Nervous system - meninges, Biology

Assignment Help:

Meninges (Singular-Meninx) -

  • Ceverings of brain.
  • By infection in meninges meningitis or brain fever is caused.
  • These menings are internally lined by squamous epithelium and of following types -

(i) Duramatter - Outer thick, fibrous attached to inner part of cranium i.e. Endorachis.

(ii) Arachnoid - Middle layer of meninges. Net like in appearance. Made up of squamous epitelium.

(iii) Piamatter - Inner most layer, thin, membranous, blood vessel present. Gives nourishment to brain. This layer enters into dorsal wall of brain & form choroid plexus or tella choroidea. In man choroid plexus are 5 (2 in lateral ventricle, 2 in 3rd ventricle & 1 in 4th ventricle) in rabbit choroid plexus are 2 (1 in dianchephalon & 2nd in medulla oblongeta).

  • Choroid plexus is responsible to form C.S.F. (cerebrospinal fluid). CSF is formed 20 ml/hr.

Note :- Arachnoid and piamatter are collectively known as leptomeninges.

  • In fishes meninx is menias premitiva. In amphibia arachnoid is absent.
  • Between meninges sub dural & sub arachnoid spaces are present filled with little CSF.

2272_meninges.png

MENINGES


Related Discussions:- Nervous system - meninges

Relevance of food packaging, Q. Relevance of food packaging? To unders...

Q. Relevance of food packaging? To understand the relevance of food packaging, it is necessary for us to understand how spoilage reduces the availability of food. In the deve

Lungs, what is the lungs structure in relation to the excretory system?

what is the lungs structure in relation to the excretory system?

Noise pollution, Sound is a main mean of communication and entertainment an...

Sound is a main mean of communication and entertainment and is also very effective alarm system for some animal. A loud and unwanted or unpleasant sound causes discomfort and is ca

Muscles of the legs contribute to the venous return, Q. How do the muscles ...

Q. How do the muscles of the legs and of the feet contribute to the venous return? The muscles of the legs mainly the muscles of the calves compress and contract the deep veins

What are pioneer species, Q. What are pioneer species? What is the role of ...

Q. What are pioneer species? What is the role of the pioneer species? The Pioneer species are those first species that colonize places where previously there were no living bei

Explain about congestive cardiac failure, Q. Explain about Congestive Cardi...

Q. Explain about Congestive Cardiac Failure? It is an end stage heart disease and a significant contributor to morbidity and mortality particularly in the elderly population. C

Impediments to infuse biology - lack of trained people, Define Impediments ...

Define Impediments to infuse biology - Lack of trained people? At present, biologists as a rule have not been trained sufficiently in quantitative approaches. A heavy dose of m

Evolution, describe the two scientific models for evolution (gradualism, pu...

describe the two scientific models for evolution (gradualism, punctuated equilibrium)

What is homocystinuria, Q. What is Homocystinuria? Homocystinuria may r...

Q. What is Homocystinuria? Homocystinuria may result from errors of methionine metabolism. This produces defects in the function of cystathionme b synthase or 5-mcthyltctrahyd

What are the two main subdivisions of the phylum Chordata, Normal 0 ...

Normal 0 false false false EN-IN X-NONE X-NONE MicrosoftInternetExplorer4 What are the two mai

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