Immune System

Question 1

Immune System

Answer 1

The immune system is a complex network of cells, tissues, organs, and proteins that protects the body from disease.

Question 2

Parts of the Immune System

Answer 2

The immune system protects the body from disease causing agents known as pathogens. Composed of innate defense and adaptive defense.

Question 3

Innate defense

Answer 3

Nonspecific response to pathogens by the immune system.

Question 4

Adaptive defense

Answer 4

A specific response by the immune system to a given pathogen.

Question 5

Innate Immune System

Answer 5

A collection of nonspecific barriers and cellular responses that serve as an inborn first and second line of defense against pathogens. Has three lines of defense. First ( skin, mucus, secretions), keeps pathogens from entering body. Second, (phagocytes, specific proteins, inflammatory response) fights pathogens that have entered body. Third, adaptive immune system, Lymphocytes, such as B-cells and T-cells fight and retain memory of the pathogen.

Question 6

Adaptive Immune System

Answer 6

A passive or active immunity in which antibodies to a particular antigen are present in the body. Lymphocytes such as B cells and various T cells fight the pathogen and retain memory of the specific pathogen.

Question 7

B cells

Answer 7

Lymphocytes that mature in the bone marrow and make antibodies in response to antigens.

Question 8

T cells

Answer 8

White blood cells that mature in the Thymus and participate in an immune response.

Question 9

Functions of the Immune System

Answer 9

Immune system prevents entry of pathogens through presence of barriers, composed of skin, secretions( acids, enzymes, and salt). If barriers are breached Adaptive immune system specifically identifies , targets and remembers pathogen.

Question 10

Function of Immune System with other Systems

Answer 10

Pathogens can enter body through openings of the digestive, urinary, reproductive systems, and injuries. Lymph system is critical to the functioning of the immune system because pathogens from the blood also circulate through the lymph. B cells and T cells reside in lymph nodes and are activated when pathogen is encountered.

Question 11

The Innate Immune System 1st Line of defense

Answer 11

A series of nonspecific barriers, physical, cellular, and soluble components impede pathogens. External barriers are the skin, mucous secretions, chemical barriers (low pH, salt, enzymes, and commensal microrganisms).

Question 12

Innate Immune System 2nd line of defense

Answer 12

If barrier is breached 2nd line of defense is activated. Ex: cut in the skin cause inflammatory response, histamines are released increasing blood flow and phagocytes to the area, which destroy bacteria. Interferons proteins that that interfere with production of viruses. Fever also speeds up immune response. Antimicrobial peptides and “Natural Killer” Lymphocytes attack host cells that harbor intracellular pathogens.

Question 13

Adaptive Immune System I

Answer 13

Adaptive immune system has two general responses to specific pathogens: cellular or humoral. Cellular reponse destroys infected cell. Humoral response destroys pathogens found in the body fluids using antibodies secreted by B cells..

Question 14

Adaptive Immune System II

Answer 14

Responds by remembering signature molecules called “antigens” from pathogens to which the body has previously been exposed. Functional cells are Lymphocytes called “T cells” and “B cells”.

Question 15

Adaptive Immune System III

Answer 15

Antigen-presenting cells (APCs) such as macrophages digest pathogens and present the pathogen antigen to “helper” T cells. Depending on the type of antigen to “helper” T cells , either a B cell or cytotoxic T cell is activated. Helper T Cell produce cytokines to activate Cytotoxic T cell. Cytotoxic T cell destroys pathogen based on antigen.

Question 16

Adaptive Immune System IV

Answer 16

Helper T cell can also activate B cells in response to a specific antigen. Induce B cell to multiply rapidly into “plasma” cells. Plasma cells produce a large amount of antibodies that bind to antigen. When antigen appears again in the body memory cells will have memory of antigen and produce specific antibody against the antigen.

Question 17

Passive and Active Immunity I

Answer 17

Passive and Active Immunity are two ways to protect the body through either passive introduction of antibodies as a protective agent or its active production by the body. both passive and active immunity can be induced artifically. Vaccinations introduce antigens, which are weakend or killed to elicit immune response. Passive immunity introduces antibodies from another source that can rapidly neutralize toxins. Ex: Rapid treatment for a snakebite is passive immunity.

Question 18

Passive and Active Immunity II

Answer 18

Many diseases are caused by malfunction of the immune system. Underactivity immune system like AIDS is caused by Human Immunodeficiency Virus (HIV), which infects helper T cells and prevents them from activating Cytotoxic T Cells and B Cells and prevents adaptive immune system from operating.

Question 19

Passive and Active Immunity III

Answer 19

An Overactive Immune System can result in allergy symptoms, such as sneezing and mucus secretion. Autoimmune Diseases, Diabetes, Rheumatoid Arthritis, and Multiple Sclerosis are all from immune system mistakenly targeting a host molecule as a foreign antigen.

Question 20

Immune System and Other Body Systems

Answer 20

Immune System works hand in hand with other body systems to transport immune cells, signaling molecules and antibodies throughout the body. Ex: Circulatory system transports white blood cells throughout the body. Lymphatic system produces white blood cells or lymphocytes. Vessels in the lymph system drain fluid from body tissues and deliver foreign material to lymph nodes to be processed by lymphocytes. Red bone marrow, found in many bones of the skeletal system also produce white blood cells. Integumentary system skin is first line of defense.

Question 21

Commensal Microorganism

Answer 21

Microscopic organisms that live in or on the human body without causing it harm.

Question 22

Histamine

Answer 22

A white blood cell secretion that triggers capillary permeability.

Question 23

Interferons

Answer 23

Proteins secreted by Leukocytes when they are infected with viruses.

Question 24

Antimicrobial

Answer 24

A substance that kills or inhibits growth of microorganisms with minimal damage to the host.

Question 25

Antigens

Answer 25

Substances on the surfaces of agents that act to identify them, to the body, as being native or foreign.

Question 26

Antigen-presenting cell

Answer 26

A cell that displays foreign antigens with major histocompatibility complexes on their surfaces.

Question 27

Helper T cell

Answer 27

A type of Lymphocyte that secretes interleukins, a protein that triggers the action of other cells, including the attack of foreign cells by the cytotoxic cell.

Question 28

Cytotoxic T cell

Answer 28

The catergory of a lymphocyte that attacks foreign cells.

Question 29

Cytokines

Answer 29

Cell signaling molecules released primarily by Helper T cells and Macrophages. Certain Cytokines activate Cytotoxic T cells.

Question 30

Antibody

Answer 30

A blood protein that counteracts a specific antigen.

Question 31

Memory Cell

Answer 31

A Lymphocyte that responds to an antigen upon reintroduction.

Question 32

Active Immunity

Answer 32

Protection against a specific pathogen resulting from the production of antibodies in response to the presence of specific antigens.

Question 33

Passive Immunity

Answer 33

Temporary immunity gained by a body that has acquired antibodies from an outside source. Ex: rapid treatment for a snake bite.

Question 34

Autoimmune Disease

Answer 34

A pathology that results from the immune system mistaking part of the body as a pathogen.

Question 35

Rheumatoid Arthritis

Answer 35

A progressive autoimmune disease that causes join inflammation and pain.

Question 36

Bone Marrow

Answer 36

A soft material within spongy bone and medullary cavity of long bones.

Question 37

Skeletal System

Answer 37

The system of bones in the body that provides protection for delicate organs and serves as the scaffold against which muscles pull for movement. Three functions: movement, protection, storage of minerals and fat.