Understanding the Human Heart: Function, Circulation, and Health

The Human Heart: Anatomy and Function

The heart is an organ about the size of a fist, located in the center of the chest, slightly to the left. It is comprised of two atria and two ventricles. Blood enters the atria through the veins and is driven out of the ventricles through the arteries. The heart has valves that force the blood to circulate in one direction.

The Heartbeat

The beating of the heart is the most noticeable manifestation of its activity. The frequency with which the heart beats varies according to the body's needs. Every heartbeat follows a set of phenomena that constitute a cardiac cycle:

• Atrial systole: The atria contract and push blood into the ventricles.
• Ventricular systole: The ventricles contract, and blood leaves through the arteries, forcing the opening of the pulmonary and aortic valves.
• Diastole: The musculature of the heart walls relaxes, preventing the blood from the arteries from flowing back into the ventricles.

Blood Circulation

The path of the blood in a full stroke involves blood passing twice through the heart: once during the pulmonary circuit and once during the general circuit. The human circulatory system, in addition to being closed, is double-tracked since blood passes twice through the heart at every turn, and there is complete separation between oxygen-rich and oxygen-poor blood.

Cardiovascular Diseases

Cardiovascular disease:

• Atherosclerosis: This is a hardening of the arteries that occurs when cholesterol plaques are deposited on the interior walls of these vessels.
• Myocardial infarction: The heart muscle needs oxygen and nutrients for proper functioning. This task is performed by the coronary arteries that leave the aorta, embrace the heart, and divide into many capillaries.

Lifestyle and Cardiovascular Health

Lifestyle and cardiovascular health: A healthy lifestyle is the best way to prevent cardiovascular disease.

• Smoking: Nicotine constricts the arteries and hardens their walls, forcing the heart to make a greater effort.
• Obesity: Excess weight is often associated with eating errors, such as over-consumption of animal fats.
• Lack of exercise: Like any muscle, the heart needs training to keep in shape.