chapter 19: functions of the blood vessels chapter 19: functions of the blood vessels

TheHuman Bodyin Healthand Illness

Barbara Herlihy

Chapter 19:Functions of the Blood

Vessels

Chapter 19:Functions of the Blood

Vessels

Copyright © 2007 by Saunders, an imprint of Elsevier Inc.

All rights reserved.

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The Blood Vessels DeliverThe Blood Vessels Deliver

• Functions of blood vessels:1. Act as a delivery system2. Regulate blood pressure3. Engage in the exchange of nutrients and

waste between the capillaries and cells4. Redistribute blood in response to changing

body needs5. Help regulate body temperature

• Functions of blood vessels:1. Act as a delivery system2. Regulate blood pressure3. Engage in the exchange of nutrients and

waste between the capillaries and cells4. Redistribute blood in response to changing

body needs5. Help regulate body temperature



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The Blood Vessels Deliver (cont’d.)The Blood Vessels Deliver (cont’d.)

• “5 Cool Ps” of occlusive arterial disease:– Pain– Pulselessness– Pallor– Paresthesia– Paralysis– Coolness

• “5 Cool Ps” of occlusive arterial disease:– Pain– Pulselessness– Pallor– Paresthesia– Paralysis– Coolness



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Blood Vessels RegulateBlood PressureBlood Vessels RegulateBlood Pressure• Blood pressure: force of blood presses

against the walls of the blood vessels• Systolic pressure: pressure in the arteries

at the peak of ventricular contraction• Diastolic pressure: pressure in the large

arteries when the ventricles of the heart are relaxing

• Pulse pressure: difference between systolic and diastolic pressure

• Blood pressure: force of blood presses against the walls of the blood vessels

• Systolic pressure: pressure in the arteries at the peak of ventricular contraction

• Diastolic pressure: pressure in the large arteries when the ventricles of the heart are relaxing

• Pulse pressure: difference between systolic and diastolic pressure



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Blood Vessels RegulateBlood Pressure (cont’d.) Blood Vessels RegulateBlood Pressure (cont’d.) • Normal range: 100 to 140 mm Hg

(systolic) and 60 to 90 mm Hg (diastolic) for adult males

• Hypertension: chronic elevation of blood pressure

• Korotkoff sounds: caused by blood flow through an artery

• Normal range: 100 to 140 mm Hg (systolic) and 60 to 90 mm Hg (diastolic) for adult males

• Hypertension: chronic elevation of blood pressure

• Korotkoff sounds: caused by blood flow through an artery



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Blood Vessels Regulate Blood Pressure (cont’d.)




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Skeletal muscle pump.Skeletal muscle pump.



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Blood Vessels Regulate Blood Pressure (cont’d.) Blood Vessels Regulate Blood Pressure (cont’d.) • Respiratory pump: effect of respiratory

activity on venous blood flow• Venoconstriction: constriction of the veins

pushes additional blood out of the veins toward the heart

• Respiratory pump: effect of respiratory activity on venous blood flow

• Venoconstriction: constriction of the veins pushes additional blood out of the veins toward the heart



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Relationship between pressure and force.Relationship between pressure and force.



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Blood Vessels Regulate Blood Pressure (cont’d.) Blood Vessels Regulate Blood Pressure (cont’d.) • Vasodilation: muscles relax and the

openings of the arterioles increase; resistance decreases in the blood vessels

• Vasoconstriction: muscles contract and the openings of the arterioles become smaller; resistance increases in the blood vessels

• Vasodilation: muscles relax and the openings of the arterioles increase; resistance decreases in the blood vessels

• Vasoconstriction: muscles contract and the openings of the arterioles become smaller; resistance increases in the blood vessels



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Blood Vessels Regulate Blood Pressure (cont’d.) Blood Vessels Regulate Blood Pressure (cont’d.) • Blood pressure = cardiac output ×

vascular resistance • Cardiac output: amount of blood pumped

by the heart each minute• Vasopressors: substances that cause

vasoconstriction and elevate blood pressure

• Blood pressure = cardiac output × vascular resistance

• Cardiac output: amount of blood pumped by the heart each minute

• Vasopressors: substances that cause vasoconstriction and elevate blood pressure



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Blood Vessels Regulate Blood Pressure (cont’d.) Blood Vessels Regulate Blood Pressure (cont’d.) • Rapidly acting mechanisms for blood

pressure regulation:– Baroreceptor reflex– Sympathetic nervous system stimulation– Parasympathetic nervous system stimulation

• Rapidly acting mechanisms for blood pressure regulation:– Baroreceptor reflex– Sympathetic nervous system stimulation– Parasympathetic nervous system stimulation



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Blood Vessels Regulate Blood Pressure (cont’d.) Blood Vessels Regulate Blood Pressure (cont’d.) • Baroreceptor reflex structures: receptors,

sensory nerves, medulla oblongata, and motor nerves

• Baroreceptors: pressure receptors located in the walls of the aortic arch and carotid sinus

• Baroreceptor reflex structures: receptors, sensory nerves, medulla oblongata, and motor nerves

• Baroreceptors: pressure receptors located in the walls of the aortic arch and carotid sinus



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Blood Vessels Regulate Blood Pressure (cont’d.) Blood Vessels Regulate Blood Pressure (cont’d.) • Slower-acting mechanisms for blood

pressure regulation:– Renin-angiotensin-aldosterone mechanism– Antidiuretic hormone (ADH)– Atrial natriuretic peptide (ANP)– Brain natriuretic peptide (BNP)

• Slower-acting mechanisms for blood pressure regulation:– Renin-angiotensin-aldosterone mechanism– Antidiuretic hormone (ADH)– Atrial natriuretic peptide (ANP)– Brain natriuretic peptide (BNP)



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Blood Vessels Act as Exchange Vessels Blood Vessels Act as Exchange Vessels



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Blood Vessels Act as Exchange Vessels (cont’d.)


• Capillaries as exchange vessels:– Thin capillary walls– Millions of capillaries– Slow velocity of blood flow

• Capillaries as exchange vessels:– Thin capillary walls– Millions of capillaries– Slow velocity of blood flow



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• Capillary exchange processes:

– Diffusion: substance moves downhill from an area of high concentration to an area of low concentration

– Filtration-osmosis: outward and inward movement of water and dissolved substances

• Capillary exchange processes:

– Diffusion: substance moves downhill from an area of high concentration to an area of low concentration

– Filtration-osmosis: outward and inward movement of water and dissolved substances



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Blood Vessels Distribute Blood FlowBlood Vessels Distribute Blood Flow

Distribution of blood flow at rest and exercise.Distribution of blood flow at rest and exercise.



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Blood Vessels Distribute Blood Flow (cont’d.)

Blood Vessels Distribute Blood Flow (cont’d.)

• Distribution of blood flow:– Vasodilation– Vasoconstriction

• Distribution of blood flow:– Vasodilation– Vasoconstriction



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Blood Vessels Regulate Body TemperatureBlood Vessels Regulate Body Temperature• Role of blood vessels:

– Dissipate heat– Conserve heat

• Role of blood vessels:– Dissipate heat– Conserve heat

chapter 19: functions of the blood vessels chapter 19: functions of the blood vessels

Documents

imprint of elsevier

blood pressure contd

blood vesselssystolic

cellsredistribute blood

blood vesselsvasoconstriction

additional blood

blood vesselscopyright

force of blood presses