Final answer:
High blood pressure is typically a result of a high cardiac output and high peripheral resistance. Increases in cardiac output or peripheral resistance lead to higher blood pressure, while the body regulates blood pressure through parasympathetic and sympathetic stimulation in response to changes in pressure levels.
Step-by-step explanation:
High blood pressure, or hypertension, is often a result of cardiac output and peripheral resistance. Cardiac output refers to the volume of blood the heart pumps out through the ventricles every minute. Peripheral resistance is the resistance to blood flow in the blood vessels. An increase in either or both will increase blood pressure.
When considering the possible answers:
- a high cardiac output and high peripheral resistance
- a high cardiac output and low peripheral resistance
- a low cardiac output and high peripheral resistance
- a low cardiac output and low peripheral resistance
The correct answer is a high cardiac output and high peripheral resistance.
When blood pressure rises too high, the body activates baroreceptors, which trigger parasympathetic stimulation of the heart, resulting in a decrease of cardiac output, and sympathetic stimulation of the peripheral arterioles decreases, causing vasodilation and subsequently a fall in blood pressure.
Conversely, when blood pressure drops too low, the rate of baroreceptor firing decreases, which causes an increase in sympathetic stimulation of the heart, leading to an increase in cardiac output, as well as sympathetic stimulation of the peripheral vessels, resulting in vasoconstriction. Thus, blood pressure is raised again.