A client who has asthma (a reactive airway disease) asks the nurse about the role of leukotrienes in this process. Leukotrienes have which immune response?
Produce the sensation of Itching.
Tighten airway and produce mucous.
Causes formation of bradykinin.
Serves as receptor for antigen.
The Correct Answer is B
Leukotrienes are inflammatory mediators derived from arachidonic acid metabolism, primarily produced by leukocytes (white blood cells) such as mast cells, eosinophils, and basophils. In the context of asthma, leukotrienes play a significant role in the pathophysiology of the disease by contributing to airway inflammation and bronchoconstriction. Here's a breakdown of their immune response:
A) Produce the sensation of itching:
Leukotrienes are not directly involved in producing the sensation of itching. Itching is often associated with histamine release rather than leukotrienes.
B) Tighten airway and produce mucous:
Correct. Leukotrienes are potent bronchoconstrictors that cause smooth muscle contraction in the airways, leading to narrowing (constriction) of the bronchioles. Additionally, they stimulate the secretion of mucus from goblet cells in the airway epithelium, contributing to airway obstruction and mucus production, which are characteristic features of asthma exacerbations.
C) Causes formation of bradykinin:
Bradykinin is a peptide mediator that is generated from the plasma protein kininogen and is involved in vasodilation, pain sensation, and inflammation. Leukotrienes are not directly responsible for the formation of bradykinin.
D) Serves as a receptor for antigen:
Leukotrienes do not serve as receptors for antigens. Instead, they are lipid mediators released in response to various stimuli, including allergens, infections, and irritants, and they act on specific receptors (e.g., leukotriene receptors) to exert their effects, such as bronchoconstriction and inflammation
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is C
Explanation
Intermittent claudication is a common symptom experienced by individuals with peripheral artery disease (PAD). It occurs due to the underlying pathophysiology of arterial occlusion and ischemia during physical activity. Here's why option C is the correct choice:
A) Reduced blood flow occurs when legs are elevated:
This statement is not accurate regarding the pathophysiology of intermittent claudication in PAD. When legs are elevated, gravity assists venous return, which may actually improve blood flow temporarily. However, intermittent claudication occurs during activity, not when the legs are elevated.
B) Reddened color occurs when the feet are dependent:
This statement is unrelated to the pathophysiology of intermittent claudication. Redness when the feet are dependent may suggest venous insufficiency rather than arterial occlusion characteristic of PAD.
C) Arterial occlusion causes ischemic pain during activity:
Correct. Intermittent claudication is caused by inadequate blood flow to the muscles during physical activity due to arterial occlusion in PAD. As the demand for oxygen increases during exercise, the narrowed arteries cannot supply sufficient blood flow, leading to ischemic pain in the affected muscles. This pain typically resolves with rest and recurs upon resuming activity.
D) Reduction in blood supply leads to muscle atrophy:
Muscle atrophy may occur in severe cases of PAD with chronic ischemia, but it is not the primary cause of intermittent claudication. Intermittent claudication is primarily attributed to inadequate blood flow during activity, which results in ischemic pain rather than muscle atrophy.
Correct Answer is C
Explanation
A) An increase in afterload results in decreased systolic pressure, which creates a decreased cardiac output:
This statement is incorrect. According to the Frank-Starling law, afterload refers to the resistance against which the heart must pump blood during systole. An increase in afterload typically results in increased systolic pressure, not decreased, as the heart works harder to overcome the increased resistance. However, increased afterload can lead to decreased cardiac output due to the increased work of the heart.
B) A decrease in afterload causes the cardiac muscles to hypertrophy, resulting in increased diastolic volume:
This statement is incorrect. A decrease in afterload typically reduces the workload on the heart, which may lead to reverse remodeling and a reduction in cardiac hypertrophy. Increased diastolic volume may occur due to reduced afterload, but it's not the direct result of hypertrophy.
C) An increase in preload results in greater shortening of myocardial fibers, thereby increasing contractility:
Correct. The Frank-Starling law states that an increase in preload (end-diastolic volume or stretch of myocardial fibers) leads to greater overlap of actin and myosin filaments within myocardial fibers during systole. This increased overlap results in stronger myocardial contraction (increased contractility), leading to an increased stroke volume and cardiac output.
D) A decrease in preload results in increasing diastolic muscle fiber length, which impedes contractility:
This statement is incorrect. Preload refers to the degree of stretch of the myocardial fibers at the end of diastole. A decrease in preload would lead to decreased stretch of the myocardial fibers, not increasing diastolic muscle fiber length. Decreased preload typically results in decreased contractility rather than an impediment to contractility due to reduced myocardial stretch.
Whether you are a student looking to ace your exams or a practicing nurse seeking to enhance your expertise , our nursing education contents will empower you with the confidence and competence to make a difference in the lives of patients and become a respected leader in the healthcare field.
Visit Naxlex, invest in your future and unlock endless possibilities with our unparalleled nursing education contents today
Report Wrong Answer on the Current Question
Do you disagree with the answer? If yes, what is your expected answer? Explain.
Kindly be descriptive with the issue you are facing.