In reference to high blood pressure-as a result in changes in the PNS and the SNS list two effects on the heart and one on blood vessels.
To understand the effects of high blood pressure on the heart and blood vessels in relation to changes in the Peripheral Nervous System (PNS) and the Sympathetic Nervous System (SNS), we first need to understand the role of these systems.
The PNS and SNS are part of the autonomic nervous system, which regulates unconscious bodily functions. The PNS helps to slow down the body's response to stress, while the SNS accelerates the body's response to stress.
Effects on the Heart:
1. Increased Heart Rate: In high blood pressure, when the SNS is activated, it stimulates the release of stress hormones like epinephrine and norepinephrine. These hormones increase the heart rate, causing it to beat faster than normal. This increased heart rate puts additional strain on the heart.
2. Increased Cardiac Output: The SNS activation also leads to increased cardiac output. Cardiac output is the amount of blood pumped by the heart in a minute. In high blood pressure, the SNS increases cardiac output by increasing the strength of heart contractions. This increased workload on the heart can eventually lead to hypertrophy (enlargement) of the heart muscle.
Effect on Blood Vessels:
1. Vasoconstriction: Both the PNS and SNS have an impact on blood vessels. In high blood pressure, the SNS stimulation causes vasoconstriction, which is the narrowing of blood vessels. Vasoconstriction occurs due to the release of norepinephrine, which causes the smooth muscles in the vessel walls to contract. This narrowing of blood vessels increases resistance against blood flow, contributing to higher blood pressure levels.
To recap:
- High blood pressure can lead to increased heart rate and increased cardiac output as a result of SNS activation.
- The SNS also causes vasoconstriction, leading to a narrowing of blood vessels, which contributes to elevated blood pressure.
It is essential to note that high blood pressure is a multifactorial condition influenced by various factors, including diet, lifestyle, genetics, and other underlying health conditions. Therefore, consulting with a healthcare professional is crucial for accurate diagnosis, treatment, and managing high blood pressure.