phagocytic leukocyte Immune System lymphocytes attacking cancer cell lymph system 2006-2007
1) recognizing the presence of an infection; 2) containing the infection and working to eliminate it; 3) regulating itself so that it does not damage the body; 4) remembering pathogens to prevent disease from recurring.
Avenues of attack Points of entry: List as many you can think of: Pathways for attack circulatory system lymph system
Attack from the outside & inside lots of organisms want you for lunch! we are a tasty vitamin-packed meal cells are packages of proteins, carbohydrates & fats no cell wall animals must defend themselves against invaders viruses HIV, flu, cold, measles, chicken pox, SARS bacteria pneumonia, meningitis, tuberculosis fungi yeast protists amoeba, Lyme disease, malaria cancer cells abnormal body cells What s for lunch?!
MUCH SMALLER! Figure 9.2
Disease-causing agents Living organisms contain cells Bacteria Fungi Parasites require a host to survive Non-living cannot grow or reproduce on own Viruses DNA in a protein shell Prions proteins Malaria Life Cycle parasite
Characteristics Prokaryotic no nucleus Single celled Use a variety of resources for growth and reproduction Can be good: break down food in intestines to give us vitamin B, decompose organic materials Infections Pneumonia, tonsillitis, tuberculosis, botulism, toxic shock syndrome, syphilis, Lyme disease, etc. You are given antibiotics to treat bacterial infections.
Causes severe fever and pneumonia Figure 9.1
Extremely small Living? Most say No. - they do not have the ability to grow or reproduce on their own. Modes of entry fuses with cell membrane Diseases AIDS, hepatitis, encephalitis, rabies, colds, warts, chicken pox Important Video: Animation Structure and Reproduction of Viruses
Infectious proteins Folding problems of normal brain proteins Cannot perform normal protein function. Cause surrounding proteins to also fold. Resist cooking, freezing, drying Diseases Bovine spongiform encephalitis (BSE, mad cow disease ) Creutzfeld-Jakob disease (CJD) Possible indications of Alzheimer's.
Transmissibility How easily it is passed from person to person Mode of transmission Respiratory, fecal oral, body fluids Virulence How much damage is caused by the infection
Functions Maintenance of blood volume in cardiovascular system Transport of fats and fat-soluble material from digestive system Filtration of foreign material to defend against infection Filters out old blood cells.
Components Lymph: protein-containing fluid, transported by lymphatic vessels Lymph nodes: cleanse lymph by filtering out material **Spleen: cleanses blood, removes dying red blood cells, helps fight infection** - Is important! Thymus: secretes thymosin and thymopoietin to cause T lymphocytes to mature Tonsils: protect throat
Figure 9.3 (2 of 6)
Figure 9.3 (3 of 6)
Why do doctors test lymph nodes for cancer? Figure 9.3 (4 of 6)
Scientists use to think the spleen was a vestigial structure. Figure 9.3 (5 of 6)
Figure 9.3 (6 of 6)
1st line: broad, external defense walls & moats skin & mucus membranes 2nd line: Non-specific patrol broad, internal defense patrolling soldiers phagocyte (eating) WBCs 3rd line: Barriers Immune system specific, acquired immunity elite trained units lymphocyte WBCs & antibodies B & T cells
Physical and chemical barriers Skin Structure: dead layer, inhospitable to microorganisms Constant replacement: many adhering microorganisms removed when dead epithelial cells fall off ph = 5 6: too acidic for many microorganisms Other barrier mechanisms: tears, saliva, earwax, digestive and vaginal acids, mucus, vomiting, urination, defecation, resident bacteria (normal flora)
Table 9.1
Phagocytosis Neutrophils - Phagocytose, or ingest, bacteria and fungi. Macrophages- large phagocytic cells that ingest dead or damaged cells and pathogens. Eosinophils - Kill parasites and destroy cancer cells. - involved in allergic responses. Digest foreign bodies with secreted enzymes.
Why enclose the bacteria in a vesicle?? Figure 9.6b
Inflammatory response Signs: redness, warmth, swelling, pain Process: tissue damage leads to release of histamine, blood vessels dilate, complement marks bacteria, phagocytic cells arrive and remove invading microorganisms PLAY Animation The Inflammatory Process
Why is the purpose of the leaky blood vessels? Figure 9.7
Natural killer cells: lymphocytes Complement system: group of plasma proteins Interferons: interfere with virus replication / spread Fever: increases host cell defenses and metabolic activity, high temperatures kill off Interferons = also known as cytokines
Death by Osmosis! Figure 9.8 (1 of 2)
Figure 9.8 (2 of 2)
Immune response targets antigens Antigens: major histocompatibility complex (MHC) proteins recognizes self from non-self cells. B cells: antibody-mediated immunity, action by antibodies Classes of antibodies: IgG, IgM, IgA, IgD, IgE Antibody structure: heavy chains and light chains, constant and variable regions
Plasma Cells = plasma B cells, plasmocytes, and effector B cells, are white blood cells which produce large volumes of antibodies Figure 9.9
Antigen Antigenbinding site Variable regions Constant regions Light chain Heavy chain Figure 9.11
Marking pathogens for attack Figure 9.10
T cells: cell-mediated immunity, action by cells Helper T cells: stimulate other immune cells Cytotoxic T cells: kill abnormal and foreign cells Memory T cells: reactivate on re-exposure Suppressor T cells: suppress other immune cells
Table 9.2
MHC = Major histocompatibility complex Figure 9.12
Figure 9.13
Primary Immune Response Process: recognition of antigen, production and proliferation of B and T cells Characteristics: lag time of 3 6 days for antibody production, peak at 10 12 days Secondary Immune Response Process: recognition of antigen, production and proliferation of T cells and plasma cells Characteristics: lag time in hours, peak in days
Figure 9.16
Active immunization: effective against viruses Passive immunization: effective against existing or anticipated infections Monoclonal antibodies: clones of hybrid cells Antibiotics: effective only against bacteria, resistance is a problem WHY??
Transplants: 75% match essential Recent advances: Improvements in immunosuppressive drugs Better techniques for tissue typing National organ bank systems Immunosuppressive drugs: prevent patient s immune system from attacking transplanted tissue Opinions?? Umbilical Cord Blood Banking http://parentsguidecordblood.org/
Allergies Hypersensitivity reaction, excessive inflammatory response mediated by IgE Localized: affect only the area exposed Systemic: affect several organ systems Anaphylactic shock Severe systemic allergic reaction Symptoms: difficulty breathing, severe stomach cramps, swelling throughout the body, circulatory collapse, fall in blood pressure
http://www.youtube.com/watch?v=y3bogdvv-_m Figure 9.18
Autoimmune Disorders Defective recognition of self Lupus erythymatosis (LE or lupus) Inflamed connective tissue Rheumatoid arthritis Inflamed synovial membrane Body attacks self!
Practice Questions: 1. Is a virus alive? Why or why not? 2. Summarize the function of the immune system? 3. What kind of symptoms might someone experience if they are taking immune suppressors? Explain.
4. Why is a fever helpful? 5. Name the structures in the lymphatic system. 6. Describe how an allergic reaction develops.
True False
True False
A. The virus that causes measles cannot enter the body a second time. B. The virus that causes measles cannot infect healthy cells a second time. C. Your immune system remembers those invaders and attacks them more quickly and effectively the second time.