Blood Pressure: Physiological Mechanisms, Genetic Influences, and Global Significance
- Health Communicator
- Jun 22
- 23 min read
Updated: Sep 3
AUDIO:
Blood pressure (or arterial pressure) is the force that blood exerts on the walls of the arterial system—a key indicator of the body’s hemodynamic state. At its core, blood pressure results from the interaction between cardiac output (the volume of blood pumped by the heart per unit of time) and total peripheral resistance, which is primarily determined by the arterioles—the smallest blood vessels responsible for regulating blood flow to tissues.
Regulating arterial pressure is critical to mammalian physiology, as even small deviations can lead to serious health consequences. This regulation depends on a delicate balance between two main factors: cardiac output, which is influenced by venous return to the heart and heart rate, and the tone of the arterioles, which determines total peripheral resistance. Arteriolar tone is, in turn, controlled by both local metabolic signals and central neurohormonal mechanisms.
At the tissue level, various metabolic substances such as adenosine, lactate, and nitric oxide play a key role in regulating regional blood flow. These molecules induce local vasodilation (the widening of blood vessels), which counteracts sympathetic-induced vasoconstriction. This enables the body to finely adjust blood distribution according to the needs of different tissues and organs, especially during times of increased metabolic demand—such as physical exertion or stress.
In parallel, powerful neurogenic control mechanisms ensure the rapid adaptation of blood pressure. Arterial baroreceptors—sensory structures located in the carotid sinuses and aortic arch—detect changes in blood pressure and trigger reflex arcs that activate sympathetic and parasympathetic nervous system responses. Additionally, the kidneys contribute to long-term regulation by controlling blood volume and secreting renin—a key enzyme in the renin-angiotensin-aldosterone system (RAAS).
