Copyright o The McGraw-Hill Companies, Inc. Per mission required for reproduction or display. TABLE 12-1 The Cardiovascular System COMPONENT FUNCTION Hear Atria Chambers through which blood flows from veins to ventricles. Atrial contraction adds to ventricular filling but is not essential for it Ventricles Chambers whose contractions produce the pressures that drive blood through the pulmonary and systemi vascular systems and back to the heart Vascular system Arteries Low-resistance tubes conducting blood to the various organs with little loss in pressure. They also act as pressure reservoirs for maintaining blood flow during ventricular relaxation Arterioles Major sites of resistance to flow, responsible for the pattern of blood flow distribution to the various organs; participate in the regulation of arterial blood pressure Capillaries Sites of nutrient, metabolic end product, and fluid exchange between blood and tissues. Venules ites of nutrient, metabolic end product, and fluid exchange between blood and tissues Low-resistance conduits for blood flow back to the heart their capacity for blood is adjusted to facilitate this flow Blood Plasma Liquid portion of blood that contains dissolved nutrients, ions, wastes, gases, and other substances. Its composition equilibrates with that of interstitial fluid at the capillaries Cells Includes erythrocytes that function mainly in gas transport, leukocytes that function in immune defenses, and platelets(cell fragments) for blood clotting
Functions of the heart Pumping(泵血) Endocrine(内分泌) Atrial natriuretic peptide(ANP) Brain natriuretic peptide(BNP) avial tensor P Degradation ANP. Other bioactivators ↓ Aldosterone ↓svR Arteria Blood Pressure ume、 Natriuresis Abbreviations: ANP, atrial natriuretic peptide: NEP, neutral endopeptidase, GFR, glomerular filtration rate: CVP, central enous pressure, co, cardiac output svR, systemic vascular
Functions of the heart • Pumping（泵血） • Endocrine（内分泌） – Atrial natriuretic peptide (ANP) – Brain natriuretic peptide (BNP) – Other bioactivators
The Heart Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. The major Arteries to head and arms external and Right pulmonary veins Left pulmonary internal parts Superior vena cava Left pulmonary of the heart are Interatrial septum Pulmonary trunk shown in this diagram Right atrium Aortic semilunar The black arrows (tricuspid)valve Left ventricle indicate the route Inferior vena cava taken by the Myocardium blood as it is Right ventricle Epicardium pumped along. milunar vaive
The major external and internal parts of the heart are shown in this diagram. The black arrows indicate the route taken by the blood as it is pumped along. The Heart
Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display semilunar va Valve partly open Openings to coronary arteries semilunar valve Left AV(bicuspid)- Right AV (tricuspid) Valve almost completely closed From R Carola, J. P Harley, and C, R. Noback, Human Anatomy and Physiology. McGraw-Hill, New York, 1990(photos by Dr. Wallace McAlpine). Valves of the heart
Valves of the heart
Pulmonary trunk Pulmonary arteries The general route of the blood Capillaries of lungs through the body is shown, Pulmonary veins including passage through the heart (colored box). Pulmonary valve Left atrium To Body Right ventricle Left AV valve From Body Right AV valve Left ventricle Right atrium Aortic valve To Lung Fror Aorta From→ Lund Arteries Arterioles Venules From Body Veins Vena cavae
The general route of the blood through the body is shown, including passage through the heart (colored box)