Which variables determine cardiac output?

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Multiple Choice

Which variables determine cardiac output?

Cardiac output is the volume of blood the heart pumps each minute, determined by how often the heart beats and how much blood is pumped with each beat. This is expressed as CO = heart rate × stroke volume. Heart rate is driven by the heart’s pacemaker and modulated by autonomic input, while stroke volume depends on preload (end-diastolic volume), afterload, and contractility. End-diastolic volume and end-systolic volume feed into stroke volume (SV = EDV − ESV) but do not directly set cardiac output on their own. Blood pressure reflects the pressure the heart must work against and is influenced by CO, but it isn’t the determinant of CO. Cardiac plexus activity affects autonomic regulation of heart rate and contractility, but the fundamental determinants of CO are the rate at which the heart beats and the volume it ejects per beat. Thus, the variables that determine cardiac output are heart rate and stroke volume.

Cardiac output is the volume of blood the heart pumps each minute, determined by how often the heart beats and how much blood is pumped with each beat. This is expressed as CO = heart rate × stroke volume. Heart rate is driven by the heart’s pacemaker and modulated by autonomic input, while stroke volume depends on preload (end-diastolic volume), afterload, and contractility.

End-diastolic volume and end-systolic volume feed into stroke volume (SV = EDV − ESV) but do not directly set cardiac output on their own. Blood pressure reflects the pressure the heart must work against and is influenced by CO, but it isn’t the determinant of CO. Cardiac plexus activity affects autonomic regulation of heart rate and contractility, but the fundamental determinants of CO are the rate at which the heart beats and the volume it ejects per beat.

Thus, the variables that determine cardiac output are heart rate and stroke volume.

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