Disease And Immunisation Flashcards
What are the 6 different categories of diseases?
- infectious (pathogenic organism, AIDs)
- dietary deficiency disease (scurvy)
- environmental disease (caused by non living factors, skin cancer from radiation)
- social disease (caused by human activities, alcoholism, emphysema, anorexia)
- ageing diseases (degeneration of the body, arthritis)
- genetic disease (caused by inherited genes, cystic fibrosis)
How may a pathogen be transmitted?
Drinking, eating, breathing in aerosol droplets, animal bites or direct contact
What steps must be taken for a pathogen to cause a disease?
- pathogen must be transmitted to human host
- pathogen gains entry to body via cuts or thinner epithelium, like lungs or digestive system
- pathogen must evade the hosts defences, stomach acid, immune system
- pathogen then harms host by reproducing inside host cells using up cellular resources and bursting out or
- producing toxins that interfere with body reactions, inhibit enzymes
How may toxins released by a pathogen harm the body?
- inhibit enzymes
- bind to DNA causing mutations
- interfere with synapses
Name 2 viral and protoctist diseases
Viral
- influenza-> myovirus
- cold -> Rhinovirus
- AIDS -> HIV
Protoctist
- malaria ->plasmodium vivas
- sleeping sickness
Name 2 bacterial and fungal diseases
Bacterial
- TB-> mycobacterium tuberculosis
- pneumonia-> pneumoniae
- cholera-> Vibrio cholorae
Fungal
- athletes foot-> Tinea pedis
- ringworm-> Tinea capititis
What does risk factor of disease mean?
Factors that specifically increase risk of getting a disease
What are the risk factors of diabetes?
Genetics, diet and exercise
What are the risk factors of AIDs?
Sexual habits, drugs and genetics
Does a scatter graph with a clear pattern show correlation or causation?
- it can be said that there is a correlation, however this may be a coincidence due to a third factor so there is no evidence for causation
What are the 4 different types of leukocytes (white blood cells)?
Phagocytes
Granulocytes
T-lymphocytes
B-lymphocytes
Describe how the different leukocytes are split into 2 categories and how each perform different functions:
Phagocytes -> phagocytosis -> non-specific immune
Granulocytes -> inflammation -> non-specific immune
T-lymphocytes-> cell-mediated response-> specific immune
B-lymphocytes-> antibody (humoral) mediated response -> specific immune
What are the 2 non-specific methods of killing foreign bodies?
Phagocytosis
Inflammation
What are the 3 stages of phagocytosis?
1) phagocyte travels through blood or tissue fluid in response to chemical released by microbe or other white blood cell
2) phagocyte engulfs microbe by phagocytosis trapping the membrane in a sac (phagosome)
3) phagosome fuses with lysosomes containing lysozyme (digestive enzymes) that hydrolyse the protein lipids and carbs making up the microbe
How do granulocytes respond to disease?
Granulocytes release chemicals (histamines and prostaglandins) which stimulate: Vasodilation Capillary leakage Sensory neurone impulse Blood clotting
Inflammation is the local response to an injury or infection, what are the 4 other responses and what is their purpose?
Vasodilation-> to increase blood flow to area
Capillary leakage -> so phagocytes and granulocytes enter tissue fluid causing swelling, then excess fluid and dead cells are released as pus
Sensory neurone impulses-> so area is tender and painful
Blood clotting-> to form a scab
How does collagen repair a wound?
- collagen stimulates growth of new cells (scar tissue)
- scar tissue is less specialised = loss of function and scarring
What kind of animals have specific immune system and non-specific? And what can be concluded?
Vertebrates
= must be a later evolutionary advancement
Definition of an antigen?
A large molecule on the outer surface of a cell that stimulates an immune response
What are antigens usually made of?
Protein
Glycoproteins
Lipoprotein
Polysaccharides
Describe the structure of an antibody (immunoglobulin)
4 polypeptide chains-> 2 heavy and 2 light
Joined together by disulphides bridges
Y shape
Constant lower region (same for all antibodies)
Variable upper region (different amino acid sequence)
What is formed when an antibody joins to its complementary antigen?
Antigen-antibody complex
What is different about receptor proteins to antibodies?
Receptor proteins can only be on the outer surface of T-cells and not in solution
Receptor proteins have 1 binding region not 2
Antigen-receptor complex forms no antigen-antibody
Describe the process of a macrophage becoming an antigen presenting cell and what doe this initiate?
- macrophage ingests non-self cell (virus, bacteria, transplant)
- the cell is digested by phagocytosis and the antigens pas to the surface to be presented
- the macrophage also secretes chemicals to stimulate clonal selection
- > this initiates specific immune response
