Module 4 - Chapter 6 - Innate Immunity Second Line Inflammation Flashcards
How does inflammation differ from the physical and biochemical barriers of the innate immune system?
While the physical and biochemical barriers of the innate immune system are relatively static, inflammation is a dynamic process that responds to cellular or tissue damage, whether the damaged tissue is septic or sterile.
What is the primary purpose of the inflammatory response in the immune system?
The primary purpose of the inflammatory response is to limit the extent of tissue damage, destroy infectious microorganisms, initiate the adaptive immune response, and promote the healing process.
What are the four main characteristics of the inflammatory response?
The inflammatory response has four primary characteristics: (1) it occurs in tissues with a blood supply; (2) it is activated rapidly (within seconds) after damage occurs; (3) it depends on the activity of both cellular and chemical components; and (4) it is nonspecific, meaning it occurs in approximately the same way regardless of the type of stimulus or prior exposure to the same stimulus.
Can you explain what is meant by the term “vascularized” in the context of inflammation?
“Vascularized” means that inflammation occurs in tissues that have a blood supply, which allows for the rapid mobilization of immune cells and molecules to the site of tissue damage.
Why is the rapid activation of the inflammatory response crucial?
Rapid activation of the inflammatory response is crucial because it allows for an immediate response to cellular or tissue damage, helping to limit the damage and initiate the immune and healing processes quickly.
What types of injuries or conditions can activate the inflammatory response in vascularized tissues?
Virtually any injury to vascularized tissues can activate the inflammatory response. This includes infections, tissue necrosis, ischemia, trauma, physical or chemical injury, foreign bodies, and immune reactions.
What are the classic or cardinal signs of acute inflammation, as described by Celsus in the first century?
The classic signs of acute inflammation, as described by Celsus, include rubor (redness), calor (heat), tumour (swelling), dolor (pain), and functio laesa (loss of function).
Why is the loss of function (functio laesa) considered one of the cardinal signs of acute inflammation?
Functio laesa, or loss of function, is considered a cardinal sign of acute inflammation because it reflects the impairment of normal tissue function at the site of injury or inflammation due to the ongoing inflammatory processes.
What is the first microscopic inflammatory change that occurs near the site of injury, and what is its effect on blood vessels?
The first change is vasodilation, which leads to an increased size of blood vessels. This causes slower blood velocity and increases blood flow to the injured site.
What happens to blood vessels during increased vascular permeability, and what is the consequence of this change?
During increased vascular permeability, blood vessels become porous due to the contraction of endothelial cells. This leads to the leakage of fluid out of the vessel, resulting in swelling (edema) at the site of injury.
How does exudation, the leakage of fluid from blood vessels, contribute to the local changes observed during inflammation?
Exudation leads to the movement of plasma outward from blood vessels, making blood in the microcirculation more viscous and causing it to flow more slowly. This increased blood flow, along with a higher concentration of red blood cells at the site of inflammation, results in locally increased redness (erythema) and warmth.
What is the process by which white blood cells participate in the inflammatory response, and where do they migrate during this process?
White blood cells adhere to the inner walls of vessels and migrate through enlarged junctions between endothelial cells lining the vessels into the surrounding tissue as part of the inflammatory response.
What is the purpose of vasodilation in the context of inflammation?
Vasodilation serves to increase the size of blood vessels, which in turn slows down blood velocity and enhances blood flow to the injured site, facilitating the inflammatory response.
How does increased vascular permeability contribute to the visible signs of inflammation?
Increased vascular permeability, by making blood vessels porous, causes the leakage of fluid (exudation) out of the vessels, leading to swelling (edema) at the injury site. This process also results in increased redness (erythema) and warmth due to higher blood flow and concentration of red blood cells.
What role do white blood cells play in the inflammatory response, and where do they migrate during inflammation?
White blood cells adhere to the inner walls of blood vessels and migrate through enlarged junctions between the endothelial cells lining the vessels into the surrounding tissue. Their role is to combat infection and participate in the inflammatory process.
How do these microscopic changes collectively contribute to the body’s response to tissue injury or inflammation?
