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227 Cards in this Set
- Front
- Back
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Resistance is |
the ability to ward off pathogens that cause disease
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Susceptibility is
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the lack of resistance.
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Resistance to disease can be grouped into two broad areas.
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Nonspecific and specific resistance(immunity)
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Nonspecific resistance to disease includes
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defense mechanisms that provide general protection against invasion by a wide range of pathogens.
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Immunity involves activation of
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specific lymphocytes that combat a particular pathogen or other foreign substance.
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Lymphatic system refers to the ________ components of this system
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structural
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Immune system refers to the _______ of this system
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functioning
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Immune system refers to the physiology of ___-________ and ______ to ,diseases.
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non-specific resistance, specific resistance(immunity)
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The lymphatic system consists of fluid called ______ flowing within ______ vessels
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lymph, lymphatic
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Several structures and organs contain lymphatic tissue which is:
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specialized reticular tissue containing larger numbers of lymphocytes
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Bone marrow is the site of _________ production.
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lymphocyte
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Interstitial tissue and lymph are basically the same composition, Their major difference is
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location.
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The lymphatic system functions:
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to drain interstitial fluidreturn leaked plasma proteins to the bloodtransport dietary fatsand protect against invasion by nonspecific defenses and specific immune responses.
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Lymphatic vessels begin as blind-ended lymph capillaries in
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tissue spaces between cells
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Interstitial fluid drains into lymphatic capillaries, thus forming
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lymph.
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Lymph capillaries merge to form larger vessels, called
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lymphatic vessels, which convey
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lymphatic vessels convey lymph into and out of structures called
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lymph nodes.
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Lymphatic capillaries are found throughout the body except in
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avascular tissue, the CNS,portions of the spleen, and red bone marrow.
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Lymphatic capillaries have a slightly larger diameter than _____ capillaries
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blood
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Lymphatic capillaries have overlapping endothelial cells that work as ______-______ valves for fluid to enter the _______ capillary.
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one-way, lymphatic
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Anchoring filaments attach endothelial cells to
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surrounding tissue cells.
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lymphatic capillary in the villus of the small intestine is the
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lacteal.
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It functions to transport digested fats form the small intestine into blood.
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lacteal
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Interstitial fluid drains into
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lymph capillaries.
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The passage of lymph is from arteries and blood capillaries (blood) to
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interstitial spaces (IF)
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The passage of lymph is from interstitial spaces to
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lymph capillaries (lymph)
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The passage of lymph is from lymph capillaries (lymph) to
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lymphatic vessels
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The passage of lymph is from lymphatic vessels to the
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lymph trunks
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The passage of lymph is from lymph trunks to either the
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right lymphatic duct or to the left lymphatic duct (aka thoracic duct) to the subclavian veins (blood).
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The passage of lymph is from right or left lymphatic duct to the
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subclavian veins (blood).
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Lymph flows as a result of the "______-_______" of skeletal muscle contractions and ________ movements.
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milking action,respiratory
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Lymph flow is also aided by lymphatic vessel ______ that prevent ________ of lymph.
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valves, backflow
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The primary lymphatic organs are the red bone marrow and the thymus gland that produce
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B and T cells.
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The secondary lymphatic organs are encapsulated structures:
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the lymph nodes and spleen
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Tertiary lymphatic organs are
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lymphatic nodules, which are clusters of lymphocytes that stand guard in all mucous membranes; also, the appendix, tonsils and adenoids.
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Most immune responses occur in
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secondary lymphatic organs.
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The thymus gland lies between the
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sternum and the heart
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The thymus gland functions in immunity as the site of
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T cell maturation.
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The thymus gland is large in the infant and after puberty is replaced by
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adipose and areolar connective tissue.
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Lymph nodes are encapsulated oval structures located along
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lymphatic vessels.
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Lymph nodes contain
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T cells, macrophages, follicular dendritic cells, and B cells.
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Lymph enters nodes through
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afferent lymphatic vessels
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Lymph is filtered to remove
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damaged cells and microorganisms
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Lymph exits through
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efferent lymphatic vessels.
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Foreign substances filtered by the lymph nodes are trapped by
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nodal reticular fibers.
