The Heart Flashcards
What body cavity is the heart in?
The mediastinum
Where do the base and apex of the heart point?
The base points towards the right shoulder and the apex points towards the lower left abdomen.
What are the three layers of the heart?
The pericardium, the myocardium, and the endocardium.
What is the pericardium of the heart made of?
It is a double walled fibrous sac
What are the layers of the pericardium? What are their functions?
Outermost layer: Fibrous pericardium is the thickest layer of the pericardium and protects and anchors the heart as well as prevents overfilling
The inner layer is the serous pericardium and is composed of a parietal layer outside of a visceral or epicardium layer outside of a fluid filled pericardial cavity.
What layer of the heart is the muscle located in?
The myocardium.
What are the cardiac muscles wrapped in?
Connective tissue wrappings
What are the three functions of cardiac connective tissue wrappings?
- They reinforce myocardium internally and anchor the muscle fibers
- It provides support for vessels and valves
- It directs the spread of actions potentials across the heart
What is the composition of the endocardium?
it is a layer of endothelium and connective tissue on the inner myocardial surface and is continuous with vessels
What are the two sulci on the heart?
The coronary sulcus or atrioventricular groove, and the anterior/posterior interventricular sulcus
What are the three sources of oxygen poor blood into the right atrium?
- The superior vena cava (above the heart)
- The inferior vena cava (below the heart)
- The coronary sinus (wall of the blood itself in the coronary sulcus)
What are the 4 veins that carry oxygenated blood?
pulmonary veins
What are the small muscles called primarily found in the right atrium?
Pectinate muscles
What is the opening between the left and right atrium found in babies called?
The foramen ovale
What does the closed foramen ovale become?
the fossa ovalis.
What blood vessel does the right ventricle send blood out of?
The pulmonary trunk
What blood vessel takes blood from the left ventricle to the body?
The aorta
What are the two types of muscle found in the ventricles? What is the differentiating characteristic?
Trabeculae carneae
Papillary muscles link the chordae tendineae
What are the two classifications of heart valves?
There are two atrioventricular valves and two semilunar valves
What are the names of the atrioventricular valves?
The right one is called the tricuspid valve and the left is called the mitral or bicuspid valve.
What are the two semilunar valves called?
The valve exiting the right ventricle is the pulmonary valve, and the valve exiting the left ventricle is the aortic valve.
What are the two types of valve problems?
Valvular insufficiency is the valves not closing all the way, and stenosis is the stiffening of the valves due to calcification or scar tissue
What has more resistance? The pulmonary blood circuit or the systemic one?
The systemic circuit has 5x the resistance.
Which ventricle has thicker walls? By how much?
The left ventricle is 3X thicker.
Where do the left and right coronary arteries come from? Where are they located?
They come from the base of the aorta and wrap around the coronary sulcus.
What does the left coronary artery branch into?
The circumflex artery (around the back) and the anterior interventricular artery.
What branches off from the right coronary artery?
The right marginal artery anteriorly, and posteriorly the posterior interventricular artery.
What is important about the coronary arteries come from the base of the aorta?
They deliver blood when it is relaxed. When the ventricles are contracting, they constrict the coronary arteries.
What are anastomoses in the heart?
They are direct linking of arteries and are important for providing alternative pathways for blood flow.
What does angina pectoris mean?
Chest pain
What is a myocardial infarction?
A heart attack is a complete blockage and no blood moving to an area of the heart.
What four cardiac veins feed into the coronary sinus?
The great cardiac vein (left)
Middle cardiac vein (posterior)
The small cardiac vein (lower right)
The anterior cardiac veins (upper right)
What is the biggest difference between skeletal and cardiac muscle cells?
Cardiac muscle has intercalated discs
What are the two types of junctions in intercalated discs?
Gap junctions for electrical coupling
desmosomes for strong cell to cell adhesion
What is the phenomenon that gap junctions allow for?
functional syncytium
What are the two types of cardiac muscle?
contractile and autorythmic
What percentage of cardiac muscle cells are pacemakers?
roughly 1 percent