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

In what ways does over-grazing lead to soil erosion, In what ways does over...

In what ways does over-grazing lead to soil erosion? Over-grazing leads to erosion because (i) the animals delete all the vegetation, so exposing the soil to heavy rain, (ii) t

Death and its significance, DE A T H - It is universal. It is ...

DE A T H - It is universal. It is last event in the degenerative process of ageing. It involves widspread cell break down & cell death. There is no heart beat, n

Explain about peptic ulcer, Q. Explain about Peptic Ulcer? Peptic ulcer...

Q. Explain about Peptic Ulcer? Peptic ulcers are one of the more serious forms of gastrointestinal disorders of the gastrointestinal tract particularly the stomach. The prevale

Calculate the amount of nacl, A saline drip is to be prepared for a lab exp...

A saline drip is to be prepared for a lab experiment that is looking at hydration in lab rats. Calculate the amount of NaCl need to make 4 liters of a 0.9% solution.

Secondary induction, Secondary Induction The two primary inductive ev...

Secondary Induction The two primary inductive events that we have described so far are significant in the patterning of early embryo. But there are another such signaling eve

Major conventional symbols & signs used in genetic family, What are the maj...

What are the major conventional symbols and signs used in genetic family trees? In the genetic family trees the male sex is usually represented by a square and the female by a

Chances of clinical risks, A foreign DNA has to target a precise chromosoma...

A foreign DNA has to target a precise chromosomal site and integrate with the host DNA. Are the methods of gene therapy strong enough to produce desired expression without mistakes

Structure and content of halsted reitan battery, Structure and Content of ...

Structure and Content of Halsted Reitan battery Although there are several versions of the Halsted Reitan battery, the differences tend to be minor, and there appears to be a

Nonsurgical retreatment will be the preferred choice, Nonsurgical retreatme...

Nonsurgical retreatment will be the preferred choice -Less invasive .. not cause problem to the pt. -Less traumatic postoperative .. most probably no post operative pain

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