What is the function of fibrin?
Fibrin creates the framework of a blood clot.
Fibrin, released from platelets, attracts other platelets.
Fibrin stimulates cell division.
Fibrin activates prothrombin.
Fibrin dissolves blood clots after tissue repair is complete.
The Correct Answer is A
Choice A rationale
Fibrin is a crucial protein in the coagulation cascade. It is formed from fibrinogen by the enzyme thrombin. Fibrin polymerizes to form a mesh-like network that traps red blood cells and platelets, creating the structural framework of a stable blood clot, effectively sealing off damaged blood vessels and preventing further blood loss.
Choice B rationale
While platelets are involved in coagulation, fibrin itself is not released from platelets to attract other platelets. Platelets release various factors like ADP and thromboxane A2 to aggregate. Fibrin's role is structural, forming the clot framework after platelet plug formation.
Choice C rationale
Fibrin does not directly stimulate cell division. Its primary role is in hemostasis and clot formation. Cell division, or mitosis, is regulated by growth factors and signaling pathways independent of fibrin's direct action, although clot removal is part of wound healing.
Choice D rationale
Fibrin is a product of prothrombin activation, not an activator of prothrombin. Prothrombin is converted into thrombin by prothrombinase, and thrombin then acts on fibrinogen to produce fibrin, which then forms the clot. The sequence is critical for proper coagulation.
Choice E rationale
Fibrin is the main component of a blood clot and needs to be dissolved for tissue repair to be complete. However, fibrin itself does not dissolve blood clots. Fibrinolysis, the process of clot dissolution, is mediated by plasmin, an enzyme that degrades fibrin.
Nursing Test Bank
Naxlex Comprehensive Predictor Exams
Related Questions
Correct Answer is D
Explanation
Choice A rationale
The mitral valve is between the left atrium and left ventricle. The pulmonary valve is between the right ventricle and the pulmonary artery. Therefore, the mitral valve opening and pulmonary valve closing do not directly correlate with left ventricular contraction in this manner.
Choice B rationale
The right AV valve (tricuspid valve) is located between the right atrium and right ventricle. When the left ventricle contracts, it is not directly involved with the right AV valve or the pulmonary valve in this specific coordinated sequence.
Choice C rationale
The right AV valve (tricuspid valve) is in the right side of the heart, controlling blood flow from the right atrium to the right ventricle. The aortic valve is on the left side of the heart. These two valves do not coordinate in this manner during left ventricular contraction.
Choice D rationale
When the left ventricle contracts during systole, the pressure within the ventricle rises. This increased pressure pushes open the aortic valve, allowing blood to be ejected into the aorta. Simultaneously, the increased ventricular pressure forces the mitral (bicuspid) valve to close, preventing blood from flowing backward into the left atrium.
Correct Answer is A
Explanation
Choice A rationale
Oxygen-poor blood from the systemic circulation enters the right atrium, then passes through the right AV (tricuspid) valve into the right ventricle. From the right ventricle, it is pumped through the pulmonary valve into the pulmonary artery, which carries it to the lungs for oxygenation. This pathway ensures deoxygenated blood reaches the pulmonary circuit.
Choice B rationale
This choice is incomplete because while oxygen-poor blood does pass through the right AV (tricuspid) valve, it must also pass through the pulmonary valve to exit the right ventricle and reach the lungs for oxygenation. Omitting the pulmonary valve provides an incomplete description of the path.
Choice C rationale
The left AV (mitral) valve and aortic valve are components of the left side of the heart, which handles oxygenated blood. Oxygenated blood from the lungs enters the left atrium, passes through the mitral valve into the left ventricle, and then through the aortic valve into the aorta for systemic distribution.
Choice D rationale
This choice describes only the entry of oxygenated blood into the left ventricle from the left atrium via the left AV (mitral) valve. It does not account for the oxygen-poor blood pathway, which involves the right side of the heart.
Choice E rationale
The pulmonary valve allows oxygen-poor blood to leave the right ventricle. However, the aortic valve allows oxygenated blood to leave the left ventricle. Therefore, the combination of pulmonary and aortic valves does not exclusively describe the path of oxygen-poor blood.
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.