Chapter 24 Flashcards
overview of the immune system
- immunity
- antigen
- pathogen
immunity
the ability to protect against disease causing agents
antigen
any substance that triggers an immune respose (bactiera, virus or fungi; OR pollen, cancer cell, dust mite, dust particle, splinter)
pathogen
an antigen capable of causing disease, specifically a bacteria, virus, or fungi
remember, pathogens normally need to adhere and multiply in order cause an infenction and disease
bacteria
extracellular - reproduce and reside outside of our cell
there are a few exceptions where bacteria go inside cells
viruses
intracellular - must go inside our cells to reproduce
extracellular - during the time after they have budded off from a cell and have not entered a new cell, they are outside of the cell
fungi
extracellular
levels of immunity
3 lines of defense
first line of defense
keep anything foreign out of our bodies "keep anything foreign out" physical and chemical barriers to keep things from entering into our bodies 1. intact skin 2. normal flora 3. Mucous membranes 4. protective membranes
second line of defense
if something does get in, there is a general, non-specific response to stop it from causing infection
third line of defense
a specific response against particular antigens
intact skin
bacteria and viruses cannot penetrate intact skin, but can enter through cuts, even microscopic ones (we do have necessary opening like eyes, nose, mouth…)
pathogen modes of transmission
the ways that bacteria and viruses spread from one person to another in order to reproduce coughing and sneezing food feces blood insects sexual activity
normal flora
the mixture of microbes regularly found on or in many sites of our bodies
we have built up immunity to most of these (stuff inside of our bodies)
these act as protectino by keeping more harmful bacteria and fungi from growing on these surfaces (act like glove)
mucous membranes
respiratory system - we have to breath, but bacteria in lungs can cause pneumonia; mucociliary blanket traps and transports objects and antigens away from the lungs by cililary action (ex: in the nose the cilia move objects backward toward the throat where they can be swallowed and killed in stomach acid or expelled through blowing your nose or sneezing
coughing and sneezing are part of our protection against microbes, by expelling them from our lungs (which is why we have to be careful when taking cough medicine because we are suppressing a cough that is trying to get bad stuff out)
protective membranes
digestive system - we have to eat, but need to keep harmful bacteria out of our intestines; stomach acids kills most microbes (however some microbes may be protected by food particles and reach the small intestines); peristalsis; thereis a refular loss of the mucous cells that line the small intestines to prevent microbes from becoming estalished
peristalsis
keeps food and microbes moving along withing our digestive system; it is the rhythmic waves of contractions by muscles in the intestines keep things moving
protective membranes
digestive system
peristalsis
keeps food and microbes moving along withing our digestive system; it is the rhythmic waves of contractions by muscles in the intestines keep things moving
digestive system
we have to eat, but need to keep harmful bacteria out of our intestines; stomach acids kills most microbes (however some microbes may be protected by food particles and reach the small intestines);
peristalsis;
there is a refular loss of the mucous cells that line the small intestines to prevent microbes from becoming estalished
role of the large intestine is to reabsorb water used in digestion; in the large intestine, the normal flora are very important in preventing the establishment of pathogenic organisms (regular bowel movements are important)
protective membranes
digestive system
urogenital system
digestive system
we have to eat, but need to keep harmful bacteria out of our intestines; stomach acids kills most microbes (however some microbes may be protected by food particles and reach the small intestines);
peristalsis;
there is a refular loss of the mucous cells that line the small intestines to prevent microbes from becoming estalished
role of the large intestine is to reabsorb water used in digestion; in the large intestine, the normal flora are very important in preventing the establishment of pathogenic organisms (regular bowel movements are important)
urogenital system
normally, the kidney, urinary bladder, and tubes are sterile as in urine
drinking water (fluids) is important for keeping this system working properly (kidney purifies the blood)
second line of defense
made up of cells and systemsthat are looking for anytning foreign that makes it paste the First Line of Defense
foreign = anythin gnot part of you
