18 Questions
What happens when a blood vessel relaxes?
It dilates, allowing more blood and oxygen to be supplied.
What is the purpose of autoregulation in the context of blood flow?
To maintain or rapidly return to normal blood flow following abrupt changes in arterial pressure.
Which theory suggests that excess oxygen or other nutrients cause increased smooth muscle contraction?
Metabolic Theory
According to the Myogenic Theory of autoregulation, what initiates the contraction or relaxation of vascular smooth muscle?
Transmural pressure changes
What is the effect of locally mediated vasodilation according to Levy's concept?
Affects small arteries and arterioles, not larger upstream arteries.
In the context of blood flow, what is reactive hyperemia?
An increase in blood flow post-occlusion to several times the baseline value.
Which of the following statements accurately describes the role of smooth muscle in regulating blood flow?
Variation in smooth muscle contraction allows preferential distribution of blood flow and control of total peripheral resistance.
Which of the following substances is NOT involved in pharmacomechanical coupling, leading to smooth muscle contraction?
Oxygen
According to the vasodilator theory of local blood flow regulation, what causes the release of vasodilator substances?
An increase in metabolism or a decrease in supply of oxygen or other nutrients
Which of the following statements accurately describes the oxygen lack theory of local blood flow regulation?
In the absence of adequate oxygen, smooth muscle is unable to maintain contraction, leading to vasodilation.
Which of the following statements accurately compares smooth muscle contraction and skeletal muscle contraction?
Smooth muscle contraction develops very slowly, while skeletal muscle contraction develops rapidly.
Which of the following statements is true regarding the baseline tone of resistance vessels?
The resistance vessels exhibit partial constriction at baseline, allowing for both vasodilation and further vasoconstriction.
What is the primary factor responsible for baseline vascular tone in the absence of nervous system input?
Myogenic activity in response to the stretch imposed by blood pressure
Which of the following substances is released from damaged endothelial cells and produces local vasoconstriction to reduce bleeding?
Endothelin
Which of the following factors is responsible for the vasodilation observed in cerebral blood vessels in response to increased carbon dioxide levels?
Increased carbon dioxide levels in the cerebral circulation
Which of the following substances is released from the posterior pituitary and functions to increase both vasoconstriction and tubular reabsorption of water?
Vasopressin (ADH)
Which of the following substances is an arteriolar dilator and increases capillary permeability following release from inflamed or damaged tissues?
Histamine
Which of the following factors leads to vasodilation in the long-term regulation of blood flow?
Increased potassium levels
Test your understanding of the mechanisms involved in the local and humoral control of tissue blood flow as discussed in NRAN 80413 Spring 2024 course by Dr. Ron Anderson, M.D. Explore topics such as acute control mechanisms, long-term control, and baseline tone of resistance vessels.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
