Immunology HAP FINAL TEST!!!!!

what is a pathogen

disease causing agent

what are considered pathogens?

Viruses, bacteria, fungi, and protozoans

what are examples of bacteria that cause infection?

E. coli, Salmonella, Staphylococcus

what are examples of viruses that cause infection?

Papovavirus – papilloma (warts)

Adenovirus – respiratory diseases

Herpes virus – herpes

Poxvirus – smallpox

Parvovirus – roseola

Picornavirus – polio

Rhinovirus – common cold

what is the body’s two types of defense?

specific and nonspecific

what is nonspecific defense?

it is general protection against many pathogens; natural resistance

what is specific defense?

defense mechanisms that are very precise targeting specific pathogens

what is categorized as nonspecific defense?

Species resistance, skin and mucous membranes, enzyme action, interferon, inflammation, and phagocytosis

what is categorized as specific defense?

specialized lymphocytes

which of the two types of defense has rapid response time and which has a slower response time?

nonspecific (rapid) specific (slower)

what are the 6 types of nonspecific defense?

1 species resistance

2. mechanical barriers

3. chemical barriers

4. phagocytosis

5. fever

6. inflammation

which of the 6 types of nonspecific resistances are 1st line of defense?

mechanical and chemical barriers

which of the 6 types of nonspecific resistances are 2nd line of defense?

phagocytosis, fever, and inflammation

species resistance

a species may be resistant to diseases that affect another species

Measles, mumps, gonorrhea, and syphilis…infect humans but not other animal species WHY???

one species may be resistant to a disease that affects another species because its tissues somehow fail to provide a suitable environment for the pathogen (temperature, chemical environment, etc.

mechanical barriers

skin, mucous membranes, fluids (sweat & mucous)…1st line defense (keep invaders OUT!)

where can mechanical barriers be found?

Linings of respiratory, digestive, urinary, and reproductive tracts

chemical barriers

consisted of bodily secretions, specialized proteins, and special chemical environments that destroy pathogens or inhibit their growth before they can enter/infect the body

what does gastric juices contain?

pepsin, a protein splitting enzyme and a low pH in HCl (lethal to pathogens)

what doe tears contain?

lysozyme, an antibacterial agent

an accumulation of what kills bacteria?

salt on the skin

what are interferons

hormone produced by lymphocytes and fibroblasts

what do interferons do once released from the viral infected cell?

they bind to receptors on uninfected cells and stimulate them to synthesize proteins that block replication of a variety of viruses

phagocytosis

removes foreign particles from the lymph and blood

neutrophils

1st on the scene of an infection to destroy pathogen; engulf and digest smaller particles

dendritic cells

in tissues close to outside

macrophages

in tissues & in blood

neutrophils and monocytes

attached by chemicals released from injured tissue

monocytes

phagocytize large particles and give rise to macrophages (histiocytes)

macrophages are found in the lining of blood vessels in the…

• bone marrow

• liver

• spleen

• lungs

• lymph nodes

fever

Higher body temp. causes the liver and spleen to sequester (isolate) iron. Also bacteria and fungi growth slows or stops, increasing the attach rate of phagocytic cells.

inflammation

tissue response to injury or infection producing redness, swelling, heat, and pain while infected cells release chemicals to attract WBC to inflammation sites

redness

blood vessel dilation

swelling

increase volume of blood

heat

blood from deeper parts of the body, which are warmer

pain

stimulation of nearby pain receptors

pus

mass of WBC, bacterial cells, and damaged tissue

how do WBC’s “slip out”?

histamine dilates capillaries & other chemicals make capillaries more permeable so that the WBC’s can slip out to the inflammation sites

fluid

inhibits the spread of pathogens and toxic substances to adjacent tissues

antigens

foreign substanaces that cause the formation of antibodies

antigens include…

• Potentially damaging microbes and their toxins

• Substances such as pollen and flea and dust mite feces

• Blood cell surface proteins

• The surface proteins of transplanted tissues and organs

antibodies

also called immunoglobulins, are proteins made in response to antigens

what do antibodies bind to?

antigens

antibodies are highly _______ and can help destroy _______.

specific; antigens

how many binding sites does an antibody have?

at least 2

before birth, body cells inventory “self” proteins and other large molecules for what reason?

for lymphocytes to then develop receptors that allow them to differentiate between nonself and self antigens

nonself antigens

combine with T cell and B cell surface receptors and stimulate these cells to cause an immune reaction

haptens

small molecules that can combine with larger ones, becoming antigenic

where do lymphocytes originate from?

