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

Foot as burrowing organ, Foot as Burrowing Organ The Scaphopoda that ...

Foot as Burrowing Organ The Scaphopoda that usually have burrowing habit, possess foot suitably modified for burrowing purpose. The conical and protrusible foot of Dentalium

Explain full liquid diet, Explain Full Liquid Diet Full Liquid Diet:  ...

Explain Full Liquid Diet Full Liquid Diet:   This diet provides foods and fluids that are liquid or semi liquid at room temperature. The type of food provided may vary dependi

Which statement is true of the energy levels, Which statement is true of th...

Which statement is true of the energy levels of electrons in shells? A) All the electrons in an atom have similar amounts of energy. B) Electrons must lose energy to move from the

Define microscopical examination of starch granules, Define Microscopical E...

Define Microscopical Examination of Starch Granules? Take a slide and make a thin film of a suspension of starch granules from different sources and examine under a microscope.

Define neural and neurotransmitter control, Q. Define Neural and Neurotrans...

Q. Define Neural and Neurotransmitter Control? Coronary arteries are richly innervated by adrenergic and parasympathetic nerves. Both alpha 1 and alpha 2 adrenergic receptors a

Explain the soft diet, Explain the soft diet The soft diet provides so...

Explain the soft diet The soft diet provides soft whole food that is lightly seasoned and moderately low in fibre. The foods have a soft  texture and are easy  to digest. Smal

Segmentation in regenerating annelids, Segmentation in Regenerating Annelid...

Segmentation in Regenerating Annelids Several worms as they grow continue to add new segments at the posterior end. In these, segmentation takes place in a growth zone located

Digestive system, describe the effects of the failure of the pancreas to pr...

describe the effects of the failure of the pancreas to produce sufficient insulin

How plants classify to photoperiodism-based flowring, How do the plants cla...

How do the plants classify according to their photoperiodism-based flowering? According to their photoperiodism-based the flowering plants classify as long-day plants, those th

Describe the uses-process and outcome of pgd, 1.  Identify and compare the ...

1.  Identify and compare the methods of somatic gene therapies for ADA deficiency described on pp. 404-405 (Lewis) and OTC deficiency described on pp. 405-406 (Lewis). 2.  Compa

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