17: The Immune System Flashcards
Module 3, Lesson 6
____ allows for rapid response to pathogens by recognizing features common to many pathogens.
Innate immunity
____ creates specific weapons to fight a particular pathogen.
Adaptive immunity
True or false:
The adaptive immune system takes longer to mount a targeted response the first time a pathogen is encountered.
True
The ____ immune system can remember a pathogen to mount a rapid response in case of reinfection.
Adaptive
List the major steps in the activation of the innate immune system.
(five)
- Receptors recognize pathogens
- Cytokines recruit immune cells
- The complement forms the membrane attack complex
- The inflammatory response is triggered
- The adaptive immune system is signaled
The first line of defense against invaders is the…
Skin
____ and ____ on the skin create an acidic coating that inhibits microbe growth.
Oil and sweat
Sweat contains ____, enzymes that break down bacteria.
Lysozymes
Skin cells produce ____ to fight off invaders.
Antimicrobial peptides
____ and ____ exist on the skin to outcompete potential invaders.
Beneficial bacteria and fungi
Other than the skin, list three potential routes of infection.
- Digestive tract
- Respiratory tract
- Urogenital tract
Tracts that open to the exterior environment are lined by epithelial cells that secrete…
Mucosa
Saliva in the mouth contains ____ to kill bacteria.
Lysozymes
Urine and tears defend against infections by…
Flushing pathogens out of the body
Pathogens that enter the stomach are killed because of…
The stomach acid’s low pH
Innate immune system activity begins when…
A receptor binds to a pathogen
In the innate immune system, the binding of receptors activates a….
Signal transduction pathway
The signal transduction pathway triggered by receptor binding results in the release/activation of…
(three)
- Cytokines
- Antimicrobial peptides
- Complement
____ are signaling molecules that recruit immune cells to the infection site and may signal other immunological responses.
Cytokines
____ bind to the membranes of gram-negative bacteria and disrupt it, promoting phagocytosis of the pathogen.
Antimicrobial peptides
The activation of the ____ assists other immune activities in clearing pathogens.
Complement
The complement forms the ____, which forms a pore in the membrane of a pathogen to kill it.
Membrane attack complex
(MAC)
____, or white blood cells, are the innate immune cells.
Leukocytes
List the eight types of leukocytes.
- Natural killers (NK)
- Monocytes
- Macrophages
- Neutrophils
- Eosinophils
- Basophils
- Mast cells
- Dendritic cells
____ kill virus-infected cells by creating a pore in their membranes and causing them to undergo apoptosis.
Natural-killer (NK) cells
____ are the immature form of macrophages and circulate in the blood until signaled to an infection site.
Monocytes
Monocytes mature into macrophages when they…
Are signaled to an infection site
____ kill pathogens by phagocytosis, and exist in the extracellular fluid to engulf any microbes or debris.
Macrophages
____ enter infected tissues to kill parasites, and also produce defensins.
Neutrophils
____ release toxins to kill parasites.
Eosinophils
____ and ____ release chemicals that trigger the inflammatory response, such as histamine.
Basophils and mast cells
____ are involved in both innate and adaptive immunity.
Dendritic cells
In the innate immune system, dendritic cells…..
Bind to pathogens, causing the release of cytokines and the inflammatory response
In the adaptive immune system, dendritic cells…
Present antigens to lymphocytes
List the five hallmarks of inflammation.
- Heat
- Redness
- Swelling
- Pain
- Possible loss of function
During the innate inflammatory response, infected cells release chemical alarm signals that cause blood vessels to…
Dilate
The dilation of blood vessels results in more blood flow, causing the site to become…
Red and warm
Swelling at the inflammation site is caused by…
Capillaries becoming more permeable
____ can enter the inflammation site through the capillaries to kill pathogens and recruit monocytes.
Neutrophils
During the innate inflammatory response, ____ release cytokine interleukin-1.
Macrophages
Cytokine interleukin-1 travels to the brain and causes the hypothalamus to…
Raise the body’s set temperature
Fever promotes ____ and impedes ____.
Phagocyte activity ; the growth of some microbes
Fever reduces the levels of ____ in the blood by causing it to be stored in the liver and spleen.
Iron
____ are foreign macromolecules that incite an imune response.
Antigens
____ are the particular sites on an antigen that elicit the immune response.
Epitopes
True or false:
Each epitope on an antigen can stimulate an immune response.
True
The adaptive immune system can remember specific pathogens by their ____ and mount a quick response to reinfection.
Specific antigen
The cells involved in adaptive immunity are called…
Lymphocytes
The adaptive immune system maintains a ____ of past invaders.
Molecular memory
The organs that support the adaptive immune system are called the…
Lymphoid organs
The ____ are the sites of lymphocyte production and maturation.
Primary lymphoid organs
List the two primary lymphoid organs.
- Bone marrow
- Thymus
B-cells and T-cells are produced in the…
Bone marrow
____ mature in the bone marrow.
B-cells
____ mature in the thymus.
T-cells
Lymphocytes undergo selection so that they can…
Properly identify self and non-self
____ are where mature lymphocytes go to search for their targets.
Secondary lymphoid organs
List the three secondary lymphoid organs.
