Heart Flashcards
What is the size of the heart?
About the size of a clenched fist (12 cm long, 9 cm wide, 6 cm thick)
Where is the heart located?
In the thoracic (chest) cavity, midline between the sternum and the vertebrae, between the 2nd and 5th ribs.
What encloses the heart?
The heart is enclosed in the pericardium, a membranous sac made up of 2 layers which protect the heart and anchors it in place.
What are the three layers of the heart wall?
1) Endocardium: a thin layer of endothelium.
2) Myocardium: middle layer of heart, makes up the bulk of the heart wall.
3) Epicardium: thin external membrane covering the heart.
What are the upper chambers of the heart called?
Atria: they receive blood returning to the heart.
What are the lower chambers of the heart called?
Ventricles: they receive blood from the atria and pump it out of the heart.
What is the function of the heart valves?
To ensure that blood flows in the proper direction.
How many valves does the heart have?
The heart has 4 valves.
What are the atrioventricular valves?
Valves located between the atrium and ventricle which allow blood to flow from the atria into the ventricles.
a) Tricuspid valve – right AV valve, has 3 cusps.
b) Bicuspid valve (mitral) – left AV valve, has 2 cusps.
What are the semi-lunar valves?
Valves that consist of 3 cusps and are located where the major arteries leave the ventricles.
a) Aortic valve – found where the left ventricle meets the aorta.
b) Pulmonary valve – found where the right ventricle meets the pulmonary artery.
