Nonspecific Host Defenses Exam 3

Front 1

resistance

Back 1

natural ability of a host to resist an infection by a microorganism that the host has never encountered before

relies on nonspecific defenses

Front 2

immunity

Back 2

enhanced resistance to a specific infections agent that arises in a host as a result of previous exposure to that infectious agent

involves the production of specific proteins called antibodies that target defense responses against the specific antigen

Front 3

conditions that can cause a persons resistance to be reduced

Back 3

old age

very young age

starvation

heredity

climate

poverty

stress

cuts and open sores

hospitalization

AIDs

cancer

immunosuppressant drugs

surgery

Front 4

what is nonspecifice resistance?

Back 4

first line of defense against infection

Front 5

physical and chemical barriers

Back 5

skin

respiratory tract

alimentary canal

eye

Front 6

skin as a barrier

Back 6

physical and mechanical barrier, some chemical against microbial infection

enzymes in sweat degrade bacterial cell walls

organic acids lower the pH

high levels of salt are caused by the evaporation of sweat

these factors inhibit microbial growth

microorganisms that survive well on the skin as normal flora are usually not well adapted to infect deeper tissues

Front 7

respiratory tract as a barrier

Back 7

upper tract is lined with mucosal epithelium which produces a sticky substance, mucous that traps microorganisms

mucous also contains antibodies

mucosal epithelium covered with cilia that move bacteria that get trapped by mucous towards the digestive tract

Front 8

alimentary canal as a barrier

Back 8

stomach has a high concentration of HCL and digestive enzymes, most bacteria are killed here

there is normal flora of the gut, esp the large intestines

number of bacteria that live in the intestines and are adapted to a commensal symbiosis with the huge host

bacteria compete against new invaders and help to exclude outsiders

Front 9

eye as a barrier

Back 9

defenses include: eyelashes, mucous, the blinking reflex, and tears

tears contain an enzyme called lysozyme that degrades bacteria cell walls

Front 10

Second line of defense against infection

Back 10

phagocytes

leukocytes

Front 11

phagocytes

Back 11

cell that can engulf and devour microorganisms

move around the body searching for foreign objects like bacteria to eat

play a role in resistence in that they can recognize and destroy invading bacteria in a nonspecific way

play role in immunity when they work with antibodies to destroy specific bacteria

Front 12

opsin independent phagocytosis

Back 12

occurs when a phagocyte binds to the bacterium because it has a receptor protein on its surface that sticks to a specific protein found o the surface of the bacterium

occurs when a phagocyte binds to and engulfs a bacterium that is coated with specific antibodies

Front 13

major types of phagocytes

Back 13

monocytes

macrophages

dendrite cells

kupffer cells

microglial cells

neutrophils

Front 14

monocytes

Back 14

leukocytes with a single large round nucleus that develop into macrophages

Front 15

macrophages

Back 15

found in various parts of the body, such as the blood, lymph nodes, epithlial layers, and mucous membranes

Front 16

dendrite cells

Back 16

found in the intestinal walls, the thymus, and other places

Front 17

kupffer cells

Back 17

macrophages in the liver

Front 18

microglial cells

Back 18

macrophages that are seen in the brain

Front 19

neutrophils

Back 19

most common polymorphonuclear leukocyte (PMN)

Front 20

leukocytes

Back 20

major player in the body's defense against infection

leuko=white -cyte=cell

white blood cells

Front 21

2 major categories of leukocytes

Back 21

lymphocytes

phagocytes

Front 22

lymphocytes

Back 22

leukocyte

nonphagocytic, involved in specific immune responses

Front 23

Complement system in 2nd line of defense

Back 23

group of 20 different proteins found in the blood serum that play a role in destroying infectious microorganisms

Front 24

complement proteins

Back 24

some bind to bacteria and other microorgs. then act like opsins, others as cytokines or chemotactic factoers, some form the membrane attack complex

circulate in the blood in an inactive form

activate by enzymes that cleave off blocking groups

contact with bacterial endotoxin (LPS) or certain bacterial glycoproteins can cause activation of complement factors

also activated by antibodies

play role in nonspecific and specific responses

Front 25

activation of complement proteins

Back 25

alternative pathway

series of enzymatic reactions involving activation of complement proteins by proteolytic cleavage to remove blocking groups

when final protein activated, they form the membrane attack complex, which can put holes in the cytoplasmic membrane of a pathogenic microorg. or an infected human cell

Front 26

Opsins

Back 26

g:sauce

substance that binds to a microorg. and increases the rate of efficiency of phagocytosis by macrophages, neutrophils, etc

Front 27

cytokines

Back 27

peptide hormone that acts as a signal causing specific cells to undergo some metabolic or developmental step, such as activation of a neutrophil as it becomes an active phagocyte or the conversion of a monocyte into a macrophage

Front 28

chemotactic factors

Back 28

chemical signal molecules that act as an attractant to a microorg. or a specific type of cell

released by damaged tissues to attract macrophages and neutrophils to the site of potential infection

Front 29

membrane attack complex

Back 29

several complementary proteins will insert themselves into a membrane whenthey are activated and will form a donut-shaped structure that puts a hole in the membrane

Front 30

inflammation

Back 30

general response to tissue damage

big part of nonspecific response b/c tissue damage is often caused by an infection or a wound

a wound provides a portal for entry for infectous microorgs.

tissue damage usually correlated to infection

Front 31

four signs of inflammation

Back 31

redness

swelling

heat

pain

Front 32

redness of skin

Back 32

in inflammation, blood flow to the damaged tissue is increased

causes redness

increases traffic of nutrient and WBCs to the damaged tissue

Front 33

swelling

Back 33

leukocytes and fluids leave the blood vessels and move into the damaged tissue causing swelling

Front 34

heated skin

Back 34

phagocytes in the area of damaged tissue become activated

activated phagocytes move more and synthesize antibacterial compounds

increased metabolism produces extra heat

Front 35

pain with inflammation

Back 35

swelling and heat irritates nerves and causes pain