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Limit this to the release of clotting factors from platelets and damaged cells resulting in the formation of thrombin. Thrombin catalyses the conversion of soluble fibrinogen into the fibrous protein fibrin, which captures blood cells.
The process of blood clotting.
A blood clot functions to seal a wound injured, preventing further invasions by bacteria.
Clotting begins when the wall of a blood vessel is damaged. There are many different clotting factors involved including; platelets, prothrombin, fibrinogen.
Platelets are small fragments that circulate along with erythrocytes (red blood cells) and leukocytes (white blood cells) in blood plasma.
- Clotting process begins with the release of incomplete fragments of cells from the damaged tissue, resulting in the formation of thrombin.
- Thrombin converts fibrinogen (always in the bloodstream) into the fibrous protein fibrin.
- Fibrin captures red blood cells and stops the fluid portion of the blood so as to provide the push for clotting.
- Blood becomes slightly solidified.
- Platelets reach this fibrous mass and send out sticky extensions to each other.
- The platelets then contract, forcing out the liquid and scabbing over the wound
Blood clotting homework question
1. What is a blood clotting process?
2. How many clotting factors are included?
3. Explain the role of each factors.
4. Shortly explain the process of blood clotting.
5. What is the benefit of blood clotting to human?
6. What is a “platelet” ?
11.1.2
Outline the principle of challenge and response, clonal selection and memory cells as the basis of immunity.
FIGURE 3.4The immune system relies on the concerted activities of a number of different cell types. At the center of this activity is the helper T-cell, which receives information about invading pathogens from macrophages and stimulates pathogen-fighting activities in other immune cell types. The helper T-cell will trigger antibody production in B-cells and will activate "killer" T-cells, which destroy other cells in the body that are infected with the pathogen. Unfortunately, the helper T-cell is the target for infection with and destruction by HIV. As the number of helper T-cells decreases throughout the progression of AIDS, the person's immune system becomes depleted and unable to fight off pathogens effectively.
List of the various cells involved in the immune response.
Define pathogen.
Define antigen.
After a macrophage eats a pathogen, what happens to the pathogen's antigens?
Why is a Helper T Cell have that name?
What two cells does a B Cell divide into?
What two cells does a T Cell divide into?
Define cytotoxic.
What are antibodies? What do they do?
Why do Memory Cells have that name?
Vocabulary
antigen: foreign particle - bacteria, virus, protist, etc.
leucocyte: white blood cell, many varieties - macrophage
antibody: protein that bonds to and stops pathogens
lymphocyte: various kinds of leucocytes that produces a response to an antigen - T Cell, Helper T Cell, Killer T Cell, Memory T Cell, B Cell, Plasma Cell, Memory B Cell
Challenge and Response
Challenge: an antigen gets past the skin, mucous membranes, and/or stomach and enters the tissue of the body.
Response: the leucocytes (white blood cells) of the immune system respond to the antigen by producing antibodies, memory cells and cytotoxic cells (cells that kill body cells that are infected by the pathogen)
Clonal Selection
a macrophage ingests a pathogen and displays the antigens on its membrane
in a lymph node, the macrophage presents the antigen to Helper T Cells
B Cells and T Cells with complementary receptors for the antigen are also stimulated
the Helper T Cell stimulates the B Cell and T Cell to divide
B Cell divides to form Plasma Cells and Memory B Cells
the Plasma Cells produce the corresponding antibody to the antigen
the T Cell divides to form Killer T Cells and Memory T Cells
the Killer T Cell destroys body cells infected by the pathogen
Memory Cells
the Memory B Cells remain and provide a fast response the next time the same antigen is encountered
the Memory T Cells remain and provide a fast cytotoxic response the next time the antigen is detected
Active immunity is immunity due to the production of antibodies by the organism itself after the body’s defence mechanisms have been stimulated by antigens.
