Test: Inflammation- 3 - NEET PG MCQ

Cytokines are small proteins that play a vital role in cell signalling.

Key points about cytokines include:

• They include interleukins, which are important for immune responses.
• They are not produced solely in sepsis; they can be released during various immune responses.
• Cytokines are classified as polypeptides, meaning they are made up of long chains of amino acids.
• They have a highly specific action, targeting particular cells to regulate immune functions.

The conversion of prothrombin to thrombin is a crucial step in the blood coagulation process. This transformation requires specific components to occur effectively.

• Factor V: This is essential for the conversion process.
• Calcium ions (Ca²⁺): These are also necessary to facilitate the reaction.

In summary, both Factor V and Ca²⁺ are required for prothrombin to be converted into thrombin.

The fragments known as anaphylatoxins are:

• C3a
• C5a

These fragments play a crucial role in the immune response by promoting inflammation and attracting immune cells to sites of infection.

Cryoprecipitate is a blood product that is particularly rich in Factor VIII, which is essential for blood clotting. It also contains other important components, but its high concentration of Factor VIII makes it crucial in treating conditions like hemophilia.

• Factor VIII is vital for the formation of blood clots.
• Cryoprecipitate is used to manage bleeding disorders.
• It is derived from plasma and is usually stored frozen.

The most important mediator of chemotaxis is C5a. Chemotaxis is the process by which cells move towards a chemical signal, and C5a plays a crucial role in this by attracting immune cells to sites of infection or inflammation.

• C3b is involved in opsonisation but is not the primary mediator of chemotaxis.
• C5-7 refers to a group of proteins, but they do not individually mediate chemotaxis.
• C2 is part of the complement system but does not directly mediate chemotactic activity.

In summary, while various components are part of the immune response, C5a is the key player that directs immune cells to where they are needed most.

Histamine is a chemical in the body that plays a vital role in the immune response. It is primarily known for its effects on blood vessels and the heart.

• Vasodilation: Histamine causes blood vessels to widen, which is known as vasodilation. This leads to increased blood flow and can result in symptoms such as redness and swelling.
• Tachycardia: It can stimulate the heart, leading to an increased heart rate, known as tachycardia. This can occur during allergic reactions or inflammatory responses.
• Vasoconstriction: While histamine primarily causes vasodilation, under certain conditions, it can also lead to vasoconstriction, narrowing the blood vessels.
• Hypertension: The overall effects of histamine can lead to fluctuations in blood pressure, sometimes causing hypertension due to the response of blood vessels and heart rate.

The secondary granules of neutrophils contain various important substances that aid in the immune response. Among these, lactoferrin is notable for its role in binding iron, which helps to limit bacterial growth. Other components include proteolytic enzymes, which assist in breaking down proteins during immune reactions.

• Lactoferrin: Binds iron to restrict bacteria.
• Proteolytic enzymes: Break down proteins in pathogens.
• Less relevant substances found in neutrophils include catalase and gangliosidase.

Thus, lactoferrin and proteolytic enzymes are significant components of neutrophil secondary granules.

Elastase, cathepsin, and leukotrienes are all substances that can help neutrophils, which are a type of white blood cell that fights infections. However, nitric oxide does not act as a mediator for neutrophils in the same way. Instead, it plays a different role in the body, mainly in regulating blood flow and having antibacterial effects.

Here’s a summary of the mediators:

• Elastase: A protein that helps break down pathogens.
• Cathepsin: An enzyme that aids in the digestion of proteins from bacteria.
• Leukotrienes: Chemicals that promote inflammation and attract neutrophils to sites of infection.
• Nitric oxide: Important for blood flow but not a direct mediator of neutrophils.

Endothelial cells are specialised cells that line the blood vessels and play a key role in various physiological processes. One notable feature of these cells is the presence of Weibel-Palade bodies. These are storage granules that contain important proteins, including von Willebrand factor, which is crucial for blood clotting and platelet function.

In contrast, Langerhans granules are found in the skin and are involved in the immune response, while abundant glycogen is typically associated with energy storage in other cell types. Kallikrein is an enzyme that is involved in blood pressure regulation and is not a characteristic feature of endothelial cells.

Therefore, the distinctive presence of Weibel-Palade bodies is a key point of identification for endothelial cells in the body.

The partial thromboplastin time (PTT) is a blood test that measures how long it takes for blood to clot. It primarily assesses the intrinsic pathway and the common pathway of the coagulation process. These pathways are crucial for proper blood clotting and involve various clotting factors.

• The intrinsic pathway is activated by damage to blood vessels and plays a key role in the initial stages of clot formation.
• The common pathway is the final stage in the coagulation cascade where both intrinsic and extrinsic pathways converge.

This test is important for diagnosing bleeding disorders and monitoring patients on anticoagulant therapy.

The bleeding time test is primarily used to evaluate the function of platelets in the blood. It measures how long it takes for bleeding to stop after a small cut. This test is important because it helps identify any issues with platelet function, which can lead to excessive bleeding.

• Platelets are small cell fragments that play a crucial role in blood clotting.
• A normal bleeding time indicates that the platelets are functioning properly in forming a clot.
• If the bleeding time is prolonged, it may suggest a problem with platelet function, which could be due to various conditions or medications.

In summary, bleeding time is a key test for assessing how well platelets are working to stop bleeding. This is essential for maintaining overall blood health.

