Eyeball - choroid, Biology

Assignment Help:

CHOROID -

  • Thin, net like made up of connective tissue, rich in blood vessels.
  • Pigment present, red in rabbit, brown or black in man. It reduces internal reflection.
  • Except cornea this layer is attached to sclerotic.
  • In front of cornea this layer froms a thin coloured partition i.e. iris. IRIS -
  • It is perforated in the middle by an aperture pupil. Iris is highly muscular
  • Circular and radial muscles are present. Circular muscles are sphincter type. Radial muscles are dilator type.
  • On contraction of circular muscles diameter of pupil is reduced it is myosis, it takes place in sharp light.
  • On contraction of radial muscles diameter of pupil is increased, it is mydriosis, it occurs in dimlight.
  • Atropine is used to dialate pupil.

2037_choroid.png

  • Basal part of iris is highly muscular having circular, radial and obligue muscles. It is known as cilliary body.
  • On its free surface 70 - 80 cilliary processes present secretes aquous humour in aquous chamber.
  • Cilliary body also affects convexity of lens.

1261_choroid1.png


Related Discussions:- Eyeball - choroid

Dictyosomes, Dictyosomes  are produced on the Organelles in the plant cells...

Dictyosomes  are produced on the Organelles in the plant cells composed of the series of flattened membrane sacs which sort, chemically modify, and package protein srough endoplasm

Explain about osseointegration, Explain about Osseointegration Osseoint...

Explain about Osseointegration Osseointegration is regarded as the process of direct bone apposition on implant surfaces where the bone in contact with the implant later underg

Animal nutrition, briefly explain the following feeding mechanisms in holoz...

briefly explain the following feeding mechanisms in holozoic animals a) filter feeding b) fluid feeding c)deposit feeding

How are poriferans characterized, Concerning digestion how are poriferans c...

Concerning digestion how are poriferans characterized? Sponges are dissimilar from other animals since they present only intracellular digestion. They do not have a digestiv

Why do ribosomes move along mrna during translation, Q. Why do ribosomes mo...

Q. Why do ribosomes move along mRNA during translation? During translation the ribosome always exposes two mRNA codons to be translated by moving along the mRNA, when a peptide

Australopithecines, The first ever australopithecine fossil was found in 19...

The first ever australopithecine fossil was found in 1924 at Taung, South Africa. It was the skull of a 6 year old child showing a mixture of human and ape like features. This a

Define phases of the absorption of iron, Define phases of the absorption of...

Define phases of the absorption of iron? The process of absorption is divided into three phases: i) Iron uptake by enterocytes (epithelial cell of the superficial layer of t

External auditors reports, External Auditors Reports The audit report...

External Auditors Reports The audit report is the final stage in the process of an audit.  The terms 'true and fair'  'present fairly' have special significance in the audit

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