Learning Objectives Chapter 15: The Immune System: Inflammation and Innate Immunity

Describe the two major systems of immunity and explain their separate yet interdependent roles.

innate

• always on

• fast

adaptive

• slow

• targets specific pathogens

Discuss the relationship between microbial structure and innate immune mechanisms.

refers to the chart of WBC stats during infection(viral, parasitic, allergic):

• WBC increases for all

Infection

• Neutrophils can be reduced

• Lymphocytes (B and T killer cells) increase

Parasitic

• Eosinophils increase in response to parasites/helminths

Allergic

• Basophil and eosinophils increase

Identify features of the immune system that affect acute versus chronic inflammation.

acute inflammation:

• short term

• damaged host cells release chemical signals

• understand process.. key step is extravasation

chronic inflammation:

• long term

• caused by peristant presence of foreign things

• caused by infection or bodily process like granuloma

Explain how activating innate immunity influences disease symptoms.

responds quickly to pathogens

1. inflammation

• overall blood slows when blood vessels dilate so blood volume at wound increases

• pain signaling

1. fever

Describe the physical barriers to infection.

skin

• salty, acidic, dry, shedding

• lots of microbes so antagonism

• SALT defense incase microbes pass skin barrier

• lengerhan cells dendritic phagocytizes invaders

mucous

• selectively permeable

• traps invaders

• contains lysozyme

• MALT

• MAMPS- peptoglycan and lipopolysaccharide

• M cells

lungs

• cillia

• if pathogen makes it to aveolar, its macrophages inject microbes

Stomach

• MALT: GALT

Intestines

• Peyer patches

• M cells take up microbes from intestine

Explain the basic roles of SALT, GALT, and M cells in innate immunity.

Describe chemical barriers employed by cells of the innate immune system.

• stomach acid

• lysozyme in tears

• superoxide radicals from host enzymes

• DEFENSINS: cationic peptides (+) that produce pores in gram pos/neg fungi/virus membrane to kill them

List the five cardinal signs of inflammation.

SHARP: swelling, heat, altered functions, redness, pain

Outline the process of inflammation.

acute:
pathogens enter, macrophage undergoes phagocytosis, sends inflammatory mediators (cytokinase, vasoactive factors) widening blood vessel and making it leaky, neutrophil comes from blood stream, undergoes extravasation to leave blood vessels

Describe the roles of vasoactive factors and cytokines.

they are sent out as signals during acute inflammation

Differentiate acute from chronic inflammation.

Describe how phagocytes recognize foreign cells.

Explain the mechanism phagocytes use to kill engulfed cells.

List some ways pathogens avoid the consequences of phagocytosis.

Discuss how our body ends the inflammatory process.

Explain fever and its cause.

Describe the advantages and disadvantages of fever.

advantages:

• stops pathogen growth

• reduces iron

disadvantages:

• discomfort

• brain damage

Define complement.

group of proteins in the blood that trigger a series of mechanisms to kill pathogenic cells

Distinguish between the classical, alternative, and lectin pathways of complement activation.

Discuss the role of complement in host defense.