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

Define integrity of epithelial tissues, Define Integrity of Epithelial Tiss...

Define Integrity of Epithelial Tissues? Vitamin A is essential for the integrity of the mucous-secreting cells. In fact vitamin A maintains the health of epithelial cells that

Photosynthesis rate varies according to the photic energy, Photosynthesis r...

Photosynthesis rate varies according to the photic energy intensity. Do the similar occur in aerobic respiration? What happens to the glucose balance as a result of these variation

Retina, Retina As invagination of the optic vesicle carries on to form...

Retina As invagination of the optic vesicle carries on to form the double walled optic cup the two layers of the optic cup start to differentiate in different directions. Pigm

Excretion in animal, Excretio n I n  Animal To give out nitrogenous...

Excretio n I n  Animal To give out nitrogenous waste products after oxidation of food is excretion. EXCRE T O R Y MATERIALS - 1 .      AMMONIA - Animals are

What is the law of limiting factors, What is the law of limiting factors? H...

What is the law of limiting factors? How would the rate of photosynthesis be affected if the soil water becomes limiting? Describe.

What is selective waste collection, Q. What is selective waste collection? ...

Q. What is selective waste collection? The Recyclable waste is waste that can be reprocessed and used again. The waste recycling depends on the separation of the recyclable res

Explain the term ageing, Explain the term Ageing? Ageing in human being...

Explain the term Ageing? Ageing in human being is of a multifunctional origin and there is a programmed senescence (ageing) of the cells in the body. The genetic make-up of an

O-linked oligosaccharides , Most proteins made by ribosomes on the RER (rou...

Most proteins made by ribosomes on the RER (rough endoplasmic reticulum) are glycoproteins, which is they hold short chains of carbohydrates (oligosaccharides) covalently related t

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