Quiz 2 IMMUNITY PG9-14 Flashcards
The ability of the body to fight off disease is called____?
Resistance
The inability of the body to fight off disease is called____?
Susceptibility
Disease producing organisms such as bacteria, viruses and parasites are called?
Pathogens
The capacity of a pathogen to cause disease is called___?
Virulence
________ refers to quick general defence mechanisms against a wide range of pathogens
Non specific resistance
( also called innate immunity)
__________ refers to a slower response to a specific pathogen involving the activation of specific lymphocytes
Specific resistance
( also called adaptive or acquired immunity)
What are some examples of non specific defence mechanisms?
Stratified squamous epithelium of mucous membranes
Stomach acid with an acidic pH
Antibacterial substance lysozyme in tears an saliva
What is the first line of defence of the body?
Skin and mucous membranes
How do mucous membranes and the skin protect the body?
1.) mechanical protection
-many layers of keratinized squamous epithelia prevent penetration of skin
-mucous secretions trap particles and pathogens
-hair in nostrils filter
2.) chemical rotection
-low pH of sebum on skin gastric ice and vaginal secretions discourage bacterial growth
-LYSOZOME of tears, saliva, urine, sweat and nasal secretions break down cell walls of some bacteria
3.) vomiting and diarrhea expel pathogens
( toxins secreted by some bacteria irritate the intestinal lining triggering premature contractions leading to diarrhea)
What is the 2nd line of defence if microbes get through the skin and mucous membranes?
1.) interferon
-a group of small proteins with antiviral properties
2.) Complement proteins
-a group of 20 inactive proteins which circulate in the blood plasma which when activated interact in a specific manner and sequence
What are the 4 actions of activated complement proteins?
1.) MAC membrane attack complex
2.) increase capillary permeability by stimulating histamine release
3.) attract leukocytes to the site of invasion (chemotaxis)
4.) OPSONIZATION (coat the surface of the microbe with opsonins, thereby making it recognizable to neutrophils and macrophages which will phagocytize it)
Specialized lymphocytes that have the ability to kill a wide range of infectious microbes are called what?
Natural killer cells
Where are natural killer cells located?
Spleen
Lymph nodes
Bone marrow
Circulate in blood
Natural killer cells can release what two things?
1.) granzymes
(-breaks down proteins and induces apoptosis)
2.) perforin
(-makes perforations, cytolysis)
This is involved in both non specific and specific responses
Phagocytosis
In non specific responses, phagocytosis involve what cells to engulf microbes?
1.) neutrophils
(-first to arrive at the site of invasion/ short lived)
2.) macrophages
A localized response to tissue damage is called?
Inflammation
How is inflammation triggered?
Histamine release from mast cells
Inflammation is characterized by what 4 symptoms?
Redness
Pain
Heat
Swelling
What does NSAIDS stand for, and what are they used for?
Non steroidal anti inflammatory drugs ( aspirin, ibuprofen, Advil)
Which inhibit synthesis of prostaglandins which act upon pain receptors
Abnormally high body temperature triggered by infection and inflammation is called___?
Fever
What are the effects of a fever?
1.) speeds up repair process
2.) inhibits growth of microbes
3.) heat enhances the immune response against invader
What are 6 innate forms of immunity?
1.) skin and mucous membranes
2.) anti microbial proteins
3.) natural killer cells
4.) phagocytosis
5.) inflammation
6.) fever
How is adaptive immunity distinguished from innate immunity?
1.) specificity
2.) memory
What are two types of immune responses?
1.) cell mediated immune responses (CMI)
2.) antibody mediated or hum oral immune responses (AMI)
Define antigens
Complex molecules recognized as foreign by immune cells, which provoke an immune response
What are two types of antigens?
1.) exogenous
2.) endogenous
What is the difference between exogenous and endogenous antigens?
1.) exogenous
-foreign antigens locate outside a cell
-bacteria and bacterial toxins
-inhaled pollen and dust
-viral particles outside cell
2.) endogenous
-foreign antigens produced inside a cell
-viral proteins produced inside a host cell
-abnormal proteins produced by cancerous cells
-transplanted tissue and organs
What is major histocompatibility complex? (MHC)
Cells that belong to our own body that have special cell membranes that identify cells as “self”
-MHC’s are unique to everyone ( except identical twins)
-MHC’s are the reason transplanted organs and tissues re rejected
What are 2 characteristics of antigens?
1.) immunogenicity ( ability to provoke immune response)
2.) reactivity ( ability of antigen to react specifically with antibodies it provoked
What is the difference between cell mediate immune responses and antibody mediated immune responses?
1.) CMI
-specific T cells transform into CYTOTOXIC T CELLS which attack the target cell
2.) AMI
-specific B cells transform into PLASMA CELLS which produce antibodies towards exogenous antigen
What is the take home message on phagocytosis?
Macrophages are big eaters. They follow bacteria by chemotaxis and when they get there they eat it ( engulfed by phagocytosis)
