Plasma protein systems

Question 1

Complement system:

Answer 1

• Recruit, activate, destroy.
• Produces biologically active fragments that recruit phagocytes, activate mast cells, and destroy pathogens.
• Most important function this cascade is the activation/production of C3 and C5
• Pathways: Classical (activated mostly by antibodies), lectin (activated mostly by plasma proteins), and alternative (activated by several different substances that are on the surface of infectious organisms.

Question 2

Clotting/Coagulation system:

Answer 2

• Forms a fibrinous meshwork at an injured or inflamed site.
• Prevents the spread of infection
• Localizes microorganisms and foreign bodies
• Forms a clot that stops bleeding
• Provides a framework for repair and healing
• Main substance is an insoluble protein called fibrin
• Pathways: Extrinsic and intrinsic

Question 3

Kinin system:

Answer 3

• Functions to activate and assist inflammatory cells
• Primary kinin is bradykinin
• Causes dilation of blood vessels, pain, and smooth muscle contraction, and also increases vascular permeability.