Unit 4 - Cardiovascular System Flashcards
What is the cardiovascular system composed of?
heart and system of vessels
What is the main two functions of the cardiovascular system?
- contribute the blood to the tissues of the body
- flow the blood through the lungs for exchange of gases
Where is the heart located?
Mediastinum - middle of the thoracic cavity, between two lungs
What is the shape of the heart?
- rounded cranial end called the base of the heart
- apex of the heart is located at the caudal end
How is the heart attached to the thoracic cavity?
Large arteries and pericardial sac
What is the pericardial sac?
membrane that surrounds the heart and keeps it locked in place, contains fluid for lubrification
What are the two components of the pericardium?
Visceral pericardium: adherent to the outer surface of the heart
Parietal pericardium: outer layer
in between lies the pericardium fluid
What are the functions of the pericardium?
- limits motion of the heart
- keeps it from over-expanding
- reduces friction when the heart is beating
What are the three layers of the heart?
Endocardium
Myocardium
Epicardium
What is the function of the endocardium?
- innermost layer of the heart
- in direct contact with the blood
- line the chambers of the heart
- forms a double layer in the valves
What is the function of the myocardium?
- placed underneath the endocardium
- consists of muscles fibers and connective tissue
- form the fibrous rings around the valves
What is the function of the epicardium?
- outermost layer which includes connective tissue
- also considered part of the pericardium
What are the two chambers of the heart?
Left atrium and right atrium
What is the function of the atria?
receive blood from large veins to the heart
How can the atria be identified from the outside of the heart?
by the auricles, blind pouches that look like “earflaps”
What are the atria separated by?
interatrial septum
What happens once the atria is full of blood?
atria wall contracts and pushes blood into the ventricles
What are the two types of ventricles?
Left ventricle and right ventricle
What is the function of the ventricles?
pump blood out from the heart and contain coronary blood vessels
What are the ventricles separated by?
interventricular septum
How are the ventricles visible from the outside of the heart by?
interventricular groove
What is the groove that separates the atria from the ventricles?
atrioventricular groove
What is the function of the septum?
Divides the heart into right and left sides, avoids mixing the oxygenated blood from the deoxygenated blood
What can the septum of the heart be divided into?
Interatrial septum
Interventricular septum
Where are the four valves of the heart located?
two are located between the right and left atria and their respective ventricles
two are located between the right and left ventricles and the arteries they eject blood into
What are the names of the four valves of the heart?
Bicuspid valve
Tricuspid valve
Pulmonary valve
Aortic valve
What is the function of the bicuspid valve?
separates the left atrium from the left ventricle and has two leaflets
What is the function of the tricuspid valve?
Has three leaflets, separates the right atrium from the right ventricle
What are the valves of the heart connected to?
Connected to fibrous tissues called chrodae tendinae
Which are in turn attached to papillary muscles
What do the contraction of the heart valve muscles do?
Contraction of the chordae tendinae and the papillary muscles makes the valves open and close
What is the function of the pulmonary valve?
opening ad closing the pulmonary trunk
What is the function of the aortic valve?
opening at the aorta