Where is a rat's heart located? - briefly
The rat’s heart lies within the thoracic cavity, positioned between the lungs and slightly left of the midline, encased by the rib cage. It is situated just posterior to the sternum and anterior to the vertebral column.
Where is a rat's heart located? - in detail
The cardiac organ of a laboratory rat resides within the thoracic cavity, embedded in the mediastinum between the right and left lungs. It is positioned slightly to the left of the midline, beneath the sternum and above the diaphragm. The apex points caudally toward the fifth intercostal space, while the base faces cranially, adjacent to the great vessels.
Surrounding structures include:
- Bilateral pulmonary lobes covering the lateral aspects.
- The trachea and esophagus situated ventrally, anterior to the heart.
- The thoracic aorta and inferior vena cava entering and exiting the base of the organ.
- The pericardial sac, a fibrous membrane that encloses the heart and attaches to the diaphragm inferiorly.
In a typical adult rat, the heart measures approximately 10–12 mm in length and 6–8 mm in width, with a mass of 0.3–0.5 g. The organ is anchored by the pericardial ligaments to the sternum and the diaphragm, providing stability during respiration. The left ventricle forms the predominant mass, reflecting the species’ high metabolic rate and the need for efficient systemic circulation.