Lecture 2 Flashcards
What is the function of arteries?
They carry blood away from the heart
What is the function of veins?
They carry blood to the heart
What is the function of capillaries?
The exchange either with other cells or air sacs in lungs
What are the layers of the heart wall?
- Epicardium
- Myocardium
- Endocardium
What is the visceral layer of the pericardium?
The epicardium
What are the cardiac muscle cells of the pericardium?
Myocardium
What layer lines the heart chamber?
Endocardium
The interventricular septum is found between the
Right and left ventricles
The pulmonary semilunar valve is found between the
Right and left atria
The tricuspid valve is found on what side of the heart?
Right
The biscuspid / mitral valve is found on what side of the heart?
Left
The AV valves open when
The atrial pressure is greater than the ventricle pressure
What happens when the ventricles contract?
They close the AV valves
What prevents the AV valves to open into the atria?
The contraction of papillary muscles and the tightening of chordae tendineae
The AV valves close when
The atrial pressure is less than the ventricle pressure
The semilunar valves open when
Ventricles contract and have greater pressure
When do the semilunar valves close?
When their cusps fill with blood
What happens when one has Valvular stenosis?
There are stiff flaps which constrict opening, making the heart exert more force to pump blood
What happens when one has an Incompetent valve?
Blood backflows so the heart repumps the same blood over and over again
The coordinated heartbeat is a result of:
- Gap junctions
- Cardiac conduction system
In an AP, depolarization occurs when
Na+ ions come in
In an AP, repolarization occurs when
K+ ions go out
Why do heart muscle cells have longer refractory periods?
Prevents tetanic contraction
