7 Flashcards
(b) Outline steps the body goes through when administered with the flu vaccine so they will be protected from the infection over the flu season.
The pathogen in the vaccine in consumed by macrophage
The non-self antigen is displayed on the cell surface to attract T cells
T-cells bind the non-self antigen and take it to the B-cells in the lymph nodes
B-cells receive information become sensitised, enlarged and divide to create plasma cells
B-cells/plasma use this information to create correct antibodies which flood the blood stream
Memory cells are formed which remain in the lymph nodes
(a) What type of pathogen causes the flu and how is it transmitted from person to person?
Virus
(Person to person) through droplets in coughing/sneezing
(d) State two reasons why people need to receive a new flu vaccine every year
Flu mutates regularly/many different strains exist and are common at different times
Protection from flu strains one year won’t guarantee protection the next year/the body’s immunity to the flu decreases over time
(e) If a person becomes infected with the flu, what type of medication could they take to reduce the severity of symptoms?
Antivirals
steps of inflammatory response
Mechanical damage is caused by mast cells to be activated by complement proteins which release histamine heparin and other chemicals
Histamine increases blood flow capillaries permeability heat redness and escape of fluid from the blood causing swelling
Heparin prevents clotting which slows the spreading of a pathogen into the tissue
Compliment system proteins and chemicals attract vego so I took Petreley neutrophils
pain is felt from receptors
phagocytes die-off - yellow pus
new cells from mitosis.
pyrogens
Released by the white blood cells act on the hypothalamus and example one is interleukin
Produced by activated macrophages or dendrite and epithelial cells.
fever benefits and downside
Inhibit the growth of some bacteria and viruses
Heat= speeding up a reactions
inhibit viral replication by allowing interferons And to operate quickly
Monocytes, neutrophils, dendrite cells
Monocytes leave bloodstream and into the tissue then differentiate into macrophages some move through tissue others are stationary
Neutrophils are granulated leucocytes love you waited nucleus abundant. It kills pathogens in cells short lifespan and is a major proportion of the puss.
Deidree cells projection from cytoplasm ability to detect and golf and process from particles use info to assist with specific immunity
Three examples of bacteria viruses fungi and animal paracites
Leprosy chlamydia gonorrhoea”
HIV Covid, ebola
Ringworm thrush tinea
lice tics roundworms
4 types of vaccines
living attenuated: reduced virulence so the person does not contract the disease but produces antibodies
inactivated vaccines: contain dead microorganisms that produce immunity for a shorter time eg whooping cough
toxoid: inactive toxins tetnis
subunit: fragments of an organism to provoke immune response HPV
difference between bacteriocidal and bacteriostatic
kill by changing the structure of the cell wall
stop reproduction by disrupting protein synthesis
Describe three (3) differences between the divisions of the nervous system identified above.
Somatic one neurotransmitter, autonomic two neurotransmitters
Somatic acetylcholine, autonomic acetylcholine and noradrenaline
Somatic voluntary, autonomic involuntary
Somatic always excitation, autonomic excitation or inhibition
first line of response
non specific
2 List the external defences that prevent the entry of pathogenic organisms into the body.
Answer: The body’s external defences include:
• cerumen, which inhibits bacterial growth in the outer ear
• the skin that forms an impervious barrier on the outside of the body
• tears, which contain the enzyme lysozyme. They cleanse the eyes and inhibit bacterial growth
• mucous membranes that line body cavities that open to the exterior
• mucus which is produced in the trachea and bronchi to trap micro-organisms
• acid in the stomach kills many micro-organisms
• acidic secretions in the vagina inhibit growth of pathogens
• mucus secreted at the anus traps micro-organisms
• urine which flushes the urethra
• the mouth cavity with a mucous membrane that is cleansed by saliva
• hairs and mucus in the nasal cavity trap micro-organisms.
List four reflexes that help to protect against infection.
Answer: Four reflexes that help to protect against infection include the following:
• Sneezing: When the walls of the nasal cavity are stimulated by such things as noxious fumes or dust particles, the forceful expulsion of the air from the lungs carries mucus, foreign particles and irritating gases out through nose
• Coughing: Irritation to the bronchi and bronchioles results in the forceful expulsion of air from the lungs, which carries with it any mucus and foreign matter up to the throat and mouth.
• Vomiting: Contraction of the muscles of the abdomen and diaphragm as a result of the presence of bacterial toxins, stretching of the stomach, or psychological factors, results in the expulsion of the stomach contents.
mast cells
Mast cells stimulate and coordinate inflammation by releasing histamine, heparin and other substances into the tissues.
Histamine
Histamine increases blood flow through the area and causes the walls of the blood capillaries to become more permeable, so that fluid is filtered from the blood.
Heparin i
Heparin is released from the mast cells to prevent clotting in the immediate area of the injury.
Phagocytes
Phagocytes such as macrophages and leucocytes are attracted by the chemicals released from the mast cells. They consume micro-organisms and cell debris at the site of the infection.
List the ways in which killer T-cells and helper T-cells can deal with an invading antigen.
Killer T-cells migrate to the site of infection and deal with the invading antigen. They attach themselves to the invading cells and secrete a substance that will destroy the antigen, and then go off in search of more antigens.
Helper T-cells play an important role in both humoral and cellular immunity. They secrete a number of substances that:
• cause lymphocytes at the infection site to become sensitised, thus intensifying the response
• attract macrophages to the place of infection so that the macrophages can destroy the antigens by phagocytosis
• intensify the phagocytic activity of macrophages.
bactericidal and a bacteriostatic antibiotic difference
bactericidal antibiotics kill bacteria (by changing the structure of the cell wall or cell membrane, or by disrupting the action of essential enzymes). Bacteriostatic antibiotics do not kill the bacteria but stop them from reproducing (usually by disrupting protein synthesis).
