Table of Contents
- 1 What controls the shape of the crystalline lens?
- 2 What is the modification of the choroid that contains the ciliary muscle?
- 3 What structure regulates the shape of the lens?
- 4 What is the ciliary body in contact continuous with?
- 5 What modification of the choroid that is not present in humans is found in the cow eye?
- 6 Why do humans need to change the shape of the convex lens?
- 7 What kind of choroid is found in the cow eye?
- 8 Which is part of the iris dilates the pupil?
What controls the shape of the crystalline lens?
The lens is flexible and its curvature is controlled by ciliary muscles through the zonules. By changing the curvature of the lens, one can focus the eye on objects at different distances from it.
What is the modification of the choroid that contains the ciliary muscle?
special senses: anatomy of the visual system
| Question | Answer |
|---|---|
| ciliary body | modification of the choroid that contains the cilliary muscle |
| scleral venous sinus | drains aqueous humor from the eye |
| retina | layer containing rods and cones |
| vitreous humor | substance occupying the posterior segment of the eyeball |
What structure regulates the shape of the lens?
The ciliary body is a circular structure that is an extension of the iris, the colored part of the eye. The ciliary body produces the fluid in the eye called aqueous humor. It also contains the ciliary muscle, which changes the shape of the lens when your eyes focus on a near object.
What causes the lens to change shape?
The lens is very elastic. Small muscles attached to the lens can change its shape, allowing the eye to focus on objects at varying distances. Tightening (contraction) or relaxing these muscles causes the lens to change shape, allowing the eyes to focus on near or far objects (accommodation).
Is human eye lens crystalline?
The lens of the eye, also called the crystalline lens, is an important part of the eye’s anatomy that allows the eye to focus on objects at varying distances. It is located behind the iris and in front of the vitreous body.
What is the ciliary body in contact continuous with?
The internal surface of the ciliary body comes in contact with the vitreous surface and is continuous with the retina [1].
What modification of the choroid that is not present in humans is found in the cow eye?
What modification of the choroid that is not present in humans is found in the cow eye? What is its function? Tapetum lucidum; to reflect light that enters the eye, thus increasing light stimulation of the retina under dim light conditions.
Why do humans need to change the shape of the convex lens?
When you are looking at a near object, the lens needs to become more rounded at the central surface in order to focus the light rays. This ability to change focus for close-up objects is called accommodation. The ability of the eye to change the shape of its lens and its focus is known as accommodation.
What helps the lens change shape or focus on an object?
The ciliary muscles, which are part of the ciliary body, are attached to the lens and contract or release to change the lens shape and curvature. The lens becomes more rounded to focus on near objects (see Figure 1): Fig.
Which is choroid controls the shape of the crystalline lens?
Modification of the choroid that controls the shape of the crystalline lens and contains the ciliary muscle Ciliary body Drains the aqueous humor from the eye Scleral venous sinus Layer containing the rods and cones Retina Substance occupying the posterior segment of the eyeball Vitreous humor Forms the bulk of the heavily pigmented vascular layer
What kind of choroid is found in the cow eye?
What modification of the choroid that is not present in humans is found in the cow eye? What is its function? Tapetum Lucidum, reflects light that enters the eye, helps with night vision What does the retina look like? At what point is it attached to the posterior aspect of the eyeball? White membrane, the optic disc
Which is part of the iris dilates the pupil?
The iris is composed of two smooth muscle layers, one arranged radially and the other circularly. Which of these dilates the pupil? The radial layer Pupils dilate in what circumstances?