Cardiovascular System Flashcards
what are the chambers of the heart?
2 receiving chambers: right and left atrium (‘entranceway’)
2 main pumping chambers: the right and left ventricles (‘hollow belly’)
describe the left and right atrium?
receives blood returning from the 2 circuits
describe the left and right ventricles?
pumps blood around the 2 circuits
describe the shape of the heart?
Hollow cone-shaped organ about the size of the fist
typical weight 250-350g
what is the largest organ in the mediastinum?
located between the lungs and oblique position with the apex lying left to the midline
what are the four corners of the heart?
Superior right
Inferior right
Superior left
Inferior left (apex point)
why is the four corners of the heart important?
imaginary lines that connect the 4 corner points delineate the normal size and location of the heart
where is the superior right corner?
at costal cartilage of 3rd rib and sternum
where is the Inferior right corner?
at costal cartilage of 6th rib lateral to the sternum
where is the superior left corner?
at costal cartilage of 2nd rib lateral to the sternum
where is the inferior left (apex point) corner?
lies in the 5th intercostal space at the midclavicular line
what is the pericardium?
a triple-layered sac that encloses the heart
what are the layers of the pericardium? describe them
fibrous and serous pericardium
fibrous pericardium, strong outer layer of dense CT (connective tissue)
serous pericardium, formed from 2 layers: the outer parietal pericardium adheres to the inner surface of the fibrous pericardium and is continuous with the visceral layer or epicardium
what are the coverings of the heart?
pericardium and pericardial cavity
what is the pericardial cavity?
between parietal and visceral layers
what is the function of the pericardial cavity?
- epithelial cells secrete a lubricating serous fluid
- reduce friction between the heart and outer wall of the pericardial sac
what are the three layers of the heart?
Epicardium
Myocardium
endocardium
what is the epicardium?
visceral layer of the serous pericardium (often infiltrated with fat)
what is the myocardium?
forms the bulk of the heart
what is the endocardium?
sheet of endothelium resting on a thin layer of CT
what is the myocardium made of?
consists of cardiac muscle tissue (layer that contracts)
CTs bind the cells into elongated circular and spiral bundles
what is the endocardium made of?
sheet of endothelium resting on a thin layer of CT
- lines the heart chambers and covers the heart valves
what are the bundles of the heart?
Function to squeeze blood through the heart in the proper directions
- inferiorly through the atria
- superiorly through the ventricles
what are the superior chambers?
Right and Left atria
divided longitudinally by the interatrial septum