chapter 15a blood flow and the control of blood pressure

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Chapter 15a Blood Flow and the Control of Blood Pressure

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Page 1: Chapter 15a Blood Flow and the Control of Blood Pressure

Chapter 15a

Blood Flow and the Control of Blood

Pressure

Page 2: Chapter 15a Blood Flow and the Control of Blood Pressure

About this Chapter

• The blood vessels• Blood pressure• Resistance in the arterioles• Distribution of blood to the tissues• Exchange at the capillaries• The lymphatic system• Regulation of blood pressure• Cardiovascular disease

Page 3: Chapter 15a Blood Flow and the Control of Blood Pressure

Figure 15-1

Functional Model of the Cardiovascular SystemElastic arteries

Aorta

Aortic valve

Left heart

Right heart

Lungs

Left ventricle

Right ventricle

Left atrium

Right atrium

Pulmonary veins

Pulmonary artery

Pulmonary valve

Tricuspid valve

Capillaries

Mitral valve

Venae cavae

Venules

Arteriole withvariable radius

Exchange ofmaterial withcells

Expandable veins

Page 4: Chapter 15a Blood Flow and the Control of Blood Pressure

Blood Vessel Structure

Figure 15-2

Page 5: Chapter 15a Blood Flow and the Control of Blood Pressure

Blood Vessel Structure & Function

PLAY Interactive Physiology® Animation: Cardiovascular System: Anatomy Review: Blood Vessel Structure & Function

Page 6: Chapter 15a Blood Flow and the Control of Blood Pressure

Metarterioles Regulate Flow into Capillary Beds

• Capillaries lack smooth muscle and elastic tissue reinforcement, which facilitates exchange

Figure 15-3

Collateralarteries

Arteriole wall is smooth muscle.

Metarterioles can act asbypass channels.

Vein

Venule

Capillaries

Arteriovenousbypass

Precapillarysphincters

Smallvenule

Page 7: Chapter 15a Blood Flow and the Control of Blood Pressure

Angiogenesis

• New blood vessel development• Necessary for normal development• Wound healing and uterine lining growth• Controlled by cytokines• Stimulate (mitogens): VEGF and FGF• Inhibit: angiostatin and endostatin

• Coronary heart disease • Collateral circulation

Page 8: Chapter 15a Blood Flow and the Control of Blood Pressure

Elastic Recoil in Arteries

Figure 15-4a

1

2

3

1

Ventricle contracts.

Aorta and arteries expand andstore pressure in elastic walls.

Semilunar valve opens.

(a) Ventricular contraction

Arterioles

2

3

Page 9: Chapter 15a Blood Flow and the Control of Blood Pressure

Elastic Recoil in Arteries

Figure 15-4a, step 1

1

1

Ventricle contracts.

(a) Ventricular contraction

Arterioles

Page 10: Chapter 15a Blood Flow and the Control of Blood Pressure

Elastic Recoil in Arteries

Figure 15-4a, steps 1–2

1

21

Ventricle contracts.

Semilunar valve opens.

(a) Ventricular contraction

Arterioles

2

Page 11: Chapter 15a Blood Flow and the Control of Blood Pressure

Elastic Recoil in Arteries

Figure 15-4a, steps 1–3

1

2

3

1

Ventricle contracts.

Aorta and arteries expand andstore pressure in elastic walls.

Semilunar valve opens.

(a) Ventricular contraction

Arterioles

2

3

Page 12: Chapter 15a Blood Flow and the Control of Blood Pressure

Elastic Recoil in Arteries

Figure 15-4b

1

2

3

1

Isovolumic ventricularrelaxation

Elastic recoil of arteries sendsblood forward into rest ofcirculatory system.

Semilunar valve shuts, preventingflow back into ventricle.

(b) Ventricular relaxation occurs.

2

3

Page 13: Chapter 15a Blood Flow and the Control of Blood Pressure

Elastic Recoil in Arteries

Figure 15-4b, step 1

1

1

Isovolumic ventricularrelaxation

(b) Ventricular relaxation occurs.

Page 14: Chapter 15a Blood Flow and the Control of Blood Pressure

Elastic Recoil in Arteries

Figure 15-4a, steps 1–2

1

21

Isovolumic ventricularrelaxation

Semilunar valve shuts, preventingflow back into ventricle.

(b) Ventricular relaxation occurs.

2

Page 15: Chapter 15a Blood Flow and the Control of Blood Pressure

Elastic Recoil in Arteries

Figure 15-4a, steps 1–3

1

2

3

1

Isovolumic ventricularrelaxation

Elastic recoil of arteries sendsblood forward into rest ofcirculatory system.

Semilunar valve shuts, preventingflow back into ventricle.

(b) Ventricular relaxation occurs.

2

3

Page 16: Chapter 15a Blood Flow and the Control of Blood Pressure

Review of Blood Flow

Table 15-1

Page 17: Chapter 15a Blood Flow and the Control of Blood Pressure

Pressure Throughout the Systemic Circulation

• Blood pressure is highest in the arteries and decreases continuously as it flows through the circulatory system

Figure 15-5

Page 18: Chapter 15a Blood Flow and the Control of Blood Pressure

Blood Pressure

• Pulse Pressure = systolic P – diastolic P• Valves ensure one-way flow in veins• MAP = diastolic P + 1/3(systolic P – diastolic P)

PLAY Interactive Physiology® Animation: Cardiovascular System: Measuring Blood Pressure

Page 19: Chapter 15a Blood Flow and the Control of Blood Pressure

Cuff pressure> 120 mm Hg

Stethoscope

Cuff pressurebetween 80 and

120 mm Hg

Cuff pressure< 80 mm Hg

Inflatablecuff

Pressuregauge

(a)

(b)

(c)

Measurement of Arterial Blood Pressure

Figure 15-7

Page 20: Chapter 15a Blood Flow and the Control of Blood Pressure

Blood Pressure

• Mean arterial pressure is a function of cardiac output and resistance in the arterioles

Figure 15-8

Elastic arteriesArterioles

Left ventricle

Mean arterial pressure

Cardiac output Variable resistance

Mean arterial pressure cardiac output resistance

Page 21: Chapter 15a Blood Flow and the Control of Blood Pressure

Blood Pressure

• Blood pressure control includes rapid responses from the cardiovascular system and slower responses by the kidneys

Page 22: Chapter 15a Blood Flow and the Control of Blood Pressure

Bloodvolume

Bloodpressure

leads to

triggers

Compensationby

cardiovascularsystem

Vasodilation Cardiac output Excretion of fluid in urineblood volume

Bloodpressureto normal

Compensationby kidneys

Stimulus

Integrating center

Tissue response

Systemic response

Slow responseFast response

KEY

Blood Pressure

Figure 15-9

Page 23: Chapter 15a Blood Flow and the Control of Blood Pressure

Factors that Influence Mean Arterial Pressure

Figure 15-10

Page 24: Chapter 15a Blood Flow and the Control of Blood Pressure

Factors that Influence Mean Arterial Pressure

PLAY Interactive Physiology® Animation: Cardiovascular System: Factors That Affect Blood Pressure