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

Can you explain antibiotics, Q. Can you explain Antibiotics? The antibi...

Q. Can you explain Antibiotics? The antibiotics are the chemicals produced by microorganisms which are able to destroy or inhibit the growth of other microorganisms. The therap

Enzymology, Ethylene glycol is a poison that causes about fifty deaths a ye...

Ethylene glycol is a poison that causes about fifty deaths a year in the United States. Treating people who have drunk ethylene glycol with massive doses of ethanol can save their

Centrosome, structure of centrosome and work

structure of centrosome and work

Explain mechanism for reduce the absorption of nutrients, Explain Mechanism...

Explain Mechanism for reduce the absorption of nutrients? The absorption of nutrients is also reduced by mechanisms other than increasing the viscosity of gastrointestinal cont

Sociability - qualitative characters, Sociability (Gregariousness) Soc...

Sociability (Gregariousness) Sociability refers to the nature of grouping of individual plants, that is, whether they grow singly, in patches, in colonies or evenly intermixed

What is the function of keratin in the epidermis, What is the function of k...

What is the function of keratin in the epidermis? The epidermis is the outer layer of the skin made of epithelial tissue. In the epidermis there are keratin-secreting cells (ke

Chronic complications of diabetes, Q. Chronic complications of diabetes? ...

Q. Chronic complications of diabetes? These occur gradually when the diabetics do not monitor the blood sugar and they are careless about eating, exercise and the medications a

Define the fehling's soxhlet method (lane-eynon method), Define the Fehling...

Define the Fehling's Soxhlet method (Lane-Eynon method)? This is a titrimetric method that is commonly used in food laboratories to estimate percentage of reducing sugars and t

Describe how dna is folded into chromatin structures , 1. DNA must be exten...

1. DNA must be extensively folded in order to fit inside a nucleus that is less than 10 um in diameter. a. Describe how DNA is folded into chromatin structures of increasing com

Are the arterial pulsations normal, Are the arterial pulsations normal? ...

Are the arterial pulsations normal? Is the pulse volume normal or increased? Is there a discrepancy of pulsation in any of the four extremities? A careful evaluation of pulsati

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