Anatomy of the Heart and Coronary Arteries Flashcards
What is the pericardium?
three-layered sac that surrounds the heart
Describe the function of the pericardium
fix the heart in the mediastinum, limit motion, protect from infections, prevent excessive dilation and provide lubrication
Name the three layers of the heart wall
Epicardium, myocardium, endocardium
What is the epicardium?
the visceral layer of the serous pericardium
What is the myocardium?
cardiac muscle (muscle fibres in bundles)
What is the endocardium?
continuous with the endothelium
Trace the flow of blood through the heart
superior vena cava and coronary sinus, right atrium through tricuspid valve, into the right ventricles and through pulmonary semilunar valve, into pulmonary trunk to the lungs (pulmonary artery), then returned to heart in four pulmonary veins into left atrium, blood passes through mitral valve into left ventricle, blood passes through aortic valve and out of aorta to the rest of the body
Describe the internal structures within the right atrium
contains SAN (near SVC) and AVN (next to coronary sinus)
Describe the internal structures within the left atrium
has pectinate muscle in auricle, smooth walls otherwise, and has the mitral valve and fossa ovalis
Describe the internal structures within the right ventricle
contains the walls (trabecular carnae) including the moderator band, has a tricuspid valve held in place by chordae tendinae and papillary muscle
Describe the internal structures within the left ventricle
contains trabeculae carnae, far thicker myocardium and aortic valve
What is cristae terminalis?
smooth ridge in the wall of the right ventricle which has the SAN at the top
What is the pectinate muscle?
meshwork-type muscle lining the atria
What is the fossa ovalis?
remnants of foramen ovale which allowed passage of blood from one atria to the other in foetal development
What is the ductus arteriosum?
present in a foetus and shunts blood from the pulmonary trunk to the aortic arch but this closes at birth to form the ligamentum arteriosum
What is the moderator band?
branch of the conducting system carried by the trabecular carnae of the right ventricular wall
What is the trabecular carnae?
walls of the ventricle with thick ridges
Describe the path of the right coronary artery
On the anterior surface it splits into the right marginal artery which goes towards the heart apex, and posteriorly the right coronary artery continues and produces the posterior descending artery
Describe the path of the left coronary artery
quickly branches into the left circumflex and the left anterior descending (interventricular) artery. There is a diagonal branch from the LAD. The left circumflex artery travels round the heart in the coronary sulcus and also gives off a branch known as the marginal vein which travels to the apex of the heart
Describe the main coronary veins
superior vena cava, inferior vena cava and coronary sinus
