Topic 4.3: Blood and Immunity Flashcards
Which of the following allows rapid change in one direction but does not achieve stability?
a) homeostasis
b) positive feedback
c) negative feedback
d) all of the above
b) positive feedback
Which of the following is an example of negative feedback?
a) uterine contractions increase as labor progresses
b) insulin decreases blood sugar levels after a meal is eaten
c) sweating increases as body temperature drops
d) platelets continue to plug an opening in a blood vessel until blood flow stops.
b) insulin decreases blood sugar levels after a meal is eaten
Which of the following is not a function of blood?
a) regulation of the body temperature
b) defense of the body
c) transport of oxygen and carbon dioxide
d) manufacture of hormones
d) manufacture of hormones
Which of the following is/are formed from megakaryocytes?
a) basophils
b) platelets
c) erythrocytes
d) fibrinogen
b) platelets
Which of the following is not a white blood cell?
a) lymphocyte
b) neutrophil
c) eosinophil
d) basophil
e) all of the above
e) all of the above
Summarize the three functions of the lymphatic system.
Excess interstitial fluid moves into the lymph vessels and is returned to the blood stream.
Fats from the small intestine move into the lymph vessels and are transported into the bloodstream.
White blood cells in the lymph system function in protecting the body from disease.
Explain how lymph is different than blood.
Lymph is the excess interstitial fluid that has been absorbed into the lymphatic vessels. It is mostly water but also contains nutrients, electrolytes, oxygen, hormones, enzymes, and wastes. Blood contains erythrocytes, leukocytes, platelets, waste solutes, and products of cells.
Distinguish between the function of a primary and secondary lymphoid organ
In the red bone marrow and the thymus, which are primary lymphoid organs, lymphocytes develop and mature. In the secondary lymph organs, such as the lymph nodes and the spleen, lymphocytes become activated.
Define lymphatic system
Organ system consisting of lymphatic vessels and lymphatic organs; transports lymph and lipids, and aids the immune system.
Define lymphatic vessels
Vessel of the lymphatic system that is responsible for transporting excess interstitial fluid, or lymph, from the tissues to the circulatory system.
Define lymphatic capillary
Smallest vessels of the lymphatic system; closed-ended; responsible for the uptake of fluids from the surrounding tissues.
Define lymph
Fluid, derived from interstitial fluid, that is carried in lymphatic vessels.
Define lymphoid organ
Organ other than a lymphatic vessel that is part of the lymphatic system; the lymphatic organs are the lymph nodes, tonsils, spleen, thymus gland, and bone marrow.
Define lymphocyte
Specialized white blood cell that functions in specific defense; occurs in two forms—T lymphocytes and B lymphocytes.
Define red bone marrow
Vascularized, modified connective tissue that is sometimes found in the cavities of spongy bone; site of blood cell formation.
Define thymus
Lymphoid organ involved in the development and functioning of the immune system; T lymphocytes mature in the thymus.
Define spleen
Large, glandular organ located in the upper left region of the abdomen; stores and filters blood.
Define lymph nodes
Mass of lymphatic tissue located along the course of a lymphatic vessel.
Define pathogen
Disease-causing agent such as viruses, parasitic bacteria, fungi, and animals.
Name on physical and one chemical barrier to infection.
The skin and mucous membranes are physical barriers; a chemical barrier is the acid of the stomach.
Summarize the stages of an inflammatory response.
- Injured tissue cells and mast cells release histamine and other chemical mediators, which cause capillaries to dilate and increase blood flow.
- Resident macrophages and dendritic cells phagocytize pathogens and release cytokines, which stimulate the inflammatory response.
- Neutrophils and monocytes (become macrophages) squeeze through the capillary wall and phagocytize pathogens.
- Blood clotting walls off capillary and prevents blood loss.
Contrast the way that macrophages typically kill pathogens with the method used by natural killer cells.
Macrophages kill pathogens by engulfing them into a vesicle that has an acid pH, hydrolytic enzymes, and reactive oxygen compounds.
NK cells induce cells that lack self-MHC-I molecules to undergo apoptosis (cell suicide).