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Macrophages then destroy some foreign substances by
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phagocytosis
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lymphocytes bring about the destruction of others by
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immune responses.
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Lymph nodes are the sites of proliferation of
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plasma cells and T cells.
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The spleen is the largest mass of lymphatic tissue in the body and is found in the
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left hypochondriac region between the fundus of the stomach and the diaphragm.
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The spleen consists of _____ and ___ pulp.
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white and red
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The white pulp of the spleen is
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lymphatic tissue.
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The _ ___________ in the white pulp of the spleen directly attack and destroy antigens in blood.
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T lymphocytes
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B lymphocytes develop into antibody producing
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plasma cells, and the antibodies inactivate antigens in blood.
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Macrophages destroy antigens in blood by
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phagocytosis.
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The red pulp of the spleen consists of _____ ______ filled with blood and _______ ________ consisting of RBCs, macrophages, lymphocytes, plasma cells, and granulocytes.
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venous sinuses,splenic cords
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Macrophages remove worn-out or defective
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RBCs, WBCs, and platelets.
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The spleen stores ___________ ___________blood platelets in the red pulp.
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blood platlets
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The red pulp of the spleen is involved in the production of _____ _______ during the second trimester of pregnancy.
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blood cells
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Lymphatic nodules are oval-shaped concentrations of
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lymphatic tissue.
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They are scattered throughout the _______ _______ of mucous membranes lining the GI tract, respiratory airways, urinary tract, and reproductive tract.
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lamina propria
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This is the mucosa-associated lymphatic tissue (MALT):
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lamina propria of mucous membranes lining the GI tract, respiratory airways, urinary tract, and reproductive tract.
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Peyer's patches are lymphatic nodules in the
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ileum of the small intestine.
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Tonsils (pharyngeal (adenoid), palatine, lingual, tubal ) are
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multiple aggregations of large lymphatic nodules embedded in a mucous membrane at the junction of the oral cavity and pharynx.
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Nonspecific Resistance First Line of Defense:
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Skin and Mucous Membranes
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Nonspecific resistance refers to a
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wide variety of body responses against a wide range of pathogens (disease producing organisms) and their toxins.
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Nonspecific Mechanical protection includes
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the intact epidermis layer of the skin, mucous membranes, the lacrimal apparatus, saliva, mucus, cilia, the epiglottis, and the flow of urine.
Defecation and vomiting also may be considered mechanical processes that expel microbes. |
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Nonspecific Chemical protection is localized
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on the skin, in loose connective tissue, stomach, and vagina.
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The skin produces sebum, which has a low pH due to the presence of
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unsaturated fatty acids and lactic acid.
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Lysozyme is an enzyme component of _____ that also has antimicrobial properties.
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sweat
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Gastric juice has a very low pH (1.5-3.0) which causes the stomach to be nearly
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sterile.
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Vaginal secretions are also slightly
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acidic.
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Second line of Defense:
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Internal Defenses
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The second line of defense involves
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internal antimicrobial proteins, phagocytic and natural killer cells, inflammation, and fever.
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Interferons are
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antiviral proteins produced from infected cells which diffuse to neighboring cells in order to prevent viral infection.
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Complement system is:
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--group of 20 proteins present in blood plasma and on cell membranes which enhance immune, allergic, and inflammatory reactions.
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Natural killer (NK) cells are
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lymphocytes that lack the membrane molecules that identify T cells and B cells and have the ability to kill a wide variety of infectious microbes plus certain spontaneously arising tumor cells.
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Phagocytes are specialized to perform
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phagocytosis
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Phagocytes include
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neutrophils and macrophages.
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The three phases of phagocytosis include
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chemotaxis, adherence, and ingestion.
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After phagocytosis has been accomplished, a _______ is formed and the lysosome in the _____________, along with lethal oxidants produced by the phagocyte, quickly kills many types of _______.
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phagolysosome, phagolysosome, microbes
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Inflammation occurs when cells are
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damaged by microbes, physical agents, or chemical agents. The injury may be viewed as a form of stress.