made up of a number of different types of white blood cells and systems to protect you
non-specific because it is not looking for a partiular antigen, but anything foreign
- immune cells
second line of defense 4 word summary
“general, non-specific response”
immunce cells
White blood cells
pagocytic cells - wander through body fluids and engulf and destroy foreign cells (macrophages are the most prevalent); kind of like pacman
second line of defense
made up of cells and systemsthat are looking for anytning foreign that makes it paste the First Line of Defense
foreign = anythin gnot part of you
made up of a number of different types of white blood cells and systems to protect you
non-specific because it is not looking for a partiular antigen, but anything foreign
- immune cells
- lymphatic system
immunce cells
White blood cells
pagocytic cells - wander through body fluids and engulf and destroy foreign cells (macrophages are the most prevalent); kind of like pacman
phagocytic cells
engulf and enclose microbes in vacuoles; macrophages
macrophages
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lymphatic system
system of viens that parallels the cirulatory (blood) system
functions of lymphatic system
- returns the fluid between cells (interstitial fluid) to the circuclatory system, just above the heart
- monitor the fluids for pathogens and cancer cells
immune cells
White blood cells
pagocytic cells - wander through body fluids and engulf and destroy foreign cells (macrophages are the most prevalent); kind of like pacman
lymphatic system
system of veins that parallels the circulatory (blood) system
organs that monitor the body for foreign objects (adenoids and tonsils for throat, bone marrow for b cell development, thymus for t cell development, lymph nodes for monitoring lymphatic system)
functions of lymphatic system
- returns the fluid between cells (interstitial fluid) to the circulatory system, just above the heart
- monitor the fluids for pathogens and cancer cells
- inflammatory response
lymph nodes
found throughout the body; lymphatic fluid slows through them
inflammatory response
an immune response triggered by physical injury or infection involving the release of substances; fever (systemic response to infection; increased temperature is thought to help immune cells perform more efficiently and hinder the growth of bacteria)
functions of lymphatic system
- returns the fluid between cells (interstitial fluid) to the circulatory system, just above the heart
- monitor the fluids for pathogens and cancer cells
- inflammatory response
- complement proteins
inflammatory response
an immune response triggered by physical injury or infection involving the release of substances; fever (systemic response to infection; increased temperature is thought to help immune cells perform more efficiently and hinder the growth of bacteria)
complement proteins
proteins that circulate in blood plasma and have several roles;
- some coat the surfaces of microbes markin them for destructino by macrophages
- other join together to make lethal holes in foreign cells, causing them to die
third line of defense
if microbes get throught the First Line of defense, the third line of Defense comes into play (at the same timeas the second line)
called acquired immunity (we acquire it); we are born with potential and it develops over our life-time, as we get sick or vaccinated
the role of the 3rd line is to protect us against specific pathogens and then devleop and retain memory, so wee don’t get the same sickness again
Involves the lympocytes (B and T cells) which are white blood cells
specific - thousands of Band T cells, eawch looking for a specific part (sequence of proteins about 16 o 18 amino acids long segments) of a particular antigen that can be found on the surface of anything foreign, including bacteria
passive immunity
comes from outside (es: mother passing antibodies to child during breast feeding)
4 word summary for 3rd line of defense
“specific response, with memory”
types of third line of defense
- humoral immunity
2. cell-mediated immunity
humoral immunit
b cells
this system protects primarily against extracellular bacteria and viruses present in body fluids
make antibodies
cell-mediated immunity
t cells
these cells attack virus-infected body cells (intracellular) and cancerous cells
antibodies
y shaped protein molecules that bind to specific proteins on the surfaces of bacteria (the stick to the protein)
antibodies
y shaped protein molecules that bind to specific proteins on the surfaces of bacteria (the stick to the protein)
3rd line - two part process
- primary immune response - the first time b or t cells are exposed to an antigen, b or t cells have to mount a response to stop the bateria or virus from harming or killing the organism (see and kill)