Summarize three major functions of the complement system
The complement system enhances phagocytosis of pathogens, activates inflammation, and kills pathogens by forming a membrane attack complex.
Define immune system
System associated with protection against pathogens, toxins, and some cancerous cells. In humans, this is an organ system.
Define immunity
Ability of the body to protect itself from foreign substances and cells, including disease-causing agents.
Define innate immunity
An immune response that does not require a previous exposure to the pathogen.
Define adaptive immunity
Type of immunity that is characterized by the response of lymphocytes to specific antigens.
Define inflammatory response
Tissue response to injury that is characterized by redness, swelling, pain, and heat.
Define mast cells
Connective tissue cell that releases histamine in allergic reactions.
Define histamine
Substance, produced by basophils in blood and mast cells in connective tissue, that causes capillaries to dilate.
Define macrophages
In vertebrates, large phagocytic cell derived from a monocyte, that ingests microbes and debris.
Define dendritic cells
Antigen-presenting cell of the epidermis and mucous membranes.
Define cytokines
Type of protein secreted by a T lymphocyte that attacks viruses, virally infected cells, and cancer cells.
Define phagocytes
Type of white blood cells that destroy pathogens using phagocytosis.
Define neutrophils
Granular leukocyte that is the most abundant of the white blood cells; first to respond to infection.
Define monocyte
Type of agranular leukocyte that functions as a phagocyte, particularly after it becomes a macrophage, which is also an antigen-presenting cell.
Define natural killer (NK) cells
Lymphocyte that causes an infected or cancerous cell to burst.
Define complement system
Collective name for a series of proteins in the blood, some of which act as enzymes and activators, which bind to antibodies and may lead to rupture of a foreign cell.
Define interferons
Antiviral agent, produced by an infected cell, that blocks the infection of another cell.
Describe 4 mechanisms that result in the generation of antigen receptor diversity .
Diversity in antigen receptors occurs because:
- Genes for T- and B-cell receptors contain segments that code for many parts of the antigen receptor.
- Enzymes in the T and B cells cut out these segments and combine them differently.
- Mutations may be introduced as these segments are combined.
- The two protein chains, containing the variation of steps 1-3 combine to produce a new receptor.
Discuss the major tenets (principles) of the clonal selection theory.
The clonal selection theory states that B cells and T cells have cell surface receptors for only one specific antigen. When the cell contacts that specific antigen, it is selected to undergo clonal expansion (divide) and differentiate into either memory cells or cells that actively fight infection.
List the five classes of human antibodies and their main functions.
IgG: Activates complement, crosses the placenta
IgM: Early response, activates compliment
IgA: protects respiratory tract
IgD: activates B cells
IgE: protects against parasites
Contrast the specific functions of helper T cells, suppressor T cells, and cytotoxic T cells.
Helper T cells recognize antigen fragments in combination with MCH molecules presented by antigen-presenting cells that have MHC class II proteins on their surface.
Cytotoxic T cells recognize antigen -presenting cells with MHC class I proteins.
Suppressor T cells inhibit these responses and act to control adaptive immunity.
Define antigen
Foreign substance, usually a protein or a polysaccharide, that stimulates the immune system to react, such as to produce antibodies.
Define clonal selection
States that the antigen selects which lymphocyte will undergo clonal expansion and produce more lymphocytes bearing the same type of receptor.
Define plasma cell
Mature B cell that mass-produces antibodies.
Define B-cell receptor (BCR)
Molecule on the surface of a B cell that binds to a specific antigen.
Define antibody
Protein produced in response to the presence of an antigen; each antibody combines with a specific antigen.
Define memory B cell
Forms during a primary immune response but enters a resting phase until a secondary immune response occurs.
Define antibody-mediate immunity
Specific mechanism of defense in which plasma cells derived from B cells produce antibodies that combine with antigens.
Define immunoglobulin (Igs)
Globular plasma protein that functions as an antibody
T-cell receptor (TCR)
Molecule on the surface of a T cell that can bind to a specific antigen fragment in combination with an MHC molecule.
MHC (major histocompatibility complex) protein
Protein marker that is a part of cell-surface markers anchored in the plasma membrane, which the immune system uses to identify “self.”
