Physiology 2130 Lecture Notes - Lecture 9: Hemorheology, Blood Doping, Hypophyseal Portal System
6 Dec 2016
School
Department
Course
Professor
Document Summary
The circulatory system is divided into two distinct loops the pulmonary circulation and the systemic circulation. The circulatory system is essentially a closed system of tubes (blood vessels) filled with fluid (blood) that is moved around by a central pump (the heart). The blood vessels consist of arteries and arterioles that transport the blood away from the heart, capillaries where gas exchange takes place, and venules and veins that return the blood back to the heart. The large arteries branch into smaller arteries, which eventually turn into smaller arterioles. These arterioles also branch into smaller vessels that lead to the capillaries. These are the smallest of all 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. There are two principal loops that the blood takes through the body: the pulmonary circulation:
