The heart Flashcards
What muscle is the heart made off?
Cardiac muscle which doesn’t fatigue
What do coronary arteries do?
They supply cardiac muscle with oxygenated blood
What are components of the heart?
Cardiac muscle, coronary arteries and pericardial membrane
What is the function of pericardial membrane?
It surrounds the heart to prevent heart from over-distending
What does over-distending mean?
Overfilling with blood
What are the valves in the heart?
Atrioventricular and semi-lunar valves
Where are the types of atrioventricular valves?
Tricuspid and bicuspid valves
Where are the atrioventricular valves located?
Between the atria and ventricle
Where is the tricuspid valve located?
Between the right atrium and right ventricle
Where is the bicuspid valve located?
Between the left atrium and left ventricle
Where is are the semi-lunar valves located?
At the end of the pulmonary artery and start of aorta
What is the function of semi-lunar valves?
They prevent blood from flowing backwards in the heart after ventricles have contracted
What is blood pressure?
The pressure exerted on the alls of the blood vessels and is the type of hydrostatic pressure
Where does blood pressure come from?
It originates from the contraction of the ventricle heart muscles
How is blood pressure measured?
In kPa
How longs does the cardiac cycle take in humans?
0.8 at 75 bpm
What does the cardiac cycle consist of?
Diastole and systole
What is diastole?
Heart ventricles relax
What is systole?
Heart ventricles contracts
What happens when cardiac muscles in ventricles relax?
Atria fills with blood and the pressure inside atria exceeds pressure in ventricles.
What is the result of atria filling?
Volume and pressure of heart builds as heart fills and pressure in arteries is minimum
What happens to the semi-lunar valves in diastole?
Semi-lunar valves in aorta and pulmonary arteries shut to prevent blood trickling back
What happens to atrioventricular valves in diastole?
They open so that as blood enters the atria, it can go straight through into the ventricles
What happens as a result of diastole?
Ventricles fills up with blood
