ch 21 the immune system part 1

Question 1

immunity

Answer 1

the ability of the body to defend itself against unfamiliar microorganisms

Question 2

immune cells use what to distinguish between cells as self or non self

Answer 2

antigens

Question 3

immunity has 2 systems

Answer 3

innate and adaptive

Question 4

innate defenses

Answer 4

nonspecific defense mechanism that is initiated very quickly in the body (does not search stuff out) it is built in when anything enters

Question 5

how do the physical barriers and certain cells initially encounter pathogens

Answer 5

they prevent pathogen entry both physically and cellularly

Question 6

2 defense lines of innate defenses

Answer 6

surface barriers and cells/chemicals

Question 7

surface barriers

Answer 7

physically prevent pathogens from entering body, skin and mucous membranes

Question 8

skin as a surface barrier

Answer 8

keratin- tough protein resistant to weak acids and bases and enzymes, it is tough and dry so bacteria cannot survive and reproduce

acid mantle- sweat and sebum on skin surface is a little acidic, bactericidal in nature inhibits growth of bacteria

Question 9

mucous membranes as a surface barrier

Answer 9

line all body cavities that open to exterior, such as repsirotry digestive and reproductive tracts

Question 10

the 6 mucous membranes

Answer 10

mucus- traps microorganisms and is thicker
nasal hairs- traps micro organisms in nasal cavity
cilia- takes mucus with the microorganisms and propels it away from nasal and respiratory
acid mantle- stomach secretes 1.3-3 pH level and vagina also prevents bacteria and fungal growth
tears/saliva- cleanses eyes and mouth with lysozyme (which destroys bacteria)
urine- acidic in nature, physically removes bacteria with pee

Question 11

cellular and chemical defenses

Answer 11

used when the surface barriers are breached, sometimes the surface gets damaged. have pattern recognition receptors, which are proteins found on cells of innate immune system

Question 12

pattern recognition receptors

Answer 12

proteins found on innate immune system cells, recognize harmful substance say presence of a shape of a molecule on pathogen but not on normal human cells.

Question 13

natural killer cells (NK)

Answer 13

target cancerous and virus infected cells, non specific, do not phagocytize, rather induce apoptosis, release perforin and creates pores

Question 14

non specific means

Answer 14

does not look for a specific cell, destroys anything not recognized

Question 15

how is apoptosis dif from lysis and why does that help prevent viral infection

Answer 15

apoptosis is programmed cell death, lysis is a cell with so much water it bursts. viruses infected body cells by hijacking cell machinery to reproduce and spread, lysis helps virus spread rather than apoptosis. apoptosis makes Sure nothing reproduces

Question 16

phagocytes

Answer 16

neutrophils and macrophages example, these cells engulf and destroy pathogenic cells or substances

Question 17

neutrophils vs macrophages on phagocytosis

Answer 17

neutrophils- become phagocytic upon encountering pathogen, can use defenses to pierce through pathogen membrane and induce lysis
macrophages- large and voracious, with free and fixed to get rid of pathogens

Question 18

free vs fixed macrophages

Answer 18

free- capable of travel through tissue tp search for pathogens, active

fixed- permanent location in tissue of a particular organ, waits for substances to flow past until something won’t belong

Question 19

why is phagocytosis not always successful

Answer 19

pathogens may be resistant to phagocytosis lysosomes, or bacteria surrounded by a capsule, or pathogens can be too large for phagocyte to ingest.

Question 20

if pathogen is resistant to phagocytic lysosome…

Answer 20

causes release of large free radicals, produces oxidizing chemicals

Question 21

if some bacteria is surrounded by a capsule…

Answer 21

phagocyte cannot recognize Infectious organism, so opsonins occur. they bind to pathogen surface and allow phagocytes to recognize and bind pathogen easily ex- antiobodies and complement

Question 22

pathogens can be too large for phagocyte to ingest …

Answer 22

phagocytes will release toxic chemicals to surrounding ECF fluid, however this has. downside… all digestive enzymes go to ECF, causing toxins to be in healthy body cells not just viral but better than nothing

Question 23

inflammation

Answer 23

nonspecific localized response to tissue injury, uses cells and chemicals . symptoms- redness, heat, swelling, pain, impaired function only around the injury

Question 24

benefits of inflammation

Answer 24

prevents spread of pathogens to the non damaged tissue, disposes of cell debris and pathogens, alerts immune System, allows repair to occur

Question 25

inflammatory chemicals released at injury site

Answer 25

histamine- release by basophils locally, causes vasodilation and increases capillary permeability kinins- derived from plasma protein kininogen, causes vasodilation and attracts leukocytes while inducing pain prostaglanins- generated by neutrophils, basophils, mast cells causing vasodilation and neutrophil chemotaxis while inducing pain