Passive immunity is immunity due to the acquisition of antibodies from another organism in which active immunity has been stimulated, including via the placenta, colostrum, or by injection of antibodies.
Active Immunity is the production of antibodies by the organism after the defence mechanisms have been stimulated by antigens.
Example:
Passive Immunity is the acquisition of antibodies from another organism, whose active immunity has been stimulated
Example:
Question: Compare active and passive immunity
11.1.4
Explain antibody production.
Limit the explanation to antigen presentation by macrophages and activation of helper T-cells leading to activation of B-cells which divide to form clones of antibody-secreting plasma cells and memory cell
Antibody production proceed
- Macrophages (macrophages are cells of the immune system that exist in tissues and help defend the body against foreign cells like bacteria) consume bacteria with antigen molecules in their membranes.
- Macrophages present these antigens on their membranes with the help of special protein structures.
- Helper T-cells come in contact with macrophages, pick up the antigens, and incorporate them into their own protein structures - this will allow them to present the antigens to B-cells. This also causes the activation of the Helper T-cells.
- Activated helper-T-cells activate B-cells by passing their antigen to B-cell receptors.
- The B-cells then divide to form clones of antibody-secreting plasma cells and memory cells.
3. What are the T-cells, B-cells role during the proceed?
4. What is the role of antibody production proceed in defending against infectious disease?
11.1.5
Describe the production of monoclonal antibodies and their use in diagnosis and in treatment.
Production should be limited to the fusion of tumour and B-cells, and their subsequent proliferation and production of antibodies.
Limit the uses to one example of diagnosis and one of treatment.
Detection of antibodies to HIV is one example in diagnosis. Others are detection of a specific cardiac isoenzyme in suspected cases of heart attack and detection of human chorionic gonadotrophin (HCG) in pregnancy test kits. Examples of the use of these antibodies for treatment include targeting of cancer cells with drugs attached to monoclonal antibodies, emergency treatment of rabies, blood and tissue typing for transplant compatibility, and purification of industrially made interferon.
Aim 8: Production of monoclonal antibodies is certain to be a growth area in biotechnology, with many potential applications and consequent economic opportunities. Some of the applications will be of most use in developing countries, raising the question of how they will be paid for, whether commercial companies should be expected to carry out pro bono research and development, or whether national governments should provide funds for it through aid budgets. Historically, the development of treatments for tropical diseases and parasites has lagged far behind those for the diseases prevalent in wealthier countries.
Guiding Questions:
1. What’s hybridoma?
2. What does hybridoma produce?
3. What can monoclonal antibodies do? (Give 3 examples)
4. What’s the emergency treatment for rabies?
Vocabulary:
- Tumor: an uncontrolled, abnormal, circumscribed growth of cells in any animal or plant tissue.
In 1975, Köhler and Milstein created technique called somatic cell hybridization. They won a Noble Prize in 1984. This process was first done on a mouse. When this was implied to humans, there were some allergic reactions. However, it was solved later on as the process was humanized (add more human molecules).
Antibody is made through using selected tumor cells. A specific B cell (cells that are capable of creating antibodies) is to join a tumor cell, then tumor cells produces ‘hybridoma’. It can produce huge amount of antibody producing cells.
ELISA test is done to test HIV. HIV patients have antibodies developed to defeat HIV, and therefore when it’s tested through blood or saliva, by detecting those type of antibodies, we can know whether that person has HIV or not.
It’s also used to detect whether a person had a heart attack or not, as there is certain antibody that indicates it.
One of the most commonly used usage of antibody is test for pregnancy. It uses human chorionic gonadotrophin (HCG) to determine whether you are a pregnant or not if you put urine on the testing kit.
Emphasize the role of memory cells. The primary and secondary responses can be clearly illustrated by a graph. Precise details of all the types of vaccine (attenuated virus, inactivated toxins, and so on) for specific diseases are not required.
