ABSTRACT
Study objectives List the functions of the circulatory system Describe how the rate of blood ow to individual tissues differs according to specic tissue function Explain the function of each component of the blood vessel wall Distinguish between arteries, arterioles, capillaries, and veins in terms of their anatomical characteristics and their functions Distinguish between diastolic pressure, systolic pressure, and pulse pressure Understand the method by which mean arterial pressure is calculated Describe how blood pressure changes as the blood ows through the circulatory system Understand Ohm’s Law and describe the relationship between blood ow, blood pressure, and vascular resistance List the factors that affect vascular resistance and explain their physiological signicance Explain why mean arterial pressure must be closely regulated Explain how the autonomic nervous system alters cardiac output, total peripheral resistance, and therefore, mean arterial pressure List the sources of input to the vasomotor center Describe the mechanism of action and the physiological signicance of the baroreceptor reex, the chemoreceptor reex, and the low-pressure receptor reex Indicate the source, the factors regulating the release, and the physiological signicance of the following vasoconstrictors: catecholamines, angiotensin II, vasopressin, endothelin, thromboxane A2, and serotonin Indicate the source, the factors regulating the release or activation, and the physiological signicance of the following vasodilators: prostacyclin, nitric oxide, atrial natriuretic peptide, histamine, bradykinin, adenosine, and epinephrine Compare and contrast the compliance of systemic arteries and systemic veins List the specic blood reservoirs and their common characteristics Explain how blood volume, sympathetic stimulation of the veins, skeletal muscle activity, and respiratory activity inuence venous return Describe the effects of gravity on the circulatory system
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Describe the mechanism of active hyperemia Dene autoregulation of blood flow Explain how the myogenic mechanism causes autoregulation of blood ow Describe the effects of acute exercise on the circulatory system Explain how blood ow through capillaries is regulated by vasomotion Describe the physiological signicance of the Starling Principle Explain how hydrostatic forces and osmotic forces regulate the bulk ow of uid across the capillary wall Describe the four general conditions that can lead to edema formation
. Introduction The circulatory system carries out many important functions that contribute to homeostasis. It obtains oxygen from the lungs, nutrients from the gastrointestinal tract, and hormones from the endocrine glands, and it delivers these substances to the tissues that need them. Furthermore, it removes metabolic waste products, such as carbon dioxide, lactic acid, and urea, from the tissues. Finally, it contributes to the actions of the immune system by transporting antibodies and leukocytes to areas of infection. Overall, the circulatory system plays a vital role in the maintenance of optimal conditions for cell and tissue function.
