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

What is coelom - body cavity explain, What is Coelom - Body Cavity explain?...

What is Coelom - Body Cavity explain? Among the bilaterally symmetrical organisms, animals have three different types of body plans with respect to body cavities. The term coel

Characteristics of river systems, Characteristics of River Systems Th...

Characteristics of River Systems The basic function of the rivers is to convey surplus rain water from land to sea. Annually the rivers carry fresh water, equivalent to 25 cm

Explain the dna hybridisation, Explain the DNA Hybridisation? This tech...

Explain the DNA Hybridisation? This technique is used to study or compare the genetic affinity between two organism. In such studies the deoxyribonucleic acid (DNA) of both org

Explain nutrition diagnosis, Explain Nutrition diagnosis Nutrition dia...

Explain Nutrition diagnosis Nutrition diagnosis is the identification and labelling that describes an actual occurrence, risk of, or potential for developing a nutrition probl

Syncytial theory - metazoa, Syncytial Theory - Metazoa This theory su...

Syncytial Theory - Metazoa This theory suggests that the ancestral metazoan was at ,first Syncytial in structure but later became cellularised by formation of cell membranes

Explain sexual reproduction, Explain Sexual Reproduction ? In most hig...

Explain Sexual Reproduction ? In most higher organisms, replication occurs by sexual reproduction. Sexual reproduction begins with a process called meiosis. The products of me

Specify the term in detail - swim bladder, Specify the term in detail - Swi...

Specify the term in detail - Swim bladder. Found in bony fish, this gas-filled chamber is used to main neutral buoyancy. Oxygen in blood is added or removed as required. Swim b

Compensatory hypertrophy, Compensatory Hypertrophy It has been seen t...

Compensatory Hypertrophy It has been seen that the exact replacement of a part or organ or tissue is not the just only way to regenerate in animals so many of the body's inte

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