List four differences between bacteria and viruses
Bacteria are living things; viruses are difficult to classify and there is debate about whether they should be seen as living or non-living because they do not have all the characteristics of a living organism.
• Bacteria are large enough to be seen with a light microscope; viruses are much smaller and can only be seen with an electron microscope.
• Bacteria have cell walls; viruses do not.
• Bacteria can live independently; viruses need host cells to survive and reproduce.
• Bacteria contain both RNA and DNA; viruses have only DNA or RNA, not both.
• Viruses have a protein coat and lipoprotein envelope; bacteria have a cell wall and cell membrane.
Compare and contrast antigens and antibodies.
Compare: Both antigens and antibodies are involved in the body’s antibody-mediated immune response. Both are required to produce the antigen-antibody complex.
Contrast: Antigens are molecules capable of stimulating an immune response, they are usually proteins but may be polysaccharides, lipids or nucleic acids. Antibodies are Y-shaped proteins produced by B-cell in response to exposure to antigens. Antigens originate wither within the body or externally whereas antibodies only originate within the body.
how cell-mediated immunity is activated
4 steps
Non-self antigen enters the body
Antigen-presenting cells detect the presence of the non-self antigen, they engulf the pathogen, digest the pathogen producing small fragments that move to the surface of the cell and present the antigen to the T-lymphocytes in the lymphoid tissue
One type of T-cell is sensitised, enlarged and divides producing a clone of T-cells
Most T-cells differentiate into Killer T-cells, Helper T-cells and Suppressor T-cells and some become memory T-cells for secondary and subsequent infections
For each situation below, state whether the humoral response or cell-mediated response would be more important.
a A heart transplant
b A viral infection
c A blood transfusion
d Tetanus toxins
e A bacterial skin infection
f A fungal infection.
A heart transplant
Answer: Cell-mediated response
b A viral infection
Answer: Cell-mediated response
c A blood transfusion
Answer: Humoral response
d Tetanus toxins
Answer: Humoral response
e A bacterial skin infection
Answer: Humoral response
f A fungal infection.
Answer: Cell-mediated response
Describe the function of helper T-cells,
They bind to the antigen on antigen-presenting cells. They secrete a substance that enhances macrophage activity, attracts more macrophages and that sensitises more lymphocytes.
, killer T-cells
Migrate to the site of the infection and deal with the invading antigen. They attach to the invading cells and secrete a chemical that will destroy the antigen, and then go in search of more antigens.
Suppressor T-cells
They release substances that inhibit T- and B-cell activity to slow down the immune response.
6 Describe the series of events that occur during antibody-mediated immunity.
An antigen presenting cell presents the antigen to the specific B-cells in lymphoid tissue. The B-cells are sensitised, enlarged and divide to form a clone. The majority of the clone form plasma cells which secrete specific antibodies capable of attaching to the active site of the antigen. The remainder of the clone become memory cells.
cell mediated works against
transplanted tissues and organs,cancer cells and cells infected by viruses or bacteria. also fungi and parasites
humoral-antibody mediated works against
bacteria, toxins and viruses before entering body cells
red blood cells of another person
humoral-antibody mediated steps 7
- Antigen presenting cells recognise, and golf and I just pathogens, displaying the antigen on their surface.
- Antigen presenting cells reach lymphoid tissue and present the antigen to lymphocytes.
- Helper T cells are stimulated by antigen presenting cells, which release cytokines
- Specific B-lymphocytes are stimulated to undergo rapid cell division
- Most new B cells develop into plasma cells, which produce antibodies and release them into blood and lymph.
- Antibodies combined with specific antigen and in activate or destroy it.
- Some of the new B cells form memory cells.
cell mediated 7 steps
- Antigen presenting cells recognise, and engulf and digest pathogens, displaying and Jenn on the surface.
- Antigen presenting cells written lymphoid tissue and present the antigen to the lymphocyte
- Helper T cells are stimulated by antigen presenting cells, which release cytokines
- Specific T lymphocytes are stimulated to undergo rapid cell division.
5 most new T cells develop into killer T cells or help us T cells, which migrate to the side of the infection. - Killer T cells destroy the antigen, will help itself promote phagocytose this by macrophages.
- Some sensitised T cells for memory cell.
What is the benefit of fever during an infection?
Elevated body temperature inhibit the growth of some bacteria and viruses. Heat speeds up the rate of chemical reactions which may increase the rate of cell repair. A fever may inhibit viral reproduction by allowing interferons to operate more quickly.
10 Define ‘fever’ and ‘pyrogen’, and explain their relationship.
11 Name one pyrogen.
Answer: Fever is an elevation of body temperature. Pyrogens are chemicals released by white blood cells released during inflammation that act on the hypothalamus to re-set the body’s thermostat. For a fever to occur, the pyrogens must be released so that the hypothalamus can raise the set point for temperature higher than normal.
Answer: Interleukin 1.
living attenuated. vaccines
contains living attenuated micro-organisms – micro-organisms of reduced virulence – that is, micro-organisms with a reduced ability to produce disease symptoms, so that the immunised person does not contract the disease but does manufacture antibodies against the antigen
toxiod vaccines
of vaccine is made from toxins. In cases where bacteria produce their effects in humans by liberating toxins, it is not necessary to use living or dead bacteria for immunisation; inactivated toxins (toxoids) can be used instead.