These microscopic changes, including vasodilation, increased vascular permeability, and white blood cell migration, collectively enhance blood flow to the site of injury, increase the delivery of immune cells to the affected area, and promote the removal of pathogens and damaged tissue, facilitating the healing process.
What are the primary outcomes of the characteristic changes associated with inflammation, and what triggers these changes?
The characteristic changes associated with inflammation result from the activation and interactions of various chemicals and cellular components in the blood and tissues. These changes deliver leukocytes, plasma proteins, and biochemical mediators to the site of injury, where they act together.
Which types of leukocytes are particularly important in the context of inflammation, and what role do they play?
Neutrophils are especially crucial leukocytes in inflammation. They migrate to the site of injury and participate in the immune response to combat infection and promote tissue healing.
How do some chemical mediators in the inflammatory process contribute to pain perception?
Some chemical mediators activate pain fibers, contributing to the perception of pain during inflammation.
What role do lymphatic vessels play in the process of acute inflammation, and what secondary effects can occur in these vessels and lymph nodes?
Lymphatic vessels drain extravascular fluid to the lymph nodes and may become secondarily inflamed. This can result in lymphangitis (inflammation of lymph vessels) and lymphadenitis (enlargement and inflammation of lymph nodes), which can be painful and hyperplastic.
How does inflammation prevent infection and further damage by invading microorganisms?
Inflammation prevents infection and further damage by diluting toxins produced by bacteria and released from dying cells. It activates plasma protein systems like complement and clotting systems, which help contain and destroy bacteria. Phagocytes like neutrophils and macrophages are recruited to destroy cellular debris and microorganisms.
What role does inflammation play in limiting and controlling the inflammatory process itself?
Inflammation limits and controls itself through the influx of plasma protein systems (e.g., clotting system), plasma enzymes, and cells like eosinophils. These components prevent the spread of the inflammatory response to healthy tissue.
How does inflammation interact with components of the adaptive immune system?
Inflammation interacts with the adaptive immune system by facilitating the influx of macrophages and lymphocytes, which destroy pathogens. This interaction leads to a more specific immune response against contaminating pathogens.
What role does inflammation play in preparing the area of injury for healing and repair?
Inflammation prepares the area of injury for healing and repair by removing bacterial products, dead cells, and other inflammatory products. This can occur through channels in the epithelium or drainage via lymphatic vessels.
How are fluid and debris that accumulate at an inflamed site removed, and what additional benefit does this process provide?
Fluid and debris at an inflamed site are drained by lymphatic vessels. This process not only removes the accumulated material but also facilitates the development of acquired immunity because microbial antigens in lymphatic fluid pass through lymph nodes, where they encounter lymphocytes.
Three key plasma protein systems are essential to an effective inflammatory response:
System 1: The complement system.
System 2: The clotting system.
System 3: The kinin system.
What do the complement system, clotting system, and kinin system have in common in terms of their protein components?
They each consist of multiple proteins found in the blood, usually in inactive forms, including enzymes that circulate as proenzymes.
What happens when the first components of these plasma protein systems are activated during inflammation?
Activation of the first components leads to sequential activation of other components in a cascade, resulting in a biological function that helps protect the individual.
What are the three cascades formed due to the sequential activation of plasma protein systems during inflammation?
The three cascades are the complement cascade, the clotting cascade, and the kinin cascade.
What percentage of the total circulating serum protein does the complement system constitute?
The complement system constitutes about 10% of the total circulating serum protein.
What is the primary function of the complement cascade within the immune response?
The primary function of the complement cascade is to activate C3 and C5, leading to the production of molecules with various functions in defending against pathogens.
What are the three main functions of the molecules produced during complement system activation?
The molecules produced during complement system activation can serve as (1) opsonins, (2) chemotactic factors, or (3) anaphylatoxins.
What is the role of opsonins in the immune response?
Opsonins coat the surface of bacteria, making them more susceptible to phagocytosis by inflammatory cells like neutrophils and macrophages.
How do anaphylatoxins contribute to the inflammatory response?
Anaphylatoxins, such as C3a and C5a, induce rapid degranulation of mast cells, leading to histamine release, vasodilation, and increased capillary permeability, which are significant components of inflammation.
What happens when terminal complement components C5b through C9 are activated?
