innate immunity

Question 1

first line of defense

Answer 1

physical barriers against infection
–> includes the skin, mucosal surfaces, and secretions

Question 2

second line of defense

Answer 2

internal defense system against infections
–> includes neutrophils, monocytes/macrophages, and nk cells (think phagocytosis, inflammation and complement cascade)

Question 3

third line of defense

Answer 3

adaptive immunity where immune cells target specific antigens

Question 4

characteristics of immune response

Answer 4

specificity:
memory:
recognition:

Question 5

cellular vs humoral components of innate immune response

Answer 5

cellular: neutrophils, macrophages, nk cells, dendritic cells (goal is to kill infected cells
humoral: complement cascade and antibodies that are naturally produced

Question 6

role of defensins in host protection

Answer 6

denature bacterial toxins
–> helps immune cells get rid of toxins

Question 7

role of pathogen recognition receptors (PRR’s)

Answer 7

receptors on immune cells that recognize and bind to PAMPS on microorganisms
–> this will activate cell to do specific function

Question 8

PAMPS vs DAMPS

Answer 8

pathogen associated mps: repeating pattern found on microorganisms
damage associated mps:
repeating pattern found on damaged/ dying cells
–> both recognized by PRRS

Question 9

roles of physiological factors on host defense

Answer 9

proper running of the immune system requires:
1. regulation of body temperature (high temperature makes inhabitable for microbes)
2. oxygen tension (can inhibit growth of bacteria)
3. nutrition (energy is required to run immune system)

Question 10

benefits/disadvantages of iron supplements

Answer 10

iron drives formation of reactive oxygen species which play role in inducing cell death and regulation of body

Question 11

role of normal microbiota

Answer 11

competes with pathogens for space in the body

Question 12

hygiene hypothesis

Answer 12

immune system is programmed with microbiota which modulates and reduces risk of intolerance
–> exposure to bacterias and microorganisms reduces sensitivity in the immune system

Question 13

probiotics

Answer 13

found in food (dairy) and already contain microbiota

Question 14

prebiotics

Answer 14

stimulates growth of normal biota
–> feeds the flora

Question 15

mononuclear phagocytic system

Answer 15

cells include macrophages, monocytes, and dendritic cells
–>monocytes circulate in blood–> release of cytokines causes monocytes to move to tissues
–> upon arrival they mature to macrophages –> macrophages will perform phagocytosis and migrate to lymphoid tissue or elsewhere

Question 16

process of phagocytes killing bacteria

Answer 16

(rolling) chemotaxis –> neutrophils move to site of infection
activation of endothelial cells and neutrophils
extravasation –> PMNs interact with neutrophils and PMNs arrest /lock to cell (selectins and integrins)
diapedisis –> PMNs squeeze between cells
contact –> PMNs and pathogens interact (opsonin identifies)
ingestion –> engulfs and holds in phagolysosome (where it is degraded)
killing –> respiratory burst kills degrade cells
exocytosis –> release oxygen and debris

Question 16

efferocytosis

Answer 16

programmed way to clear dying cells
IMPORTANT: tells macrophages they need to be engulfed to prevent inflammation

Question 16

molecules involved in attaching neutrophils to endothelial cells

Answer 16

selectins: mediate inital attachment
integrins: cause tight binding between them (lock in place)

Question 16

examples of opsonins

Answer 16

IgG, C3b, C-reactive protein

Question 17

key features of inflammatory response

Answer 17

inducible and nonspecific
–> does not have a target but does have to be activated (by cytokines)
1. activated by cytokine release
2. blood flow increases at site, dilated capillaries warms + reddens skin, and creates gaps between cells, blood leaks plasma into tissue causing swelling
3. neutrophils are produced and migrate to site
4. clot formation to reduce bleeding and trap microorganisms
5. more macrophages clean up infection

Question 18

role of macrophages and neutrophils

Answer 18

phagocytosis: they engulf dying cells or pathogens
inflammation: they fight infection and clean debris

Question 19

acute phase protein examples

Answer 19

C-reactive protein, fibrinogen (coagulation)

Question 20

c-reactive protein test

Answer 20

CRP is a early indicator of acute inflammation so CRP test detects levels of inflammation
–> CRP is produced within hours making it more sensitive and responsive that ESR test

Question 21

CRP and heart disease

Answer 21

atherosclerosis is associated with inflammation of blood vessels therefore CRP can be indicative of the disease