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Explore the components and functions of the cardiovascular system along with the organization, vasculature, cardiac cycle, and blood pressure. Learn how exercise impacts blood flow, pressure regulation, and the heart's blood supply.
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Components of Cardiovascular System Exercise Physiology
Functions • Deliver oxygenated blood to muscles; 1900 gals/day • Aerate blood in lungs • Transport heat to surface • Deliver nutrients to tissues • Transport hormones Organization of Circulatory System
Heart Chambers Two Pumps in One • Right heart to lungs • Left heart to body • Right and left atrioventricular valves prevent backflow into atria: tricuspid-right, bicuspid (mitral)-left • Right and left semilunar valves prevent backflow into ventricles: pulmonic-right, aortic-left Circulatory System: Valves
Heart wall composed of 3 layers • Epicardium • Myocardium • Endocardium • Differs from skeletal • Intercalated discs connect cells to permit electrical transmission • Homogenous muscle fibers similar to slow twitch fibers Circulatory System: Myocardium
Cardiac Cycle Circulatory System: Heart
Vasculature • Arteries: highly muscular, elastic • Capillaries: thin, porous single layer • Capillary branching increases cross section area • Flow velocity inversely proportional to area, so broad capillary beds have slow blood flow Circulatory System
Vasculature • Veins Thinner walls, less muscular Serve as blood reservoir Venous return facilitated by flaps Active cool-down facilitates blood flow Circulatory System
Blood Pressure Blood Pressure = cardiac output x total peripheral resistance
Systolic Blood Pressure: pressure in blood vessel due to surge of blood in aorta and subsequent recoil of aortic wall propagates awave of pressure through circuit. • Diastolic Blood Pressure: pressure in blood vessel during diastole. • DBP provides indication of peripheral resistance or ease of flow from “a to c”. • Normal systolic BP < _?_ mm Hg and diastolic BP < _?_ mm Hg. Blood Pressure at Rest
During RHYTHMIC exercise, increase in blood flow and dilation of blood vessels in active muscles cause SBP to __?__ and DBP to __?___. • During RESISTIVE exercise, sustained muscular forces compress peripheral arteries causing blood pressure __?__. • Upper body exercise has ___ BP than exercise with legs. Blood Pressure during Exercise
A bout of light- to moderate-intensity exercise decreases SBP for up to ___ hrs. • Pooling of blood in visceral organs and lower extremities reduces central blood volume which contributes to hypotensive recovery response. Blood Pressure during Recovery
Openings for left and right coronary arteries are in aorta just above the aortic valve. • Aortic valve flaps close coronary arteries during ejection phase. Heart’s Blood Supply
Myocardial oxygen utilization is 70% to 80% at rest, contrast to 25% other tissues. • In vigorous exercise, coronary blood flow increases 4-6x above normal. Heart’s Blood Supply
Impaired coronary blood flow: angina pectoris (chest pain). • Rate pressure product: estimate of myocardial work (SBP x HR) • Myocardium almost completely aerobic Heart’s Blood Supply