The pericardium

What condition results from an acute type of pericardial effusion where fluid or gas accumulates in the pericardium, resulting in slow or rapid compression of the heart?

Cardiac tamponade

Briefly, what are the four layers/sections of the pericardium?

F - Fibrous layer of the pericardium P - Parietal layer of the serous pericardium S - Serous fluid V - Visceral layer of the serous pericardium

What are the names of the two pericardial sinuses? And what, and where are they?

Transverse pericardial sinus: • Transverse space between the aorta and the pulmonary trunk • It can be used to occlude the pulmonary trunk and aorta during a pulmonary embolectomy or other cardiac operations Oblique pericardial sinus: • Blind sinus located posterior to the left atrium.

Serous pericardium

o Mainly mesothelium that lines the internal surface of the fibrous pericardium and the external surface of the heart visceral epicardium o There's a small amount of serosal fluid within the pericardial cavity o The serous pericardium joins the parietal pericardium and becomes continuous with tunica aventitia (Outer layer of the heart) o It is attached to the posterior sternum via the sternopericardial ligaments

Double serous inner layer

o Parietal serous pericardium o Lines the fibrous layer and is reflected on to the heart at the origin of the great vessels to become continuous with visceral layer of serous pericardium which forms the epicardium of the heart.

Tough outer layer:

• Conical sac covering the heart and great vessels - protects the heart and great vessels. It protects the heart from sudden over filling. • Tough outer layer - fibrous pericardium, this is continuous with and tethered to the central tendon of the diaphragm

What are the functions of the pericardium?

• Fixes the heart in the mediastinum and limits motion . It is attached to the diaphragm • Prevents overfilling of the heart It's a relatively in-extendable fibrous layer and it stops the heart from increasing in size too much • Lubrication A thin fluid, serous between the two layers reduces friction • Protection from infection The pericardium serves as a physical barrier from the muscular body and adjacent organs.

Arteries of the pericardium

• Pericardiophrenic • Musculophrenic • Bronchial • Oesophageal • Superior phrenic • Coronary

Veins of the pericardium

• Pericardiophrenic • Tributaries to azygos

Innervation of the pericardium

• Phrenic nerves (C3-C5) o Sensory o Common cause of referred pain in the shoulder and left arm • Cardiac plexus o Vagus nerves • Parasympathetic Sympathetic trunks Vasomotor