micro ppt 13

what are the goals of host defenses

protection and health

why do we need diversity of the host mechanisms involved in defense

there is diversity in the types of pathogens and the pathogen abilities

is innate immunity fast

yes (minutes/hours)

speed of adaptive immunity

slow (days)

examples of innate immunity

complement proteins, granulocytes, phagocytes

examples of adaptive immunity

B cells, T cells, antibodies

symptoms of innate immunity

fever, inflammation

what do innate and adaptive immunity have in common

both have cytokines

what are cytokines

chemical, soluble messengers made by 1 cell delivered to another

what cytokines does adaptive immunity have

IL-interleukins

INF-interferons

TNF-tumor necrosis factor

another word for innate immunity

nonspecific immunity

characteristics of nonspecific immunity

always present

ready to act

acts immediately

physical barriers associated with nonspecific immunity

skin and mucous memebransn

chemical barriers associated with nonspecific immunity

lysozyme/low pH stomach

cellular defense of nonspecific immunity

phagocytosis (macrophages)

inflammation is a response to

tissue damage

fever is an increase in

systemic temp

molecular defense utilizes cytokines, which are

small soluble proteins acting as cell-cell messengers

cytokine that helps clear viral infections

interferon

cascade of proteins that enhance inflammation/act as opsonins/create a pore leading to lysis

complement cascade

in adaptive immunity how long does it take to develop

days to weeks

in adaptive immunity, products only react with eliciting foreign substances to produce

antigens

lymphocytes are involved in what 2 immunities

humoral immunity, cell mediated immunity

humoral immunity makes

antibodies - B

cell mediated immunity makes

T = t-helper (Th) and T-cytotoxic (Tc)

T-helper

helps B cells increase antibody production, macrophages increase killing, and Tc increase killing

T-cytotoxic

kills infected/abnormal cells

what to Th and Tc have in common

both cytokines, both do cell-cell interactions

nonspecific immunity is the first line of defense and offered resistance to

any microbe or foreign material

does nonspecific immunity have immunological memory

no

does nonspecific immunity adapt

no, stays the same

the skin is a strong

mechanical barrier to microbial invasion (multiple layers)

produces keratin in the outer layer

keratinocytes

intact skin is

impenetrable

presenting antigens

showing antigens to another cell type (typically a T cell)

the skin is an inhospitable environment for

microbes

another example of physical barrier

mucous membranes

MM resists penetration and traps

microbes

____ contains a lot of antimicrobials

mucus

MALT

mucosal associated lymphoid tissue

a breath in physical barrier allows

cellular defense to take over

development of blood cells in bone marrow

hematopoiesis

all blood cells arise from

pluripotent stem cells

platelets aid in

blood clotting

erythrocytes

red blood cells

leukocytes

white blood cells

what is important about leukocytes

superstar of immune system

high count indicates infection

leukocytes are involved in what kind of immunity

both specific and nonspecific

macrophages and dendritic cells are found where

in tissues

agranulocytes are found where

circulation

NK is an innate cell that

acts like Tc

neutrophils (PMNs) make up what percent of circulating leukocytes

50-90%

PMNs

polymorphonucleus

neutrophils are highly

phagocytic

neutrophils are the

1st responder cell from circulation

neutrophils circulate in blood and then migrate to

sites of tissue damage

what do neutrophils do when they reach the tissue damage

release granule contents/phagoc to kill and present Ag

neutrophils weapon of choice

enzymes and reactive oxygen and nitrogen metabolites

where are the weapons contained

in granules

basophils make up what percent of WBC in circulation

<1%

describe basophils

nonphagocytic/allergic resp.

basophils release

nasoactive molecules

causes swelling to make vessels leaky, allowing WBC to reach sites of infection

histamine

eosinophils make up what percent of WBC in circulation

1-3%

describe eosinophils

weakly phagocytic/allergy and parasitic reactions

mast cell locations

in most tissues including connective tissues and epithelia

how many mast cells in a skin biopsy

~10,000cells/mm³

one function of mast cells is to recruit

specific and nonspecific effector cells to the site

upon activation, mast cells release

granule contents

what are the granule contents

cytokines, chemokine, vasoactive amines, enzymes, antimicrobial peptides

increases the flow of lymph from infection sites

vasodilation

vasodilation recruits leukocytes to the site of

infection

vasodilation triggers

muscle contraction

this muscle contraction will clear the

invader

what is wound throbbing caused by

mast cells increasing vasodilation

mast cell granules also contain

histamine (vasoactive amine)

what can histamine cause

constriction of throat/bronchi

constriction of intestine

dilation of blood vessels

what two characteristics of histamine cause expulsion

constriction of throat/bronchi

constriction of intestine

what characteristic kills the invader

dilation of blood vessels

extremem histamine respinse

Anaphylaxis = shock/organ failure/death

how to treat anaphylaxis

epinephrine to reform epithelial junctions and inhibit granule release/correct heartbeat, relax constricted muscles

monocytes and macrophages are highly

phagocytic cells

monocytes are found in

the blood

another way to describe monocytes

mononuclear agranulocytic phagocytic leukocytes

how long are monocytes in circulation

~8hrs

what do monocytes do in circulation

enter tissues and mature into macrophages

describe macrophages

larger, more complex, long lived cells

where do macrophages live

in tissues

macrophages have a variety of

surface receptors

macrophages are phagocytic cells that recognize, ingest, and kill

extracellular microbes

macrophages present antigens to

T cells

steps of respiratory burst

find pathogen

bind

ingest

digest

present Ag

bodys defense to tissue damage

inflammation

examples of tissue damage

pathogen, physical trauma, cuts, wounds, UV light, chemicals, insect bites, allergies, drugs

4 cardinal signs of inflammation

erythema, edema, heat, pain

3 goals of inflammation

kill invading microbes

clear away tissue debris

process of cells leaving circulation and arriving at the site of injury

extravasation

RBC engorgded capillaries causes

erythema

Accumulation of fluid (exudate) and cells

swelling/edema

localized increase in metabolic activity

heat