How Does Stretching the Common Carotid Artery Affect Blood Pressure?

Update Date: 2024-06-13 Source: Network

Stretching the carotid artery can lead to a drop in blood pressure and a slowdown in heart rate. Once this occurs, the harm can be quite significant, posing a serious threat to life safety. The reason why stretching the carotid artery causes a drop in blood pressure is closely related to the stimulation of the carotid sinus. In such cases, prompt treatment is necessary to prevent further harm.

1. How does stretching the common carotid artery cause a drop in blood pressure?

Stretching one side of the carotid artery can stimulate the carotid sinus, exciting the sinus nerve to transmit signals to the medulla oblongata. The medulla oblongata stimulates the cardiac inhibitory center, leading to the excitation of the vagus nerve and a slowdown in heartbeat. Additionally, the medulla oblongata suppresses the activity of the cardiac accelerator center, inhibiting the excitation of the cardiac sympathetic nerve and further slowing the heartbeat. Finally, the medulla oblongata suppresses the activity of the vasoconstrictor center, inhibiting the excitation of the sympathetic nerve and resulting in vasodilation.

2. The Impact of Stretching the Common Carotid Artery

Stretching the common carotid artery can cause a drop in blood pressure and a slowdown in heart rate. This is because the terminal end of the common carotid artery and the beginning of the internal carotid artery have a dilation, which is usually located at the superior margin of the thyroid cartilage. This dilation is due to the rich sensory nerve endings in the adventitia of the vessel wall. Under an electron microscope, it appears as an oval structure with several layers, known as a pressure receptor, which is related to the regulation of blood pressure and is referred to as the carotid sinus.

Stretching the common carotid artery can directly affect the carotid sinus, causing it to mistake the elastic changes in the vessel wall as a result of an increase in blood pressure, or changes in pressure. This triggers a corresponding response, leading to a reflexive drop in blood pressure, a slowdown in heart rate, and sometimes even posing a risk to life.