Ch. 24 Immune System Flashcards Preview

AP Biology > Ch. 24 Immune System > Flashcards

Flashcards in Ch. 24 Immune System Deck (58):


a nonspecific defensive, phagocytic white blood cell that can engulf bacteria and viruses in infected tissue; has a multi-lobed nucleus



a phagocytic white blood cell that can engulf bacteria and viruses in infected tissue; has a large oval or horseshoe-shaped nucleus



a large, amoeboid, phagocytic white blood cell that develops from a monocyte
- "Big Eater”
- Wander actively in interstitial fluid to eat bacteria and virus infected cells


Natural Killer Cells

a nonspecific defensive cell that attacks cancer cells and infected body cells, especially those harboring viruses



a nonspecific defensive protein produced by virus-infected cells and capable of helping other cells resist viruses
- Short term and most effective against influenza/cold
- Made by body in small quantity, use recombinant DNA


Complement Proteins

a family of nonspecific defensive blood proteins that cooperate with other components of the vertebrate defense system to protect against microbes; can enhance phagocytosis, directly lyse pathogens, and amplify the inflammatory response


Inflammatory Response “setting on fire”

a nonspecific body defense caused by a release of histamine and other chemical alarm signals, which trigger increased blood flow, a local increase in white blood cells, and fluid leakage from the blood. The results include redness, heat, and swelling in the affected tissues.
- Aims to disinfect and clean injured tissues
- Helps to prevent the spread of infection to surrounding tissues



a chemical signal released by injured cells that causes blood vessels to dilate during an inflammatory response


Lymphatic System

the organ system through which lymph circulates; includes lymph vessels, lymph nodes, and the spleen. The lymphatic system helps remove toxins and pathogens from the blood and interstitial fluid, and returns fluid and solutes from the interstitial fluid to the circulatory system



a fluid similar to interstitial fluid that circulates in the lymphatic system


What are the functions of the lymphatic system?

1) return tissue fluid to circulatory system
2) fight infection


Immune System

the organ system that protects the body by recognizing and attacking specific kinds of pathogens and cancer cells
- More effective than nonspecific resistance → amplifies certain nonspecific responses
- Extremely specific and has remarkable “memory” for antigens it has encountered before → react faster



a foreign (nonself) molecule that elicits an immune response



a protein dissolved in blood plasma that attaches to a specific kind of antigen and helps counter its effects



resistance to specific body invaders
- Acquired by natural infection or vaccination



a procedure that presents the immune system with a harmless variant or derivative of a pathogen, thereby stimulating the immune system to mount a long term defense against the pathogen



a harmless variant or derivative of a pathogen used to stimulate a host organism’s immune system to mount a long term defense against the pathogen


Active Immunity

body is stimulated to produce antibodies in its own defense


Passive Immunity

temporary immunity obtained by acquiring ready-made antibodies or immune cells; lasts only a few weeks or months because the immune system has not been stimulated by antigens



a type of white blood cell that is chiefly responsible for the immune response; found mostly in the lymphatic system


B Cells

a type of lymphocyte that matures in the bone marrow and later produces antibodies; responsible for humoral immunity


T cells

a type of lymphocyte that matures in the thymus and is responsible for cell-mediated immunity; also involved in humoral immunity


Humoral Immunity

the type of specific immunity brought about by anti-body producing B cells; fights bacteria and viruses in body fluids
- Antibodies carries in lymph/blood to site of infection
- Can be passively transferred by injecting blood plasma


Cell Mediated Immunity

the type of specific immunity brought about by T-Cells; fights body cells infected with pathogens
- Cannot be transferred passively with plasma but with actual T cells from an immune individual
- T cells work against bacteria, virus, fungi, protozoans
- Work indirectly by promoting phagocytosis by other WBC and by stimulating B cells to produce antibodies


Antigen Receptors

protein molecules produced when certain genes are turned on that are capable of binding one specific type of antigen


Antigen Determinants

A region on the surface of an antigen molecule to which an antibody binds
- Recognized by complementary shapes w/ antigen-bind site
- Antigen has different several determinants → different antibodies can bind to same antigen


Clonal Selection

the production of a lineage of genetically identical cells that recognize and attack the specific antigen that stimulated their proliferation. The mechanism that underlies the immune system’s specificity and memory of antigens.


