Biology 2601A/B Lecture : organismal phys
20 Feb 2012
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The systemic circuit: blood is delivering oxygen and nutrients and picking up waste products (and delivering them to the kidneys). Linear flow rate or velocity is reduced when blood goes through the systemic circuit and the cross-sectional area increases due to lots of capillaries. There is also lower pressure because of this. The blood slows because it has a greater cross-sectional to pass through. Also the capillaries are short, so the blood must move slowly in order to have enough time to exchange with the tissues. The venous part of the systemic circuit is a low-pressure, low-resistance system. Major arteries: composed of muscular, elastic thick walls (smooth muscle and elastin). Some arteries are the aorta, carotid artery, and femoral artery. The pressure in the arteries 16 kpa when the heart muscle is contracting and 10 kpa when the heart is relaxing. Terminal arteries deliver blood to tissues and have a lower pressure (12/8 kpa).
