It is a closed sac having two layers: the visceral layer (epicardium), immediately surrounding the heart, and the outer parietal layer, forming the sac, composed of strong fibrous tissue, the fibrous pericardium, lined with a serous membrane, the serous pericardium. Synonym(s): heart sac, theca cordis.
The right and left cavernous sinuses are interconnected by the anterior and posterior intercavernous sinuses. Tributaries of the cavernous sinus include the superior ophthalmic, superficial middle cerebral, and inferior cerebral veins and the sphenoparietal sinus.
Kidneys are bean shaped organs approximately 11 to 14 centimeters long, 6 centimeters wide and 4 centimeters thick. Located in the abdominal cavity, they lie retroperitoneally. The right kidney is placed lower than the left, with the latter being slightly more medial than the former. The left kidney is at the level of T12 to L3, and its counterpart slightly lower.[ 2 ]. The image shows the location of both kidneys: the left at the T12 to L3 level and the right lower than the other.