functions of the immune system to protect the entire body from a variety of harmful substances ...
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Functions of the Immune System
Functions of the Immune System
To protect the entire body from a variety of harmful substances pathogenic microorganisms allergens toxins malignant cells
Antigen-Antibody Reactions
Antigen-Antibody Reactions
Antigen - any substance that the body regards as foreign (virus, bacterium, toxin)
Antibody - a disease fighting protein developed by the body in response to the presence of an antigen
Structures of the Immune SystemStructures of the Immune System
Not contained in a single system
Action depends on structures from lymphatic, cardiovascular, and Integumentary systems
Works primarily through antigen-antibody reaction
Check for Understandin
g1.1. What other body What other body
systems work with the systems work with the immune system? immune system? How How do they do they work together? work together? Hint* Think back to the Hint* Think back to the past units. past units.
2.2. What are all the What are all the different vocabulary different vocabulary words that mean words that mean viruses, bacteria and viruses, bacteria and fungus?fungus?
External Defenses
Intact skin and mucous membranes Form physical barriers that stop the
entry of pathogens
Certain cells of the mucous membranes produce mucus A viscous fluid that traps microbes
and other particles
Body’s Defenses In the trachea, ciliated epithelial cells
Sweep mucus and any entrapped microbes upward, preventing the microbes from entering the lungs
Figure Figure 43.343.3
1010mm
•Secretions of the skin Secretions of the skin and mucous membranesand mucous membranes
•Provide an Provide an environment that is environment that is often hostile to often hostile to microbesmicrobes
•Secretions from the skinSecretions from the skin•Give the skin a pH Give the skin a pH between 3 and 5, between 3 and 5, which is acidic enough which is acidic enough to prevent colonization to prevent colonization of many microbesof many microbes•Also include Also include lysosymeslysosymes, that , that digests the cell walls of digests the cell walls of many bacteriamany bacteria
Check for Understandin
g1.1. What is the trachea? Where What is the trachea? Where
is it located?is it located?2.2. What is an epithelial cell?What is an epithelial cell?3.3. What is a lysosome? What is a lysosome?
Where is it found? Why Where is it found? Why would skin cells need them would skin cells need them more? more? Hint* Think back to the Hint* Think back to the cell unit.cell unit.
4.4. If your body is fighting a war If your body is fighting a war against pathogens, why is it against pathogens, why is it smart to put defenses where smart to put defenses where it did? Where are they it did? Where are they placed? Why is that placed? Why is that strategic?strategic?
ImmunityImmunityImmunity-state of being resistant or not susceptible
to a specific disease
Body’s reaction to invaders
Passive Acquired
Active Acquired
Acquired Immunity Passive
Acquired
Injecting antibodies (not patients) to fight a disease
Mother to newborn
Active Acquired
Natural types are people recovering from a disease and can’t get it again
Artificial types are vaccines
Check for Understandin
g1.1. What is the difference What is the difference
between injecting between injecting antibodies and antibodies and injecting a vaccine? injecting a vaccine? How does your body How does your body respond differently?respond differently?
WBCs for Immune Reactions
WBCs for Immune Reactions
Monocytes - formed in bone marrow/transported where needed by body become macrophages
Macrophage - phagocytic cell that protects body by ingesting invading cells
Lymphocytes - major class of WBCs formed in lymphatic
tissue
Figure Figure 43.143.1
33mm
Where
Imm
une
Cells co
me fro
m
Macrophage•Large numbers are Large numbers are released during infectionsreleased during infections
•Short lived – die after Short lived – die after digesting bacteriadigesting bacteria
•Found in the organs, not the blood.•Made in bone marrow as monocytes, called macrophages once they reach organs.•Initiate immune responses as they display antigens from the pathogens to the lymphocytes.
Phagocytosis
Process of engulfing and destroying cells.
