29 Questions
Which of the following factors is the main determinant of vascular resistance on a minute-to-minute basis?
Radius of the vessel
Which site represents the primary site of vascular resistance maintaining normal blood pressure?
Resistance arterioles
Which of the following hormones is responsible for increasing arterial blood pressure by vasoconstriction?
Angiotensin II
Which endothelium-derived factor is responsible for vasodilation?
Prostacyclin (PGI2)
Which enzyme catalyzes the conversion of angiotensinogen to angiotensin I?
Renin
What is the main function of angiotensin II?
Sodium conservation
Which hypothesis of autoregulation suggests that acute pressure-induced stretch of the arterial and arteriolar walls stimulates immediate constriction?
Myogenic hypothesis
What is the role of vasopressin (AVP) in regulating vascular resistance?
Vasoconstriction
During exercise, blood flow is redistributed to areas with greater metabolic need. This is an adaptive mechanism that ensures oxygen and nutrients are delivered to active tissues.
True
Which layer of blood vessels is composed of concentric layers of smooth muscle cells?
Tunica media
Which type of blood vessel has the thickest walls and can withstand higher pressures?
Arteries
Which of the following best describes the primary goal of the pulmonary circulation?
To carry oxygen from the lungs to the tissues
What is the main function of the systemic circulation?
To carry nutrients from the digestive tract to the tissues
Which of the following statements about blood flow in the pulmonary circulation is true?
Pressure and vascular resistance are lower compared to the systemic circuit
What is the purpose of blood flow redistribution in the systemic circulation?
To direct blood flow to areas with greater metabolic need
Which mediator is responsible for preventing orthostatic hypotension?
Epinephrine
Which mediator is responsible for reducing circulating volume by stimulating natriuresis and diuresis?
Atrial natriuretic peptide/BNP
Which mediator is targeted by the heart failure drug sacubitril?
Atrial natriuretic peptide/BNP
Which mediator is responsible for inhibiting platelet aggregation and promoting vasodilation?
Prostacyclin (PGI2)
According to the Law of Laplace, which of the following occurs when the arterial wall weakens in response to increased pressure, causing a vicious cycle of dilation, increased radius, increased tension, and ultimately a weakened wall?
Aneurysm
What is the role of nitric oxide (NO) in maintaining vessel patency and vascular wall health?
Promoting vasodilation
What happens to endothelial shear stress in areas of vascular branching and downstream from an atherosclerotic plaque?
It decreases
What is the major role played by vascular smooth muscle cells and the sympathetic nervous system in blood pressure regulation?
Maintaining systemic vascular resistance
Which of the following is a compensatory response to an acute drop in blood pressure?
Increased firing of sympathetic fibers to vascular smooth muscle
What is the most likely cause of the patient's fainting spell?
Vasovagal Syncope
Which of the following is a hypothesis of the origin of hypertension?
Initial defect in sodium and water retention
Which of the following is a possible cause of secondary hypertension?
Primary hyperaldosteronism
What is the main function of angiotensin II?
Vasoconstriction
What is the main function of the systemic circulation?
Exchange of gases and nutrients with tissues
Test your knowledge on the major functions and regulatory mechanisms of the sympathetic vasoconstrictor mediator in the body. Explore how it plays a role in resistance and regulation in both health and disease. Learn about the circadian rhythm of blood levels, its impact on blood pressure, and the role of epinephrine in preventing orthostatic hypotension.
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