23.1:
Overview of the Heart
The heart is a hollow muscular organ that pumps blood through the body.
It is cone-shaped and weighs about 250 to 300 grams on average.
The heart is approximately 12 cm long, 6 cm thick, and 9 cm wide.
It has four chambers.
The right atrium accepts oxygen-depleted blood from the body and transfers it to the right ventricle, which then propels it to the lungs for oxygenation.
After oxygenation in the lungs, the blood travels to the left atrium and is subsequently directed to the left ventricle, from where it is pumped throughout the body.
Arteries function as blood vessels that transport blood from the heart to the rest of the body, whereas veins transport blood toward the heart.
Both arteries and veins link to capillaries, slender-walled blood vessels that facilitate gas and nutrient exchange between the blood and surrounding tissues.
The heart's pumping action maintains a constant supply of oxygen and nutrients throughout the body and carries away the waste.
23.1:
Overview of the Heart
The heart, a muscular organ located in the chest, functions as the body's pump, circulating blood through the vascular system. It has four chambers: two atria on top and two ventricles below. The right atrium receives deoxygenated blood from the body and passes it to the right ventricle, which pumps it to the lungs for oxygenation. The left atrium receives oxygenated blood from the lungs and transfers it to the left ventricle, which pumps it to the rest of the body.
The heart's structure includes valves that ensure one-way blood flow: the tricuspid valve between the right atrium and right ventricle, the pulmonary valve between the right ventricle and pulmonary artery, the mitral valve between the left atrium and left ventricle and the aortic valve between the left ventricle and aorta.
The heart's electrical system controls its rhythmic contractions. The sinoatrial (SA) node in the right atrium acts as the natural pacemaker, initiating electrical impulses that cause the atria to contract. The impulses travel to the atrioventricular (AV) node through the bundle of His and Purkinje fibers, causing the ventricles to contract.
Coronary arteries supply the heart muscle with oxygen-rich blood. Disorders like coronary artery disease can impair blood flow, leading to conditions such as angina and myocardial infarction (heart attack). Maintaining cardiovascular health is crucial for overall well-being.