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Symptoms of inflammation:
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(a) Redness
(b) Pain (c) Heat (d) Swelling (e) Loss of function . (f) Fever (usually caused by the pathogen toxin; high body temperature inhibits some microbes and speeds up body reactions that aid repair) |
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Stages of inflammation:
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(a) Vasodilation and increased vessel permeability
(b) Phagocytic migration (c) Tissue repair |
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Substances which contribute to inflammation are
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histamine, kinins, prostaglandins, leukotrienes, and complement.
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Pus is the
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accumulated tissue debris and dead phagocytes.
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Specific Defenses:
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Immunity
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Immunity is the
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ability of the body to defend itself against specific invading agents.
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Antigens are substances recognized as
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foreign by the immune responses.
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The distinguishing properties of immunity are
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specificity and memory.
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Immunology is the
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branch of science that deals with the responses of the body when challenged by antigens.
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Both T cells and B cells derive from ______ ______ in bone marrow.
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stem cells
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B cells complete their development in
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bone marrow.
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T cells develop from pre-T cells that migrate to the
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thymus.
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Before T cells leave the thymus or B cells leave bone marrow, they acquire several distinctive surface proteins; some function as
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antigen receptors, molecules capable of recognizing specific antigens.
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Types of Immune Responses
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1. Cell-mediated immunity
2. Antibody-mediated (humoral) immunity |
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Antigens are chemical substances that are recognized as foreign by
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antigen receptors when introduced into the body.
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Antigens are both
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immunogenic and reactive.
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An antigen that gets past the nonspecific defenses can get into ________ tissue by entering an ______ blood vessel and being carried to the spleen
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lymphatic,injured
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An antigen that gets past the nonspecific defenses can penetrate the skin and enter lymph vessels leading to lymph
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nodes
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An antigen that gets past the nonspecific defenses can penetrate mucous membranes and lodge in
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mucosa-associated lymphoid tissue.
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Antigens are large, complex
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molecules.
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Antigens are most often proteins, but sometimes are
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nucleoproteins, lipoproteins, glycoproteins, and certain large polysaccharides.
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Specific portions of antigen molecules, called
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antigenic determinants, or epitopes, immune responses.
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Major histocompatibility complex (MHC) antigens are unique to each person's
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body cells.
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These (MBC) self-antigens aid in the _________ of foreign invaders.
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detection
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For an immune response to occur, B and T cells must recognize that a _______ _______ is present.
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foreign antigen
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B-cells can recognize and bind to antigens in
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extracellular fluid
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T cells, however, can only recognize fragments of antigenic proteins that first have been processed by a _______ and then presented in association with
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macrophage,MHC self-antigens.
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Peptide fragments from foreign antigens help stimulate :
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MHC molecules.
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Cells called antigen-presenting cells (APCs) process _______ antigens (antigens formed outside the body) and present them together with :____ _____ __ molecules to T cells.
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exogenous,MHC class II
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APCs include
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macrophages, B cells, and dendritic cells.
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Steps in in processing and presenting exogenous antigens by an APC:
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(1) Ingestion of the antigen
(2) Digestion of antigen into peptide fragments (3) Fusion of vesicles (4) Binding of peptide fragments to MHC-II molecules (5) Insertion of antigen-MHC-II complex into the plasma membrane |
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In a cell-mediated response, an antigen is
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recognized (bound), a small number of specific T cells proliferate and differentiate into a clone of effector cells (a population of identical cells that can recognize the same antigen and carry out some aspect of the immune attack), and the antigen (intruder) is eliminated.
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T cell receptors recognize antigen fragments associated with MHC molecules on the ______ of a body cell.
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surface
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Proliferation of T cells requires costimulation, by cytokines such as
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interleukin-l and interleukin-2
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Proliferation of T cells can require costimulation by pairs of
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plasma membrane molecules, one on the surface of the T cell and a second on the surface of an APC.
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Helper T cells display CD4 protein, recognize ________ fragments associated with ___-__ molecules,and secrete several ________.
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CD4,antigen, MHC-II, cytokines
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Helper T cells recognize interleukin-2 which acts as a costimulator for other
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helper T cells, cytotoxic T cells, and B cells
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Cytotoxic T cells develop from T cells that display ___ proteins
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CDS
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Cytotoxic T cells recognize antigen fragments associated with MHC-l molecules.
