The heart

• What does the right side of the heart do?

  Pump deoxygenated blood to the lungs
• What does the left side of the heart do?

  Pump oxygenated blood to the rest of the body
• How many pumps joined together does the heart consist of?

  2
• What muscle is the heart made of?

  Cardiac
• What supplies the cardiac muscle of the heart with oxygenated blood and what does this do?

  Coronary arteries to keep it contracting and relaxing all the time.
• What do inelastic pericardial membranes do?

  Surround the heart to stop it from over-distending with blood.
• Why does the hart have two separate pumping mechanisms?

  Blood pressure drops in the lungs as it flows through the capillary. A single pump would slow the blood flow to the body cells. Two pumps increase the pressure before the blood circulates.
• What does the septum do?

  separates the two sides of the heart, preventing oxygenated and deoxygenated blood from mixing
• What are the atrioventricular valves of the heart?

  Found between the atria and ventricles of the heart, preventing backflow.
• What are the semi-lunar valves?

  Located between the ventricles and pulmonary artery and aorta. Preventing back flow into ventricles when they relax.
• What does the pulmonary vein do?

  Moves oxygenated blood into the left atrium from the lungs.
• What does the aorta do?

  Moves oxygenated blood from the left ventricle to the rest of the body.
• What does the vena cava do?

  Moves deoxygenated blood into the right atrium from the body.
• What does the pulmonary artery do?

  Moves deoxygenated blood from the right ventricle to the lungs.
• What blood vessels are involved with the left side of the heart?

  The aorta and pulmonary vein
• What blood vessels are associated with the right side of the heart?

  Pulmonary artery and vena cava (although pulmonary artery looks like its on the right)
• How do ventricles differ to atria?

  Ventricles have thicker walls with more muscle. Due to the fact atria only need enough pressure to pump blood a short distance into the ventricles but ventricles need a lot of pressure to pump blood a long distance to other organs.
• How does the left ventricle differ to the right ventricle?

  The left ventricle wall is thicker than the right ventricle wall with more muscle. This is due to the right ventricle only needing enough pressure to pump deoxygenated blood a short distance to the lungs whilst the left ventricle needs a lot of pressure to pump oxygenated blood to further away organs of the body.
• How does a valve open?

  If there’s higher pressure behind the valve, then it will be forced open
• How does a valve close?

  If there’s higher pressure in front of the valve, it is forced shut
• What is the cardiac cycle?

  The sequence of events and contraction and relaxation of the cardiac muscle in the walls of the heart in a single heartbeat. Composed of diastole and systole.
• What does it mean by cardiac muscle is myogenic?

  It beats on its own/ has its own intrinsic rhythm of around 60bpm. This prevents the body wasting resources maintaining the basic heart rate.
• What’s the average resting heart rate of an adult?

  70bpm
• What are the three stages of the cardiac cycle?

  Atrial systole, ventricular systole and diastole
• What occurs during stage one of the cardiac cycle?

  Ventricles relax and the atria contract. This decreases the volume and increases the atrial pressure. The pressure of the atria rises above that in the ventricles. This opens the atrioventricular valves so blood flows into the ventricles. There’s a slight increase in ventricular pressure and chamber volume as the ventricles receive blood from the atria. Ventricular diastole coincide with atrial systole
• What occurs during stage 2 of the cardiac cycle?

  The ventricles contract and the atria relax. The ventricular volume decreases and the pressure increases.

  The pressure in the ventricles rise above that in the atria. This forces atrioventricular valves to lose.

  The pressure in the ventricles rises above that in the aorta and pulmonary artery. This causes the semi-lunar valves to open. Blood lows into the arteries. During ventricular systole, atrial diastole coincides.
• What happens during the third stage of cardiac cycle?

  The ventricles and atria relax. The pressure in the ventricles drops below the pressure in the aorta and pulmonary artery. This causes the semi-lunar valves to close. Blood flows passively into the atria from the vena cava and pulmonary vein.

  Pressure in the atria rises above that in the ventricles. This causes the atrioventricular valves to open. Blood flows passively into the ventricles without the need of atrial systole. The cycle then begins starting with atrial systole.
• What causes the two sounds of a heartbeat? (Lub dub)

  The closing of the valves due to blood pressure. The first sound occurs through the atrioventricular valves closing at the start of ventricular systole preventing the backflow of blood into the atria. The second sound occurs through the semilunar valves closing at the start of ventricular diastole preventing the backflow of blood into the ventricles.