Control of cardiac output / David B. Young.

Format:

Book

Author/Creator:

Young, David B.

Series:

Colloquium series on integrated systems physiology ; #6.

Integrated systems physiology : from molecule to function to disease ; lecture #6

Language:

English

Subjects (All):

Cardiac output.

Physical Description:

1 online resource (110 p.)

Place of Publication:

[San Rafael, Calif.?] : Morgan & Claypool Life Sciences, 2010.

Language Note:

English

System Details:

Mode of access: World Wide Web.

Summary:

Although cardiac output is measured as the flow of blood from the left ventricle into the aorta, the system that controls cardiac output includes many other components besides the heart itself. The heart's rate of output cannot exceed the rate of venous return to it, and therefore, the factors governing venous return are primarily responsible for control of output from the heart. Venous return is affected by its pressure gradient and resistance to flow throughout the vascular system. The pressure gradient for venous return is a function of several factors including the blood volume flowing through the system, the unstressed vascular volume of the circulatory system, its capacitance, mean systemic pressure, and right atrial pressure. Resistance to venous return is the sum of total vascular resistance from the aortic valve to the right atrium. The sympathetic nervous system and vasoactive circulating hormones affect short-term resistance, whereas local tissue blood flow autoregulatory mechanisms are the dominant determinants of long-term resistance to venous return. The strength of contraction of the heart responds to changes in atrial pressure driven by changes in venous return, with small changes in atrial pressure eliciting large changes in strength of contraction, as described by the Frank-Starling mechanism. In addition, the autonomic nervous system input to the heart alters myocardial pumping ability in response to cardiovascular challenges. The function of the cardiovascular system is strongly affected by the operation of the renal sodium excretion-body fluid volume-arterial pressure negative feedback system that maintains arterial blood pressure at a controlled value over long periods. The intent of this volume is to integrate the basic knowledge of these cardiovascular system components into an understanding of cardiac output regulation.

Contents:

1. Introduction

Functional characteristics of the vascular system

Local tissue autoregulation of blood flow and its importance in determining cardiac output

Summary

2. Venous return

Determinants of venous return

The venous return curve

Alterations of the venous return curve

3. Cardiac function

Cardiac output curves

Factors that alter cardiac output by changing the effectiveness of the pumping ability of the heart

Factors that alter cardiac output by changing extracardiac pressure

4. Integrated analysis of cardiac output control

Graphical analysis of cardiac output regulation based on combined venous return and cardiac function curves

Algebraic analysis of cardiac output regulation

5. Analysis of cardiac output regulation by computer simulation

Rationale for building and using mathematical models of the cardiovascular system

Cardiac output analysis using a simplified cardiovascular model

Cardiac output analysis using an expanded cardiovascular model

Local tissue autoregulation

Cardiac function effects on regulation of cardiac output

Autonomic nervous system effects on cardiac output regulation

Digital human

6. Analysis of cardiac output control in response to challenges

Reflexes initiated by baroreceptors and other factors

Changes in blood volume

Circulatory shock

Heart failure

Exercise

7. Conclusion

References

Author biography.

Notes:

Part of: Colloquium digital library of life sciences.

Series from website.

Includes bibliographical references.

Title from PDF t.p. (viewed on March 15, 2010).

Cited in:

Google scholar

Google book search

ISBN:

1-61504-022-6

OCLC:

698135146