Pericardium

The heart and its pericardium make up the contents of the middle mediastinum. The left and right phrenic nerves and their adjacent arteries (pericardiacophrenic) lie to the left and right of the pericardium and anterior to the roots of the lungs.

Parietal and visceral pericardium are continuous. This continuity takes place at the points where the major blood vessels enter and leave the heart. The parietal pericardium has two inseparable parts, an outer fibrous part and an inner smooth part, the serous part.The potential space between the visceral and serous parietal pericardium is the pericardial cavity.

Second View:

The fibrous pericardium is the outermost layer, and it is firmly bound to the central tendon of the diaphragm. Extrapericardial fat, which may be visible radiographically, is often found in the angles between the pericardium and diaphragm on each side. The pericardium is attached to the sternum (by the sternopericardial ligaments) and is adherent to the mediastinal pleura except where the two are separated by the phrenic nerves.

The serous pericardium  is a closed sac, the parietal layer of which lines the inner surface of the fibrous pericardium and is reflected onto the heart as the visceral layer, or epicardium. The potential space between the parietal and visceral layers contains a thin film of fluid and is known as the pericardial cavity.

Pericardial Sinuses

Within the pericardial cavity, at the points where the visceral and parietal pericardia are continuous with one another, small chambers or sinuses are located. In this diagram, the heart has been removed and you are looking toward the posterior wall of the pericardial cavity.

The pericardial sinuses: transverse pericardial sinus oblique pericardial sinus The transverse pericardial sinus can easily be reached by sticking your finger between the superior vena cava and the ascending aorta and pulmonary trunk. This sinus is a leftover from heart development in the embryo. Again, slide two or three fingers under and behind the heart until they reach a dead end. Your fingers are now in the oblique pericardial sinus. 1. The pericardium starts to form during the _______ week of developme Correct . 5th 2. Which statement is true about the pleuropericardial folds? Correct answer: a. they partition the thorax into a pericardial cavity and two pleural cavities 3. What anatomic structure is located within, and migrates with, each pleuropericardial fold? Correct answer: b. phrenic nerve 4. The pleuropericardial folds initially form and grow along a _________ plane. Correct answer: d. coronal (frontal)