red bone marrow

where would lymphoctyes be released into?

the blood before they differentiate (thymus= T cells; B cells= mature in red bone marrow)

T cells

• Interact with antigen-bearing agents directly

• Secrete cytokine: enhance cellular responses to antigens

• Secrete substances that are toxic to their target cells

B cells

interact indirectly with antigen-bearing agents: humoral immunity

t cell activation

An antigen presenting cell displays a foreign antigen causing the t cell to act on the antigen. Macrophages would phagocytizes and digest the agent.

helper t cells

activate when encounter antigens that its specialized to react to, contacting a B cell associated with antigen while a T cell secretes cytokines, stimulating B cell proliferation and attracting macrophages

b cell activation

when is encounters an antigen that fits its antigen receptors, it proliferates and enlarges its clone, with some specializing into antibody-producing plasma cells

antibodies

proteins called immunoglobulins (Ig)

what are the 5 major types or classes of antibodies?

IgG, IgA, IgM, IgD, and IgE.

what is the antibodies animation?

• attack antigens directly

• activate complement

• stimulate local tissue changes that are unfavorable to antigen-bearing agents

IgG

highest opsonization and neutralization activities and is classified into four subclasses (IgG1, IgG2, IgG3, and IgG4)

IgM

produced first upon antigen invasion

IgA

expressed in mucosal tissues, forming dimers after secretion

IgD

unknown function

IgE

involved in allergy

agglutination

atibodies clump together

precipitate

antibodies form insoluble masses

by attacking antigens directly, antibodies make it easier for…

phagocytes to engulf the antigens /antigen-bearing agents & eliminate them

when antibodies are attached to antigen

the pathogen as been neutralized

can antibodies enter into other cells?

no

active immunity

naturally acquired & artificial (passively) acquired

naturally acquired

encounter pathogen and has immune response

artificial (passively) acquired

vaccine of dead weakened pathogen

immune response

person receives antibodies produced by another individual; short term lasting as long as the antibodies remain in the blood (person remains vulnerable) - NO MEMORY CELLS

NATURALLY ACQUIRED PASSIVE IMMUNITY:

fetus acquires limited immunity from mother through placenta and/or breast milk (including colostrum)

ARTIFICIALLY ACQUIRED PASSIVE IMMUNITY:

person receives an injection of antiserum (antibodies) collected from a person who has already developed immunity against a particular disease

what is a result of allergic reactions

mast cells bursting and releasing allergy histamine

delayed reaction allergy

occur in anyone and inflame the skin

immediate reaction allergy

inborn ability to overproduce IgE

allergic reactions are triggered by antigens known as…

allergens

what are the four types of allergic reactions?

skin contact, injection, ingestion, inhalation

hypersensitivity

an immune system response to an antigen beyond what is considered normal.

hypersensitivity reactions occur when a person has been __________ to an antigen?

sensitized

how does the body react to the allergen?

cause the release of histamine from mast cells

what do histamine cause?

blood vessels to dilate, tissues to swell, contraction of bronchial and intestinal smooth muscles, increased mucus production

hayfever

an allergic reaction to airborne substances such as: dust, molds, pollens, and animal fur or feathers.

asthma

chronic (long term) disease of the lungs. inflames and narrows the airways, resulting in difficulty breathing. common disease, affecting 22 million people in the US. occurs in people of all ages, but most commonly first appears in childhood.

asthma involves the production of…

histamines

where does the reaction for asthma occur?

in the small airways (bronchioles) where the histamine causes constriction, accumulation of fluid and mucus, and inability to breathe.

what are treatments for immune disorders?

surgery, radiotherapy, drugs & physical therapies, immunotherapy, gene & cell therapy

autoimmune disorder

immune system manufactures autoantibodies that attack one’s own body tissue

• Previous viral infection

• Faulty T cell development

• Reaction to a nonself antigen that resembles a self antigen

Lupus erythematous

autoantibodies attack DNA (can affect whole body as result)

Rheumatoid arthritis

autoantibodies attack cartilage of joints

Insulin-dependent diabetes

T-cells cause destruction of insulin producing cells in pancreas

Multiple sclerosis

T-cells destroy myelin sheath around neurons

Grave’s disease

autoantibodies to thyroid stimulating receptor (overproduce thyroid stimulating hormone; involved in metabolism)

Crohn’s Disease

immune system attacks alimentary canal (leading to chronic inflammation)

what is an example of IMMUNODEFICIENCY DISEASE

HIV

at 60 years

the volume of thymus tissue is only about 5% of that of a newborn.