Flashcards
The Structure of the Heart and the Cardiac Cycle
Flashcards do conjunto (11)
- 1Describe the structure of the heart
- 2What are the valves held in place by?Cords (valve tendons)
- 3What is the role of valves?Heart valves prevent backflow of blood; they only open one way (depends on the relative pressure of the heart chambers)
- 4Complete the sentences: If there is a __________ pressure behind a valve, it is forced open. If there is a higher pressure in front of the valve, it is forced _________. This means that the flow of blood is _____________ - it only flows in ______ ____________If there is a HIGHER pressure behind a valve, it is forced open. If there is a higher pressure in front of the valve, it is forced SHUT. This means that the flow of blood is UNIDIRECTIONAL - it only flows in ONE DIRECTION.
- 5What is the role of the cardiac cycle?The cardiac cycle keeps the blood continuously circling around the body
- 6Within the human heartbeat, you can hear a 'lub-dub' sound. What is the 'lub' and the 'dub' sound caused by?The 'lub' is caused by the atrioventricular valves closing
The 'dub' is caused by the semi-lunar valves closing - 7What are the 3 stages of the cardiac cycle?Atrial systole
Ventricular systole
Diastole - 8What happens during atrial systole?Ventricles are relaxed
Atria contract, decreasing the volume and increasing the pressure
This pushes the blood into the ventricles through atrioventricular valves - 9What happens during ventricular systole?Atria relax
Ventricles contract, decreasing the volume and increasing their pressure
The pressure becomes higher in the ventricles than the atria, which forces the AV valves to shut to prevent backflow
The pressure in the ventricles is also higher than in the aorta and pulmonary artery, which forces open the SL valves and blood is forced out into these arteries - 10What happens during diastole?Ventricles and atria relax
The higher pressure in the arteries closes the SL valves to prevent backflow
Blood returns to the heart and the atria fill again
This increases the pressure of the atria and the AV valves open
This allows blood to flow passively into the ventricles from the atria - 11—
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- O usuário eliminou as informações de disciplina FlashCards sobre The Structure of the Heart and the Cardiac Cycle, criado por Usuário eliminado em 05-03-2018.
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- Criado por Yinka F · 1 fev 2018
- Copiado por Yinka F · 5 mar 2018
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