Human heart Flashcards
Structure of the heart:
4 chambers:
-right atrium - right ventricle
-left atrium -left ventricle
Each chamber is connected to a blood vessel:
Pulmonary artery, vena cava, aorta, pulmonary vein
Where does blood become oxygenated?
Blood becomes oxygenated in the lungs.
It moves from the lungs to the heart via the pulmonary vein.
It moves from the heart to the rest of the body via the aorta.
What are the valves in the heart called?
atrioventricular valves
Semi-lunar valves
Role of the valves
To prevent backflow of blood
What is the correct order of structures that blood passes through on the right side of the heart?
Right atrium,
Atrioventricular valve,
Right ventricle,
Semi-lunar valve
What is the correct order of structures that blood passes through on the left side of the heart?
Left atrium,
Left ventricle,
Atrioventricular valve,
Semi-lunar valve
What are the vessels that supply the heart with blood called?
Coronary arteries
Explain how a myocardial infarction/ heart attack occurs.
A myocardial infarction occurs when blood flow in the coronary arteries reduces.
This means the amount of oxygen reaching the heart muscle also reduces.
As a result, the heart cells respire less and start to die.
Factors associated with cardiovascular disease
-smoking
-high blood pressure
Blood enters the atria via…
Pulmonary veins & Vena Cava
Cardiac cycle:
1) blood enters the atria
2) Then the atria contract, pushing blood into the ventricles
3) Finally, the ventricles contract, pushing blood out of the heart
1) Diastole
Atria and ventricles are both relaxed and blood enters the atria. When the pressure of the blood in the atria is greater than the ventricles, the atrioventricular valves open. Allows blood too enter ventricles as well.
2) Atrial Systole
Atria contract, causes volume of atria to decrease and pressure in atria to increase . This pushes blood out of atria and into ventricles
3) Ventricular Systole
Ventricles are filled with blood. When the pressure in the ventricles is greater than the pressure in the atria, the atrioventricular valves close. This prevents back flow of blood into the atria. Then ventricles contract which causes volume to decrease and pressure to increase. When the pressure in the ventricles is greater than the pressure in the blood vessels, the semi- lunar valves open.
When the pressure in the ventricles is greater than the pressure in the atria, the atrioventricular valves close.
They do this to…
Prevent backflow of blood in the atria