Primary Immune Response

occurs when lymphocytes are first exposed to an antigen and form a clone of effector cells
- Antibodies start to show up in blood


Secondary Immune Response

A second exposure to the same antigen elicits a faster and stronger response
- Lasts longer than primary immune response


Memory Cells

one of a clone of long-lived lymphocytes formed during the primary immune response; remains in a lymph node until activated by exposure to the same antigen that triggered its formation. When activated, a memory cell forms a large clone that mounts the secondary immune response.
- Survive for decades, remain in lymph nodes


Plasma cells

an antibody secreting B cell


Antigen-binding site

a region of the molecule responsible for the antibody’s recognition-and-binding function


Monoclonal Antibodies

an antibody secreted by a clone of cells and, consequently, specific for the one antigen that triggered the development of the clone
- Descendants of a single cell → identical antibody
- Harvested from cell cultures (not animals)


Cytotoxic T cells

a type of lymphocyte that attacks body cells infected with pathogens


Helper T cells

a type of lymphocyte that helps activate other types of T cells and may help stimulate B cells to produce antibodies


Antigen-Presenting Cells

one of a family of WBC that ingests a foreign substance or a microbe and attaches antigenic portions of the ingested material to its own surface, thereby displaying the antigens to a helper T cell


Self protein

a protein on the surface of an antigen-presenting cell that can hold a foreign antigen and display it to helper T cells. Each individual has a unique set of self proteins that serve as molecular markers for the body. Lymphocytes do not attack self proteins unless the proteins are displaying foreign antigens; therefore, self proteins mark normal body cells as off-limits to the immune system.


Nonself Molecules

a foreign antigen; a protein or other macromolecule that is not part of an organism’s body



a protein secreted by a cytotoxic T cell that lyses (ruptures) an infected cell by perforating its membrane


Autoimmune diseases

an immunological disorder in which the immune system attacks the body’s own molecules


Immunodeficiency diseases

an immunological disorder in which the immune system lacks one or more components, making the body susceptible to infectious agents that would ordinarily not be pathogenic



a disorder of the immune system caused by an abnormal sensitivity to an antigen; symptoms are triggered by histamines released from mast cells



an antigen that causes an allergy


Mast Cells

a vertebrate body cell that produces histamine and other molecules that trigger the inflammatory response)



a drug that interferes with the action of histamine, providing temporary relief from an allergic reaction


Anaphylactic shock

a potentially fatal allergic reaction caused by extreme sensitivity to an allergen; involves an abrupt dilation of blood vessels and a sharp drop in blood pressure


Non Specific Defense

1st line of defense against invaders
- treats all pathogens/invaders the same

1) Structure
2) Cells
3) Molecules


What are the structures of non specific defense?

1) Skin
2) Ciliated Mucus Membranes
3) Stomach Acids
4) Nostril Hair


What are the cells of non specific defense?

Leukocytes (WBC)
- neutrophils/monocytes
- macrophages
- natural killers


What are the molecules of non specific defense?

Antimicrobial Proteins
- interferons and compliment proteins


What are the steps of the inflammatory response?

1) Damage cells release histamine
2) Dilate blood vessels and make it leaky to release some plasma
3) Plasma flows from interstitial fluid
4) Phagocytes etc. brought to infected area and tissue is cleaned/disinfected
5) Pus left over is the remains of the response composed of cell debris, fluids, and dead WBC


What are symptoms of inflammatory response?

1) Infected area is red due to increase in blood flow as vessel is dilated
2) Swelling due to leaky capillaries
3) Warm due to blood which inhibits micro growth
4) Pain due to swelling against nerves thus cause less damage


What is the reason for limited effectiveness of nonspecific immunity on pathogens?

Slow and unselective


Specific Immunity

Body recognizes/defends against specific invaders
- extreme specificity and long term memory
- often amplifies non specific responses and enhances the compliment protein reaction
- Important aspects: antigen, antibodies, immunity


How do people get HIV (AIDS)

By the exchange of bodily fluids w/ someone who is HIV+
- unprotected sex
- sharing hypodermic needles
- transfusion of infected blood
- mother to child in womb


Who are the 3 groups of people who have AIDS/HIV the most? And who are starting to get it more?

IV drug users, gay men, hemophiliacs

Heterosexual teens and epidemic in Africa


What are the 3 enzymes of HIV?

Reverse transcriptase, integrase, protease


How can we cure AIDS/HIV?

Block a step in the reproductive cycle that is unique to HIV/AIDS but it evolves rapidly
- AZT, AIDS cocktails, HIV Resistant stem cells