The terms “vascular system” and “cardiovascular system” are often used interchangeably, leading to confusion about whether they refer to the exact same anatomical structure. While the two concepts are intimately related, they are not precisely synonymous. Understanding the distinction involves recognizing that one term refers to the network of vessels, while the other describes the entire organ system responsible for circulation. This relationship is one of part to whole.
Defining the Vascular System
The vascular system is the complex network of vessels that permeates the entire body. Its primary role is to serve as the body’s plumbing, transporting fluid throughout all tissues and organs. This system consists of three main vessel types: arteries, veins, and capillaries.
Arteries are thick-walled, muscular tubes that carry blood away from the heart, which is typically oxygenated blood under high pressure. These vessels branch into smaller arterioles and eventually into microscopic capillaries, which are composed of a single cell layer. Capillaries are the sites where oxygen and nutrients are delivered to the cells, and waste products like carbon dioxide are collected.
The deoxygenated blood then moves from the capillaries into small venules, which merge to form larger veins that carry the blood back toward the heart.
Defining the Cardiovascular System
The cardiovascular system is the complete, integrated organ system that includes both the heart (“cardio”) and the vast network of blood vessels (“vascular”). It is the entire circulatory apparatus. The heart is the central, muscular pump that provides the force necessary to drive the fluid through the vessels.
This system operates in two main circuits: the pulmonary circulation, which moves blood between the heart and lungs for gas exchange, and the systemic circulation, which carries oxygenated blood to the rest of the body. Therefore, the vascular system is understood as an extensive, but subordinate, component of the larger cardiovascular system.
Why the Distinction Matters in Health
The distinction between the two terms holds practical value for medical professionals when diagnosing and treating conditions. Healthcare providers use the terms to localize a problem, even though both systems share similar risk factors like high blood pressure and high cholesterol.
The term “vascular disease” often refers to conditions affecting the vessels, typically outside of the heart itself. Examples include peripheral artery disease (PAD), which involves narrowed arteries in the limbs, or carotid artery disease, which affects vessels leading to the brain.
In contrast, “cardiovascular disease” (CVD) is a broader, umbrella term that encompasses all diseases affecting either the heart or the blood vessels. This includes heart-specific issues, such as heart attack, heart failure, or arrhythmias, and all forms of vascular disease. This difference helps specialists focus on whether the disease is primarily a pump issue or a vessel issue, which directly influences the appropriate treatment strategy.