Pathogens and virus pathogenesis Flashcards
What is pyrexia?
Fever
What is tachycardia?
Increased pulse
What is a pathogen?
An organism which can cause a disease
What is a commensal?
An organism which is part of normal flora
What is normal flora?
Bacteria that are found in our bodies on a semi-permanent basis
What are exotoxins?
Toxins released extra-cellularly by the micro-organism
Give an example of an exotoxin
Tetanus
What is an enterotoxin?
An exotoxin that acts on the GI tract
What are endotoxins structurally a part of?
Gram negative cell wall
What are super antigens?
Certain exotoxins of strep. pyogenes and staph. aureus
What can super antigens do?
Able to stimulate division of T-cells in the absence of the specific antigen
Which mechanism do HIV use to kill T4+ cells?
Cell destruction following virus infection
What is antigenic drift?
Minor changes in genes or flu virus
What is antigenic shift?
Abrupt major changes in virus antigenic structure
What causes antigenic shift?
Generation of new types of virus
What happens to the virus following primary infection?
Virus migrates from epithelium to ganglia
What happens when a latent virus is stimulated?
Virus migrates to epithelium, where it replicates and is released
What is innate immunity?
Non-specific defence mechanisms
What is opsonisation?
When organism is coated with antibody or complement
Name 3 examples of phagocytic cells?
Neutrophils
Eosinophils
Basophils
Name 2 different basic types of lymphocyte
T cells and B cells
What is acquired immunity?
A specific response to the antigen concerned
Immunological memory created
What does antibody do in infection?
Neutralises bacterial toxins
Neutralises viruses in viraemic stage