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MHC-I
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Memory T cells are programmed to recognize the
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original invading antigen,
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Programmed Memory T Cells allow initiation of a ____ _______ reaction should the pathogen invade the body at a later date.
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much swifter
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Cytotoxic T cells fight foreign invaders by killing the target cell (the cell that bears the same antigen that stimulated activation or proliferation of their progenitor cells) without damaging the
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cytotoxic T cell itself.
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Immunological surveillance is carried out by
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cytotoxic T cells.
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They recognize tumor antigens and destroy the
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tumor cell.
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The body contains not only millions of different T cells but also millions of different _ cells
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B
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Each B cell is capable of responding to a _______ antigen.
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specific
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During activation of a B cell, an antigen binds to antigen _________ on the cell _________.
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receptors, surface
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B cell antigen receptors are chemically similar to the _________ that will eventually be secreted by their progeny.
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antibodies
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Some antigen is taken into the B cell, broken down into peptide fragments and combined with the MHC-II self-antigen, and moved to the
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B cell surface.
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Helper T cells recognize the antigen-MHC-II combination and deliver the costimulation needed for B cell ___________ and ______________
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proliferation and differentiation.
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Some activated B cells become ___________-_____________ plasma cells.
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antibody-secretion
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Others activated B Cells become B cells.
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memory
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An antibody is a
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protein that can combine specifically with the antigenic determinant on the antigen that triggered its production.
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Antibodies consist of heavy and light ______ and variable and constant ______
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chains, portions.
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Based on chemistry and structure, antibodies are grouped into five principal classes each with specific biological roles. These are:
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(IgG, IgA, IgM, IgD, and IgE)
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Name the functions of antibodies:
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a. neutalizing antigenb. Immobilization of bacteriac. Agglutination and precipitation of antigend. Activation of complemente. Enhancing phagocytosisf. Providing fetal and newborn immunity
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Immunological memory is due to the presence of _____-______ antibodies and very ______-______ lymphocytes that arise during ____________ and ____________ of antigen-stimulated B and T cells.
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long-lived, long-lived, proliferation and differentiation
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Immunization against certain microbes is possible because memory B cells and memory T cells
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remain after the primary response to the antigen.
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The secondary response (immunological memory) provides protection should the
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same microbe enter the body again.
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There is rapid proliferation of memory cells, resulting in a far greater antibody _____ (amount of antibody in serum) than during a primary response.
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titer
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Immune properties of skin
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stratified squamous is hard to penetrate, keratin and the acid mantle (sweat and sebum) make the epidermal surface acidic thereby inhibiting bacterial growth.
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Immune properties of Mucous membranes
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besides acting as a physical barrier that frequently possess hairs and cilia, these membranes produce a variety of protective chemicals
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Immune properties of Mucus
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sticky chemical that traps many microorganisms while nasal hairs and cilia filter and propel debris-laden mucus away from lower respiratory passageways
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Immune properties of Lysozymes
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enzymes that destroy bacteria are found in saliva and lacrimal fluid (tears).
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Immune properties of Sebum
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waxy secretion from skin contains normal flora of bacteria that keeps individual bacteria in check
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Macrophages
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found in bloodstream and tissues. Can be free (alveolar monocytes and microglia) or fixed (Kupffer cells)
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Neutrophils
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become phagocytic whenever they encounter infectious material in the tissues
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Eosinophils
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limited phagocytic ability but are important in defending against parasitic worms
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Mast cells
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(origin unknown) most important in allergic reactions
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Alarm call
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the release of numerous inflammatory chemicals that cause vasodilation and increased permeability of the local blood vessels.
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Margination
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when cell adhesion molecules of the neutrophils cling to the endothelial cells of the capillary walls.
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Diapedesis
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neutrophils squeeze through the capillary walls. Also called emigration.
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Adherence
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Monocytes and other macrophages follow the neutrophils where the microbes begin to sticky by opsonization.
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Ingestion
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the phagocyte engulfs the invading particle by pseudopodia forming a phagosome
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Digestion
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the phagosome merges with a lysosome to form a phagolysosome.
