
What type of immunity is always active, nonspecific, rapid, and able to work against a variety of pathogens?
Innate Immunity
What are the main cells of the bodies so-called 3rd line of defense?
Lymphocytes
How is the bodies 3rd line of defense different from the first 2?
The 3rd line is composed of lymphocytes which respond to unique pathogens and alter the bodies defenses to be more effective to said pathogens. So the 3rd line is specific whereas the first 2 or nonspecific.
What structures work to prevent pathogens from entering the body in the first place?
2 points
- Skin
- Mucous membranes
Which layer of sknin contains hair follicles, glands, and nerve endings?
The dermis
What makes the skin an effective defense against pathogens?
2 nonspecific answers
- Its physical structure
- Its chemical components
What 2 characteristics of innate immunity does the skin illustrate? How?
- Barriers: tightly packed epithelial cells act as a barrier to pathogens
- Clearance: outermost dead cells slough off, taking any microorganisms with them
The epidermis contains defensive cells called what?
Dendritic Cells
What cells devour pathogens non-specifically while also playing a role in adaptive immunity?
where are these cells located?
Dendritic cells in the epidermis
What fibers give skin strength and the pliability to prevent skin penetration?
Collagen
What are the skins chemical defenses against pathogens?
Name the 2 structures (not how the defense works itself)
- Dermal cells
- Sweat glands
How do sweat glands chemically protect against pathogens?
Perspiration from sweat glands contain salt, antimicrobial peptides, and the enzyme lysozome. The salt draws water from invading cells, effectively killing them.
3 components not as important, just how salt kills pathogens
What are antimicrobial peptides?
Positively charged chains of amino acids that act against microorganisms
What class of antimicrobial peptides do sweat glands secrete?
Dermcidines
Explain dermcidins?
Broad-spectrum antimicrobial peptides that act against gram-negative and positive bacteria & fungi
How does lysozyme in perspiration defend against pathogens?
Lysozome is an enzyme that breaks down cell walls of bacteria. Without a cell wall, bacteria is more easily destroyed by the bodies other defenses
How does sebum protect the skin?
- Its oily nature keeps the skin pliable
- Fatty acids in sebum lower the pH of the skin to 5 while also destabilizing cells’ membranes.
What characteristics of the skin make it a inhospitable environment to most microorganisms?
4 points
- Salt
- Antimicrobial peptides
- Lysozome
- Acidity
Where is bacteria that finds the skin a suitable environment typically abide?
2 points
- In crevices around hairs
- In the ducts of glands
Where are mucous membranes located?
generally speaking
In any body cavity open to the outside environment
How are epithelial cells in mucous membranes different from skin epithelial cells?
3 pointss
- Form a thin layer, sometimes only one cell thick (skin iss thick)
- Are alive and play roles in bodily functions (skin are dead so they can slough off eventually)
- Moist surface (skin is dry)
Why is the number of resident microbiota much higher on mucous membranes than on the skin?
Because mucous surfaces are very moist, which is conducive to bacterial growth
What do dendritic cells underneath the mucous epithelium do?
- Devour invaders
- can extend pseudopods between epithelial cells to “sample” the lumen (mucous membrane)
What is the lacrimal apparatus?
Generally speaking
A group of structure that produce & drain away tears
How are the eyes protected against pathogens?
2 things
- Tears which are carried away by the Lacrimal apparatus
- Lysozome in tears (which destroys bacteria)
How does the microbiome affect the bodies 2nd line of defense?
It stimulates it and boosts the body’s production of antimicrobial substances
Why is using antimicrobial products not necessarily wise?
Because it removes all microbes from your body, including those part of your microbiota, potentially making you more senstitive to infection.
When does the bodies second linne of defense come into play?
Once a pathogen has successfully penetrated the skin or a mucous membrane
What is a major difference between the bodies first and second line of defense?
Think overall function of disease fighting
The second line has no “barriers” like the first line.
involves cells, chemicals, and processes
When blood clots, what is the remaining liquid called?
Serum