Define helper T cells
Secretes lymphokines, which stimulate all kinds of immune cells.
Define cytotoxic T cell
T lymphocyte that attacks and kills antigen-bearing cells.
Define antigen-presenting cells (APC)
Cell that displays an antigen to certain cells of the immune system so they can defend the body against that particular antigen.
Define memory T cells
T cell that differentiates during an initial infection and responds rapidly during subsequent exposure to the same antigen.
Define cell-mediated immunity
Specific mechanism of defense in which T cells destroy antigen-bearing cells.
Describe 3 different types of vaccines.
Attenuated (live, but nonvirulent).
Genetically engineered (also called subunit vaccines.)
DNA vaccines.
Explain why the passive transfer of antibodies is of great importance for the newborn.
The immune system of the newborn is immature, plus the newborn has not been exposed to any infectious agents, so it would be very susceptible to infectious diseases if it did not receive antibodies from its mother.
Explain how the interaction of cytokines with receptors on target cells may be blocked.
The interaction of cytokines with their receptors could be blocked using antibodies that react with the cytokine or possibly with the receptor.
Summarize the advantage of using a monoclonal antibody or diagnosis or treatment.
Monoclonal antibodies are extremely specific because they react with only on antigen. Because of their specificity and purity, reaction against the preparation is avoided.
Define active immunity
Ability to produce antibodies due to the immune system’s response to a microorganism or a vaccine.
Define passive immunity
Protection against infection, acquired by transfer of antibodies to a susceptible individual.
Define immunization
Strategy for achieving immunity to the effects of specific disease-causing agents.
Define vaccine
Preparation that acts as a preventative measure against a disease by using antigens that promote immunity without causing the actual disease.
Define monoclonal antibodies
One of many antibodies produced by a clone of hybridoma cells that all bind to the same antigen.
Explain the immunological reason why immediate allergic responses can occur within seconds after being re-exposed to an allergen, whereas delayed-type responses may take days.
Immediate allergic responses are caused by IgE antibodies that have already been produced against the offending allergen; delayed-type responses take longer because they require sensitized T cells to secrete cytokines that cause inflammation.
Discuss why Rh incompatibility is only a problem when a fetus is Rh- positive and the mother is Rh- negative.
If a mother is Rh-positive, she will not produce anti-Rh antibodies that would react with the antigens of the fetus.
Discuss the potential side effect of the drugs cyclosporine and tacrolimus, which function by inhibiting cytokine production (rather than inhibiting specific responses to transplanted organs).
Drugs that inhibit cytokine production may inhibit certain desirable immune responses that protect the individual .
Define allergies
Immune response to substances that usually are not recognized as foreign.
Define immediate allergic response
Allergic response that occurs within seconds of contact with an allergen; caused by the attachment of the allergen to IgE antibodies.
Define asthma
Condition in which bronchioles constrict and cause difficulty in breathing.
Define anaphylactic shock
Severe systemic form of anaphylaxis involving bronchiolar constriction, impaired breathing, vasodilation, and a rapid drop in blood pressure with a threat of circulatory failure.
Define delayed allergic response
Allergic response initiated at the site of the allergen by sensitized T cells, involving macrophages and regulated by cytokines.
Describe 4 examples of autoimmune diseases.
Muscular weakness occurs in patients with myasthenia gravis because antibodies attach to and disrupt neuromuscular junction.
In multiple sclerosis, T cells attack the myelin surrounding nerves and hamper nerve conduction.
Antibody-antigen complexes form in people with systemic lupus erythematosus and these get deposited in organs, including the kidneys.
Antibody-antigen complexes form in rheumatoid arthritis and these primarily affect the joints.
List two immunodeficiency diseases, and identify them as either congenital or acquired.
A congenital immunodeficiency disease is severe combined immunodeficiency.
AIDS is an acquired immunodeficiency disease.
Define autoimmune disease
Disease that results when the immune system mistakenly attacks the body’s own tissues.
Define immunodeficiency disease
Condition that is the result of the immune system’s inability to protect the body.
