Biogenic Amines and the Complement System

These flashcards cover biogenic amines like histamine and bradykinin, along with the main features and functions of the complement system.

What role does histamine play in the body?

Histamine stimulates retraction of endothelial cells of the venules, leading to increased permeability.

How is histamine inactivated in the body?

Histamine is inactivated by histaminase.

From which plasma protein is bradykinin derived?

Bradykinin is derived from kininogen.

What activates kallikrein in the body?

Kallikrein is activated by Hageman factor.

What effects does bradykinin have?

Bradykinin induces pain and has similar effects as histamine.

What is the complement system composed of?

The complement system is composed of a group of plasma proteins produced by the liver, circulating in an inactive form.

How is the complement system activated?

The complement system is activated through classical or alternative pathways.

What are some results of complement activation?

Activation leads to the formation of biologically active fragments (e.g., C3a), intermediate complexes (e.g., C567), and the terminal membrane attack complex (MAC).

What is one function of opsonization in the complement system?

Facilitated phagocytosis of bacteria.

What is one function of anaphylaxis related to the complement system?

Histamine release with increased vessel wall permeability.

What is chemotaxis in relation to the complement system?

Chemotaxis refers to the migration of leukocytes.

What is the terminal effect of the membrane attack complex (MAC) in the complement system?

Cell lysis through the action of MAC.