Physiology 2130 Lecture Notes - Lecture 9: Pulmonary Circulation, Red Blood Cell, Circulatory System
9 Sep 2020
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Document Summary
It is through the blood vessels that blood is pumped and circulated/distributed throughout our entire body. This circulation is divided into two basic loops the pulmonary circulation and the systemic circulation. The circulatory system therefore comprises of the central pump (heart), arteries and arterioles that carry blood away from the heart, capillaries for gas exchange, and venules/veins that return blood back to the heart. Large arteries branch into smaller arteries, which eventually branch into arterioles. These arterioles branch into smaller vessels that lead to capillaries. These are the smallest of the blood vessels and are the functional units of the circulatory system where substances enter and leave. The capillaries converge into small venules, which get larger and larger to form veins. Blood is returned to the heart by the veins. In pulmonary circulation, blood leaves the right side of the heart (in blue) and passes through blood vessels that eventually become pulmonary capillaries within the lungs.
