Human Physiology Ch 14 Cardiovascular System

Chapter 14: Cardiovascular Physiology

Cardiovascular Physiology
 Chapter 14 "
Heart anatomy " Cardiac muscle cells " Autorhythmic cells " Cardiac cycle " Cardiac output "
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Functions of Circulatory System "
 Transportation"
– Respiration"
 Transport 02 and C02."

– Nutrition"
 Absorbed digestion products delivered to liver and tissues"

– Excretion"
 Carry metabolic wastes to kidneys"

– Hormonal: "
 Carry hormones to target tissues"

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The cardiovascular system circulates blood to tissues "
 Pulmonary circulation"  Coronary circulation"  Systemic circulation"

Fluid Mechanics "
 Blood flow rate (vol/min) = Cardiac Output"  5 L/min at rest = total blood volume per minute"  Pressure produced by heart pushes blood through vessels"  Vessels become successively smaller"  Blood pressure drops as blood moves away from heart"
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Fig. 14.1, pg. 465"

Bio5, Denise Lim

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Chapter 14: Cardiovascular Physiology

Pressure is measured in 
 mm Hg "
 Units refer to the force required to push mercury (Hg) up a barometer"
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Pressure is greatest at aorta, lowest at vena cava "

Fig. 14.2, pg. 466"

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Pressure drops over distance "

Drop in pressure over distance keeps blood moving "
 Change in pressure over distance produces a pressure gradient"  Without difference in pressure, blood would stop flowing"

 Hydrostatic pressure: no flow"  Pressure is constant"

 Hydraulic pressure: fluid in motion"  Pressure decreases" 7

Fig. 14-3a&b, pg. 468"

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Bio5, Denise Lim

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Chapter 14: Cardiovascular Physiology

Flow depends on the pressure gradient "

Resistance (friction)
 opposes flow "
 Peripheral resistance = resistance in vessels (not in heart itself)"  Resistance is determined by:"
– Viscosity = v" – Vessel length = l" – Vessel radius = r"

" R ∝ vl " r4"

Fig. 14.3, pg. 468"

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Resistance