Cardiovascular System

The cardiovascular system is a complex network of the heart and blood vessels that transports oxygen, nutrients, and waste products throughout the body. The heart, made up of four chambers, pumps blood through arteries (carrying oxygen-rich blood) and veins (carrying carbon dioxide-rich blood). Blood also carries hormones for organ communication and helps regulate body temperature.

The system includes two circulations:

1. • Pulmonary Circulation: Blood moves from the heart to the lungs to exchange oxygen and carbon dioxide, then returns oxygenated blood to the heart.

   • Systemic Circulation: Oxygen-rich blood is pumped to the body via the aorta, where it travels through arteries, arterioles, and capillaries to exchange gases and nutrients. The blood then returns to the heart.

   • Blood vessels connect through networks called anastomosis, which offer alternative routes if there's a blockage. In some cases, vessels have no alternative route, like the central retinal artery in the eye, where a blockage can lead to blindness.

   • The portal venous system, such as the hepatic portal system, links two capillary beds (in the digestive tract and liver) for nutrient processing before returning blood to the heart. The cardiovascular system is essential for transporting materials, regulating body temperature, and ensuring blood flow.