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

Permeability, Permeability Permeability is the ability of a soil to tra...

Permeability Permeability is the ability of a soil to transmit water or air. Permeability or infiltration rate is measured in terms of the rate of water flow through the soil i

Explain phylum zygomycetes, Phylum Zygomycetes 1) Asexual reproduction ...

Phylum Zygomycetes 1) Asexual reproduction by non-motile spores produced from a stalked spore case which is known as sporangium. 2) They reproduced by- conjugation between n

Dreams, what do our brain and heart do when we are asleep?

what do our brain and heart do when we are asleep?

Explain that a peptide bond a covalent, Is a peptide bond a covalent or a n...

Is a peptide bond a covalent or a non-covalent bond? Please explain.

Tropical seasonal forests - ecosystem, Tropical seasonal forests - Ecosyste...

Tropical seasonal forests - Ecosystem Tropical seasonal forests occur in regions where total annual rainfall is very high but segregated into pronounced wet and dry periods. T

Express the term - amnion, Express the term - Amnion One of the extraem...

Express the term - Amnion One of the extraembryonic membranes found in terrestrial vertebrate. The amnion is filled with fluid and the developing embryo of reptiles, birds, and

Solubility, Solubility You are aware that gases are soluble in liquid...

Solubility You are aware that gases are soluble in liquid. Solubility of a gas in a liquid depends on the partial pressure, temperature and presence of other solutes. Table

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