Unit Two: The Heart Flashcards
What are the two main layers of the pericardium?
- Fibrous pericardium. 2. Serous pericardium.
What are the 2 layers of the serous pericardium?
- Visceral (epi)pericardium. 2. Parietal pericardium.
Where is the visceral pericardium located?
On the surface of the heart.
What is the fibrous pericardium? What is it composed of?
The tough outer sac. Dense network of collagen fibers.
What is the serous pericardium?
The two layered lining of the pericardium.
What is the pericardial cavity?
The space between the parietal pericardium and the epicardium (visceral pericardium) that covers the outer surface of the heart.
What are the three layers of the wall of the heart? (from superficial to deep)
- Epicardium. 2. Myocardium. 3. Endocardium.
What is the function of the fibrous pericardium?
To stabilize the position of the heart.
What are the two layers of the epicardium?
- A mesothelium. 2. An underlying, supporting layer of areolar tissue.
What is the myocardium?
Cardiac muscle tissue that forms the atria and ventricles. It is the thickest layer.
What is the function of the endocardium?
It covers the inner surfaces of the heart, including those of the heart valves.
What is of clinical significance about the endocardium?
This simple squamous epithelium is continuous with the endothelium of the attached great vessels.
Which has thicker walls atria or ventricles?
Ventricles.
Which ventricle has thicker walls?
The left ventricle.
What do the right and left coronary arteries supply?
The heart wall muscles with oxygen and nutrients.
What are the two branches of the right coronary artery?
- Right marginal. 2. Posterior interventricular.
What does the right marginal artery supply?
The right border of the heart.
What does the posterior interventricular artery supply?
The posterior surface of the left and right ventricle.
What do the coronary arteries branch off of?
The ascending aorta.
What are the two branches of the left coronary arteries?
- Anterior inter-ventricular. 2. Circumflex.
What does the anterior interventricular artery supply?
The anterior surface of both ventricles and most of the inter-ventricular septum.
What does the circumflex artery supply?
The left atrium and ventricle.
Where do the coronary veins bring deoxygenated blood?
The right atrium.
What does the great cardiac vein run alongside?
The anterior interventricular artery.
What does the middle cardiac vein run alongside?
The posterior interventricular artery.
What does the small cardiac vein run alongside?
The marginal artery.
Where do all the cardiac veins drain into?
The coronary sinus.
Where is the coronary sinus located?
In the posterior part of the coronary sulcus.
Where do the right and left coronary arteries travel within?
The coronary sulcus.
What node generated impulses?
Sinoatrial node (pacemaker).
Where do impulses generated in the heart pause?
The atrioventricular node.
What bundle connects the atria to the ventricles?
The atrioventricle bundle.
What stimulates the contractile cells in both ventricles?
Subendocardial conducting network (Purkinje fibers).
A blockage in which coronary vessel would result in a disruption of the conduction system of the heart?
The anterior interventricular.
What happens during systole?
Chambers contract.
What happens during diastole?
Chambers filling/relaxing.
What happens during atrial systole?
Atrial contraction forces a small amount of blood into the relaxed ventricles.
What valves are open during atrial systole?
The atrioventricular (AV) valves (Tricuspid and mitral valve).
What valves are open during ventricular systole?
The semi-lunar valves (aortic and pulmonary valves).
What is blood pressure?
The force of the blood pushing against the inside walls of blood vessels.
What is the systole blood pressure?
Pressure of blood on artery walls while ventricles are contracting.
What is the diastolic blood pressure?
Pressure of blood on artery walls while the ventricles are not contracting.
What creates the “lub” sound?
The AV valves closing.
What creates the “dub” sound?
The semi-lunar valves closing.
What are the chordae tendineae?
Connective tissue fibers where the free edges of the cusps attach.
What are papillary muscles?
Where the fibers of the chodae tendineae arise. They are muscular projections of the inner surface of the right ventricle
What is the function of the chordae tendineae?
They limit the movement of the cusps when the valve closes. This prevents backflow of blood from the right ventricle into the right atrium.
What are the trabeculae carneae?
A series of irregular muscular ridges inside the internal surface of the right ventricle.
Where are pectinate muscles found?
They extend along the inner surface of the right auricle and across the anterior wall of the right atrium.
What structures allow a bypass of pulmonary circulation before lungs are needed?
Foramen/Fossa ovalis and ductus arteriosus.
What is cardiomegaly?
An abnormal enlargement of the heart.
What is a pericardial effusion?
When there is fluid within the pericardial cavity, causing less blood to be able to be taken in.
What is constrictive pericarditis?
A thickening/fibrosis of the parietal pericardium.
