What is the anatomical position of the heart within the chest?
The heart is located in the middle mediastinum and is covered anteriorly by the costal cartilages of the third, fourth and fifth ribs.
Describe the reflections of the pericardium and describe the location of the transverse and oblique sinuses
The pericardium is made up of a visceral layer, which is adherent to the heart, and a parietal layer, which forms the inner surface of the pericardial sac. There is a small amount of serous pericardial fluid between the two layers. There are two recesses within the pericardium: the transverse sinus and the oblique sinus. The transverse sinus is bounded anteriorly by the posterior surface of the aorta and the pulmonary trunk and posteriorly by the anterior surface of the interatrial groove. The oblique sinus is the space behind the left atrium and is bounded by the pericardial reflections of the inferior vena cava and the pulmonary veins.