Lysozymes breakdown the ingested particle. |
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Resolution of infection
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wastes are released by exocytosis
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Natural Killer Cells
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a. Non-phagocytic cells that circulate in the bloodstream looking to attack infected virus cells, cancerous cells, etc.
b. They kill the cells by releasing cytolytic chemical called perforins that punch holes in the intruder's plasma membrane. |
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Histamine
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released from mast cells and basophils; promotes vasodilation of local arterioles and increased permeability of local capillaries
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Kinins
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(example bradykinin) is plasma protein; promotes vasodilation of local arterioles, increases permeability of local capillaries, and induces chemotaxis and pain
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Prostaglandins
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made from fatty acids of cell membranes; generated by neutrophils, basophils, and mast cells; amplifies the effects of other inflammatory mediators; induces pain
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Complement
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intensifies inflammatory response by inducing vasodilation, enhancing phagocytosis by opsonization, and lyses cells
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Cardinal signs of inflammation
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redness, pain, swelling, and temperature.
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Sepsis
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inflammatory response goes out of control due to severe bacterial infection in patients with weakened immune systems.
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Interferons
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defend against viral infections by protecting nearby cells; prevents viral replication at the ribosome.
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Complement
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lyses microorganisms, enhance phagocytosis by opsonization, and enhances the inflammatory response.
a. Classical pathway=involves the formation of antigen-antibody complexes. b. Alternate pathway=involves the interaction of factors B, D, and P with the cell wall polysaccharides. |
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Pyrogens
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chemicals secreted by leukocytes and macrophages that stimulate increased body temperature or fever. Can be dangerous because it denatures proteins
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Characteristics of Adaptive Immunity
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a. is specific (the cells can recognize specific foreign substances and immobilize, neutralize, or destroy the invaders).b. is systemic (not restricted to the site of infection). c. has a memory (produces a stronger response to a pathogen that it has encountered before)
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Antigen
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any substance that can elicit an immune response.
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apoptosis
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programmed cell death
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IgG
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most common and diverse antibody in plasma (75 to 85%) protects against bacteria, viruses, and toxins. Can cross the placenta. A MONOMER
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IgM
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indicates initial infection and is active in stimulating complement (pentamer)
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IgD
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important in the activation and maturity of B cells.
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IgA
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found commonly in body secretions such as saliva, sweat, milk, etc. and helps prevent attachment of pathogens to epithelial cell surfaces (dimer)
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IgE
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binds readily to basophils and when triggered by antigen causes the release of histamine and other chemicals that mediate inflammation and allergic reaction.
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Precipitation
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soluble molecules clump forming large complexes that settle in solution making it easier for phagocytosis to occur.
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Lyses
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complement is used to punch holes in bacterial cells.
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Agglutination
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antibodies bind to the foreign cells causing them to clump together making phagocytosis easier
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Neutralization
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antibodies block the binding sites that are found on foreign cells and toxins which are normally used to invade tissue cells to cause injury
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Helper T cells
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produce cytokines (such as interleukin 1 and 2) that stimulate the proliferation of all other immune cell types including more T cells and B cells to join the attack against infection.
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Cytotoxic T cells
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also called killer T-cells; stimulated by the APCs and helper T cells to attack virus-infected body cells and cancer cells
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Suppressor T cells
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also known as regulatory T cells; slows activity of T and B cells once the infection has been conquered.
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Memory T cells
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cells that remain in circulation to respond to future infections
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Isografts
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tissues from genetically identical twins
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Allografts
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tissues from non-genetically identical persons
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Xenografts
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tissues from organisms of different species
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Severe combined immunodeficiency (SCID)
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syndrome is a congenital condition that results from a genetic disorder leading to deficits in both B and T cells.
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Acquired immunodeficiency
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not genetic and can result from cancer, drugs, or viral infections
Examples: a. Hodgkin's disease or cancer of the B cells within the lymph nodes. b. Acquired immune deficiency syndrome (AIDS) is caused by the Human immunodeficiency virus (HIV) is a condition that destroys the helper T cells thus depressing cell-mediated immunity. |
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Multiple sclerosis
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degradation of the white mater of the brain and spinal cord.
