What do you mean by pericardium, Biology

Assignment Help:

Q. What do you mean by Pericardium?

Pericardium is the sac covering the heart. Pericardium consists of two layers-the visceral pericardium (epicardium) and the parietal pericardium. The visceral pericardium directly lines the heart surface. The cavity between the two layers of the pericardium contains approximately 15 to 35 ml. of serous fluid-the pericardial fluid. The visceral pericardium is a thin membrane-a monolayer of mesothelial cells, while the parietal pericardial thickness may be up to 2.5 to 3.0 mm. Perietal pericardium is attached loosely by ligaments to sternum and vertebral bodies and firmly to central tendon of the diaphragm.

The phrenic nerves lie over the parietal pericardium and supply most of it. Vagal fibres from oesophageal plexus also supply pericardium. The internal mammary arteries and small branches from aorta supply the pericardium. The parietal pericardial lymphatics drain to the anterior and posterior mediastinal nodes while the visceral pericardial lymphatics drain to tracheal and bronchial mediastinal nodes. The pericardium buttress the thinner chambers of the heart, the atria and right ventricle and maintains the normal diastolic pressures and dimensions in these chambers. The pericardium can prevent acute cavitary dilatation. The pericardial fluid reduces the friction during heart movement. The ligamentous attachment of pericardium to the neighbouring structures prevent cardiac displacement. The normal intrapericardial pressure can vary from -5 to +5 mm. of Hg. though mostly it is negative. The pericardial pressure varies during respiration along with pleural pressure.


Related Discussions:- What do you mean by pericardium

What is the dissociation and double dissociations, Dissociation and double ...

Dissociation and double dissociations Neuropsychologists typically try to design studies that provide evidence of the differential performance of brain damaged and control subj

What phrase best describes oxidation- reduction reaction, What phrase best ...

What phrase best describes oxidation- reduction reaction? A. phosphoryrylation energezing endergounic reactions b. transferring of electrons from one molecule to another c. shar

Organs in animal - excretion, Normal 0 false false false ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4

Explain about bone lining cells, Explain about Bone lining cells Bone ...

Explain about Bone lining cells Bone lining cells are basically inactive osteoblasts (in terms of making bone) that line bone surfaces. Osteocytes are osteoblasts that have be

Difference between rough and smooth endoplasmic reticulum, Q. What is the d...

Q. What is the difference between rough and smooth endoplasmic reticulum? The endoplasmic reticulum is a delicate membranous structure contiguous to the nuclear membrane as wel

Solubility, Solubility You are aware that gases are soluble in liquid...

Solubility You are aware that gases are soluble in liquid. Solubility of a gas in a liquid depends on the partial pressure, temperature and presence of other solutes. Table

State the term in brief -asconoid sponge, State the term in brief -Asconoid...

State the term in brief -Asconoid sponge? Of the three different sponge architectures, it is the simplest. It comrpsies a central choanocyte lined spongocoel which opens to the

Define selectivity - terminologies used in chromatography, Define Selectivi...

Define Selectivity - terminologies used in chromatography? Selectivity is a measure of preference a stationary phase shows for one solute over another and is expressed as:

What is an accommodation, What is an accommodation? Accommodation is th...

What is an accommodation? Accommodation is the ability of the eye to focus on an object situated at variable distances from the eye. Like a camera, even the eye requires to cha

Write Your Message!

Captcha
Free Assignment Quote

Assured A++ Grade

Get guaranteed satisfaction & time on delivery in every assignment order you paid with us! We ensure premium quality solution document along with free turntin report!

All rights reserved! Copyrights ©2019-2020 ExpertsMind IT Educational Pvt Ltd