Respiratory Quiz - Module 3

The statement that the underlying pathological process behind chronic asthma is airway spasm is false. While airway spasm is a symptom of asthma, it is not the underlying cause. Chronic asthma is primarily caused by chronic inflammation of the airways, which leads to the narrowing and swelling of the airways, making it difficult to breathe. Airway spasm is a result of this inflammation and constriction of the airways.

Allergies are not mediated via IgG antibodies stuck onto mast cells and basophils. Instead, allergies are primarily mediated by IgE antibodies that bind to mast cells and basophils. When an allergen enters the body, it triggers the production of specific IgE antibodies, which then attach to mast cells and basophils. Upon re-exposure to the allergen, the IgE antibodies on these cells bind to the allergen, leading to the release of inflammatory substances such as histamine, resulting in an allergic reaction. Therefore, the given statement is false.

Leukotrienes are not pre-formed chemical mediators that are released immediately from mast cell granules. They are actually synthesized and released in response to various stimuli, such as allergens or inflammation. Therefore, the correct answer is False.

Histamine is indeed a pre-formed chemical mediator that is released immediately from mast cell granules. When mast cells are activated, histamine is rapidly released into the surrounding tissue. This release of histamine plays a crucial role in allergic reactions and inflammation, as it causes blood vessels to dilate and become more permeable, leading to symptoms such as redness, swelling, and itching. Therefore, the statement is true.

Interleukins are a group of signaling molecules that play a crucial role in regulating the immune response. In the context of allergic inflammation, interleukins can both control and exacerbate the inflammatory process. Certain interleukins, such as IL-4 and IL-13, promote allergic inflammation by stimulating the production of IgE antibodies and recruiting inflammatory cells. On the other hand, other interleukins, like IL-10 and IL-12, have anti-inflammatory effects and help regulate the immune response. Therefore, it is accurate to say that interleukins control and exacerbate allergic inflammation.

The explanation for the correct answer is that the sympathetic nervous system is actually not under voluntary control, while the parasympathetic nervous system is. The sympathetic nervous system is responsible for the body's fight-or-flight response, which occurs automatically in response to stress or danger. In contrast, the parasympathetic nervous system is responsible for the body's rest and digest response, which can be consciously controlled. Therefore, the statement that the sympathetic nervous system is under voluntary control is incorrect.

The sympathetic nervous system is responsible for the "fight or flight" response in the body. When activated, it releases adrenaline, which binds to B2 receptors in the airway muscles. This binding causes relaxation of the airway muscles, leading to increased airflow. Therefore, it is true that the sympathetic nervous system works through adrenaline on the B2 receptors to cause airway relaxation.

The parasympathetic nervous system does not cause airway relaxation through acetylcholine on the cholinergic receptors. In fact, it is the sympathetic nervous system that causes airway relaxation through the release of epinephrine on the adrenergic receptors. The parasympathetic nervous system, on the other hand, causes airway constriction through the release of acetylcholine on the cholinergic receptors. Therefore, the statement is false.