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

Insulators - transgenic animals, Insulators Numerous experiments showed...

Insulators Numerous experiments showed that a transgene is generally poorly expressed when it contains a cDNA rather than the corresponding genomic DNA; when it is integrated a

Phylogenetic systems of classification, Q. Phylogenetic systems of classifi...

Q. Phylogenetic systems of classification? As already pointed out 'earlier that in Phylogenetic system, the plants are classified according to their evolutionary relationships.

How would you perform abo blood grouping, Question 1 How would you perform...

Question 1 How would you perform ABO blood grouping? Add a note on advantages and disadvantages of each method. Also discuss the precautions you may take to avoid errors in variou

Drugs for hepatitis b, Drugs for hepatitis B Chronic HBV infection is ...

Drugs for hepatitis B Chronic HBV infection is currently treated with interferon alfa, lamivudine or adefovir. Lamivudine is much better tolerated than interferon and much les

Soil mixing, Soil Mixing The larger soil organisms are responsible for ...

Soil Mixing The larger soil organisms are responsible for considerable mechanical mixing and weathering of soil. The wedge-like action of roots and other underground plant orga

Explain the meaning of anthropometric measures, Explain the Meaning of anth...

Explain the Meaning of anthropometric measures Anthropometric Measures mean and its uses. The term Anthropometric refers comparative measurement relating to the body structure.

What is prostaglandins , Prostaglandins and the structurally associated mol...

Prostaglandins and the structurally associated molecules prostacyclins, leukotrienes and thromboxanes, are called as eicosanoids because they having 20 carbon atoms. These hormones

Evolutionary innovation presented by nematodes, Q. What is the major evolut...

Q. What is the major evolutionary innovation presented by nematodes? What is the benefits of that innovation? The major evolutionary innovation of nematodes is the complete dig

Does ploidy reduction occur in mitosis, During which meiosis division does ...

During which meiosis division does ploidy reduction occur? Does ploidy reduction occur in mitosis? In the cell division by meiosis ploidy reduction occurs in meiosis II. Initia

Complications in celiac disease, Q. Complications in celiac disease? Pa...

Q. Complications in celiac disease? Patients with severe form of celiac's disease for long period are at risk for several complications mainly due to nutrient absorption probl

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