Please enable JavaScript.
Coggle requires JavaScript to display documents.
Concept Map: 10 Immune System Viriahelyn Calvillo P:6 -…
Concept Map: 10 Immune System
Viriahelyn Calvillo P:6
Major Functions of the Lymphatic & Immune System
Immune system:
provides resistance to disease
eliminates almost any pathogen or abnormal cell in the body
produce antibodies against antigens
is a functional system
Lymphatic system:
maintain fluid levels in our body tissues
remove fluids that leak out of blood vessels
protect body from invaders
absorb digestive tracts fats
removing cellular wastes
is an organ system
Location of Lymphatic Organs and their Functions
Primary Lympoid Organs:
thymus: located in the chest behind the sternum, functions to create lymphocytres called T cells
red bone marrow located in the long bones, functions to produce red blood cells and immune cells
Secondary Lymphoid Organs
lymph nodes: located in many parts of the body (neck, armpit, chest, abdomen, groin) function to clean the lymph and allow for lymphocyte activation and proliferation
spleen: located in the upper left side of the abdomen, functions to cleanse blood and remove aged or defective RBC's
tonsils: located at each side of the back of the throat, functions to stop germs from entering the body from the mouth
peyer's patches: aggregated lymphoid nodules located in the small intestine that function to monitor intestinal bacterial populations
appendix: located in the lower right part of the abdomen, functions to house bacteria and destroy it
MALT: a network of lymphoid cells and tissues in submucosal layers of tracts, functions to prevent pathogens from penetrating mucous membrane and a site for lymphocyte activation and proliferation
Purpose and Examples of first second and third line of defenses
First Line of Defense: Surface Barriers- apart of the innate (nonspecific) defensive system
skin and mucous membranes produce protective chemicals that inhibit or destroy microorganisms
external body membranes (skin and mucous) exmaples: skin, tears,mucus, cilia, stomach acid, and urine flow
Second Line of Defense: Cells and Chemicals -apart of the innate (non specific) defense system
antimicrobial proteins, phagocytes, and other cells that inhibit the spread of invaders; inflammation is the most important mechanism
example: inflammatory responses, fever, phagocytosis, pus
Phagocytosis: phagocyte adheres to pathogens or debris and eventually toxic compounds destroy pathogens
Third line of Defense: apart of the adaptive (specific) defensive system
recognizes and targets specific antigens and mounts an even stronger attack to "known antigens"
example: humoral immunity and cellular immunity
Innate immune defenses and adaptive immune defenses
Innate (natural) immune Defenses and Adaptive (acquired) immune defenses
Adaptive Defenses:
Humoral Immunity: B cells (antibodies are produced by lymphocytes that circulate freely in body fluids and bind temporarily to target cell)
Cellular Immunity: C cells (lymphocytes that act against the target cell either directly or indirectly; directly kills or indirectly by releasing chemicals
Innate Defenses (first and second)
First Line-surface barriers: skin and mucous membranes along with their secretions
Acid: acidity of skin and some mucous membranes inhibit growth called acid mantle
Enzymes: lysozome of saliva, respiratory mucus, and lacrimal fluid that kills microorganisms; enzymes in stomach also kill
Mucin: sticky mucus that lines digestive and respiratory tract that traps microorganisms
Respiratory system has mucus coated hairs and cilia of upper respiratory tract that functions to stop pathogens
Second Line - internal defense cells and chemicals: necessary if microorganisms invade deeper tissues
Phagocytes: white blood cells that ingest and digest (eat) foreign invaders
Natural Killer cells: nonphagocytic, large granular lymphocytes that police blood and lymph, attack cells that lack "self" surface receptors and induce apoptosis
Inflammation
Humoral response and cellular responses
Humoral Immune
when B cells encounter target antigen, it provokes humoral immune response an antibodies specific for that particular antigen are then produced
Cellular Immune
T cells provide defense against intracelluar anitgens directly killing cells or releasing chemicals that regulate immune response
Antigens and antibodies
Antibodies:
also called immunoglobulins
Capable of binding specifically with antigen detected by B cells
grouped into one of five Ig classes
Basic antibody structure:
overall T or Y shaped antibody monomer consists of four looping polypeptide chains linked by disulfide bonds
Consists of four chains: two identical heavy (H) chains with hinge region at "middles" and two identical (L)chains
variable region at one end of each arm combine to form two identical antigen binding sites
stems make up constant (c) regions)