The prothrombin level test is primarily used to evaluate various clotting factor deficiencies. However, it is particularly not useful for assessing factor IX deficiency. Here's a brief overview of the factors:

• Factor II (Prothrombin): Levels are directly measured by this test.
• Factor V: Related to prothrombin but the test is less specific.
• Factor VII: Also assessed through prothrombin levels.
• Factor IX: This factor is not evaluated by the prothrombin test.

In summary, while prothrombin levels can indicate deficiencies in factors II, V, and VII, they do not provide information about factor IX.

Histamine is a chemical released during allergic reactions, contributing to symptoms like itching and swelling.

Proteases are enzymes that can break down proteins but are not specifically linked to anaphylaxis.

Eosinophilic chemotactic factor attracts eosinophils, a type of white blood cell, but it is not a primary mediator in anaphylaxis.

Leukotriene B₄ is a secondary mediator that plays a significant role in the inflammatory response during anaphylaxis, leading to symptoms such as bronchoconstriction and increased vascular permeability.

Birbeck's granules are specific structures found in the cytoplasm of certain cells. They are primarily associated with Langerhans cells, which are a type of immune cell found in the skin and mucous membranes. These granules play a role in the immune response and the processing of antigens.

• Birbeck's granules are not found in Mast cells, which are involved in allergic responses.
• They are also absent in Myelocytes, which are immature white blood cells.
• Lastly, Thrombocytes, or platelets, do not contain these granules as they are involved in blood clotting.

In summary, Birbeck's granules are characteristic of Langerhans cells and are significant for their role in the immune system.

Eosinophils are a type of white blood cell that play a key role in the immune system, particularly in fighting off parasites and in allergic reactions. They secrete various substances to help with these functions.

• Major basic protein: This is a potent protein that damages the membranes of parasites.
• Hydrolytic enzymes: These enzymes help break down proteins and other molecules, aiding in the destruction of pathogens.
• Reactive forms of O₂: These are highly reactive molecules that can kill bacteria and other pathogens.
• Eosinophilic chemotactic factor: This substance attracts other immune cells to the site of infection or inflammation.

However, eosinophils do not secrete all of these substances. In this context, one of the options listed is not secreted by eosinophils.

The product that promotes platelet aggregation and vasoconstriction in the Lipooxygenase pathway of arachidonic acid metabolism is:

• Thromboxane A2 - This compound is essential for blood clotting and narrowing blood vessels.

Other options do not play a significant role in these processes:

• C5a is involved in inflammation.
• Leukotriene B4 primarily attracts immune cells.
• C1 activators are related to the complement system.

C3a and C5a are both important components involved in chemotaxis, which is the process by which cells move towards chemical signals.

These components play a significant role in the immune response:

• C3a acts as a chemotactic factor, attracting immune cells to sites of infection.
• C5a is also a potent chemotactic agent that enhances the movement of immune cells.

Therefore, both C3a and C5a contribute to the chemotactic activity of complement components.

Prostaglandins E1 and E2 play significant roles in the inflammatory process. Here are their main effects:

• Vasodilatation: They help widen blood vessels, increasing blood flow to the affected area.
• Increased gastric output: They stimulate the production of gastric juices, aiding digestion.
• Decreased body temperature: They can help lower fever by acting on the body's temperature regulation.
• Vasoconstriction: This effect is generally not associated with prostaglandins E1 and E2 during inflammation.

In summary, prostaglandins E1 and E2 primarily cause vasodilatation and increase gastric output, while they do not lead to vasoconstriction.

Opsonins are molecules that enhance the ability of the immune system to identify and eliminate pathogens, such as bacteria and viruses. They work by binding to these foreign invaders and marking them for destruction.

• C3a is a component of the complement system but is not considered an opsonin.
• IgM is an antibody that can act as an opsonin, helping to tag pathogens for destruction.
• Carbohydrate binding proteins, such as lectins, can also function as opsonins, recognising specific sugars on pathogens.
• Selectins are adhesion molecules that help immune cells stick to the sites of infection, but they do not directly mark pathogens.

In summary, opsonins are crucial for guiding immune responses and enhancing the effectiveness of phagocytosis.

Inflammatory mediators are substances that play a key role in the body's response to inflammation. One of the major mediators of systemic inflammation is TNF (Tumour Necrosis Factor). This cytokine is produced primarily by macrophages and is crucial in promoting inflammation.

Other important inflammatory mediators include:

• IL-1 (Interleukin-1): This cytokine contributes to the inflammatory response and can induce fever.
• IL-2 (Interleukin-2): Primarily involved in the growth and activation of T-cells, it is less directly associated with systemic inflammation.
• Interferon alpha: This is mainly involved in antiviral responses and does not primarily mediate systemic inflammation.

In summary, while multiple cytokines are involved in inflammatory processes, TNF is particularly significant in generalized systemic inflammation.

Cytokines are important proteins involved in cell signalling within the immune system. They help regulate various functions, including inflammation and immune responses. Here’s a brief overview of the terms related to this topic:

• Monoclonal antibodies: These are laboratory-made molecules that can mimic the immune system's ability to fight off pathogens such as viruses. They are not classified as cytokines.
• Interleukins: These are a type of cytokine that facilitate communication between immune cells, playing a vital role in the immune response.
• Chemokines: These are also cytokines, specifically involved in the movement of immune cells towards sites of inflammation or infection.
• TNF (Tumour Necrosis Factor): This is a cytokine involved in systemic inflammation and is part of the immune response.

In summary, monoclonal antibodies are the only option that does not belong to the cytokine category, as they are not naturally occurring proteins in the immune signalling process.

The girl is most likely suffering from an acute attack of bronchial asthma. The figure shows the presence of an activated mast cell. These cells are similar to the basophils.