Innate Immunity

Question 1

Immunity

Answer 1

ability to ward off disease

Question 2

suceptibility

Answer 2

lack of resistance to a disease

Question 3

innate immunity

Answer 3

defence against any pathogen

• rapid
• present at birth
• first and second lines of defense

Question 4

first line of defense

Answer 4

skin and mucous membranes

Question 5

second line of defense

Answer 5

natural killer cells, phagocytosis, inflammation, fever, and antimicrobial substances

Question 6

adaptive immunity

Answer 6

specific
slower
memory

Question 7

Skin

Answer 7

dermis = inner portion of connective tissue
epidermis = outer portion of tightly packed epithelial cells with keratin (protective protein)
-shedding + drying inhibits microbial growth

Question 8

Mucous membrane

Answer 8

• epithelial layer that lines GI, respiratory, and genitourinary tract
• mucous = viscous glycoproteins that trap microbes and prevent drying out

Question 9

ciliary escalator

Answer 9

-transports microbes trapped in mucous away from lungs

Question 10

physical first line defenses

Answer 10

• tears
• saliva
• ear wax
• urine
• vomit
• poop
• vaginal secretions

Question 11

sebum

Answer 11

forms a protective film that lowers pH of skin bc of unsaturated fatty acids

Question 12

lysozyme

Answer 12

in sweat, tears, saliva, and urine

-destroys bacterial cell wall

Question 13

gastric juices

Answer 13

-super acidic, so it kills bacteria

Question 14

vaginal secretions

Answer 14

pretty acidic, so it inhibits microbes

Question 15

normal microbiota

Answer 15

• compete with pathogens via competitive exclusion
• well adapted
• create substances (like hydrogen peroxide in vagina) that are harmful to pathogens
• commensalism

Question 16

probiotics

Answer 16

live microbial cultured administered for beneficial effect

Question 17

3 things in blood

Answer 17

erythrocytes (RBC)
leukocytes (WBC)
Platelets
-created in red bone marrow stem cells via hematopoiesis

Question 18

Granulocytes

Answer 18

leukocytes with visible granules in cytoplasm with light microscope

• neutrophils = phagocytic + work in early stages of infection
• basophils = release histamine + work in allergic responses
• eosinophils = phagocytic + toxic against parasites + helminths

Question 19

Agranulocytes

Answer 19

leukocytes w/o visible granules

• monocytes = mature into macrophages in tissues where they’re phagocytic
• dendritic cells = found in skin, mucous membrane, and thymus + phagocytic
• lymphocytes = T cells, B cells, and NK cells

Question 20

lymph system

Answer 20

lymph carries microbes to lymph nodes where lymphocytes and macrophages destroy them

Question 21

fixed vs free macrophages

Answer 21

pretty obvious

Question 22

Phases of Phagocytosis

Answer 22

• Chemotaxis = chemical signals attract phagocytes to microorganisms
• adherence = attachment of phagocyte to surphace of microbe
• ingestion = sometimes uses opsonization where microbe is coated with serum proteins to make it easier to eat
• digestion = eated inside phagolysosome

Question 23

Inflammation

Answer 23

• PRISH
• destroys or inhibits injurious agents
• repairs and replaces tissue
• activates acute phase proteins that cause vasodilation
  1. vasodilation of blood vessels
  2. phagocyte migration + phagocytosis
  3. tissue repair + inflammation

Question 24

acute phase proteins

Answer 24

histamine
kinins
prostaglandins
leukotrienes
cytokines

Question 25

fever

Answer 25

cytokines cause hypothalamus to release prostaglandins that reset body temp - temp stay high until cytokines are eliminatied - as temp falls (crisis) vasodilation and sweating happens

Question 26

advantages and disadvantages of fever

Answer 26

advantages: increases transferrins which bind iron - increases IL-1 activity which promotes T cell production - produces interferon which stops replication of some virueses - tissue repair could be faster Disadvantages: tachycardia - acidosis - dehydration - 44-46 C is fatal

Question 27

complements system

Answer 27

- serum proteins produced by liver that enhance immune system - act in cascade --> complement activation 1. classic pathway = activated by antibody 2. alternative pathway = activated by proteins or polysacchrides on virus or host surface 3. activated by lectins = proteins that bind to carbs

Question 28

classic pathway

Answer 28

- antibodies bind to antigens, activating C1 - C1 splits and activates C2 and C4 - C2a and C4b combine and activate C3 - C3a function in inflammation - C3b functions in cytolysis and opsonization

Question 29

Alternative pathway

Answer 29

C3 in the blood combines with factors BDP on microbe surfaces -C3 splits into Ca and C3b

Question 30

Lectin Pathway

Answer 30

- macrophages ingest pathogens, releasing cytokines that stimulate lectin production in liver - Mannose-binding lectin binds to mannose on pathogens, activating C2 and C4 - C2a and C4b activate C3

Question 31

outcomes of complement activation

Answer 31

- cytolysis = complement proteins create a membrane attack comlex - opsonization = promotes attachment of phagocyte - inflammation = activated complement proteins bind to mast cells, releasing histamine - regulatory proteins break don complement proteins after - sometimes capsules prevent comllement activation

Question 32

interferons

Answer 32

- cytokines produced by cells --> antiviral activity - proteins, not antibodies - interfere with viral replication - alpha and beta are produced by cells in response to viral infections --> cause neighboring cells to produce antiviral proteins - gamma causes neutrophils and macrophages to kill - not specific - species specific bacteria

Question 33

iron binding proteins

Answer 33

- transferrin = blood and tissue - lactoferrin = milk, saliva, and mucus - ferritin = liver, spleen, and red bone marrow - hemoglobin = RBC - bacteria produce siderophores