Antibody classes: Five major classes:
IgM, IgA, IgD,IgG, and IgE
Function and targets:
antibodies dont destroy antigens; they inactivate and tag them
form antigen antibody (immune) complexes
defensive mechanisms used by antibodies:
neutralization
agglutination
precipitation
Complement Fixation
Antigens:
substances that can mobilize adaptive defenses and provoke an immune response
targets all of adaptive immune responses
most are large, complex molecules not normally found in body (non-self)
Charcateristics of Antigen:
can be complete antigen or hapten
contain antigenic determinants
can be a self antigen
APC:
engulf antigens and present fragments of antigens to T cells for recognition
3 major types:
dendritic cells
macrophages
B cells
don't activate naive T cells
present antigens to helper T cells to assist their own activation
Passive vs. Active Immunity
Passive
occurs when ready made antibodies are introduced into body. B cells are not challenged by antigens and immunological memory doesn't occur
naturally acquired: formed in response to actual bacteria or viral infection
artificially acquired: formed in response to vaccine of dead or attenuated pathogens
Active:
occurs whenB cells encounter antigens and produce antibodies against them, there are 2 types
naturally acquired: formed in response tp actual bacteria or viral infection
artificially acquired: formed in response to vaccine of deaf or attenuated pathogens
Cells involved in the immune system and their functions
clone cells become plasma cells (antibody secreting effector cells)
clone cells that don't become memory cells provide immunological memory and mount immediate responses to further exposures to same antigen
Regulatory T cells prevent autoimmune reactions
Lymphocytes: bind to only one antigen; proliferate (makes copies of itself) and differentiate; become effector T cells and memory cells
B lymphocytes (B cells): in humoral immunity, triggers receptor mediated endocytes, leads to proliferation and differentiation of B cells onto effector cell
Naive lymphocyte encounter antigen and develop further
T lymphocytes ( T cells): in cellular immunity, recognizes only antigens on MHC proteins
Antigen presenting cells: don't respond to specific antigen
Dendritic cells: act as mobile sentinels of boundary tissues and phagocytize pathogens that enter tissues; also present antigens to T cells in lymph nodes; link between innate and adaptive immunity
B Lymphocyte: don't activate naive T cells and present antigens to helper T cells to assist their own activation
Macrophages: present antigen to T cells which activates T cell and activates macrophages, activated macrophages become phagocytic killer, trigger inflammatory responses and recruit additional defenses
Cytotoxic: T cells: directly attack and kill other cells, search for body cells with antigen, target cancer cells, foreign cells, bacteria, stimulates apoptosis
CDB cells become cytotoxic T cells and cause dendritic cells to express molecules for CDB cell activation, capable of destroying cells harboring foreign antigen CD4 cells become helper T cells or regulatory cells (moderate immune response)
Helper T cells: activate humoral and cellular arms, help activate B cells and T cells, induce proliferation, secrete cytokines that recruit other immune cells, with out TH, no immune responses
Second Line of defense Cells:
Phagocytes: white blood cells that ingest and digest (eat) foreign invaders
Neutrophils: most abundant phagocytes, die fighting and become phagocytic on exposure to infectious material
Macrophages: develop from monocytes and are chief phagocytic cells: release interleukin which stimulates T cells to release interleukin 2
Natural Killer Cells: nonphagocytic, large granular lymphocytes that police blood and lymph
Disorders associated with the immune system
Immunodeficiency: congenital or acquired conditions that impair function or production of immune cells or molecules
Severe combined immunodeficiency (SCID): genetic defect with marked deficit in B and T cells
Hodgkin's Disease: an acquired immunodeficiency that causes cancer of B cells, which depresses lymph node cells and thus leads to immunodeficiency
Aquired immune deficiency syndrome (AIDS); Human immunodeficiency virues (HIV) cripples immune system by interfering with activity of helper T cells
Autoimmune disease results when immune system loses ability to distinguish self from foreign
Autoimmunity: production of auto antibodies and sensitized TC cells that destroys body tissues
Rheumatoid arthritis: destroys joints
Myasthenia gravis: impairs nerve muscles connections
Multiple Sclerosis: destroys white matter myelin
Graves Disease : cause hyperthyroidism
Type 1 diabetes mellitus: destroys pancreatic cells
Hypersensitivities: immune responses to perceived (otherwise harmless) threat that cause tissue damage