A5 Heart Flashcards
Name the 4 chambers of the heart
Left and right atrium
Left and right venricle
Describe the direction of blood flow from the right atrium
to the pulmonary artery
Right atrium –> atrioventricular valve –> right ventricle –>
semi lunar valve –> pulmonary artery
Name the 2 veins that bring blood into the atria
Vena Cava
Pulmonary vein
Name the blood vessel labelled B and state its function
Aorta
Carries blood from the left ventricle to the rest of the body
Name the blood vessel labelled A
Coronary artery
Name the chambers labelled A, B, C ad D
A = Right atrium
B = Right ventricle
C = Left atrium
D = Left ventricle
Name the 2 arteries that carry blood away from the ventricles
Aorta
Pulmonary artery
Name the valves found in the heart
Atrioventricular valves
Name the blood vessel labelled A and state its function
Pulmonary artery
Transports blood from right venricle to the lungs for gas exchange
What is the function of the atrioventricular valves?
Prevent the back flow of blood into the atria when the ventricle walls contract.
Explain why the atria walls are thinner than the ventricle walls.
Blood does not need to be pushed under high pressure so walls do not need to contain large amounts of muscular tissue
Name the blood vessel labelled C
Vena cava
What is the function of the blood vessels labelled A
Deliver oxygen and glucose to the heart muscle cells
Required for aerobic respriation
Releases ATP
ATP provides energy fpr heart muscle contraction
Describe what happens during atrial systole
Atria contract.
Blood pressure in the atria increases
Atrioventricular valves open
Blood is pushed into the ventricles.
Name the structure labelled X and state its function
Atrioventricular valve
Prevent blood flow from left ventricle to left atrium
when the ventricle wall contracts
Describe what happens during ventricular systole
Ventricles contract.
Blood pressure in the ventricles increases
Atrioventricular valves close
Semi lunar valves open
Blood flows into the arteries.
The heart tissue is myogenic. What does this mean?
The contraction of the heart is initiated from within the muscle rather than by nerve impulses.
Explain how the contraction of the heart is controlled.
SAN generates a wave of electrical excitement that cross the atria, causing the muscle to contract
AVN receives, delays and then passes an electrical impulse down the bundle of His to the apex of the heart.
Impulse travels into the Purkinje fibres which branch across the ventricles causing them to contract from the apex upwards
Why does the AVN delay the impulse along the bundle of His?
Allow time for the blood to pass through the
atrioventricular valve and into the ventricles
Name the blood vessel labelled X
Pulmonary vein
Name the blood vessel that delivers blood to the kidney
Renal artery
Name the blood vessels that transport blood to and from the lungs
Pulmonary artery
Pulmonary vein
The graph shows the pressure changes in the heart.
Describe what happens at point A
Atrioventricular valve closes
Pressure in the ventricle is higher than in the atrium
The graph shows the pressure changes in the heart.
Describe what happens at point B
Semi lunar valve opens
Pressure in the ventricle is higher than in the aorta
The graph shows the pressure changes in the heart.
Describe what happens at point C
Semi lunar valve closes
Pressure in the aorta higher than in the ventricle
The graph shows the pressure changes in the heart.
Describe what happens at point D
Atrioventriclar valve opens
Pressure in the atrium is higher than in the ventricle