Activation of C5b through C9 results in the formation of a complex known as the membrane attack complex (MAC), which creates pores in the outer membranes of cells or bacteria, leading to cell death.
How many major pathways control the activation of complement, and what are they?
There are three major pathways controlling complement activation: the classical pathway, the alternative pathway, and the lectin pathway.
What primarily activates the classical pathway of complement activation?
The classical pathway is primarily activated by antibodies, which bind to antigens on target cells or pathogens.
What activates the alternative pathway of complement activation?
The alternative pathway is activated by certain substances found on the surface of infectious organisms, such as bacteria and yeast.
How does the lectin pathway of complement activation differ from the classical pathway?
The lectin pathway is similar to the classical pathway but does not depend on antibodies. It is activated by specific plasma proteins that recognize carbohydrate patterns on the surfaces of various pathogenic microorganisms.
What are the four main functions of the products of the complement cascade?
The products of the complement cascade have four main functions: opsonization (C3b), anaphylatoxic activity resulting in mast cell degranulation (C3a, C5a), leukocyte chemotaxis (C5a), and cell lysis (C5b–C9 [MAC]).
What is the clotting (coagulation) system, and what does it create when activated?
The clotting system is a group of plasma proteins that, when activated sequentially, forms a blood clot, which is a meshwork of protein (fibrin) strands.
What are the three primary functions of blood clots in the body?
Blood clots plug damaged vessels to stop bleeding, trap microorganisms to prevent their spread, and provide a framework for future repair and healing.
What substances can activate the clotting system during tissue injury and infection?
The clotting system can be activated by substances like collagen, proteinases, kallikrein, plasmin, and bacterial products such as endotoxins.
How are the clotting pathways similar to the complement cascade in terms of activation?
Just like the complement cascade, different pathways that converge can activate the coagulation cascade, resulting in blood clot formation.
Just like the complement cascade, different pathways that converge can activate the coagulation cascade, resulting in blood clot formation.
Just like the complement cascade, different pathways that converge can activate the coagulation cascade, resulting in blood clot formation.
How do the intrinsic and extrinsic pathways of the clotting system converge, and what do they lead to?
How do the intrinsic and extrinsic pathways of the clotting system converge, and what do they lead to?
What are fibrinopeptides (FPs) A and B, and how do they influence the inflammatory response?
Fibrinopeptides (FPs) A and B are protein fragments produced when fibrin is created. They enhance the inflammatory response by being chemotactic for neutrophils and increasing vascular permeability, similar to how bradykinin (from the kinin system) affects endothelial cells.
What is the kinin system?
The kinin system is one of the plasma protein systems involved in inflammation.
How does the kinin system interact with the coagulation system?
The activation of Hageman factor (factor XII) to factor XIIa can initiate both the clotting and kinin systems.
What is another name for factor XIIa, and what does it do in the kinin system?
Factor XIIa is also known as prekallikrein, and it enzymatically activates the first component of the kinin system.
Factor XIIa is also known as prekallikrein, and it enzymatically activates the first component of the kinin system.
The final product of the kinin system is a small-molecular-weight molecule called bradykinin.
Where does bradykinin come from, and what are its effects in inflammation?
Bradykinin is derived from a larger precursor molecule called kininogen. It has several effects in inflammation, including causing blood vessel dilation, working with prostaglandins to induce pain, promoting contraction of smooth muscle cells, and increasing vascular permeability.
Why is tight regulation of plasma protein systems essential?
Tight regulation is essential because these systems are critical for survival and can produce potent substances that may be harmful if not controlled.
What happens when one plasma protein system is activated?
Activation of one system can lead to the production of biologically active substances that further activate other plasma protein systems.
What are some mechanisms to regulate plasma protein systems during inflammation?
Mechanisms include enzymes that destroy inflammation mediators, such as carboxypeptidase, kininases, and histaminase.
How does blood clot formation relate to other plasma protein systems?
Blood clot formation activates a system that limits clot size and removes it. This system can also activate the complement and kinin cascades.
What is the role of bradykinin in the kinin system?
Bradykinin, produced in the kinin system, causes blood vessel dilation, works with prostaglandins to induce pain, contracts smooth muscle cells, and increases vascular permeability.
