Final answer:
Cardiac output can be increased by influencing either heart rate or stroke volume. Factors that can lead to an increase in cardiac output include autonomic innervation, endocrine control, preload, contractility, afterload, electrolyte levels, and metabolic products.
Step-by-step explanation:
Cardiac output, which is the measurement of blood flow from the heart through the ventricles, can be increased by influencing either heart rate or stroke volume. There are several factors that can lead to an increase in cardiac output by influencing these parameters:
- Autonomic innervation: The autonomic nervous system can increase heart rate through sympathetic stimulation.
- Endocrine control: Hormones, such as epinephrine, norepinephrine, and thyroid hormones, can increase heart rate and stroke volume.
- Preload: The amount of blood returning to the heart during diastole, known as preload, can increase stroke volume and therefore cardiac output.
- Contractility: The strength of the heart's contractions, known as contractility, can increase stroke volume and cardiac output.
- Afterload: The resistance the heart needs to overcome to eject blood, known as afterload, can influence stroke volume and cardiac output.
- Electrolytes: Electrolyte levels, such as calcium ion levels, can affect both heart rate and stroke volume, leading to changes in cardiac output.
- Metabolic products: Metabolic byproducts in the blood can also influence heart rate and stroke volume, thus affecting cardiac output.