Chapter 15 - Innate Immunity Flashcards
innate immunity
aka non specific immunity
- body’s first line of defense
- structures, chem, + processes that work to prevent pathogens that are entering the body
structures of innate immunity
- skin
- mucous membrane: respiratory, digestive, urinary, + reproductive sytm
chemicals of innate immunity
-natural proteases
processes of innate immunity
-phagocytic cells
Skin
- has chemical that defend against pathogens
- perspiration
- sebum
2 layers of Skin
epidermis: layer of dead skin cells, prevents most pathogens fr getting in
dermis: below epidermis; where most immune cells would be
Perspiration
- secreted by sweat glands
- salt inhibits pathogen growth
- antimicrobial peptides
- lysozymes destroy cell wall of bacteria
sebum
- secreted by sebaceous (oil) glands
- helps keep skin pliable
- lowers skin pH to an inhibitory level to many bacterias
Lysozyme
an enzyme that catalyzes the destruction of the cell walls of certain bacteria, occurring notably in tears and sweat
-breaks cell wall peptidoglycan of GRAM-POS bacteria
mucous membrane
-line all the body cavities open to the environment
2 layers of the mucous membrane
1 epithelium
2 deeper connective tissue layer
Epithelium of Mucous Membrane
- thin outer covering
- cells are living
- tightly packed to prevent entry of pathogens
- continuous shedding of cells carries away microbes
- mucous physically traps microbes
- mucous secretions has antimicrobial chemicals
Lacrimal Apparatus
- produces + drains tears
- blinking spreads tears + washes surface of eye
most eye infections are caused by ____
most eye infections are caused by GRAM NEGATIVE
what targets gram positive bacteria in the eye
lysozyme
Microbial Antagonism
normal microbiota compete w potential pathogens
Normal microbiota + innate immunity
- normal flora makes it difficult for pathogens to compete
- consume nutrients
- create an environment unfavorable to other microbes
- help stimulate body’s second line of defense
- promote overall health by providing vitamins to host
body’s second line of defense
- operates when pathogens penetrate the skin or mucous membrane
- consist of plasma, cells, antimicrobial agents
Plasma
- mostly water containing electrolytes, dissolved gases, nutrients, + protein
- includes iron-binding compounds, complement proteins, + antibodies
- 55% of whole blood
Serum
-fluid remaining from plasma when fibrinogen (clotting factors) is removed
Fibrinogen
clotting matter
3 types of Cells/Cell Fragments
1 erythrocyte
2 platelet
3 leukocyte
formed elements
cells and cell fragments in plasma
-leukocyte, platelet, + erythrocyte
erythrocyte
carry oxygen + carbon dioxide in the blood
platelet
involved in blood clotting
leukocyte
- involved in defending the body against invaders
- divided into granulocytes + agranulocytes
monocytes
differentiates into macrophage when leaving the blood stream
5 types of white blood cells
never let monkeys eat bananas neutrophil lymphocyte monocyte eosinophil basophil
hematopoiesis
process of production, multiplication, + specialization of blood cells in the bone marrow
3 types of granulocytes
1 Basophil
2 Eosinophil
3 Neutrophil
basophil
stain color and dye
stains blue
basic dye with methylene blue
eosinophil
stain color and dye
stain color red/orange
acidic dye eosin
neutrophil
stain color and dye
stain is lilac
mix of acid + basic dyes
neutrophils + eosinophils
- phagocytize pathogens
- capable of diapedesis
- can kill bacteria by non-phagocytic means
2 types of agranulocytes
1 lymphocyte
2 monocyte
leukocyte most involved in adaptive immunity
lymphocyte
when ___ leave the blood + moves into tissues, they mature into macrophage
monocytes
diapedesis
the passage of blood cells (by squeezing) through capillary walls into the tissues
differential white blood cell count
-lab analysis can signal signs of disease
.incr eosino: allergies, parasitic worms
.incr leuko + neutro:bacterial disease
.incr lympho:viral infection
5 stages of phagocytosis
1 chemotaxis 2 adherence 3 ingestion 4 killing 5 elimination
Eosinophil
nonphagocytic killing
- secrete toxins that weaken/kill the helminth
- attack parasitic helminths by attaching to their surface
- mitochondrial DNA + proteins form structures that kills some bacteria
an indication of helminth (worm) infestation
elevated eosinophil
Neutrophil
nonphagocytic killing
- produce chem that kill nearby invaders
- generate extracellular fibers called NEUTROPHIL EXTRACELLULAR TRAPS that bind + kill bacteria
can use phagocytic + non-phagocytic means to kill bacteria
eosino + neutro
NK lymphocytes
nonphagocytic killing
- secretes toxins onto surface of VIRALLY INFECTED CELLS + TUMORS
- differentiate normal body cells bc they have membrane proteins similar to NK cells
- kills cells w/o MHC
Interferons
chem killing
- released by virally infected host cells to nonspecifically inhibit the spread of viral infections
- cause of many symptoms associated w viral infections
2 types of interferons
Type I (alpha + beta) Type II (gamma)
Complement
chem killing
- set of serum proteins designated numerically according to their order of discovery
- complement activation results in lysis of the foreign cell
complement activation
1 classical pathway
2 alternative pathway
3 lectin pathway
products of complement cascade
1 triggering inflammation
2 attracting phagocytes to sites of infection
3 killing the microbe by MAC attack
MAC attack
membrane attack complex
Inflammation
- redness, heat, swelling, pain
- nonspecific response to tissue damage fr various causes
2 types of Inflammation
1 Acute 2 Chronic (long lasting)
Acute Inflammation
- important for second line of defense
- develops quickly + short-lived
- typically beneficial
acute inflammation for second line of defense
- dilation increased permeability of blood vessels
- migration of phagocytes
- tissue repair
Fever
- temp over 37 celsius
- result when pyrogens trigger the hypothalamus to increase the body’s core temp
3 types of pyrogens
- bacterial toxins
- cytoplasmic contents of bacteria released by lysis
- antibody-antigen complexes
