Question

The process of decrease in any vessel diameter that occurs due to smooth muscle contraction is called:

Answer 1

Answer:

c. vasoconstriction

Explanation:

In condition of excess blood loss(haemorrhage) or exposure to  very cold temperature, or drop in blood pressure, the process by which  the smooth muscle cells of the walls of the artery and arteriole contract  to  increase  the resistance of the  vessels to reduce  blood flow  is called vasoconstriction.

The mechanisms, involve Increase stimuli from epinephrine and sympathetic nervous system  which leads  to increase in influx of Ca+ ions into the saccolemma  reticulum of the smooth muscle cells.

Calcium-modulated -protein in the saccolema  binds   with Calcium. This results in a signal pathways , of calcium binding with tropin, tropomyosin exposure of  myosin-binding sites,and formation of cross-bridges for sacomere shortening  leading to contraction of smooth muscles for the  narrowing of blood vessels.

Certain drugs called  vasoconstrictors can also cause vasoconstriction of blood vessels. They are drugs prescribed for elevation of  blood pressure.

Answer 2

Answer:

c. vasoconstriction

Explanation:

Vasoconstriction is a process which involves the narrowing or tightening of blood vessels which becomes smaller when the smooth muscles of these vessels become contracted. The tightening or narrowing of the blood vessels results in an increase in resistance as blood pressure rises, which leads to the restriction of blood flow. Vasoconstriction is the opposite of vasodilation.