18 Questions
What is the relationship between blood flow (F) and resistance (R)?
Blood flow is inversely proportional to resistance.
What factor is resistance (R) directly proportional to?
Blood viscosity
How does increased Hematocrit affect blood flow?
Decreases blood flow
Which of the following factors affects the resistance in a vessel?
Vessel radius to the power of 4
What does cardiac output equal in relation to systemic circulation?
Total tissue blood flow
How is blood viscosity compared to water (H2O)?
Blood viscosity is greater than H2O
What is the main trigger for the continuous generation of blood flow?
Increased shear stress
How do vasodilator drugs affect the arterial blood pressure?
Decrease it
Which vasodilator drug induces strong vasoconstriction, especially in veins?
Endothelin-1
What effect does Prostacyclin (PGI2) have on blood vessels?
Decreases platelet aggregation
How does autoregulation of blood flow to tissues respond to changes in arterial blood pressure?
Remains constant despite changes in arterial blood pressure
What effect do vasoconstrictors like Endothelins have on blood vessels?
Increase platelet aggregation
What is the main molecular mechanism of vasodilators?
Endothelial or platelets-mediated vasoactive substances
How does vascular smooth muscle respond to stretch?
By contracting
Which of the following is NOT a vasodilator?
Endothelin
What is the advantage of partial contraction of vascular smooth muscle?
It allows for further contraction or relaxation by physiological mediators
Which molecule has a short physiological half-life of a few seconds?
Nitric Oxide
What causes the opening of ion channels in vascular smooth muscle?
Blood pressure stretching the muscle
Learn about the autoregulatory mechanisms and metabolic regulation of arterioles, as well as the impact of vasoactive substances on arteriolar diameter and blood flow. Understand how these factors influence local regulation of blood flow in the circulatory system.
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