Topic 5: Health & Disease Flashcards
What is health?
A state of complete physical, mental and social well being, and not merely the absence of disease or infirmity
What can cause ill health?
Diseases
What can having a disease do to your body?
Can weaken your body - makes you more susceptible to other diseases
What are the two types of diseases?
Communicable diseases
Non-communicable diseases
What are communicable diseases?
A disease that can spread from person to person or between animals and people
What are non-communicable diseases?
A disease that cannot spread between people or between animals and people
What are properties of viruses?
They aren’t cells
They infect living cells to reproduce
What are the two pathways a virus can take when it enters an organism?
Lysogenic pathway
Lytic pathway
What happens in the lysogenic pathway?
- The virus inserts its DNA into the host cell and the DNA becomes incorporated into the host DNA
- As the host cell replicates, the viral DNA also replicates
- Changes in the environment can cause the viral DNA to move to the lytic pathway to make new virus particles
What happens in the lytic pathway?
- The virus infects the host cell and injects its DNA into the cytoplasm
- The virus uses proteins and enzymes within the host cell to produce new virus particles
- The host cell then bursts, this releases the virus particles into the host organism
- More cells are infected by the virus particles
What is a pathogen?
An organism that causes a communicable disease
What pathogen causes chalara ash dieback?
Fungus
How is chalara ash dieback spread?
Wind and air
Transfer of disease trees
What are the symptoms of chalara ash dieback?
Leaf loss
Bark lesions (wounds)
How can spread of chalara ash dieback be reduced?
Remove & dispose of infected ash trees
Restrict imports
What pathogen is malaria caused by?
Protist - plasmodium
How is malaria spread?
Mosquito vectors
What are the symptoms of malaria?
Damage to red blood cells
Damage to liver
Fever
Headaches
How can spread of malaria be reduced?
Mosquito nets
Insect repellents
Anti malarial tablets
What pathogen is cholera caused by?
Bacterium
How is cholera spread?
Contaminated water sources
What are the symptoms of cholera?
Diarrhoea
Stomach cramps
How to reduce spread of cholera?
Vaccine
Drink and use clean water
What pathogen is tuberculosis (TB) caused by?
Bacterium
How is tuberculosis spread?
Airborne droplets (coughs and sneezes)
What are the symptoms of tuberculosis?
Coughing
Lung damage
Fever
How to reduce spread of tuberculosis?
Vaccine
Stay away from infected people
Anti biotics
What pathogen are stomach ulcers caused by?
Bacterium
How are stomach ulcers spread?
Oral transmissions e.g. saliva
What are symptoms of stomach ulcers?
Stomach pain
Nausea
Vomiting
How can the spread of stomach ulcers be prevented?
Have clean water supplies
Antibiotics
Hygienic living conditions
What pathogen is Ebola caused by?
Virus
How is Ebola spread?
Bodily fluids e.g. blood
What are symptoms of Ebola?
Fever
Internal bleeding
Muscle pain and weakness
How can spread of Ebola be reduced?
Isolated infected individuals
Sterilise areas
BUT NO TREATMENT
What is a sexually transmitted disease?
Infection spread through sexual contact
What pathogen is chlamydia caused by?
Bacterium
How is chlamydia spread?
Sexual contact and sexual bodily fluids
What are the symptoms of chlamydia?
No symptoms
Pain when urinating
Can lead to infertility
How can the spread of chlamydia be reduced?
Wear a condom
Avoid sexual contact
Antibiotics
What pathogen is HIV caused by?
Virus
How is HIV spread?
Bodily fluids
What are symptoms of HIV?
Reduces immune response/damages immune system
Flu like illness is developed 2-6 weeks after infection
How to reduce the spread of HIV?
Wear a condom
Take medication
Avoid sharing needles
What are the two types of human defences against disease?
- Physical barriers
- Chemical barriers
What are the different types of physical barriers against disease in humans?
Skin - thick and covers whole body - acts as a barrier to pathogens
Hairs and mucus in nose - traps particles containing pathogens
Cilia in the respiratory system - move mucus across the ciliated cells which therefore gets rid of pathogens and sends them to the throat
What the types of chemical barriers against disease in humans?
Hydrochloric acid in the stomach - kills pathogens
Lysozymes in tears - enzyme that kills bacteria secreted by skin
What is specific immune response?
The immune response to a specific pathogen