Question 26

4 step mobilization process of inflammation before beginning to defend the body undergone by neutrophils and macrophages

Answer 26

leukocytosis, margination, diapedesis, chemotaxis

Question 27

leukocytosis in inflammation

Answer 27

step 1, increase in number of WBC to blood, has leukocytosis inducing factors which attracts more

Question 28

margination in inflammation

Answer 28

phagocytes cling to inside of endothelial wall of capillaries, preventing phagocyte from being washed away

Question 29

diapedesis in inflammation

Answer 29

cells clling too wall will squeeze between cells of endothelial wall. important for immune system functioning and body defense because the phagocyte will flatten itself and squeeze through, allowing WBC to actually leave and go. if WBC was restricted, alll pathogens would have to go into blood supply so this is great, prevents closer pathogens to blood

Question 30

chemotaxis in inflammation

Answer 30

inflammatory chemicals are chemotactic agents, phagocytes and WBCs use positive chemotaxis to locate injury site.

Question 31

positive chemotaxis

Answer 31

WBC senses inflammatory chemical, travels, stronger concentration of that chemical then closer WBC will get

Question 32

which cell arrives first to the site of inflammation

Answer 32

neutrophils, then monocytes bc they will take a bit to form macrophages. macrophages will replace the neutrophils that are worn out, and dispose of cellular debris

Question 33

antimicrobial proteins

Answer 33

proteins that can attack microorganisms,s directly or interfere with their reproduction

Question 34

interferons, a type of microbial protein

Answer 34

released by cells infected by a virus to protect surrounding non infected cells. diffuse into cell and noninflected cells will synthesize proteins to degrade viral DNA. OVERALL warn the healthy cells there is an impostor.

Question 35

complement ,a type of microbial protein

Answer 35

group of 20 plasma proteins synthesized by liver. normally inactive in healthy blood, it amplifies immune system response. activates massive release of inflammatory chemicals, which complements innate defenses. stimulates phagocytes to clear debris and damaged stuff, and can lyse and kill several bacteria and other cell types.

Question 36

fever

Answer 36

body wide systemic response to pathogens, abnormally high body temp. normal body temp is 98.6, low grade fever 99-100.4 and fever of 103 plus is very concerning

Question 37

pyrogens

Answer 37

circulate up to hypothalamus, reset it to higher temperature.

Question 38

benefits of fever

Answer 38

causes spleen and liver to store more iron, bacteria cannot use it for growth. fever also increases metabolic rate of tissue cells, speeding up repair.

Question 39

adaptive defenses

Answer 39

slower than innate, but more specific. gets rid of what does not belong. cells here must be exposed to an antigen before they can react, 1 lymphocyte looks for 1 antigen

Question 40

humoral immunity

Answer 40

antibodies present in body fluids, humors. circulate freely after release, mark and temporarily inactivate target cells for destruction. B CELLS

Question 41

cellular immunity

Answer 41

when lymphocytes directly defend the body, can either kill target cels directly or release chemicals that increase inflammatory response and activative macrophages T CELLS

Question 42

adaptive defenses differ from innate defenses with these 4 things

Answer 42

adaptive uses lymphocytes, more specific bc identifies pathogens, systemic and not restricted to infection site, and adaptive has memory previously identified pathogens can be identified fast before infection can even get the chance to occur

Question 43

antigens

Answer 43

any substance that can mobilize the adaptive defense system

Question 44

immune system recognizes self vs non self by binding to what

Answer 44

antigens

Question 45

complete antigens are

Answer 45

immunogenic, stimulates lymphocyte proliferation and generates immune response. reacts with lymphocytes and antibodies. any foreign molecule can react as a complete antigen (protein, polysach, lipid, nucleic acid)

Question 46

hapten or incomplete antigens are

Answer 46

can only carry immune response when attached to protein carrier. if it was bound to a carrier protein, immune system may recognize it as non self. if no protein carrier attached, no immune response. ex, poison ivy and pet dander or detergents.

Question 47

how do antigens begin their adaptive defenses

Answer 47

lymphocytes and antibodies must bind to antigenic determinants on antigen surface. one antigen can have many determinants on its surface, so many antibodies can interact with one antigen. determinants may have ,many shapes n forms, body antibodies and lymphocytes can only recognize one antigenic determinant

Question 48

self antigens (MHC proteins)

Answer 48

self antigens that belong to your own body, on individual basis. we produce it ourself.

Question 49

major histocompatability complex (MHC) proteins

Answer 49

class of glycoprotein on cell surface, must be there for self antigen to work. genes code for this class of proteins, unlikely that 2 indivudals have same gene set. MHC protein + self antigen = no immune response.

Question 50

why are the MHC proteins necessary for immune system function

Answer 50

T lymphocytes can't interact with any antigen unless it is bound to MHC protein.