Answer
The terms for the widening and narrowing of a blood vessel by muscular contraction and relaxation are:
1. **Vasoconstriction:** This term refers to the narrowing of a blood vessel due to the contraction of the smooth muscle in its walls. Vasoconstriction reduces the diameter of the vessel, which can lead to increased resistance to blood flow and a decrease in blood flow to the tissues supplied by that vessel.
2. **Vasodilation:** Vasodilation is the opposite of vasoconstriction. It refers to the widening or relaxation of a blood vessel's walls, specifically the smooth muscle layer. This results in an increased diameter of the vessel, allowing for greater blood flow and decreased resistance.
Both vasoconstriction and vasodilation play crucial roles in regulating blood flow and blood pressure throughout the body. These processes are controlled by various factors, including hormonal signals, neural inputs, local tissue factors, and metabolic demands.
Work Step by Step
The terms for the widening and narrowing of a blood vessel by muscular contraction and relaxation are:
1. **Vasoconstriction:** This term refers to the narrowing of a blood vessel due to the contraction of the smooth muscle in its walls. Vasoconstriction reduces the diameter of the vessel, which can lead to increased resistance to blood flow and a decrease in blood flow to the tissues supplied by that vessel.
2. **Vasodilation:** Vasodilation is the opposite of vasoconstriction. It refers to the widening or relaxation of a blood vessel's walls, specifically the smooth muscle layer. This results in an increased diameter of the vessel, allowing for greater blood flow and decreased resistance.
Both vasoconstriction and vasodilation play crucial roles in regulating blood flow and blood pressure throughout the body. These processes are controlled by various factors, including hormonal signals, neural inputs, local tissue factors, and metabolic demands.
