No.
Vasodilatation, ie, widening of vascular lumen is caused due to vascular smooth muscles' relaxation.
While, vasoconstriction, ie, decrease in diameter of the lumen is caused due to smooth muscle contraction.
Yes
Contraction of smooth muscle in arterioles would lead to vasoconstriction, which would increase resistance to blood flow and subsequently increase blood pressure. Conversely, relaxation of smooth muscle in arterioles (vasodilation) would decrease resistance and lower blood pressure.
Vasoconstriction is primarily initiated by the release of vasoconstrictor substances such as norepinephrine and angiotensin II, which cause smooth muscle contraction in blood vessel walls. Conversely, vasodilation is triggered by factors like nitric oxide, prostacyclin, and certain hormones, leading to the relaxation of smooth muscles and widening of blood vessels. Additionally, local metabolic signals such as increased carbon dioxide and decreased oxygen levels can also prompt vasodilation in specific tissues. Thus, these processes are regulated by a complex interplay of neural, hormonal, and local factors.
The sympathetic nervous system regulates blood flow by causing either vasodilation (widening of blood vessels) or vasoconstriction (narrowing of blood vessels). When activated, the sympathetic nervous system releases norepinephrine, which binds to receptors on blood vessels. This can either relax the smooth muscle in the vessel walls, causing vasodilation and increased blood flow, or contract the smooth muscle, leading to vasoconstriction and decreased blood flow.
smooth muscle
tetanic contraction.
Asthma causes contraction of the bronchial smooth muscle.
Vasodilation
smooth muscle
It can cause vascular smooth muscle contraction
Because it is an involuntaru muscle contraction
smooth muscle