8.) Topic 8 Disease, Defence And Treatment Flashcards
What are micro-organisms?
Microscopic organisms
What is a non-pathogenic microorganism
Any microorganism that does not cause disease
Give an example of a non-pathogenic microorganism
- Gut bacteria to help digest food
- Skin flora help to prevent infection by competing with pathogens for resources
What is a pathogen?
A microorganism causing disease
Give 4 types of pathogens/microorganisms and give an example for each one
Bacteria - Salmonella
Viruses - HIV, potentially leading to AIDS
Protists - Malaria
Fungi - Athlete’s foot
Give 6 features of bacteria cells
- Cell membrane
- Cell wall (made of murein)
- Cytoplasm
- Plasmid loops of DNA
- No nucleus
- Reproduce by dividing in two to form clones - binary fission
- Exist as single cells
- Sometimes have a slime capsule around the cell wall to stop them drying out
- May have pili to attach to surfaces, or flagella to allow them to move
Give 4 features of viruses
- Smaller than bacteria
- Contain a protein coat surrounding a number of genes
- Only reproduce in a host cell
- Producing new viruses destroys the host cell as the new viruses are released. They are then free to attack other cells
What are diseases caused by pathogens called?
Communicable disease
Give 6 ways in which diseases can be spread
- Direct contact
- Aerosol
- Body fluids
- Water
- Insects
- Contaminated food
What is Tuberculosis caused by?
b) Type of organism
c) Symptoms
d) Prevention
Mycobacterium
b) Bacteria
c) Chest pain and a very bad cough. Occasionally may cough blood if infected
d) Vaccine
What is Malaria caused by?
b) Type of organism
c) Symptoms x4
d) Prevention x4
e) Mode of transmission
Plasmodium falciparum
b) Protist
c) Fever
Vomiting or diarrhoea
Headaches
Muscle and/or abdominal pain
d) Wear long clothing
Wear mosquito repellent
Sleep with mosquito nets
Use malaria prevention tablets
e) Insects/animals
What is Influenza caused by?
b) Type of organism
c) Symptoms x6
d) Prevention
Flu virus
b) Virus
c) Chills Sore throat Fever Muscle pains Coughing Severe headaches
d) Vaccine
What is food poisoning caused by?
b) Type of organism
c) Symptoms
d) Prevention
e) Mode of transmission
Salmonella or E. coli
b) Bacteria
c) Diarrhoea
Kidney failure
d) Meat is thoroughly cooked and vegetables are washed in clean water
e) Contaminated food
What is Chlamydia caused by?
b) Type of organism
c) Symptoms x3
d) Prevention
e) Mode of transmission
Chlamydia trachomatis
b) Bacteria
c) Pain when urinating
Painful discharge from the penis or vagina
Bleeding between periods for women
d) Wear condoms during sex
e) Direct contact
What is Athlete’s foot caused by?
b) Type of organism
c) Symptoms x2
d) Prevention x3
Dermatophytes or trichophyton
b) Fungi
c) Itching and flaking of the affected skin
Blisters
d) Avoid sharing towels and clean footwear and shower floors
What is Chicken pox caused by?
b) Type of organism
c) Symptoms x4
d) Prevention
e) Mode of transmission
Varicella
b) Virus
c) Itchy rash on head and neck
fever
Headache
Sore throat
d) Vaccine
e) Direct contact
Give 5 non-specific human defences to disease
The skin acts as a barrier
Stomach acid kills ingested pathogens
Mucus traps pathogens
Sweat contains antimicrobial chemicals
Blood clots prevent pathogen entry into wounds
What is the bodies 3 lines of defences against infection by pathogens?
- the skin stops microbes getting into the body
- Platelets stop microbes getting into the body through a cut
. White blood cells defend against microbes that are inside of the body by 3 ways:
1 - Phagocytes ingest bacteria
2 - Lymphocytes produce antibodies to inactivate bacteria or viruses
3 - Lymphocytes produce anti toxins that counteract toxins released by bacteria
What in inflammation and in which line of defence is it present?
Blood capillaries widen and more blood flows to the scene
2nd line of defence
What do white blood cells produce?
Antibodies and anti toxins
What is an antigen
A protein found on the surface of the pathogen that triggers an immune response
What is an antibody
A protein produced by the immune system which attacks specific antigens
What is an antitoxin
A type of antibody produced by white blood cells to neutralise toxins
What is a phagocyte
A type of white blood cell which engulfs and digests pathogens
What is a lymphocyte
White blood cells which attack antigens by producing antibodies
Give 2 ways that the body can respond to detecting a pathogen
- They can produce antibodies that are specific to the antigens on the pathogen that activate phagocytes
- They can produce anti toxins to neutralise the toxins released by the pathogen
How do phagocytes respond to detecting a pathogen?
Phagocytes engulf and break down pathogens in a process known as phagocytosis
What do platelets release and cause?
Release chemicals that cause soluble proteins to form a mesh of insoluble fibres across the wound and stick together to form clumps when platelets get stuck in the mesh