Lecture 8: Innate Immunity

Question 1

The _____ fights off foreign material that threatens the body

Answer 1

immune system

Question 2

what are the two branches of the immune system?

Answer 2

innate immunity
adaptive immunity

Question 3

innate immunity is _____

Answer 3

non-specific

Question 4

adaptive immunity is _____

Answer 4

highly specific

Question 5

T/F: innate immunity is always the same from birth to forever

Answer 5

true

Question 6

innate immunity is natural host resistance and has no _____

Answer 6

memory

Question 7

Pathogens prefer a _____ body site to initiate infection

Answer 7

specific

Question 8

how do pathogens pick a specific body site to initiate infection?

Answer 8

Based on nutritional and metabolic needs

Mechanism of spread
* Aerosols vs blood/bodily fluids

Question 9

T/F: Susceptibility to pathogens varies from one species to another

Answer 9

true!
natural host resistance always plays a part in infectivity!

ex: Anthrax causes fatal blood infection in cattle and cutaneous infection in
humans

HIV can infect human cells but not mice or guinea pigs

Question 10

what are the two physical barriers we have to prevent infection?

Answer 10

skin and mucous membranes

Question 11

______: Prevents invasion by microbes

Rich in tough protective protein
* Keratin

Slightly acidic ~pH 5

High [NaCl]- periodic drying

Some fungal infections can grow right on the _____’s surface
* Many require broken _____ in order to penetrate and cause infection

Answer 11

skin

Question 12

T/F: skin is an organ because it consists of two+ types of tissue

Answer 12

true!

Question 13

why does our skin have high [NaCl]?

Answer 13

because it dries our skin out, which in turn dehydrates bacteria and limits their growth! how we protect ourselves!

Question 14

______: Line tracts in the body

• Respiratory tract, digestive tract, reproductive tract, urinary tract
• _____ produced by goblet cells
• Traps microbes preventing
  infection
• Contains antimicrobial secretions

Answer 14

mucous membranes

Question 15

T/F: mucous membranes are not open to the outside environment

Answer 15

false!

Question 16

______: Contains the mucocilliary escalator
* Mucosal epithelial cells contain cilia
* Serve to filter incoming air
* Sweeping action of cilia allows the removal of mucous and trapped microbes from the
lungs

Answer 16

respiratory tract

Question 17

what two parts of our body compose the gastrointestinal tract?

Answer 17

stomach and small intestine

Question 18

______: Strongly acidic: pH~2
* Contains proteases
* Few microbes are able to survive in this
environment
part of the gastrointestinal tract

Answer 18

stomach

Question 19

______: Pancreatic juice buffers acidity of incoming
contents from the stomach: pH ~7
* Contains pancreatic enzymes
* Contains bile from the liver
* Very difficult for microbes to maintain cellular integrity in this harsh environment
part of the gastrointestinal tract

Answer 19

small intestine

Question 20

why is the stomach strongly acidic?

Answer 20

low pH denatures proteins, exposes cut sites for proteases to destroy organic material

Question 21

______: Contains the normal microbiota
Normal resident bacteria that live symbiotically inside of the colon
Use attachment sites to persist
Consume undigested nutrients
* Competitive exclusion
Produce antimicrobial compounds
* Microbial antagonism

Answer 21

large intestine (colon)

Question 22

T/F: the large intestine has more bacteria than human cells

Answer 22

true!

Question 23

why can one person absorb many more calories from the same meal as another person?

Answer 23

we don’t have transporters in the colon, so we’re done absorption of nutrients

BUT if the bacteria in our colon produce non-polar waste products, we CAN absorb those through membranes! which adds to the total calories absorbed

gut flora affects obesity!!

Question 24

what does competitive exclusion in our colon mean?

Answer 24

there’s no space for bad bacteria (in an environment they would LOVE to colonize)… our good bacteria out-compete them! however, if we take anti-biotics and wipe out our normal flora… bad guys can move right in!

Question 25

what does microbial antagonism mean?

Answer 25

bugs create poisons/toxins that destroy other bugs to wipe out their competition

Question 26

_______: Genital and urinary tracts are separate in females and joint in males Urinary tract contains urine * Includes many toxins that are intolerable by bacteria The act of urination physically removes contaminating microbes The female reproductive tract contains normal microbiota * Glycogen secreted by vaginal epithelial cells supplies nutrients for microbial growth

Answer 26

genitourinary tract

Question 27

why do women have Lactobacillus acidophilus in their vagina?

Answer 27

ferments glucose to lactic acid, drops pH to ~4.5, provides a defense against sexually transmitted infections/diseases

Question 28

______: Composed of organs and vessels that allow immune cells to contact foreign antigenic material

Answer 28

lymphatic system

Question 29

An _____ is foreign material that is able to activate cells of the immune system

Answer 29

antigen

Question 30

what are the two components of the lymphatic system?

