High blood pressure is also called as Hypertension which is caused due to ___________

Correct option is C

The correct answer is (c) Constriction of arterioles.
Explanation
Blood pressure is determined by two main factors: cardiac output (the amount of blood the heart pumps) and total peripheral resistance (how much resistance the blood encounters as it flows through the blood vessels).
When arterioles, the smallest arteries, constrict (a process called vasoconstriction), their diameter decreases.
This narrowing increases the total peripheral resistance, forcing the heart to pump harder to push blood through the narrowed vessels.
The increased resistance and harder pumping lead to a rise in the force of blood against the artery walls, resulting in high blood pressure or hypertension.
Information Booster
The constriction of arterioles is controlled by the smooth muscles in their walls, which can be influenced by various factors including hormones (like angiotensin II) and the sympathetic nervous system.
Over time, chronically high blood pressure can cause structural changes in the walls of the arterioles, making the vessel walls thicker and less elastic. This further increases peripheral resistance and contributes to hypertension.
Many antihypertensive medications work by causing vasodilation (relaxation and widening) of the arterioles to reduce blood pressure.
Additional Knowledge
Contraction of heart muscles (Option A)
The contraction of heart muscles (cardiac output) is one of the factors affecting blood pressure.
An increase in cardiac output can lead to higher blood pressure, but the specific cause of sustained hypertension often lies with the increased peripheral resistance caused by arteriolar constriction. In fact, prolonged, uncontrolled high blood pressure can eventually lead to the heart muscles thickening and weakening (left ventricular hypertrophy), potentially causing heart failure.
Relaxation of veins (Option B)
The relaxation of veins (venous dilation) would increase the storage capacity of the vascular system.
This would decrease the venous return to the heart, leading to a decrease in cardiac output and, consequently, a decrease in blood pressure, not an increase.
Relaxation of arterioles (Option D)
The relaxation of arterioles (vasodilation) causes their diameter to increase.
This leads to a decrease in peripheral resistance and, therefore, a decrease in blood pressure.
Many medications for high blood pressure work by causing this effec