Blood Flow Flashcards
The Circulatory System (13 cards)
What happens when we are actively exercising?
The muscles use up much more oxygen and nutrients, and produce more carbon dioxide and other wastes, than when we are sitting at rest.
How does the blood flow change to cater for these changes?
- By changing the output of blood from the heart
- By changing the diameter of the blood vessels supplying the tissues
What is the cardiac cycle?
The cardiac cycle, or heartbeat, is the sequence of events that occurs in one complete beat of the heart.
What is systole?
The pumping phase of the cycle, when the heart muscle contracts, is called systole
What is diastole?
The filling phase, as the heart muscle relaxes, is called diastole
What happens to the atria and ventricle during the diastole phase?
For a short time both atria and ventricles are in diastole.
The atria fill with blood and the ventricles also receive blood as the valves between them are open.
What is atrial systole?
Atrial systole, the contraction of the atria, then follows and forces the remaining blood into the ventricles.
What happens to the atria and ventricles during ventricular systole?
The atria then relax and refill while the ventricles contract in ventricular systole
What is ventricular systole?
Ventricular systole forces blood into the arteries.
The left/right sides of the heart operate together.
Both atria contract simultaneously, as do both ventricles.
What is cardiac output?
Tjkjkhe amount of blood leaving one of the ventricles every minute
What is the heart rate?
The number of times the heart beats per minute
What is the stroke volume?
The volume of blood forced from a ventricle of the heart with each contraction
What is the cardiac output volume?
stroke volume (mL) × heart rate (beats/minute)
