Heart And Circulatory System (Part-I)

Oxygenated blood is circulated by the Pulmonary vein. The pulmonary veins carry oxygen-rich blood from the lungs back to the left atrium of the heart.

Small upper chambers of the heart are called Atria. The human heart has four chambers: two upper atria (receiving chambers) and two lower ventricles (pumping chambers).

Oxygenated blood flows out of the heart through the Aorta. The aorta is the largest artery in the body, originating from the left ventricle and distributing oxygenated blood to the rest of the systemic circulation.

The smallest blood vessels, which are one-cell thick, are called Capillaries. Capillaries are microscopic vessels that form a network throughout the body's tissues, facilitating the exchange of oxygen, nutrients, and waste products between blood and cells.

The smallest blood vessel in the body is the Capillary. Their extremely thin walls and narrow lumens are perfectly adapted for efficient gas and nutrient exchange at the cellular level.

Swollen bluish veins resulting from valves that do not close properly are called  Varicose veins. This condition occurs when the valves in the veins weaken or are damaged, leading to blood pooling and the veins becoming enlarged and twisted.

In a closed circulatory system, blood is completely enclosed within Blood Vessels. In this type of system, blood remains within arteries, veins, and capillaries, circulating continuously without directly bathing the body tissues.

Christiaan Barnard is famous for: performing the world’s first human heart transplant. He performed this groundbreaking surgery in South Africa in 1967, marking a significant milestone in medical history.