- Lymph nodes
- Spleen
- Mucosa-associated lymphoid tissue (MALT)
Cells of the ____ travel to secondary lymphoid organs to present the antigen of the invading pathogen to lymphocytes.
Innate immune system
The cells that present antigens to the lymphocytes are called…
Antigen-presenting cells
(APCs)
____ and ____ are APCs that signal the adaptive immune system.
Dendritic cells and macrophages
Antigen-presenting cells are recognized by specific…
Helper T-cells
____ secrete cytokine to stimulate the adaptive immune response.
Helper T-cells
List the two parts of the adaptive immune response.
- Humoral immunity
- Cell-mediated immunity
In ____, B-cells use antibodies embedded in their cell membranes to recognize intact antigens on invading pathogens.
Humoral immunity
In ____, T-cells bind to antigens that have been digested and presented by APCs.
Cell-mediated immunity
True or false:
Humoral immunity is what causes the T-cells to respond to foreign antigens on transplanted tissues.
False
Cell-mediated immunity does this
____ are B-cells that have not been activated and have antibodies on their surfaces.
Naive B-cells
When a naive B-cell is is activated, it differentiates into…
Plasma cells and memory B-cells
____ produce antibodies against the antigen that activated the naive B-cell.
Plasma cells
____ recognize virally-infected host cells or tumor cells using antigens on the cell’s surface.
Cytotoxic T-cells
____ direct the immune response by releasing cytokines, activating naive B-cells, and producing memory helper T-cells.
Helper T-cells
True or false:
Helper T-cells do not kill host cells or pathogen cells directly.
True
The ____ direct cell-mediated immunity by indicating self and non-self.
Major histocompatibility complex proteins
Major histocompatibility complex proteins are encoded by the ____ in DNA, and are unique to each individual.
Major histocompatibility complex
(MHC)
____ dot the surface of tissue cells to mark them as self, and bind to fragments of other proteins.
MHC proteins
If an MHC protein binds to a fragment of a foreign antigen, it will…
Activate the cell-mediated immune response
In a healthy cell, most of the protein fragments bound to MHC proteins are…
Fragments of normal proteins
List the two types of MHC proteins.
- MHC class 1
- MHC class 2
____ are found on every nucleated cell in the body, and can activate cytotoxic T-cells.
MHC class 1 proteins
____ are found on APCs and activate helper T-cells.
MHC class 2 proteins
The only cells that have both classes of MHC proteins on their surfaces are…
Antigen-presenting cells
____ are activated when they encounter MHC class 2 proteins bound to antigens on APCs.
Helper T-celsl
When activated, helper T-cells undergo cell division to produce…
Memory helper T-cells and activated helper T-cells
____ determine to what extent the immune response will be cell-mediated or humoral.
Activated helper T-cells
If a helper T-cell finds a B-cell that is presenting an antigen, it will…
Secrete cytokines that activate humoral immunity
If a helper T-cell finds a macrophage presenting an antigen, it will…
Secrete cytokines that activate cell-mediated immunity
The secretion of cytokines by helper T-cells is a form of…
Paracrine signaling
In cell-mediated immunity, ____ are activated when they encounter an MHC class 1 protein bound to an antigen on an APC.
Naive cytotoxic T-cells
When naive B- or T-cells are activated, they divide and differentiate, a process called…
Clonal expansion
Naive cytotoxic T-cells undergo clonal expansion to produce…
Activated cytotoxic T-cells and memory cytotoxic T-cells
____ roam the body and destroy cells that display the same antigen as the one that activated the naive T-cell.
Activated cytotoxic T-cells
____ remember an antigen and allow for a speedy reaction if future body cells are infected by the pathogen.
Memory cytotoxic T-cells
Antibodies are also sometimes called…
Immunoglobin
____ are proteins that bind to antigens but do not directly kill pathogens.
Antibodies
____ help kill pathogens by causing an immune response or activating complement.
Antibodies
Each antibody is made up of two heavy chains and two light chains that interlock to form a…
Y shape
The ____ of an antibody is unique to that antibody and is the region that binds to the antigen.
Variable region
The ____ of an antibody is the same within each class of antibodies, and determines the antibody’s function.
Constant region
The response of the adaptive immune system to a new pathogen is slow because…
There may only be a few lymphocytes with the appropriate receptors
The response of the adaptive immune system to a pathogen it’s encountered before is fast because…
When a memory cell encounters its antigen, it responds faster than a naive cell
____ occur when the immune system attacks self cells as if they were pathogens.
Autoimmune diseases
____ occur when the immune system responds too strongly to benign non-self antigens.
Allergies
____ occurs when a full-blown immune response is triggered every time an allergen is encountered.
Immediate hypersensitivity
In an allergy, B-cells produce ____ which attach to the surface of cells in the innate immune system, causing them to become sensitized to the allergen.
IGE antibodies
When an allergen is encountered, cells in the innate immune system release ____, triggering an inflammatory response.
Histamine
____ is an allergic reaction that can be severe enough to lead to anaphylatic shock and death.
Systemic anaphylaxis
