General Disease Info Flashcards
What is a disease?
A disease is any condition that interferes with how an organism or any part of it, functions.
When is a disease infectious?
Disease are described as infectious (communicable), if they are caused by an invasion by a pathogen and can be transmitted from one host to another. contagious conditions that impair the functioning of an organism.
What is a host?
A host is an organism infected with a pathogen.
When does an infection occur?
Infection occurs if a pathogen has entered a host, has established itself and is replicating.
When do symptoms arise?
Unwanted signs and symptoms usually result from damage to the tissues and organs of the host.
How do microbiologists identify the cause of a specific disease?
- The potential pathogen must always be present when the disease occurs
- The organism can be isolated from the host and grown in pure culture.
- When organism from the pure culture are inoculated into a healthy, susceptible host and the disease develops this is further evident for a specific cause
- The organism can them be re-isolated, grown in pure culture and compared with the organism first injected for confirmation.
What is a pathogen?
A pathogen is an infectious agent that causes disease.
List all the viral diseases in this course.
- Influenza
- Ross River Virus Disease
- Viral Diseases of Honeybees
- Australian Bat Lyssa-virus
List all the bacterial diseases in this course.
- Tuberculosis
- Tetanus
- Crown Gall Disease of Plants
List all the fungal diseases in this course.
- Chytridiomycosis (amphibian chytrid fungus disease)
List all the protist diseases in this course.
- Malaria
- Phytophthora Dieback
What are contagious diseases?
Disease that are easily transmitted by close contact with an infected organism or their secretions (body fluids) are called contagious.
What are zoonotic diseases?
Zoonotic disease are infectious diseases that can be transmitted from one vertebrate group to another.
When can indirect contact occur?
May occur when a susceptible host comes into contact with areas where infected animals live or roam, where surfaces or objects have been contaminated.
What are the three types of contact?
- Close contact
- Direct contact
- Indirect contact
What is pathogenicity?
A pathogen’s disease-causing capacity.
What are symptoms?
The effects the pathogens has on the body of the host
What is the definition for incubation period?
The time between infection and the onset of symptoms is known as the incubation period.
Why does the incubation period occur?
Pathogen may have to divide many times to reach number sufficient to cause disease, may take time to reach the target tissues that are susceptible to that particular pathogen, toxins produced by bacteria as waste products may take time to accumulate to a level that affects the host.
What are viruses ?
Viruses are non-cellular pathogens. they consist of one or more strands of nucleic acid inside a protein coat. they maintain this structure during the inert phase of their life cycle, that is when they are non inside a host.
Are viruses considered non-living?
Viruses are non made out of cells are therefore are non-living. they possess no metabolic machinery for processes such as cellular respiration. can’t be classified as eukaryotic or prokaryotic.
Describe structure of viruses.
Instead of cellular features such as ribosomes and mitochondria, they have some nucleic acid and a protective coat.
What is a obligate parasite?
An organism that cant function outside the host cell.
What is a protein coat also know as?
Capsid.
Why are viruses specific?
Each virus is usually limited to infected a specific host cell or organism. this is because the virus is able to recognise and bind to receptors the are expressed only on certain cells.
Why are viruses pathogenic
Becaause all viruses require host cells to replicate, and therefore all viruses are pathogenic. The host will experience symptoms when a virus is replicating inside the host’s cells.