HIV and viruses Flashcards
What does HIV stand for?
Human immunodeficiency virus
What does HIV lead to?
Acquired immune deficiency system (AIDS)
What does HIV do to helper T-cells?
Infects and kills them
What do the helper T-cells act as for the virus?
Host cells
What is the effect of not having enough helper T-cells?
They send chemical signals that activate phagocytes, cytotoxic t-cells and b-cells so without enough the body is not able to develop an effective response to infections
When does someone with HIV develop AIDS?
When the number of helper T-cells in the body reach a critically low level
What is the latency period?
When HIV replicate slows after replication is rapid after initial infection.
What happens during the latency period?
It can last for years and the infected person won’t experience any symptoms so they won’t know the have it
What is the average time between infection with HIV and development of AIDS without treatment?
10 years
What are initial symptoms of AIDS?
Minor infections of mucous membranes and recurring respiratory infections
What are some symptoms as AIDS progresses?
They become more susceptible to more serious infections including chronic diarrhoea, severe bacterial infections and tuberculosis
What happens during the late stages of AIDS?
Patients have a very low number of immune system cells and can develop a range of serious infections such as toxoplasmosis of the brain and candidiasis of the respiratory system
What are the components of a virus particle?
Core
Envelope
Capsid
Attachment proteins
What does the core contain?
Genetic material in the form of RNA
Enzyme reverse transcriptase
What are attachment proteins used for?
Helping the HIV attach to the host helper T-cell
