L3 Innate Immunity

Question 1

What is the innate immune system?

Answer 1

The body’s first line of defence against infections. Will immediately act on an encounter with an infectious agent.
* Instruct adaptive immune system to respond to different microbes.
* A part of the clearance of dead tissues and the initiation of repair after tissue damage.
* Responds in essentially the same way to repeat encounters with a microbe so no memory it has trained immunity.

Question 2

What is trained immunity?

Answer 2

Long term finctional reprogramming of innate immune cells, by exogenous or endogenous activation events, leading to an altered response to a secoundary cjallenge after the return to a non-activated state.

Question 3

List some defensive barriers

Answer 3

• Stomach Acidity* inhibit microbial growth*
• Normal Flora compete with pathogens in the gut and skin
• Flushing of urinary tract prevents infection
• Lysozymes in tears dissolves cell walls
• Mucus and cilia lining trachea suspend and move microorg-out of body
• Blood and lymph proteins inhibit microbial growth
• Rapid pH change Inhibit microbial growth
• Epithelial cells Tight junctions inhibit pathogen invasion and infection

Question 4

Skin and mucusal surfaces have _____ protective systems that limit entry of invasion microorg-.

Answer 4

non-specific

Question 5

The complement system desc

Answer 5

Involves several plasma proteins that become activated in sequence by proteolytic cleavage to generate fragments of the C3a and C5a proteins, which promote inflammation, or opsonize and promote phagocytosis of microbes.

And kills microbes

Question 6

The complement system desc outcomes

Answer 6

• Results in direct killing of some bacteria (mmostly in outer lipid bilayer and susceptible to lytic complex[C5b-C9])
• Production of C3b - important opsonin
• Releases C3a and C5a involved in inflammation

Question 7

The complement system is activated on what type of surface

Answer 7

microbial surfaces and not on normal host cells

Question 8

Imflammation will attract and activate

Answer 8

• Neutrophils
• Act: mast cells that will release histamine and leukotriene contributes to increase vascular permeability.