• Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month
Page
  1. 1
    1
  2. 2
    2
  3. 3
    3
  4. 4
    4
  5. 5
    5
  6. 6
    6
  7. 7
    7
  8. 8
    8
  9. 9
    9
  10. 10
    10
  11. 11
    11
  12. 12
    12
  13. 13
    13
  14. 14
    14
  15. 15
    15
  16. 16
    16
  17. 17
    17
  18. 18
    18
  19. 19
    19
  20. 20
    20

IB Biology notes on infection and the body's responses.

Extracts from this document...

Introduction

IB BIOLOGY Notes From IB Biology HL Pearson I. What causes infectious disease? A. pathogen: an organism or virus that causes a disease 1. includes viruses, bacteria, fungi, parasitic worms etc. II. The Body's Defences Against Infection A. Non-specific Defences 1. Barriers to pathogen entry a. Skin and mucous membranes in the respiratory, digestive and urinary tracts are mechanical barriers b . cilia in upper respiratory tract sweep mucus and particles up to the throat to be swallowed c. Secretions from oil glands of the skin inhibit bacterial growth on skin d. low pH of stomach inhibits bacterial growth/kills bacteria 2. Phagocytes and Natural Killer Cells a. neutrophils are white blood cells that can leave the blood and phagocytize bacteria in connective tissue b. eosinophils are phagocytic but are mainly used to attack large animal parasites c. Natural killer cells kill virus-infected cells and tumour cells by cell-to cell contact 3. Inflammatory Response a. occurs when tissue gets damaged b. inflamed area becomes red, painful, swollen and hot c. Damaged tissue releases histamine i. along with mast cells (a type of white blood cell) causes vasodilation and increased permeability of nearby capillaries a. results in redness and increase in temperature ii. Swelling from escaped fluid and proteins occurs iii. ...read more.

Middle

Benefits of vaccination 1. total elimination of certain diseases 2. preventing epidemics/pandemics 3. decreased health care costs 4. preventing harmful side effects of disease F. Possible dangers of vaccination 1. Side effects such as soreness near the injection site, low-grade fever 2. allergic reactions to some of the vaccine's ingredients a. e.g. Some vaccines contain egg proteins, yeast proteins, antibiotics, (leftover from the production process), human serum albumin (help stabilize live virus), formaldehyde (eliminates the effects of bacterial toxins and makes viruses unable to replicate), aluminum salts (help the vaccine work better), or gelatin that may cause an allergic reaction 3. a preservative called thimerosol contains mercury and there have been concerns about its safety (in the US it "has been removed from or reduced to trace amounts in vaccines for children 6 years of age and younger with the exception of the inactivated influenza vaccine" (Iannelli, 2008)) 4. possible overload of the immune system 5. IB lists possible links to autism but... For a comprehensive list of side effects for many vaccines, try this website: http://www.cdc.gov/vaccines/vac-gen/side-effects.htm G. So...should you use vaccines? 1. Personal choice of informed individuals is the key V. Antibiotics A. antibiotic: a chemical that inhibits the growth of microorganisms, particularly bacteria 1. ...read more.

Conclusion

BLOOD CLOTTING (same as from Circulatory System package) A. Clotting: formation of a solid mass of platelets, red blood cells and fibrin (a protein) 1. also called coagulation 2. Fibrinogen: a protein found in blood that is the precursor of fibrin 3. Prothrombin: inactive form of thrombin found in blood a. Vitamin K is necessary for production of prothrombin 4. Serum: blood plasma without fibrinogen B. STEPS IN BLOOD CLOTTING 1. Blood vessel is damaged 2. platelets clump at the site and partially seal the leak 3. platelets and damaged tissue release prothrombin activating factor 4. prothrombin activating factor converts prothrombin to thrombin a. requires calcium ions (Ca2+) 5. thrombin acts as an enzyme that removes 2 short amino acid chains from each end of a fibrinogen molecule, making them "sticky" 6. shortened fibrinogen molecules join end to end forming long threads of fibrin 7. fibrin threads tangle themselves around the platelets that are plugging the leak 8. red blood cells are trapped in the network of fibrin and give colour to the clot 9. when repair of blood vessel initiated, the enzyme plasmin destroys fibrin network A cute video, some details are slightly different from the notes though: http://www.youtube.com/watch?v=9QVTHDM90io&feature=related C. Rewind: Thrombosis 1. thrombosis: formation of a clot in a blood vessel a. often the result of damage to the wall of a blood vessel as in atherosclerosis b. other causes are outlined below: http://www.nhs.uk/Conditions/Thrombosis/Pages/Causes. ...read more.

