Disease And Immunity Flashcards
Define disease
Condition that impairs normal functioning of an organism
What organism causes disease?
Pathogen
Types of disease causing pathogens
- Bacteria
- Viruses
- Fungi
- Protoctists
Define communicable disease
A disease that can spread between organisms
Name some disease caused by bacterium
- Tuberculosis
- Bacterial meningitis
- Ring rot
Name some diseases caused by viruses
- HIV/AIDS
- Influenza
- Tobacco mosaic virus
Name some diseases caused by fungus
- Black Sigatoka
- Ringworm
- Athletes foot
Name some diseases caused by Protoctists
- Potato/tomato late blight
- Malaria
What are the two types of transmission?
- Direct transmission
- Indirect transmission
Describe direct transmission
When a disease is transmitted directly from one organism to another
How can direct transmission occur?
- Droplet infection
- Sexual intercourse
- Directly touching an infected organism
Describe indirect transmission
When a disease is transmitted from one organism to another via an intermediate
Through what intermediates can disease be transmitted?
- Air
- Water
- Food
- Vector
What factors can impact/affect transmission
- Living conditions
- Social factors
- Climate
How can living conditions affect transmission?
Overcrowded living conditions can increase the transmission of many communicable diseases
How can social factors affect transmission?
Worse social conditions can lead to increased likelihood of disease; income, occupation, area a person lives in.
-People with limited access to good resources, education and health care may suffer more
How can climate affect transmission?
Provides optimum conditions for breeding of vector or growth of pathogen
What animal defences against pathogens are there?
- The skin
- Mucous membranes
- Blood clotting
- Inflammation
- Wound repair
- Expulsive reflexes
How does the skin protect against pathogens?
- Acts as a physical barrier, blocking pathogens from entering the body
- Acts as a chemical barrier, producing anti microbial chemicals that kill or slow down MO and can lower pH to inhibit pathogen growth
How do mucous membranes protect an organism from pathogens?
- Protect body openings exposed to environment
- Secrete mucus that traps pathogens and contains antimicrobial enzymes
How does blood clotting help defend against pathogens?
- Blood clots plug wounds to prevent pathogen entry and blood loss
- Formed by a series of chemical reactions that take place when platelets are exposed to damaged blood vessels