What is the term for localized swelling caused by fluid accumulation?
a) lymph
b)lupus
c) edema
d) complement
c) edema
Which of the following is a function of the spleen?
a) produces T cells
b) removes warn-out red blood cells
c) produces immunoglobulins
d) produces macrophages
e) regulates the immune system
b) removes warn-out red blood cells
Which of the following is not a function of the lymphatic system?
a) produces red blood cells
b) returns excess fluid to the blood
c) transports lipids absorbed from the digestive system
d) defends the body against pathogens
a) produces red blood cells
Which of the following is most directly responsible for the increase in capillary permeability during the inflammatory reaction?
a) pain
b) white blood cells
c) histamine
d) tissue damage
c) histamine
Which of the following is not a goal of the inflammatory reaction?
a) bring more oxygen to damaged tissues
b) decrease blood loss from a wound
c) decrease the number of white blood cells in damaged
d) prevent entry of pathogens into damaged tissues
c) decrease the number of white blood cells in damaged
Which of the following is not correct concerning interferon?
a) interferon is a protective protein
b) virus-infected cells produce interferon
c) interferon has no effect on viruses
d) interferon can be used to treat certain viral infections
c) interferon has no effect on viruses
The adaptive immune defenses respond to which of the following?
a) specific antigens
b) general pathogens
c) interferon
d) histamine
e) all of the above
a) specific antigens
Which of the following does not pertain to B cells?
a) have passed through the thymus
b) have specific receptors
c) are responsible for antibody-mediated immunity
d) synthesize antibodies
a) have passed through the thymus
Which of the following characteristics pertains to T cells?
a) have specific receptors
b) are of more than on type
c) are responsible for cell-mediated immunity
d) stimulate antibody production by B cells
e) all of the above
e) all of the above
What do V and C stand for on the IgG molecule diagram?
V= variable regions
C= constant regions
Active immunity can be produced by
a) having a disease
b) receiving a vaccine
c) receiving gamma globulin injections
d) both a and b are correct
e) both b and c are correct
d) both a and b are correct
Which of the following does not occur during a secondary immune response?
a) antibodies are made quickly and in great amounts
b) antibody production lasts longer than in a primary response
c) clonal selection occurs for B cells
d) all of these occur during a secondary immune response
d) all of these occur during a secondary immune response
A sudden drop in blood pressure in response to an antigen in the body is a characteristic of which of the following?
a) inflammatory response
b) passive immunity
c) cell-mediated immunity
d) anaphylactic shock
e) none of the above
d) anaphylactic shock
Which of the following conditions occurs when T cells attack the myelin sheath covering nerve fibers?
a) lupus
b) rheumatoid arthritis
c) multiple sclerosis
d) myasthenia gravis
c) multiple sclerosis
Which of the following is not an example of an autoimmune disease?
a) multiple sclerosis
b) rheumatic fever
c) hemolytic disease of the newborn
d) systemic lupus erythematosus
c) hemolytic disease of the newborn
Which of the following causes damage to the cells of the immune system and allows for opportunistic infections to develop?
a) inflammatory response
b) AIDS
c) complement
d) edema
e) all of the above
b) AIDS
Some primitive organisms, such as invertebrates, have no lymphocytes and thus lack an adaptive immune system, but that have some components of an innate immune system, including phagocytes and certain protective proteins. What are some general features of innate immunity that make it very valuable to organisms lacking more specific antibody-and cell-mediated responses? What are some disadvantages to having only an innate immune system?
Innate immune mechanisms are valuable mainly because they can react very quickly to a wide variety of pathogens. However, organisms lacking adaptive immunity are not able to mount specific antibody and T-cell responses targeted at one specific organism, nor are they able to develop memory cells that are able to respond faster to subsequent exposures to the same organism.
Describe the experiments Pasteur used to disprove the idea of spontaneous generation.
Pasteur demonstrated that sterile broth enclosed in a flask that was not open to the air did not spontaneously generate microbes.
List the major groups of microbes studied in microbiology .
Microbes include bacteria, archaea, protists, fungi, and viruses.
Explain what is meant by the term microbiota.
