Anatomy of The Heart Flashcards
What are the boundaries of the middle mediastinum?
Superior - sternal angle (T4/5)
Inferior - xiphisternum (T9)
Left Lateral - 5th intercostal space
Right lateral - along sternal border
What is the pericardium?
A tough, double-layered sack covering the heart that contains serous fluid.
What are the layers of the pericardium?
Visceral (epicardium) - serous epithelium closely applied to the heart and continuous with the parietal layer
Parietal layers - (1) serous epithelium continuous with the visceral layer and (2) thick, fibrous layer continuous with the great vessels entering and leaving the heart
What condition results if blood fills beneath the pericardium?
Pericardial tamponade, which can strangle the heart.
Where are the sinuses formed on the heart by the visceral and parietal layers where they are continuous with the great vessels entering and leaving the heart?
Transverse sinus - lies above the entry of the 4 pulmonary veins
Oblique sinus - below the pericardial reflection between the pulmonary veins
Both are located posteriorly and seen from the left where the reflections are located
What is the path of blood flow through the heart?
The SVC and the IVC carry deoxygenated s to the right atrium
The right atrium contracts sending blood through the tricuspid valve to the right ventricle
The right ventricle contracts, pumping the deoxygenated blood through the pulmonary semilunar valve into the pulmonary trunk and into two pulmonary arteries.
Four pulmonary veins, carry oxygenated blood into the left atrium
The left atrium pumps blood through the bicuspid/mitral valve to the left ventricle
The left ventricle contracts sending blood through the aortic semilunar valve into the aorta
What are the 5 important features of the right atrium and their function?
Pectinate muscles - rough, comb-like muscle lining the atrium
Coronary sinus - receives deoxygenated blood from cardiac veins
Crista terminalis - a bump on the inside of the RA below the SVC that contains the SA node
SVC and IFC both open into the right atrium
Fossa Ovalis - adult remnant of the foramen ovale
What are the 5 important features of the right ventricle and their function?
Tricuspid valve
Chordae tendinae - tendonous cords that connect the tricuspid valves to papillary muscles
3 Papillary muscles - keeps the valve from prolapsing (anterior, posterior, septal)
Trabeculae carnae - rough meat; rough muscle lining the ventricle
Moderator band (septomarginal trabeculae) - a bump containing the bundle of His conductive fibers
What are the 4 important features of the left atrium and their function?
Fossa ovalis - adult remnant of foramen ovale
Openings of pulmonary veins - returns oxygenated blood from the lungs
Pectinate muscles - rough muscular lining
Auricle - increases volume of the left atrium
What are the 4 important features of the left ventricle and their function?
Bicuspid/Mitral Valve
Chordae Tendinae - tendinous cords that connect the bicuspid valves to papillary muscles
2 Papillary Muscles - keeps the valve from prolapsing (anterior and posterior)
What branches supply the heart?
The right and left coronary arteries from the aorta.
What are the branches of the right coronary artery and the veins they travel with?
Right posterior descending artery (located at septum) with the middle cardiac vein
Right Marginal artery with the small cardiac vein
What are the branches of the left coronary artery and the veins they travel with?
Left anterior descending artery with the great cardiac vein (“The Widowmaker”)
Left circumflex artery
What supplies parasympathetic innervation to the heart?
The vagus nerve (CN X) slow heart right.
What supplies sympathetic innervation to the heart?
Postganglionic fibers from T1 - T5 of the sympathetic trunk to increase heart rate
