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

Explain the mechanisms of heat loss, Name and explain the mechanisms of hea...

Name and explain the mechanisms of heat loss that are contributing to Joel's feelings of coldness. Be sure to name ALL the mechanisms that are contributing!

State diploblastic in brief, State Diploblastic in brief. Organisms for...

State Diploblastic in brief. Organisms formed from only two primitive cell layers- ectoderm and endoderm. Though there may be some type of a matrix between two cell layers, gen

Synthesis of triacylglycerols , Triacylglycerols are synthesized from fatty...

Triacylglycerols are synthesized from fatty acyl CoAs and glycerol 3-phosphate.The   glycolytic   intermediate   dihydroxyacetone phosphate   is   first reduces   to glycerol   3-p

What do we mean by culture media, What Do We Mean By Culture Media? Cul...

What Do We Mean By Culture Media? Culture media, you would realize, is a solid or liquid preparation containing all the nutrients required by microbes for growth. So then, what

Explain the requirement of nutrition during stress, Explain the requirement...

Explain the requirement of Nutrition during Stress? We all experience stress at some time or the other in life. Stress is the condition or stimulus that threatens the body's ho

Name the molecules make active transport through membranes, Which are the m...

Which are the molecules that make possible active transport through membranes? Active transport is made by exact membrane proteins. These proteins are called "pumps" because

Horse diseases-epidemiology, Epidemiology Infection is transmitted   b...

Epidemiology Infection is transmitted   by direct contact between infected domestic and wild animals and susceptible livestock; by arthropod vector (Phlebotomus, Aedes and Cul

Clinical manifestations of bronchial asthma, Clinical Manifestations C...

Clinical Manifestations Can be chronic to acute, mild to severe. Acute attack often occur at night. During an acute attack, audible inspiratory and expiratory wheezing. Patie

What are the applications of pcr, Polymerase chain reaction already has ext...

Polymerase chain reaction already has extremely widespread applications and new uses are being devised on a regular basis. Some and definitely not all of the applications are given

Explain oncogenes or defective tumour suppressor genes, 1.  Explain why a g...

1.  Explain why a gain of function would be a dominant effect and a loss of function would be a recessive effect. Which types of genes are each associated with: oncogenes or defect

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