The heart Flashcards
Draw a diagram showing the internal structure of the heart and label the components
What side of the heart does deoxygenated blood flow into?
The right side of the heart
What side of the heart does oxygenated blood flow into?
The left side of the heart
Which side of the heart pumps the blood around the rest of the body?
The left side of the heart
Which side of the heart pumps the blood to the lungs?
The right side of the heart
Which side of the heart is bigger and more muscular?
The left side of the heart
What separates the two sides of the heart?
The septum
What do the coronary arteries do?
They carry oxygenated blood to the cardiac muscles of the heart which enables the heart to keep contracting
How is the heart prevented from over distending with blood?
The heart is surrounded by inelastic pericardial membranes which prevents this from happening
Draw a diagram showing the external structure of the heart and label the components
Which sections of the heart does the blood flow into?
The atriums
How does the deoxygenated blood from the top half of the body enter the heart?
Through the superior vena cava
At what pressure does the blood enter the heart?
At relatively low pressure
How does the deoxygenated blood from the lower part of the body enter the heart?
Through the inferior vena cava
How do the walls of the atria compare to the walls of the ventricles?
The muscular walls of the atrium are relatively thin compared to the walls of the ventricles; which need more muscle in order for a more powerful contraction.
How does the blood move from the right atrium to the right ventricle?
As the blood flows into the right atrium the pressure slowly builds up until the atrio-ventricular valve (tricuspid valve) opens to let the blood pass into the right ventricle.
What happens when both the right atrium and ventricle are filled with blood?
The atrium contracts, forcing all the blood into the ventricle which stretches the ventricle walls
How is the back flow of blood to the atrium prevented as the ventricle starts to contract??
The atrio-ventricular valve closes
What do the tendinous cords do?
They stop the valves from being turned inside out by the pressure from when the ventricles contract.
How does the blood enter the pulmonary artery?
The right ventricle contracts fully and pumps the deoxygenated blood through the semi-lunar valves and into the pulmonary arteries
Where does the pulmonary artery lead to?
The capillary beds of the lungs
How is the back-flow of blood from the pulmonary artery to the heart prevented?
Via the semi-lunar valves
What is the septum and what is its function?
The septum is an inner wall of the heart which divides both sides. It is there to prevent oxygenated and deoxygenated blood from mixing.
When is the development of the septum complete in a human?
Until after birth
What is a gap in the septum referred to?
A hole in the heart
What does a hole in the heart sound like under a stethoscope?
A heart murmur
true or false? Many people have a small hole in their septum
TRUE
What is the cardiac cycle?
It describes the events in a single heartbeat
How long does a single heartbeat last in the average adult human?
0.8 seconds
What is diastole?
When the heart relaxes