Answer 30

lymphatic vssels lymphoid organs

Question 31

________: Carry lymph from the tissues to the lymph nodes * Unidirectional (always away from tissues) * Lymph is rich in leukocytes (white blood cells) * Free of erythrocytes (red blood cells)

Answer 31

lymphatic vessels

Question 32

T/F: there are primary and secondary lymphoid organs

Answer 32

true!

Question 33

what are the primary lymphoid organs?

Answer 33

bone marrow thymus gland

Question 34

what are the secondary lymphoid organs? **All contain a high concentration of leukocytes

Answer 34

lymph nodes spleen mucosa associated lymphatic tissue (MALT)

Question 35

_____: Leukocytes are produced here

Answer 35

bone marrow make all our blood cells here!

Question 36

_____: Some leukocytes mature here

Answer 36

thymus gland

Question 37

where do B-lymphocytes mature?

Answer 37

bone marrow

Question 38

where do T-cells mature?

Answer 38

thymus gland

Question 39

______: Associated with all mucous membranes

Answer 39

MALT (mucosa associated lymphatic tissue)

Question 40

_____: Leukocytes present here are constantly phagocytosing material in their surroundings in search of foreign content

Answer 40

GALT (Gut associated lymphatic tissue)

Question 41

what are the main cells that form our cellular defenses?

Answer 41

leukocytes

Question 42

______: Circulate in the blood and the lymphatic system * Reside in the tissues and the lymph nodes * Play a role in both innate and adaptive immunity

Answer 42

leukocytes (white blood cells)

Question 43

what are the two broad categories of leukocytes?

Answer 43

granulocytes and agranulocytes

Question 44

______: Large, visible granules in the cytoplasm Granules are reactive * Can kill microbes * Can serve as signaling molecules to recruit and activate other components of the immune system

Answer 44

granulocytes

Question 45

what are the three types of granulocytes?

Answer 45

neutrophils, eosinophils, basophils/mast cells (BEN)

Question 46

______: Cytoplasmic granules contain * Lysozyme * Defensins Circulate in the blood * Exit the capillaries during periods of infection Strongly phagocytic Very important cells of the innate immune system

Answer 46

neutrophils

Question 47

why are neutrophils able to exit the capillaries during periods of infection?

Answer 47

capillaries become leaky when vasodilation occurs in response to injury, lets these big clunky neutrophils through to combat infection

Question 48

______: Non-phagocytic cells Cytoplasmic granules will stain with acidic dyes Work to destroy large parasitic cells * Protozoa and parasitic worms * Secrete extra-cellular enzymes and reactive oxygen species * Can also exit the capillaries into infected tissues

Answer 48

eosinophils

Question 49

_______: Cytoplasmic granules stain with basic dyes Not strongly phagocytic Basophils circulate in the blood Mast cells reside in mucosal tissue Degranulate in response to appropriate stimuli * Release histamine * Important part of the allergic response * Causes vasodilation locally * Causes life threatening vasodilation and bronchiolconstriction when released systemically

Answer 49

basophils and mast cells

Question 50

basophils are found where?

Answer 50

the blood

Question 51

mast cells are found where?

Answer 51

in tissue

Question 52

when vasodilation occurs, what happens in the blood? why do people go into multiple organ failure?

Answer 52

when vasodilation occurs, flow increases but pressure drops, causes multiple organ failure when blood is not reaching vital organs (especially our brain!)

Question 53

________: Contain cytoplasmic granules that are much smaller and more difficult to view than granulocytes

Answer 53

agranulocytes

Question 54

what are the two types of agranulocytes?

Answer 54

monocytes lymphocytes

Question 55

what are the two types of monocytes?

Answer 55

macrophages dendritic cells

Question 56

_______: Located in the tissues * Lungs, connective tissue, spleen, liver Contain special surface receptors that allow them to recognize many pathogens with one receptor * Toll-like Receptors (TLRs) * Recognize things like LPS, peptidoglycan, elements of the fungal cell wall Binding of the toll-like receptor to antigen induces phagocytosis

Answer 56

macrophages

Question 57

T/F: macrophages have toll-like receptors which are very specific

Answer 57

false! non-specific recognition, don't care WHO it is, just that macrophage needs to bind and destroy

Question 58

_______: Found in tissues that are often sites of entry for infectious materials * In the skin they’re called Langerhan’s Cells Also found in the mucus membranes of the nose, the lungs and the intestines Regularly sample the surroundings and phagocytose antigens * Phagocytosed antigen is carried to lymphoid organs * Presented to other cells of the immune system (T/B lymphocytes) * Activate the adaptive immune response

Answer 58

dendritic cells

Question 59

when dendritic cells pull bacteria off of our skin in advance to show our immune cells and teach our immune system how they work, this is an example of what kind of immunity?