- secondary immune response - the memory cells produced during the primary response are activated by a second exposer to the same antigen; the response is faster and stronger (can happen weeks, years.. after)
3rd line - two part process
- primary immune response - the first time b or t cells are exposed to an antigen, b or t cells have to mount a response to stop the bateria or virus from harming or killing the organism (see and kill)
- secondary immune response - the memory cells produced during the primary response are activated by a second exposer to the same antigen; the response is faster and stronger (can happen weeks, years.. after)
role of antibodies
neutralization
agglutination
activation of complement protein
neutralization
coats and blocks viruses and bacteria, marks them for destruction
agglutination
causes bacteria and viruses…
activation of complement protein
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memory
once they encunter a particular antigen, b and t cells mount an atatck and generate numerous memory cells that will be looking for this antigen in the future
many memory cells looking for antigen to protect you in the future
memory
once they encunter a particular antigen, b and t cells mount an atatck and generate numerous memory cells that will be looking for this antigen in the future
many memory cells looking for antigen to protect you in the future
helper t cells
when they are stimulated they release chemicals to direct the entire immune response
considered the most important immune cell
these are the generals, conductors in the orchestra, they are in charge
also make memory cells
cytotoxic t cells
bind to the affected cell
release proteins that makes holes in the membrane of the infected cell
cell is destroyed
also make memory cells
cytotoxic t cells
bind to the affected cell
release proteins that makes holes in the membrane of the infected cell
cell is destroyed
also make memory cells
vaccine
a harmless variant or part of a pathogen used to stimulate the organism’s immune system
trigger a primary immune response so if you eveer encounter the pathogen again you body mounts a secondary response, which protects you from it
they basically trick the immune system into a primary immune response to thing that you’re sick and make memory cells, which protects you for life
why is HIV so dangerous
- it attacks the helper t cell which directs the immune response, most important cell in the immune system
- once a helper t cell is infected it becomes less effective and cytotoxic t cells will attack and destroy infected helper t cells (further reducing the number of helper t cells)
- it mutates so quickly that the immune system does not “recognize” the new strain of HIV as something it has seen before (it is hard to make an effective vaccine against it)
why is HIV so dangerous
- it attacks the helper t cell which directs the immune response, most important cell in the immune system
- once a helper t cell is infected it becomes less effective and cytotoxic t cells will attack and destroy infected helper t cells (further reducing the number of helper t cells)
- it mutates so quickly that the immune system does not “recognize” the new strain of HIV as something it has seen before (it is hard to make an effective vaccine against it)
allergens
antigens that cause allergies
proteins on pollen grains, dust mites, and animal dander (actually proteins in their saliva) are some common allergies
allergies
abnormal sensitivities to antigens
symptoms include sneezing, coughing, wheezing, upset stomach, and itching ( can occur in many parts of the body including nasal passages)
allergic reactions
the result of a two stage sequence (primary and secondary)
sensitization
primary immune response to allergen
anaphylactic shock
can occur in very sensitive persons
bee stings, shell fish, etc
mast cells release their histamines very suddenly, in great amounts, causing blood vessels to dilate rapidly and the blood pressure to drop severely
antibiotics
work by preventing bacteria from building their cell walls, when they are trying to divide and multiply
useless against viruses since viruses do not have cell walls
antibiotics
work by preventing bacteria from building their cell walls, when they are trying to divide and multiply
useless against viruses since viruses do not have cell walls
anthrax
endospore-forming bacilli
capsule
endospore (doesn’t die easily)
attacks macrophages
virulence factors
factors that intensify the effect of a pathogen
medical countermeasure to anthrax
vaccination priot to exposure…….
west nile virus
spread by insects, usually mosquitoes
most human infections are mild (fever, headache, body ache, skin rash, swollen lymph nodes
can be life-threatening if the virus crosses the blood-brain barrier, which can cause encephalitis (inflammation of the lining)
