Identify the parts of the right atrium.
Pectinate muscles are more developed in the right atrium than left, also found in auricles. Auricle is an ear-shaped muscular pouch, often a place where blood stasis occurs and thrombi form. AV orifice is the opening between the R atrium and ventricle, guarded by the tricuspid valve. Coronary sinus is a collection of coronary veins on the posterior side of the heart. Crista terminalis is the origin of the pectinate muscles, may be important in development of atrial arrhythmias.
Identify the parts of the right ventricle.
Moderator band- muscle attaching IVS to anterior papillary muscle. part of electrical conduction pathway (RBB of AV bundle).
Conus arteriosus- conical pouch in upper left of rt ventricle, where pulmonary trunk/artery originates.
Trabeculae carneae, pulmonary & tricuspid valves, papillary muscles, chordae tendineae, IVS.
Identify the parts of the left atrium.
Left auricle/left atrial appendage (LAA)- small muscular pouch, potential area for blood clots in A-fib, mediates thirst & produces ANP.
Smooth walled vs right atrium. Left & Right pulmonary veins, Left AV orifice, Mitral/bicuspid valve.
Identify the parts of the left ventricle.
Apex, chordae tendineae, papillary muscles, mitral valve, aortic valve.
Smaller, more numerous trabeculae carneae
Identify the great vessels (aorta, pulmonary trunk (R&L
pulmonary arteries), pulmonary veins, superior vena cava, inferior vena cava, brachiocephalic artery (R&L), subclavian & carotid arteries, brachiocephalic veins.
Identify the ligamentum arteriosum.
Remnant of the ductus arteriosus. Small ligament connecting left pulmonary artery to proximal descending aorta. Associated w/ left recurrent laryngeal nerve, which branches off left vagus nerve, loops around the aortic arch, and posterior to the ligamentum arteriosum, then ascends to larynx.
Identify the RCA, Rt marginal branch, Posterior interventricular branch (if Rt dominant,~67%), and conal branch (off of RCA, supplies conus arteriosus (conical pouch in upper left RV from which the pulmonary trunk arises).
ID the LCA, LAD/anterior interventricular, LCX, left marginal branches. Left & Right conal branches.
Left and right conal branches connect/anastamose (source of collateral flow, supplies conus arteriosus).
Posterior interventricular branch from LCA in some people (~33%).
ID the cardiac veins.
Anterior cardiac veins- 3-4 small vessels that collect blood from the R ventricle & drain directly into the R atrium (unlike most other cardiac veins that drain into the coronary sinus).
Great cardiac vein w/ left marginal vein & posterior vein of L ventricle, middle cardiac vein, small cardiac vein, coronary sinsus.
Location of SA & AV nodes.
SA node is at the junction b/w SVC & crista terminalis.
AV node is at the posteroinferior region of the interatrial septum, near the opening of the coronary sinus into the R atrium.
ID the thoracic aorta.
part of aorta in the thorax, continuation of descending aorta, w/in the posterior mediastinum.
Bronchial arteries supply lungs (2 left, 1 right)
Esophageal arteries supply middle 1/3rd of esophagus (4 or 5)
Posterior intercostal arteries supply the intercostal spaces (11-12)
ID the thoracic duct.
b/w azygous vein & descending aorta
ID the esophagus.
ID lung fissures.
ID trachea, main bronchi, lobar bronchi, segmental bronchi.
ID costomediastinal and costodiaphragmatic recesses.
ID parietal and visceral pleura.
ID the pulmonary ligament and post-mortem lung impressions.
Pulmonary ligament is a double layer of pleura (parietal and visceral) below the root of the lung & anterior to the esophagus.
Rt lung impressions (SVC, brachiocephalic vein, IVC, small cardiac impression, azygous arch, esophagus).
Lft lung impressions (large cardiac impression, lft subclavian artery, aortic arch and descending aorta)
ID lung lobes, lingula, cardiac notch.
Holds heart in place, limits expansion, allows movement for contraction (wringing movement).
ID mediastinal divisions.
Transverse thoracic plane- sternal angle to T4-T5 vertebral bodies.
Superior mediastinum contains trachea & great vessels.
Middle mediastinum- heart,
Inferior mediastinum- descending aorta, thoracic duct, azygous veins, sympathetic chain & splanchnic nerves, esophagus, etc.