Answer 59

adaptive immunity

Question 60

______: Leukocytes the are involved in the adaptive immune response Circulate through the blood and remain in the lymphoid organs

Answer 60

lymphocytes

Question 61

what are the three different kinds of lymphocytes?

Answer 61

B lymphocytes T lymphocytes Natural Killer Cells (NK)

Question 62

_____: Also called B cells or plasma cells * Antibody producing/secreting cells * Form the main component of humoral immunity

Answer 62

B lymphocytes

Question 63

_______: Also called T cells * Different types * Form the main component of cell mediated immunity

Answer 63

T lymphocytes

Question 64

______: Destroy abnormal cells in the body (cancer cells, infected cells)

Answer 64

Natural Killer cells

Question 65

when we have swollen lymph nodes what is this an indicator of?

Answer 65

an immune response, our lymphocytes are proliferating (rapid cell division) to mount an immune response

Question 66

where do B lymphocytes mature? where are they made?

Answer 66

in bone marrow

Question 67

where are T cells made? where do they mature?

Answer 67

made in bone marrow, mature in thymus gland

Question 68

T/F: Natural Killer cells kill our own cells!

Answer 68

true! destroy our OWN abnormal cells

Question 69

T/F: molecular defenses are just one single molecule

Answer 69

true!

Question 70

molecular defenses are secreted where?

Answer 70

mucosal sites

Question 71

what are two examples of molecular defenses secreted at mucosal sites?

Answer 71

lysozyme defensins

Question 72

______: Cuts b-1,4 glycosidic bonds in peptidoglycan

Answer 72

lysozyme

Question 73

______: Antimicrobial peptides that poke holes in bacterial cell membranes inside granules in neutrophils

Answer 73

defensins

Question 74

_____: Destroys pathogens that may have never before been encountered in the body

Answer 74

phagocytosis

Question 75

phagocytosis involves capable leukocytes, what are they?

Answer 75

neutrophils and macrophages

Question 76

___ and ____: Recognize pathogen associated molecular patterns (PAMPS) * Lipopolysaccharide, lipoteichoic acid, flagellin to perform phagocytosis

Answer 76

neutrophils and macrophages

Question 77

PAMPs are recognized by ___s located on the surface of phagocytic cells

Answer 77

TLRs also known as pattern recognition receptors (PRRs)

Question 78

Interaction of PAMP with a TLR triggers _____

Answer 78

phagocytosis

Question 79

explain the process of phagocytosis

Answer 79

Cell membrane invaginates around a foreign particle Engulfs it into a phagosome Phagosome fuses with a lysosome to form a phagolysosome Oxygen independent killing Neutrophils perform exocytosis * Fragments are expelled from the cell Macrophages and Dendritic cells become antigen presenting cells * Fragments of the intruder are presented on the cell surface to trigger an adaptive immune response

Question 80

what are lysosomes filled with?

Answer 80

Lysozyme and defensins Proteases (degrade proteins) Lipases (degrade phospholipids) Nuclease (degrade nucleicacids)

Question 81

______: Activated phagocytes produce reactive oxygen compounds: * H2O2, O2*, OH*, HOCl, NO Kill ingested microbes by oxidizing cell components

Answer 81

oxygen dependent killing

Question 82

_____: Occurs non-specifically in response to tissue damage, toxins, and infectious material

Answer 82

inflammation

Question 83

what are the five cardinal signs of inflammation?

Answer 83

Redness (erythema), warmth, pain, swelling (edema) and loss of function

Question 84

In response to infection injured tissue and leukocytes release _____

Answer 84

pro-inflammatory cytokines

Question 85

what do pro-inflammatory cytokines do?

Answer 85

cause blood vessels to dilate (vessel walls become more permeable... no more pressure of inflammation of blood vessel), allow more leukocytes to access the area where they can attack invading pathogens

Question 86

_____ increase may slow the growth of pathogens Also promotes faster healing of damaged tissues

Answer 86

Temperature

Question 87

Blood leaking into tissue spaces can _____ * Prevents movement of pathogens

Answer 87

clot

Question 88

_______: An increase in body temperature * Controlled by the hypothalamus of the brain * It is triggered by toxins, LPS, and chemicals produced by the immune system * All of these things reset the bodies thermostat

Answer 88

fever

Question 89

hypothalamus is the regulator of...

Answer 89

homeostasis

Question 90

what does a fever result in? (only up to a certain temp... above 43C can cause death)

Answer 90

Muscle contraction-shivering Increased temperature-faster metabolism and promoted healing Faster phagocytosis Slower growth of microbes

Question 91

why can fevers be lethal to humans?

Answer 91

because we're made of the same material as the bacteria we're trying to kill!