The Cardiovascular System

The Cardiovascular System

Structure and Function

  • The Cardiovascular System comprises the heart, blood vessels and blood. Its main function is to transport oxygen, nutrients, hormones and waste materials around the body.

  • The heart consists of four chambers: left and right atria and left and right ventricles. It acts as a pump to circulate blood.

  • Arteries carry oxygenated blood away from the heart (except pulmonary arteries). They have thick, elastic walls to handle high pressure.

  • Veins carry deoxygenated blood towards the heart (except pulmonary veins). They have valves to prevent backflow, as blood pressure is low.

  • Capillaries are the smallest blood vessels. They allow exchange of oxygen, nutrients, and waste products between blood and body tissues.

Blood Circulation

  • There are two main circuits in the human circulatory system: the systemic circulation and the pulmonary circulation.

  • Systemic circulation: Oxygen-rich blood is circulated from the left side of the heart to all body tissues, and returns as oxygen-poor blood to the right side of the heart.

  • Pulmonary circulation: Oxygen-poor blood is moved from the right side of the heart to the lungs, where it becomes oxygenated, and returns to the left side of the heart.

Heart Functions and Components

  • The heart beats due to a natural pacemaker called the sinoatrial node (SA node). This initiates each heartbeat, controlling the rate and timing of contractions.

  • Electrocardiogram (ECG) traces can show the electrical activity of the heart, helping identify heart conditions.

Disorders and Diseases

  • Coronary heart disease (CHD) involves the build-up of cholesterol plaques in the arteries that can restrict blood flow, leading to heart attacks.

  • Hypertension or high blood pressure can stress your heart and can lead to CHD.

  • Stroke is the interruption of blood supply to part of the brain, which can cause brain damage.

  • Anaemia is a condition where the body lacks enough healthy red blood cells to carry adequate oxygen to the body’s tissues.

Prevention and Treatment

  • Healthy lifestyle choices like balanced diet, regular exercise, avoiding smoking and controlling stress can reduce the risk of cardiovascular diseases.

  • Treatment options include medications, surgical intervention, and lifestyle changes. Regular check-ups can help in timely detection and management of problems.

  • Pharmaceuticals like anticoagulants and antiplatelets prevent blood clots, and statins reduce cholesterol levels.

  • Surgical interventions, such as angioplasty and bypass surgery, can restore the blood supply to the heart.

Please note: Understanding the key terms in bold will be beneficial for your understanding and will likely feature in assessments.