innate immunity final - Sheet1 Flashcards
What are plasma protein systems?
Plasma protein systems are distinct protein systems that work together to protect against pathogens. They include the complement, clotting, and kinin systems.
How are plasma protein systems activated?
Plasma protein systems contain inactive enzymes (proenzymes) that are sequentially activated. The activation of the first component leads to the activation of subsequent components.
What is the role of the complement system?
The complement system defends against bacterial infections. It can destroy pathogens directly and activates or collaborates with other components of the immune system.
How is the complement system activated?
The complement system can be activated via three pathways: classical (antibody-antigen binding), lectin (bacterial carbohydrates), and alternative (bacterial/fungal cell wall polysaccharides).
What are the functions of the complement system?
Functions include anaphylatoxic activity (mast cell degranulation), leukocyte chemotaxis (WBC recruitment), opsonization (marking pathogens for phagocytosis), and cell lysis.
What is the role of the coagulation system?
The coagulation system forms a fibrinous mesh to stop bleeding, prevent infection spread, and create a framework for tissue repair.
How is the coagulation system activated?
It has two pathways: extrinsic (triggered by tissue factor outside the vascular space) and intrinsic (triggered by vascular wall damage).
What is the primary role of the kinin system?
The primary role is to activate and assist inflammatory cells. It also works with the coagulation system to compartmentalize and trap pathogens.
What does the kinin system produce?
The primary kinin produced is bradykinin, which causes blood vessel dilation, pain, smooth muscle contraction, vascular permeability, and leukocyte chemotaxis.
What is leukocyte chemotaxis?
Leukocyte chemotaxis is the recruitment of neutrophils and macrophages to the site of injury or infection.
How are kinins regulated?
Kinins are broken down by kininases in plasma and tissues to regulate their effects.
How are the plasma protein systems regulated?
The interactions between the complement, coagulation, and kinin systems are finely regulated to prevent damage to healthy tissue.
What are some inhibitors of plasma protein systems?
Examples of inhibitors include carboxypeptidase (inhibits C3a and C5a), histaminase and arylsulfatase (inhibit histamine), kinase (inhibits kinins), and C1-esterase inhibitor (inhibits complement).
What are the local manifestations of inflammation?
Heat, redness, swelling, pain, and loss of function.
What causes heat and redness in inflammation?
Vasodilation and increased blood flow.
What causes swelling in inflammation?
Exudate accumulation and fluid leakage due to increased capillary permeability.
What causes pain in inflammation?
Pressure exerted by exudate accumulation, prostaglandins, and bradykinins.
What are the functions of inflammation?
Dilutes toxins, carries plasma proteins and leukocytes to the injury site, removes bacterial toxins and debris.
What is serous exudate?
Watery exudate, typically indicates early inflammation.
What is purulent (supportive) exudate?
Pus, indicating a bacterial infection.
What is hemorrhagic exudate?
Exudate containing blood, indicating bleeding.
What is fibrinous exudate?
Thick, clotted exudate, indicating more advanced inflammation.
What are the systemic manifestations of inflammation?
Fever, leukocytosis, and increased plasma protein synthesis (acute-phase reactants).
What causes fever in inflammation?
Exogenous and endogenous pyrogens (e.g., IL-1) act on the hypothalamus to raise body temperature.
