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

Original density in CFU/ML, a nutrient agar plate labelled 10^(-5)ml had 15...

a nutrient agar plate labelled 10^(-5)ml had 154 colonies after incubated. what is the cell density in the original sample

Define essential parts of photocolorimeter - sample cuvettes, Define Essent...

Define Essential Parts of Photocolorimeter - Sample Cuvettes? For accurate and precise reading, cuvette must be transparent, clean, devoid of any scratches and there should be

Scientific name, what is a scientific name of mango?

what is a scientific name of mango?

Relation between the hypophysis and the hypothalamus, Q. What is the relati...

Q. What is the relation between the hypophysis and the hypothalamus? The hypothalamus is a part of the brain situated just above the hypophysis and the hypothalamus gets centra

Explain the types of basic forces, Q. Explain the types of basic forces? ...

Q. Explain the types of basic forces? Compression: This refers to the squeezing of the test material so that it still remains as a single undivided unit but may occupy less v

What is class asteroidea, What is Class Asteroidea ? Sea stars are prob...

What is Class Asteroidea ? Sea stars are probably one of the most recognizable of all Echinoderms. Often beautifully colored and symmetrical, they are predators that feed vorac

Cation exchange capacity, Cation Exchange Capacity The adsorption of a ...

Cation Exchange Capacity The adsorption of a cation by a colloid nucleus or micelle and the accompanying release of one or more ions held by the micelle is termed as 'cation ex

What are non-threshold approaches, Non-threshold  approaches For  gene...

Non-threshold  approaches For  genetic carcinogenes, the  "NOEL-safety factor"  approach  is generally  not considered a suitable method for setting the acceptable intake level

Explain adverse effects of ribavirin, Adverse Effects of Ribavirin  Sys...

Adverse Effects of Ribavirin  Systemic ribavirin has been associated with hemolytic anemia. Oral ribavirin plus interferon appears to cause a higher incidence of cough, pruritu

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