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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. - PowerPoint PPT Presentation
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Components of Cardiovascular System
Exercise Physiology
Organization of Circulatory System
Functions◦Deliver oxygenated
blood to muscles; 1900 gals/day
◦Aerate blood in lungs
◦Transport heat to surface
◦Deliver nutrients to tissues
◦Transport hormones
Circulatory System: Valves
Heart Chambers Two Pumps in One
Right heart to lungsLeft heart to bodyRight 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: Heart
Circulatory System: Myocardium
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: Heart
1. Ventricular DiastoleVentricular filling andAtrial contraction
A-V valve opensAortic valve closes
2. Beginning of Ventricular SystoleIsovolumetric Ventricular contraction
A-V valve closes,Aortic valve closed
3. Ventricular SystoleVentricular ejection
A-V valve closedAortic valve opens
4. Beginning of DiastoleIsovolumetric Ventricular relaxation
A-V valve closedAortic valve closes
Cardiac Cycle
Circulatory System
VasculatureArteries: highly
muscular, elasticCapillaries: 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
VasculatureVeins
Thinner walls, less muscular
Serve as blood reservoir
Venous return facilitated by flaps
Active cool-down facilitates blood flow
Blood PressureBlood Pressure = cardiac output x total peripheral resistance
Blood Pressure at Rest
Systolic Blood Pressure: pressure in blood vessel due to surge of blood in aorta and subsequent recoil of aortic wall propagates a wave 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 during Exercise
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 Recovery
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.
Heart’s Blood Supply
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
