The Cardiovascular System

Introduction to the Cardiovascular System

  • The cardiovascular system, also known as the circulatory system, includes the heart, blood, and blood vessels.
  • This system’s function involves delivering oxygen and nutrients to body tissues and removing waste products, such as carbon dioxide.
  • It’s also responsible for temperature and pH balance (homeostasis), and it aids in immune response.

Structure of Heart

  • The heart, the main organ of this system, is a muscular pump situated slightly left in the upper chest area.
  • Composed of four sections: the left and right atria (upper chambers) and the left and right ventricles (lower chambers).
  • The heart wall is made up of three layers: the endocardium (inner layer), the myocardium (middle layer), and the epicardium (external layer).

Cardiovascular Circulation

  • There are two key circulatory routes: systemic circulation and pulmonary circulation.
  • Systemic circulation distributes oxygen-rich blood from the left side of the heart to the body’s tissues, and it brings deoxygenated blood back to the heart.
  • Pulmonary circulation carries oxygen-depleted blood from the heart’s right side to the lungs for oxygenation, and it returns oxygenated blood back to the heart.

Heartbeat and Blood Pressure

  • A normal heartbeat rate at rest ranges from 60-100 beats per minute. During exercise, the rate can increase to up to 200 beats per minute.
  • Blood pressure, the force exerted by blood on vessel walls, averages 120/80 mm Hg at rest. The first number (systolic pressure) measures pressure when the heart contracts, and the second number (diastolic pressure) measures pressure when the heart is at rest.
  • Exercise can cause temporary increases in blood pressure but can lower resting blood pressure over time.

The Cardiovascular System and Physical Activity

  • Regular physical activity improves cardiovascular health. It strengthens the heart, reduces resting heart rate and blood pressure, and enhances blood flow.
  • Understanding the cardiovascular system is critical for exercise planning and performance. It can help optimise training benefits and promote good heart health.
  • Awareness of the system’s workings can also ensure safety during workouts and prevent undue stress on the heart.