Lymphocytes T cells or T Lymphocytes
mature in thymus gland Cell mediated immunity
B cells or B Lymphocytes mature in bone marrow antibody-mediated
immunity
Check for Understandin
g1.1. What is the What is the
relationship between relationship between monocytes and monocytes and macrophages? macrophages?
2.2. What is the What is the relationship between relationship between Lymphocytes, B-Cells Lymphocytes, B-Cells and T-Cells?and T-Cells?
3.3. Where are Where are macrophages found?macrophages found?
4.4. Where are B-Cells Where are B-Cells found?found?
5.5. Where are T-Cells Where are T-Cells found?found?
T Cell or T LymphocyteT Cell or T Lymphocyte
T Cell (cell mediated immunity) Helper T-cells
The Helper T-cells coordinate the attack.
Killer T-cells Killer T-cells do the
work of destroying the infected cells.
B-Cells• There are 10 million different B-
lymphocytes, each of which make a different antibody.
• Some activated B cells become PLASMA CELL PLASMA CELL .
• Plasma cells produce antibodies ~1000/sec
Antibodies
Antibodies don’t Antibodies don’t attack viruses. attack viruses.
Antibodies attach Antibodies attach to viruses, and to viruses, and bring them in bring them in clumps to clumps to macrophage. macrophage.
B-Cells Other Roles Some activated B cells MEMORY CELLS.
Memory cells divide rapidly as soon as the antigen is reintroduced.
When the pathogen/infection infects again it is destroyed before any symptoms show.
Check for Understandin
g1.1. What is the relationship What is the relationship
between antibodies and between antibodies and macrophages?macrophages?
2.2. Where do antibodies Where do antibodies come from?come from?
3.3. How many T-Cells are How many T-Cells are there and what are their there and what are their individual jobs?individual jobs?
4.4. Why are B-Cells so Why are B-Cells so special that they are special that they are called “morphing” cells?called “morphing” cells?
Major events in the local inflammatory response
Figure 43.6Figure 43.6
PathogenPathogen PinPin
MacrophageMacrophage
Chemical signalsChemical signals
CapillaryCapillaryPhagocytic cellsPhagocytic cells
Red blood cellRed blood cell
BloodBloodclottingclottingelementselements
Blood clotBlood clot
PhagocytosisPhagocytosis
Fluid, antimicrobial proteins, Fluid, antimicrobial proteins, and clotting elements move and clotting elements move from the blood to the site.from the blood to the site.Clotting begins.Clotting begins.
22Chemical signals released Chemical signals released by activated macrophages by activated macrophages and mast cells at the injury and mast cells at the injury site cause nearby capillaries site cause nearby capillaries to widen and become more to widen and become more permeable.permeable.
11 Chemokines released by various Chemokines released by various kinds of cells attract more kinds of cells attract more phagocytic cells from the bloodphagocytic cells from the bloodto the injury site.to the injury site.
33 Neutrophils and macrophagesNeutrophils and macrophagesphagocytose pathogens and phagocytose pathogens and cell debris at the site, and thecell debris at the site, and the tissue heals.tissue heals.
44
Function of Lymphatic
System• Returns excess interstitial fluid (from
tissues) to circulatory system
• Absorption of fat and fat soluble vitamins from GI system
• Defense against invading pathogens and disease
Lymphatic System
Lymphatic System
Major structures lymph vessels lymph nodes lymph fluid Tonsils Lymphatic trunks Collecting ducts
Also spleen thymus
Lymph SystemLymph System Fluid in lymphatic
capillaries are called “lymph”
Lymphatic vessels are like blood veins with valves
Lymph nodes are specialized organs
Lymph NodesLymph Nodes located in lymph
vessels
small round or oval structures (filters)
depositories for cellular debris
bacteria and debris phagocytized
Swollen if bacteria is overwhelming
Check for Understandin
g1.1. Glue the lymph model Glue the lymph model
in your notebook and in your notebook and label all major lymph label all major lymph nodes and clusters. nodes and clusters.
