defense

What is a pathogen?

A disease-causing agent that disrupts the normal physiology of an infected organism.

What are the two types of pathogens?

Cellular (bacteria, fungi, parasites) and non-cellular (viruses, prions).

How does a virus multiply?

By inserting its genetic material into a host cell.

What is a prion?

An infectious protein that has folded abnormally into a disease-causing structure.

What is the first line of defense in the immune system?

Surface barriers that prevent the entry of pathogens.

What are phagocytic leukocytes?

White blood cells that engulf and digest pathogens.

What triggers the inflammatory response?

Infection that activates non-specific defense mechanisms.

What kind of response does the adaptive immune system have to pathogens?

A specific response that targets antigens produced by pathogens.

What role do lymphocytes play in the immune system?

They recognize specific antigens and are involved in the adaptive immune response.

What is the main function of antibodies?

To specifically recognize and bind to antigens, facilitating pathogen elimination.

What is immunodeficiency?

A condition in which the immune system is compromised or absent.

How can zoonoses be transmitted to humans?

Directly from non-human hosts or via vectors that carry the pathogens.

What is the purpose of antibiotics?

To specifically target prokaryotic features of bacterial pathogens.

What is the principle behind vaccination?

To provide active acquired immunity through the injection of weakened or inactivated pathogens.

What is herd immunity?

Indirect protection of non-vaccinated people when a large percentage of the population is immune.

What distinguishes an epidemic from a pandemic?

An epidemic occurs within a specific community or region, while a pandemic spreads globally.

What is a phagocyte's role in the immune response?

To engulf and digest broad types of pathogens and present antigens.

What are memory cells?

Cells that remain in the body for years and produce faster immune responses upon re-exposure.

What molecular markers are on the outer surfaces of pathogens?

Antigens.

What is the process of phagocytosis?

The engulfing of pathogens by phagocytes using cellular extensions.

What initiates the clotting cascade?

The release of clotting factors from damaged cells or platelets.