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Rheumatoid arthritis
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destroys joints
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Systemic lupus erythematosus
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affects various organs including the kidneys, heart, lungs and skin
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Grave's disease
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thyroid tissue produces excessive amounts of thyroxine
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Type I diabetes mellitus
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destroys pancreatic cells that produce insulin
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Glomerulonephritis
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impairment of renal function
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Myasthenia gravis
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impaired communication between nerves and skeletal muscle
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Delayed hypersensitivity (Type IV)
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occurs within 1-3 days and lasts for a week or more. a. Contact dermatitis b. Tuberculosis skin test
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Subacute hypersensitivity
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onset is 1-3 hours after exposure and the duration is 10-15 hours
a. Cytotoxic hypersensitivity (Type II)=mismatch blood b. Immune-complex hypersensitivity (Type III)=farmer's lung |
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Immediate hypersensitivity (Type I)
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begins within seconds of exposure to the allergen and lasts half to one hour a. Atopy b. Anaphylactic shock
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CD4
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receptor for helper T cells
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CD8
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receptor for cytotoxic T cells
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MHC-Class II
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protein that is found only on certain cells that act in the immune response (macrophages).
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leukocytosis
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creation of WBC. Alarm calls result in neutrophils, monocytes, and eosinophils being released from the bone marrow in large quantities.
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lacteals
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specialized lymph capillaries in the intestines that transport chyle
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chyle
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fatty lymph
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lymph
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protein-containing interstitial fluid. Picked up from between the cells
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Lymph capillaries
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microscopic blind-ended vessels consisting of simple squamous epithelium and widely distributed mini-valves
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Lymphatic collecting vessels
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formed from merging lymph capillaries
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Lymphocytes
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warriors of the immune system arise in the bone marrow and mature into one of two types
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Macrophages
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engulf and destroy foreign cells
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Dendritic cells
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activate T-cells
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Reticular Cells
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similar to fibroblast cells that produce reticular fibers or a network that supports other cell types
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Lymphoid tissue
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composed of loose connective tissue called reticular connective tissue which dominates all lymphoid organs except the thymus.
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Diffuse lymphoid tissue
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consist of a few scattered reticular tissue elements and is found in virtually every body organ.
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Lymphatic follicles (nodules)
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lack a capsule but tend to be solid spherical bodies consisting of tightly packed reticular elements and cells. These often exhibit lighter-staining centers called germinal centers
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Inner Medulla
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filled with macrophages plus T cells, B cells, and plasma cells. Has no follicles
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Outer Cortex
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germinal centers contain mostly B lymphocytes while the deeper part contains transit T lymphocytes. Follicles are here
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Peyer's patches
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large clusters of lymphoid follicles (similar to tonsils) found in the walls of the small intestine.
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Appendix
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similar follicles heavily concentrated in the junction between the small intestine and large intestine.
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Mucosa-associated lymphatic tissue (MALT)
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patches of lymphoid follicles in the walls of the bronchi or respiratory tree
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Respiratory pump
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changes in pressure in the thoracic and abdominal cavities due to respiration
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Buboes
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swollen lymph nodes
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Elephantiasis
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caused by a parasitic worm known as Wucheria bancrofti
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Hodgkin's disease
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characterized by Reed-Sternberg cells
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thymus
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1. Bilobed organ located superiorly in the thoracic cavity between the aorta and the sternum
2. Changes size with age (prominent in newborns, continues to enlarge during early childhood becomes smaller after puberty 3. Site for T lymphocyte maturation. |
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spleen
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1. Soft, blood-rich organ located in the upper left abdomen.
2. Have numerous spaces for blood storage since one of its primary functions is to extract aged and defective blood for destruction 3. Removes debris, foreign matter, bacteria, viruses, toxins. 4.Stores some products of RBC breakdown (iron) and platelets. 5.Site of erythrocyte production in developing fetus. |
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tonsils
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1. Lymphatic tissue that forms a protective ring around the entrance to alimentary and respiratory tracts.
2. Blind-ended crypts trap bacteria and particulate matter where most are destroyed. 3. Early exposure develops immune cells with a memory for the pathogens if future infection occurs. |
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germinal center
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part of lymphatic follicle where the WBC multiply to be sent out to fight infections (where they are trained)
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