2.2. Why are lymph nodes Why are lymph nodes so important?so important?
3.3. Why are Why are lymph lymph vessels and the vessels and the cardiovascular system cardiovascular system so closely connected?so closely connected?
SpleenSpleen Sac-like mass of lymphatic tissue
filter for blood from lymph
Phagocytic cells (macrophages) used to destroy bacteria and toxins
ThymusThymus Primary role: matures T
cells
T cell development: cells migrate from bone marrow and differentiate into T cells
Thymus gets progressively smaller (and less active) through life
TonsilsTonsils Used to catch
pathogens before they are swallowed into the GI tract.
any or all may become so loaded with bacteria that the pathogens gain dominance.
Should not be Should not be removed unless removed unless absolutely absolutely necessarynecessary
Lymph Carry proteins back into blood
Absorb dietary fats
Transport pathogens to lymph nodes to be destroyed
Maintain balance of pressure in tissue fluid
Exercise is important
Lymphatic vessels are not muscles
Need physical exercise to contract and push lymph through vessels
Squeezing vessels cause flow to go into collecting ducts
Check for Understandin
g1.1. Why do elderly people get sick Why do elderly people get sick
more often than young adults? more often than young adults? Give specific examples and Give specific examples and reference specific organs. reference specific organs.
2.2. What immune cells are found in What immune cells are found in the bone marrow? the bone marrow? Hint* Look Hint* Look through all your notes.through all your notes.
3.3. What immune cells are found in What immune cells are found in the Thymus? the Thymus?
4.4. How areHow are blood vessels and blood vessels and lymph vessels different? lymph vessels different?
5.5. Why do people say that Why do people say that exercise and health go exercise and health go together?together?
Acquired Immune Deficiency Syndrome
(AIDS)
Acquired Immune Deficiency Syndrome
(AIDS) Caused by HIV (Human Immunodeficiency Virus)
HIV infects T-helper cells with often a long incubation of up to 10 years
AIDS name applied during advanced stages of disease
After immune system destroyed, opportunistic infections occur.
Autoimmune DisordersAutoimmune Disorders
Antigens stimulate development of antibodies that are unable to distinguish antigens of internal cells.
Body makes antibodies and T cells against itself and attacks own tissues.
Multisystemic involvement.
Myasthenia gravis, rheumatoid arthritis
Edema Hypoproteinemia
lowers osmotic pressure within blood large amounts of plasma pass out of blood
poor lymph drainage
increased capillary permeability
congestive heart failure
localized edema, ascites
Hemophilia Hereditary blood clotting disorder
sex-linked, usually in men
lack factor VIII, essential for blood clotting
hematomas
hemarthrosis
Infectious Mononucleosis
Infectious Mononucleosis
Acute infection caused by virus.
Fever, sore throat, swollen lymph glands, atypical lymphocytes, splenomegaly, hepatomegaly, abnormal liver function, and bruising.
transmitted by droplet infection
Infection confers permanent immunity
Treatment symptomatic
Oncology, the study of tumors
Oncology, the study of tumors
Metastasis, Metastasize
Carcinoma Malignant Melanoma Adenocarcinoma
Sarcoma (arises from bone, fat, muscle, etc.) Osteocarcoma Osteosarcoma Myosarcoma Myeloma
Leukemia Major oncological disorder
of blood-forming organs
Monocytes develop quickly in to B or T cells but do not die
Cancerous B or T cells overcrowd the body and organs until other cells can’t function normally
Hodgkin’s DiseaseHodgkin’s Disease Malignant disorder- Cancer
cells can spread
Cancerous B cells begin to form and grow abnormally large
Painless, progressive enlargement of lymph tissue
Anorexia, weight loss, anemia
Kaposi’s Sarcoma Malignancy associated with AIDS
lesions emerge as purplish-brown macules and develop into plaques and nodules