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

Simple proteins, SIMPL E PROTEINS The proteins are made of amino acids...

SIMPL E PROTEINS The proteins are made of amino acids only. Additional chemicals are absent. These are of two types -    (i) Fibrous        (ii) Globular ( i )

Determine the concept of numeric pyramid, In a numeric pyramid to which tro...

In a numeric pyramid to which trophic level does the base always refer? What about the top level? In a numeric pyramid the base corresponds to the first trophic level, i.e., to

Explain the cell cycle in details, Explain the cell cycle in details? M...

Explain the cell cycle in details? Most cells of higher organisms follow a cyclic pattern of division. The bulk of the cycle consists of the stage known as interphase, the peri

Donor selection and kidney preservation, DONO R SELECTION & KIDNEY PRESERV...

DONO R SELECTION & KIDNEY PRESERVATION - A kidney donor should be free of hypertension, diabetes & melignancy. Cardaveric kidney is obtained from brain death person. Kidney

Are bacteria the only prokaryotic beings, Are bacteria the only prokaryotic...

Are bacteria the only prokaryotic beings? Prokaryotic beings are classified into two big groups: archaebacteria and bacteria (this last also known as eubacteria). Compared

Why poriferans and cnidarians do not have excretory systems, Poriferans and...

Poriferans and cnidarians do not have excretory systems. Do platyhelminthes have an excretory system? Platyhelminthes have a primitive excretory system made of flame cells (als

What are the factors to measure such a prediction, You are interested in pl...

You are interested in plant life history evolution, you come across a population of the California poppy that i spolymorphic (mixed) for both iteroparous ans semeparous individuals

Illustrate about nervous system, Illustrate about Nervous System Functi...

Illustrate about Nervous System Functional unit of nervous system is neuron. Neuron is nerve cell. Information passes through neurons by nerve impulses. Nervous system corre

What is the enzyme reverse transcriptase present in hiv, Q. Which type of v...

Q. Which type of virus is the HIV? What is the enzyme reverse transcriptase present in HIV? HIV is a retrovirus that is RNA viral (its genetic material is RNA and not DNA).

What is the formula of the net primary production, Q. What is the formula o...

Q. What is the formula of the net primary production (NPP)? How does NPP relate to the energy pyramids? The Net primary production is the gross primary productivity less the or

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