37 Questions
Which molecule is considered the most potent vasoconstrictor among Endothelins?
Endothelin-1
What effect does Prostacyclin (PGI2) have on blood vessels?
Decreased platelet aggregation
Which molecule released by platelets causes vasoconstriction and increased platelet aggregation?
Thromboxane A2
What is the main trigger for the generation of Nitric Oxide (NO) in blood vessels?
Increased shear stress on the blood vessel wall
Which substance contributes to maintaining a localized clot without excessive extension?
Prostacyclin (PGI2)
Which molecule released by the endothelium causes vasodilation?
Prostacyclin (PGI2)
Which effect do Nitrovasodilators, such as Nitroglycerin, have on capacitance vessels?
Decrease the venous return
What is the main site of action of Vasodilator drugs like Nitrovasodilators?
Large diameter arterioles
What is the role of Nitric Oxide (NO) in autoregulation of blood flow?
Causing hyperpolarization and relaxation by opening ATP-sensitive K+ channels on smooth muscle
Which of the following is true about Endothelium Derived Hyperpolarizing Factor (EDHF)?
It increases blood flow by opening ATP-sensitive K+ channels on smooth muscle
What is the role of Prostacyclin (PGI2) in blood flow autoregulation?
Mediating the release of vasodilator prostaglandins
How does Thromboxane A2 impact blood flow regulation?
Inducing vasoconstriction through H+ ions release
What is the effect of Endothelins (ET-1, ET-2, ET-3) on blood flow autoregulation?
Decreasing O2 levels, leading to vasoconstriction
Which mechanism leads to increased local blood flow by accumulation of Vasodilator Metabolites like Adenosine?
Opening ATP-sensitive K+ channels causing hyperpolarization and relaxation
What happens in response to Hypoxia in the context of autoregulation?
[O2] decrease opening ATP-sensitive K+ channels inducing vasodilation
Which factor increases blood flow by causing hyperpolarization and relaxation?
[H+] ions accumulation resulting in relaxation
What is the main site of peripheral resistance?
Arterioles
Which factor causes vasodilation by decreasing vasomotor tone?
Nitric Oxide (NO)
Which type of blood flow occurs when changes in blood velocity turn streamline flow into turbulent flow?
Turbulent Flow
Mild narrowing produced by atherosclerosis results in large reductions in blood flow due to:
Decreased vessel diameter
What is the physiological effect of small changes in arteriolar diameter?
Large changes in flow
Which of the following substances causes vasoconstriction?
Endothelins (ET-1, ET-2, ET-3)
What effect does increased diameter of the vessel have on resistance?
Decreases resistance
What is the physiological half-life of Nitric Oxide (NO)?
A few seconds
Which of the following is NOT a vasodilator?
Thromboxane A2
Which substance acts as the Endothelium-derived Relaxing Factor (EDRF)?
Nitric Oxide (NO)
What is the role of Endothelium Derived Hyperpolarizing Factor (EDHF) in blood vessels?
Induces vasodilation
Which compound plays an important role in physiological and pathological conditions as a vasodilator?
Prostacyclin (PGI2)
What is the main molecular mechanism of Vasodilators like Endothelium-derived substances?
Partial depolarization of smooth muscle cells
Which of the following substances is NOT considered a vasodilator?
Thromboxane A2
What is the molecular mechanism behind the Bayliss Effect in vascular smooth muscle?
Stretch by blood pressure leading to partial depolarization and contraction
Which vasoactive substance is produced by the endothelium and causes vasodilation by increasing intracellular cGMP levels?
Prostacyclin (PGI2)
Which vasoactive substance is released by damaged endothelium and has potent vasoconstrictor effects?
Endothelins (ET-1, ET-2, ET-3)
Which vasoactive substance acts as a potent vasodilator produced by the vascular endothelium and causes smooth muscle relaxation?
Nitric Oxide (NO)
Which vasoactive substance is derived from arachidonic acid metabolism and acts to promote platelet aggregation?
Thromboxane A2 and prostaglandin H2
Which vasoactive substance is produced by the endothelium and functions as a paracrine agent to regulate vascular tone?
Endothelium Derived Hyperpolarizing Factor (EDHF)
Which vasoactive substance is a potent vasoconstrictor peptide that plays a role in blood pressure regulation?
Endothelins (ET-1, ET-2, ET-3)
Test your knowledge on how changes in hematocrit, plasma protein concentration, and vessel diameter affect blood viscosity and resistance. Learn about the factors that influence arterial blood pressure and the use of blood transfusion in hemorrhage.
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