Your microbiota are all the microbes, the beneficial ones and the harmful ones, that live on or with you.
Define microbiota
Typical complement of bacterial species found on the human body; includes species found both internally and externally.
List some key characteristics of archaea, bacteria, and eukarya.
Archaea and bacteria lack a nucleus and membrane-bound organelles in the cytoplasm. Archaea shares features with eukarya like introns (sometimes), histones, several types of polymerase, and methionine is a start of protein synthesis.
Explain how the plasma membranes of archaea differ from those of bacteria and eukaryotes.
The plasma membranes of archaea have a monolayer of lipids with branched side chains, compared to the lipid bilayer of bacterial and eukaryote membranes. This contributes to the ability of many archaea to grow at very high temperatures.
Describe adaptations that allow archaea to survive in extremely hot or salty environments.
In addition to the membrane structural variations, archaeal enzymes must be able to function at high temperatures and/or salt concentrations that would inactivate the enzymes of most other organisms.
Discuss why a dedicated environmentalist might give up eating beef.
Archaea living in the digestive tracts of cattle produce methane that contributes to global warming. Giving up beef in your diet would help to reduce this cause of global warming.
Define prokaryotes
Organism that lacks a nucleus and the membrane-bound organelles typically found in eukaryotes.
Define archaea
Prokaryotic organisms that are members of the domain Archaea.
Define halophiles
Type of archaea that lives in extremely salty habitats.
Define thermoacidophile
Type of archaea that lives in hot, acidic, aquatic habitats, such as hot springs or near hydrothermal vents.
Define methanogens
Type of archaea that lives in oxygen-free habitats, such as swamps, and releases methane gas.
Describe the 3 basic shapes of bacteria.
Bacillus (rod)
Coccus (spherical)
Spirillum (spiral-shaped)
Explain how bacterial conjugation differs from transformation and transduction.
In bacterial conjugation, actual physical contact (via a sex pilus) is required for two bacteria to share DNA.
Transformation is the uptake of DNA from the environment by a bacterial cell, and in transduction DNA is transferred from one bacterium to another by viruses.
Compare the nutritional strategy of a heterotrophic bacterium with that of a chemoautotroph.
Heterotrophic bacteria use organic compounds from their environment for energy. Chemoautotrophs reduce CO2 to an organic compound using electrons derived from ammonia, hydrogen gas, and hydrogen sulfide, and sometimes minerals such as iron.
Consider how antibiotics work, and then describe two specific mechanisms bacteria could use to become resistant.
Antibiotics work by interfering with normal bacterial metabolism such as protein synthesis and cell wall synthesis. Bacteria can become resistant to antibiotics if a mutation occurs that alter the target of the drug (often enzyme). Alternatively, some bacteria may acquire the ability to alter the antibiotic itself, so the drug is destroyed or inactivated.
Define bacteria
(pl., bacteria) Single-celled prokaryotic organisms that are members of the domain Bacteria. Lack a nucleus and membrane-bound organelles.
Define Gram stain
Method of determining whether a culture of bacteria possess a layer of exposed peptidoglycan outside of their plasma membranes; historically used to classify bacteria as Gram-positive or Gram-negative, now used to determine the most effective antibiotic treatment.
Define lipopolysaccharide
Lipid-sugar molecules that are found on the exterior of some species of bacteria; presence indicates that the species is Gram-negative.
Define flagella
(sing., flagellum) Long, slender extension used for locomotion by some bacteria, protozoans, and sperm.
Define nucleoid
Region of the cytoplasm in prokaryotic cells where DNA is located; it is not bound by a nuclear envelope.
Define binary fission
Splitting of a parent cell into two daughter cells; serves as an asexual form of reproduction in bacteria.
Define endospore
Spore formed within a prokaryotic cell that protects the DNA within the cell from environmental stress.
Define conjugation
Transfer of genetic material from one cell to another.
Define transformation
Taking up of extraneous genetic material from the environment by bacteria.
Define transduction
Exchange of DNA between bacteria by means of a bacteriophage.
Define cyanobacteria
(pl., cyanobacteria) Photosynthetic bacterium that contains chlorophyll and releases oxygen; formerly called a blue-green alga.