The above preview is unformatted text

This student written piece of work is one of many that can be found in our International Baccalaureate Biology section.

Found what you're looking for?

  • Start learning 29% faster today
  • 150,000+ documents available
  • Just £6.99 a month

Not the one? Search for your essay title...
  • Join over 1.2 million students every month
  • Accelerate your learning by 29%
  • Unlimited access from just £6.99 per month

See related essaysSee related essays

Related International Baccalaureate Biology essays

  1. The Effects of Salinity on Wheat Germination

    not thus affected however one possibility is that the species of mould that was growing on the unhealthy seeds in the 5% solution may have picked up on some biological signal or the other healthy plants may have had some adaptation that may have prevented the mould getting a foothold

  2. What is the effect of different body positions i.e. lying down, sitting and standing ...

    Data Collection: Qualitative Data: Table 1: Qualitative results taken when participants were in three different positions (lying down, sitting down, standing up) Participant Age (years) Gender Lying down Sitting down Standing up 1 16 Female * Talked a little bit * legs straight * Relaxed * laughed * Relaxed *

  1. Biology Lab - frequency of cell division in animal and plant cell

    They are different because interphase occurs more in the onion root tip cells compared to the whitefish blastula cells. Part 3: Creating a Cell-Division Clock g) % of Cells Dividing = Number of cells dividing X 100 Total Number of cells counted Onion Root Tip Cell: Prophase (%)

  2. Enzyme IA Biology

    Record temperature of thermometer onto Row 2 Column 1 next to Room Temperature 10. Conduct Data a. Pour 10ml of Liver solution into 10ml graduated cylinder b. Use Pipet to gather 1ml of liver solution changing the concentration in the graudated cylinder from 10ml to 9ml c.

  1. biology extended essay - How different diets: vegetarian, vegan and a meat centered diet ...

    * Lower death rates for some chronic diseases. * Beneficial for overweight individuals. * Beneficial for women with premensrual syndrome. * Beneficial for individuals with diabetes, high blood pressure and cardiovascular diseases. 1.2.6 Are there any disadvantages of becoming or being a vegetarian or vegan? [6] Some people think that the main risk is a lack of protein,

  2. How the Heart Works

    Commonly, people suffer from high blood pressure. Some suffer heart disease as a result of diabetes. Others develop an arrhythmia, murmur, or irregular heartbeat. According to research women are becoming the greater half of the population to have heart disease, which might imply that they are more easily struck by it than men are.

  1. Effect of Detergent on Membrane Permeability

    This means that the absorption rate increases proportionally with the concentration detergent, without the beetroot. However when beetroot is added to the solution, the absorption rate of the solution increases exponentially. This means that the beetroot cells? plasma membranes are being destroyed exponentially as the concentration of detergent increases.

  2. Beet Lab. Aim: To determine the effects of temperature on the permeability of ...

    As long as the temperature does not go beyond what the membrane is supposed to withstand, the permeability of the plasma membrane should not be affected. Water expands, putting pressure on the membranes from within. The lipid part of the membrane liquefies, making it more prone to leakage.

  • Over 160,000 pieces
    of student written work
  • Annotated by
    experienced teachers
  • Ideas and feedback to
    improve your own work