What is inflammation, and where does it occur?
Inflammation is a process in vascular tissue. It occurs in both blood and tissue surrounding blood vessels.
What are endothelial cells, and what is their role during inflammation?
Endothelial cells line blood vessels and help maintain normal blood flow. During inflammation, they coordinate blood clotting and the movement of cells and fluids into tissues.
What are mast cells, and what role do they play in inflammation?
Mast cells are key activators of inflammation. They are found in tissues near blood vessels and release substances that initiate the inflammatory process.
What are dendritic cells, and how do they connect to the immune response during inflammation?
Dendritic cells are cells that bridge the innate and acquired immune responses. They are present in tissues near blood vessels and help coordinate immune system actions during inflammation.
What types of cells are present in the bloodstream, and what are their functions?
Blood cells include erythrocytes (red blood cells, for oxygen transport), platelets (involved in clotting), and leukocytes (white blood cells, part of the immune system).
What are granulocytes, and how do they differ from each other?
Granulocytes are a type of leukocyte with enzyme-filled granules. They include basophils, eosinophils, and neutrophils and differ based on granule staining. They play roles in immune responses.
What are monocytes, and where are they found?
Monocytes are precursors to macrophages and are found in tissues. They contribute to the body’s immune defense by transforming into macrophages.
What are lymphocytes, and what forms do they come in?
Lymphocytes are white blood cells with various forms, including natural killer (NK) cells and B and T cells. They have roles in both the innate and acquired immune responses.
What attracts immune cells to the site of cellular damage?
Molecules produced at the site of damage attract immune cells to enhance the protective response.
Where do chemotactic molecules that recruit immune cells come from?
Chemotactic molecules can originate from damaged cells, microbes, activation of plasma protein systems, or secretions by other immune cells.
What happens when immune cell surface receptors bind to these molecules?
Binding of these molecules to immune cell surface receptors leads to intracellular signaling and cell activation.
What can occur when immune cells are activated?
Activation of immune cells can result in gaining functions crucial to inflammation or the release of additional substances that promote inflammation.
What are the primary goals of inflammatory cells, protein systems, and their products at the site of tissue injury?
Their goals include containing damage, eliminating microorganisms, clearing cellular debris, and activating processes for healing, tissue regeneration, or repair.
What are the surface receptors of B and T lymphocytes in the adaptive immune system called?
They are called T-cell antigen receptors (TCR) and B-cell antigen receptors (BCR).
What type of receptors do cells in the innate immune system have?
Cells in the innate immune system have pattern recognition receptors (PRRs).
What do PRRs recognize?
PRRs recognize two types of molecular patterns: PAMPs (molecules expressed by infectious agents) and DAMPs (products of cellular damage).
Why do PRRs allow innate immune cells to respond to both sterile and septic tissue damage?
PRRs recognize DAMPs (sterile tissue damage) and PAMPs and DAMPs (septic tissue damage).
How many different PRRs are there, and what do they recognize?
There are over 100 different PRRs that recognize more than 1,000 different molecules.
Where are PRRs typically found in the body?
PRRs are typically found on cells near the body’s surface, including the skin, respiratory tract, GI tract, and genitourinary tract.
What is the role of Toll-like receptors (TLRs) in the immune system?
TLRs recognize various PAMPs and are present on cells with early contact with potential pathogens.
What types of molecules do TLRs recognize?
TLRs recognize molecules like bacterial LPS, viral RNA, and flagellin.
Where are complement receptors found, and what do they recognize?
Complement receptors are found on various immune cells and recognize fragments produced during complement system activation.
What is the function of scavenger receptors, and where are they mainly found?
Scavenger receptors facilitate recognition and phagocytosis of pathogens and damaged cells, mainly on macrophages.
What do NOD-like receptors (NLRs) recognize, and where are they located?
NLRs recognize products of microbes and damaged cells and are cytoplasmic receptors.
What are cytokines?
Cytokines are small-molecular-weight soluble signaling molecules that regulate innate or adaptive immunity.
What is a cytokine storm, and when can it occur?
A cytokine storm is an unregulated immune response involving excessive cytokine production. It can occur in response to infections, malignancy, and other disorders.
