Question

1. The surface of the heart has three layers of membranes to anchor the heart in its place and for lubrication purposes. What is the name of the 2 layers that secret serous fluid for lubrication purpose?

2. Using the skeleton as the reference points, where is the cardiac apex (Left or right of the sternum? Which intercostal space?)

Answer 1

Ans 1) Three layers of membrane of the heart which anchors it to its place perfectly and helps in lubrication is the outermost layer of heart known as pericardium. It surrounds the heart and it helps in protecting as well as lubricating the heart and keep it intact within the chest. The functions of pericardium include: -

• It helps in keeping the heart fixed in its position within the chest cavity
• It helps in preventing friction by lubricating heart and hence it does not create friction with tissues.
• It prevents the heart from overfilling with blood and hence prevents it from being stretched.

The pericardium consists of two layers of serous membrane and as it releases the serous fluid, it prevents the friction by lubricating the heart. Two layers of the pericardium are fibrous and serous pericardium. The fibrous pericardium is the outer layer of pericardium and is attached to the diaphragm which is made of loose and dense connective tissue. It prevents expansion of the blood. The serous pericardium is the one which is responsible for lubricating the heart by producing serous fluid. The two layers which produce the serous fluid are parietal and visceral layer. The visceral layer is the inner layer of serous pericardium and it protects the layers of heart through production of pericardial fluid. The parietal layer is outer layer of serous pericardium which is sandwiched between fibrous and visceral pericardium. The pericardial cavity is present between the visceral and parietal pericardium.