Chapter 14, part A
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Chapter 14, part A. Cardiovascular Physiology. About this Chapter. Blood flow pumping & distribution Anatomy and histology of the heart Mechanism of cardiac contraction Heart beat sequence–how the pump works Regulators of hear beat and volume pumped. Overview of the Cardiosvascular System.
Chapter 14, part A
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Chapter 14, part A Cardiovascular Physiology
About this Chapter • Blood flow pumping & distribution • Anatomy and histology of the heart • Mechanism of cardiac contraction • Heart beat sequence–how the pump works • Regulators of hear beat and volume pumped
Overview of the Cardiosvascular System • Heart and Blood vessels • Products transported to sustain all cells Table 14-1: Transport in the Cardiovascular System
Circulation Reviewed • Heart – "four chambered" • Right atrium & ventricle • Pulmonary circuit • Left atrium & ventricle • Systemic circuit • Blood Vessels – "closed circulation" • Arteries –from heart • Capillaries– cell exchange • Veins – to heart
Circulation Reviewed Figure 14-1: Overview of circulatory system anatomy PLAY Animation: Cardiovascular System: Anatomy Review: The Heart
Blood Flow: Pressure Changes • Flows down a pressure gradient • Highest at the heart (driving P), decreases over distance • Hydrostatic (really hydraulic) pressure in vessels • Decreases 90% from aorta to vena cava
Blood Flow: Pressure Changes Figure 14-2 : Pressure gradient in the blood vessels
Some Physic of Fluid Movement: Blood Flow • Flow rate: (L/min) • Flow velocity= rate/C-S area of vessel • Resistance slows flow • Vessel diameter • Blood viscosity • Tube length Figure 14-4 c: Pressure differences of static and flowing fluid
Some Physic of Fluid Movement: Blood Flow Figure 14-6: Flow rate versus velocity of flow
Heart Structure • Pericardium • Chambers • Coronary vessels • Valves-(one-way-flow) • Myocardium Figure 14-7 g: ANATOMY SUMMARY: The Heart
Cardiac Muscle Cells: • Autorhythmic • Myocardial • Intercalated discs • Desmosomes • Gap Junctions • Fast signals • Cell to cell • Many mitochondria • Large T tubes Figure 14-10: Cardiac muscle
Mechanism of Cardiac Muscle Excitation, Contraction & Relaxation Figure 14-11: Excitation-contraction coupling and relaxation in cardiac muscle
Modulation of Contraction • Graded Contraction: proportional to crossbridges formed • More [Ca++]: crossbridges, more force & speed • Autonomic n & epinephrine modulation
Modulation of Contraction Figure 14-12: Modulation of cardiac contraction by catecholamines
More Characteristics of Cardiac Muscle Contraction • Stretch-length relationship • stretch, Ca++ entering • contraction force • Long action potential • Long refractory period • No summation • No tetanus
More Characteristics of Cardiac Muscle Contraction Figure 14-13: Length-tension relationships in skeletal and cardiac muscle
More Characteristics of Cardiac Muscle Contraction Figure 14-15c: Refractory periods and summation in skeletal and cardiac muscle