The Heart Flashcards
What is the heart?
- Muscular organ
- Main pump of the body
- Site of attachment of the great vessels
How does the heart lie?
- Oblique lie at approximately 45 angle degree towards the left side
- Sits slightly left of the sternum
What is the apex of the heart?
- Projects inferior, anterior, and left
- Formed entirely by LV
What is the base of the heart?
- Projects superior and posterior
- Pulmonary and aortic vessels sit superiorly
What is the cardiac cycle?
Rhythmic cycle (chambers alternatively contract and reflex)
What is one complete cardiac cycle?
one heart beat. (One systole and diastole)
What are the two types of heart valves?
- Artrioventrocular valves (2)
- Semilunar valves (2)
Each heart valves contains what?
- A ring or annulus
- Leaflets
The AV leaflets also have what?
Papillary muscles and chordae tendinae. These structures serve as anchors for the AV leaflets
What are the atrioventricular valves?
- Inflow valves
- Blood flows from the atria into ventricles
- Opens during ventricular diastole
What are the two AV valves?
Tricuspid and mitral (bicuspid)
What are the semilunar valves?
- Exit ports of the ventricles
- Valves between the ventricles and great vessels
- Contains three crescent shaped cusps
- Open during ventricular systole
What are the two semilunar valves?
Aortic and pulmonary
What are the three layers of the wall?
- Epicardium
- Myocardium
- Endocardium
What is the epicardium?
- Outer layer
- Smooth, thin visceral layer
What is the myocardium?
- Middle layer
- Thick, contractile muscle