Cardiovascular system – basic features

The cardiovascular system serves a number of important functions in the body, most of which support other physiological systems. The major cardiovascular functions fall into six categories:

• Delivery of oxygen and other nutrients
• Removal of carbon dioxide and other metabolic waste
• Transport of hormones
• Thermoregulation
• Maintenance of acid-base balance and overall body fluid balance
• Immune function.

The cardiovascular system delivers oxygen and nutrients to, and removes carbon dioxide and metabolic waste products from, every cell in the body. It transports hormones from endocrine glands to their target receptors. The cardiovascular system supports body temperature regulation, and the blood’s buffering capabilities help control the body’s pH. The cardiovascular system maintains appropriate fluid balance in the body and helps prevent infection from invading organisms. Although this is just an abbreviated list of roles, the cardiovascular functions listed here are important for understanding the physiological bases of physical activity. Obviously these roles change with the challenges imposed during exercise.

All physiological functions and virtually every cell in the body depend in some way on the cardiovascular system. Any system of circulation requires three components:

• A pump(the heart)
• A system of channels or tubes(the blood vessels)
• A fluid medium(the blood).

In order to keep the blood circulating continually, the heart must generate sufficient pressure to drive the blood through the continuous network of blood vessels in this closed-loop system. Thus, the primary goal of the cardiovascular system is to ensure that there is adequate blood flow throughout the circulation to meet the metabolic demand of the tissues.