Guiding Questions:
1. What enters your body when you are vaccinated?
2. What are the roles of memory cells in this process?
3. Why is the rate of response quicker in the second infection?
4. Would pathogens make you unwell if you are vaccinated?
Some viruses are deadly, so that vaccine is injected to minimize the effects of that virus. In vaccine, there are modified (weakened or dead) pathogens in it, which will not cause you to get the disease. Vaccine works as the normal immune system defeats the weakened or dead pathogen which entered the body, and form memory cells as the immune system fights against the pathogen and it would remember the way to defeat against this kind of pathogen and detect the protein coat of the pathogen, so that there is a quick response to it so that you wouldn’t get disease cause by this particular type of pathogen when it comes to attack you.
The benefits should include total elimination of diseases, prevention of pandemics and epidemics, decreased health-care costs and prevention of harmful side-effects of diseases. The dangers should include the possible toxic effects of mercury in vaccines, possible overload of the immune system and possible links with autism.
Aim 8: For parents there are ethical decisions to be made, to minimize risk for one’s own child, but also to help to prevent epidemics that could affect other children.
Int: The international dimension could be addressed here, given that some diseases have the potential to become pandemics and that the example of smallpox shows how effective international cooperation can be in combating infectious diseases.
TOK: This is an area where it is important to estimate accurately the size of risks, using good scientific data. The use of double-blind trials for vaccines or for drug treatments could be discussed. The placebo effect could also be considered, together with the complex interplay between mind and body in feelings of illness and health. Does the patient or the doctor decide whether the patient is well or not?
There are also questions about the relationship between the scientific community and the general public. How can the general public be given clear information about the benefits and risks of vaccination? What went wrong in the recent case of misplaced fears about the measles, mumps and rubella (MMR) vaccine in the UK? There are ethical questions here about who should decide vaccination policy in a country, and whether it is ethically acceptable to have a compulsory vaccination programme.
A vaccination stimulates the immune of an individual to develop adaptive immunity to a disease.
Since vaccinations exist, the human immune system has been able to resist from numerous disease. Even though most doctors agree that vaccinations are generally safe, risks are always present.
Benefits:
- Eliminate some disease
- Less people get some kind of disease such as measles
- Avoid possible disability in the case of polio for instance
- Herd immunity which reduces the chance of an unvaccinated individual to get a disease as most of the population is protected against diverse virus.
- Decrease health care costs
Dangers:
- Overloading the immune system of an individual would have a negative effect through the reduction of the capability to fight against numerous infections and virus. It might also lead to a disorder of neural development at the childhood (scientifically not 100% proven)
- Various other pathogens could be formed in the vaccine injected and affect the immune system negatively.
- Vaccination may have a high side effect on the immune system of an individual making it at risk.
- Artificial immunity which is the process to intentionally expose a body to small quantity of immunity becomes less effective. Childhood diseases avoided as a child may cause a more serious disease to an adult
Parents are the ones who worry the most about vaccination due to the potential risk it could have on their child’s immune system. It could certainly be a lifesaving but the concept to inject pathogen into a loved one’s body which could lead to his death, is terrifying.
The smallpox is a great example which has been completely eradicated from the list of the infectious disease since 2011 and proves how the impact of vaccination had been beneficial for people all around the world.
Actual issues for the spread or continuous existence of certain disease:
What are the global issues which prevent some disease to get eradicated from the list?
TOK: This is an area where it is important to estimate accurately the size of risks, using good scientific data. The use of double-blind trials for vaccines or for drug treatments could be discussed. The placebo effect could also be considered, together with the complex interplay between mind and body in feelings of illness and health. Does the patient or the doctor decide whether the patient is well or not?
There are also questions about the relationship between the scientific community and the general public. How can the general public be given clear information about the benefits and risks of vaccination? What went wrong in the recent case of misplaced fears about the measles, mumps and rubella (MMR) vaccine in the UK? There are ethical questions here about who should decide vaccination policy in a country, and whether it is ethically acceptable to have a compulsory vaccination programme.
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