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

Echinoderms, Phylogenetic considerations

Phylogenetic considerations

Why photoperiodism affect the flowering of some plants, How does the photop...

How does the photoperiodism affect the flowering of some plants? Flowering is a typical and simple to observe instance of photoperiodism. Most flowering plants flower only duri

#Types of Blastula, Give a detailed description of stereoblastula, please ?...

Give a detailed description of stereoblastula, please ?#

Explain ground system, G round system:  Plant tissue system, composed com...

G round system:  Plant tissue system, composed commonly of parenchyma cells with some collenchyma and sclerenchyma cells, that occupies the space between the epidermis and the va

Are the limbs modified into wings of bats, Are the limbs modified into wing...

Are the limbs modified into wings of bats and the wings of birds examples of evolutionary analogy or homology? What about whale fins compared to fish fins? Bat and bird wings h

What are symptoms found in patients with hyperthroidism, What are some sign...

What are some signs and symptoms found in patients with hyperthyroidism? The hormones made by the thyroid gland stimulate the basal metabolism of the body. In hyperthyroidism t

Assessment of iron status - haemoglobin and haematocrit, Define Assessment ...

Define Assessment of iron status - Haemoglobin and Haematocrit? In the final stages of iron deficiency, anaemia occurs. Haemoglobin and Haematocrit levels indicate prevalence o

Adaptations in skeleton for upright posture, ADA PTATIONS IN SKELETON FOR ...

ADA PTATIONS IN SKELETON FOR UPRIGHT POSTURE - 1.      Foramen magnum is directed downward so that the head may rest vertically on the vertebral column. 2.      Four curves

Ameoba, locomotion in amoeba

locomotion in amoeba

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