Anatomy and Physiology of the Heart Flashcards
What is the apex of the heart?
-Bottom of the heart formed by tip of left ventricle and positioned just above the diaphragm to the left of the sternum at the fifth intercontinental space, midclavicular line
What is the point of maximal impulse?
The physical examination landmark of the apex of the heart (5th left intercostal space, midclavicular line) which can be palpated during ventricular contraction
-Indicator of the heart’s position within the thorax
Name the three layers of the heart.
Pericardium: the outermost layer
Myocardium: the middle muscular layer
Endocardium:the inner layer
What is the function of the pericardium?
-Encloses and protects the heart
-Consists of two components
1. Fibrous Pericardium
2. Serous Pericardium
What is the pericardial space?
The space between the parietal and visceral layer of the serous pericardoum containing 10-30ml of thin, clear fluid called pericardial fluid
What is the myocardium?
The thick, middle, muscular layer that makes up the bulk of the heart wall
-Composed primarily of cardiac muscle cells which are responsible for the heart’s ability to contract
What is the endocardium?
A thin layer of tissue thar lines the inner surface of the heart muscle and heart chambers
-Extensions and folds of this tissue form the valves of the heart
What is the pulmonary circuit?
A small circuit including blood vessels within the lung and those carrying blood between the heart and lungs
What is the systemic circuit?
A large circuit that includes coronary circulation, blood vessels within the body, and those carrying blood to and from the body
Describe the difference in blood flow between the pulmonary artery and the pulmonary vein.
PULMONARY ARTERY: the right ventricle pumps venous (deoxygenated) blood through the pulmonary arteries into the lungs
PULMONARY VEIN: arterial (oxygenated) blood returns through the pulmonary vein to the left heart
Where is the tricuspid valve?
Separates the right atrium from the right ventricle
Where is the pulmonic valve?
Separates the right ventricle from the pulmonary arteries
Where is the mitral valve?
Separates the left atrium from the left ventricle
Where is the aortic valve?
Separates the left ventricle from the aorta
What is the primary function of the valves of the heart?
Allows blood to flow in one direction through the heart’s chambers and prevent a backflow of blood (regurgitation)
Which valves make up the atrioventricular valves?
- Tricuspid Valve
- Mitral (Bicuspid) Valve
Which valves make up the semilunar valves?
- Pulmonic Valve
- Aortic Valve
What is the function of the chordae tendinae and papillary muscles?
- When the AV valves are open they and the valve leaflets form a funnel to promote blood flow into the ventricles
- Backflow of blood into the atria is prevented by contraction of the papillary muscles and the tension in the chordae tendinae
The closure of which valves makes up the first heart sound (S1)?
-Tricuspid and mitral valves
-Best heard at the apex of the heart (5th left intercostal space, midclavicular line)
The closure of which valves makes up the second heart sound (S2)?
-Aortic and Pulmonic Valves
-Best heard over the second intercostal space on the left or right side of the sternum
Describe atrial kick and it’s purpose.
ATRIAL KICK: atrial contraction that accounts for an additional 20-30% to ventricular filling volume
-A loss of atrial kick may result in incomplete filling of the ventricles and a reduction in cardiac output
Name the coronary arteries.
- Right Main Coronary Artery
- Left Main Coronary Artery
-Left Circumflex Coronary Artery
-Left Anterior Descending - Posterior Descending Artery (determines dominance)