Define antibiotics
Chemicals that interfere with the physiological activities, or structure, of bacteria.
Describe the basic structure of an enveloped virus, including capsid, nucleic acid, envelope, and spikes.
A typical enveloped virus has a protein capsid that contains its nucleic acid (DNA or RNA) and is surrounded by a lipid envelope in which protein spikes are embedded.
Explain the six stages of a typical animal virus reproductive cycle.
Attachment: Viral spikes bind to receptor molecules on host cell.
Entry: Viral envelope fuses with plasma membrane and capsid, and then viral genome enters cell.
Replication: Viral enzyme makes copies of its genome.
Biosynthesis: More capsid and spike proteins are made on host ribosomes.
Assembly: Capsid forms around viral genome.
Budding: New viruses containing some host plasma membrane and spikes are release from cell.
List 3 viral diseases for which a vaccine is available, and three for which there is no vaccine.
Vaccines are available for measles, mumps, and rubella.
Vaccines are not available for HIV, hepatitis C, and mononucleosis.
Compare how viruses differ from viroids and prions.
Viruses, viroids, and prions are all acellular pathogens. Viroids’ genomes are a single strand of circular RNA that is 1/10 the size of a viral genome. It codes for no proteins. Viroids cause disease in plant and not animals. Prions are proteinaceous molecules that are derived from normal proteins that have changes shape. They lead to neurological wasting diseases in animals, including humans.
Define viruses
Acellular parasitic agent consisting of an outer capsid of protein and an inner core of nucleic acid (DNA or RNA).
Define capsid
Protective protein containing the genetic material of a virus.
Define envelope
Lipid covering of some viruses; located outside of the capsid.
Define retroviruses
RNA virus, containing the enzyme reverse transcriptase, that carries out RNA/DNA transcription.
Define viroid
Infectious strand of RNA devoid of a capsid and much smaller than a virus.
Define prion
Infectious particle consisting of protein only and no nucleic acid.
- Decomposers
a) break down dead organic matter in the environment by secreting digestive enzymes.
b) break down living organic matter by secreting digestive enzymes
c) destroy living cells and then break them down with digestive enzymes
d) live in close association with another species
a) break down dead organic matter in the environment by secreting digestive enzymes.
- Which of the following best describes the term microbiota?
a) microbes that are smaller than a eukaryotic cell
b) microbes that cause disease
c) microbes that are decomposers
d) microbes that are naturally found on or within our bodies
d) microbes that are naturally found on or within our bodies
- Archaea differ from bacteria in that they
a) have a nucleus
b) have membrane-bound organelles
c) have peptidoglycan in their cells walls
d) are often photosynthetic
e) none of the above
d) are often photosynthetic
- While studying an ancient lake, you discover that the water in the lake had an exceptionally high concentration of salt. What type o bacteria would you have expected to live in this lake?
a) cyanobacteria
b) thermoacidophiles
c) methanogens
d) halophiles
d) halophiles
- Which of the following describes a bacterium that is spherical in shape?
a) bacillus
b) coccus
c) spirillum
b) coccus
- In this process, bacterial pick up DNA from the environment,
a) binary fission
b) transduction
c) conjugation
d) transformation
d) transformation
- The DNA of a bacteria is contained where in the cell?
a) in the nucleus
b) in a region of the cytoplasm called the nucleoid
c) at the ribosomes
d) within the lipopolysaccharide layer
b) in a region of the cytoplasm called the nucleoid
- Prions contain
a) DNA only
b) protein only
c) RNA only
d) DNA, RNA, and protein
b) protein only
- Small changes in influenza surface antigens lead too
a) antigenic drift
b) antigenic shift
c) antigenic recombination
d) antigenic schism
a) antigenic drift
- The envelope of an animal virus is usually derived from the _______ of its host cell.
a) cell wall
b) plasma membrane
c) capsule
d) receptors
b) plasma membrane
- Capsid proteins are synthesized during which phase of viral replication?
a) replication
b) biosynthesis
c) assembly
d) proteination
e) all of the above
b) biosynthesis
