Anatomy of the Eye

Podcast Beta

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the main function of the aqueous humour in the anterior cavity?

To provide nutrition and immunity to the avascular ocular tissues (correct)

To provide mechanical support to the cornea and lens

To control the amount of light entering the eye

To regulate the movement of the iris and pupil

What is the percentage of water in the aqueous humour?

95%

90%

98% (correct)

99%

What is the name of the pathway through which the aqueous humour drains out of the eye?

Trabecular meshwork

Uveoscleral pathway

Canal of Schlemm

All of the above (correct)

What is the name of the layer sandwiched between the sclera and the retina?

Choroid Signup and view all the answers

What is the name of the fluid that fills the vitreous chamber?

Vitreous humour Signup and view all the answers

What is the name of the anatomical structure that forms the pupil?

Iris Signup and view all the answers

What is the name of the section of the eye that includes the anterior and posterior chambers?

Anterior cavity Signup and view all the answers

What is the name of the pathway that provides a small amount of refraction in the eye?

Aqueous humour pathway Signup and view all the answers

What is the main composition of the vitreous humour?

99% water, with some cells, salts, sugars, and collagen fibrils Signup and view all the answers

What is the function of the crystalline lens in the eye?

To provide variable refractive power, allowing the eye to focus on objects at different distances Signup and view all the answers

What is the function of the vitreous humour in the eye?

To provide support for the eyeball and additional refractive power Signup and view all the answers

What is the structure that covers the entire surface of the lens?

Elastic capsule Signup and view all the answers

What is the name of the cavity located behind the lens and in front of the retina?

Vitreous chamber Signup and view all the answers

What is the purpose of the zonules in the eye?

To hold the lens in place Signup and view all the answers

What happens to the vitreous humour with age?

It starts to liquify and the collagen fibres degrade Signup and view all the answers

What is the location of the posterior cavity?

Behind the lens and in front of the retina Signup and view all the answers

What is the main component of the vitreous humour?

Water Signup and view all the answers

What is the chamber of the eye that contains the vitreous humour?

Vitreous chamber Signup and view all the answers

What is the main difference between the vitreous humour and the aqueous humour?

The vitreous humour is more viscous Signup and view all the answers

What is the structure that separates the anterior and posterior cavities of the eye?

Lens Signup and view all the answers

What is the consequence of the collagen fibres breaking in the vitreous humour?

Small floaters or complete posterior vitreous detachment Signup and view all the answers

What is the term for the variable refractive power of the crystalline lens?

Accommodation Signup and view all the answers

Which of the following is NOT a part of the ocular anatomy?

Adrenal gland Signup and view all the answers

What is the part of the eye that controls the amount of light entering the eye?

Pupil Signup and view all the answers

Study Notes

Anterior Cavity

The anterior chamber is a space between the cornea and iris, approximately 3 mm in depth.
It is filled with aqueous humour, a transparent fluid that provides nutrition, immunity, and support to avascular ocular tissues.
Aqueous humour is 98% water and contains amino acids, glucose, and few proteins.
It constantly circulates, being secreted by the ciliary body and draining out through the trabecular meshwork and uveoscleral pathway.

Posterior Chamber

The posterior chamber is the space between the iris and lens.
The aqueous humour also extends into the posterior chamber.
The anterior and posterior chambers together form the anterior cavity (also known as the anterior segment).

Uvea

The uvea is made up of three parts: the choroid, ciliary body, and iris.
The uvea gets its name from the Latin word for "grape" due to its dark red, wrinkled, and grape-like appearance when removed.

Choroid

The choroid is a vascular layer sandwiched between the sclera and retina.

Vitreous Chamber

The vitreous chamber is the largest of the three chambers, located behind the lens and in front of the retina.
It is filled with vitreous humour, also known as the vitreous body.
Vitreous humour is a clear gel that is 99% water, with some salts, sugars, and a network of collagen fibrils that make it gel-like.

Vitreous Humour

Vitreous humour provides support for the eyeball and additional refractive power.
With age, the collagen fibres degrade, and the vitreous humour starts to liquify.
The fibres holding the surrounding membrane to the retina can break, potentially leading to small floaters or even complete posterior vitreous detachment.

Pupil

The pupil is the dark circular opening in the centre of the iris that controls the amount of light entering the eye.
Pupil size varies in diameter (from 2 to 8 mm) depending on the amount of light present.
Pupil abnormalities can be indicative of a wide range of ocular and neural pathologies.

Lens

The crystalline lens provides variable refractive power, allowing the eye to focus on objects at different distances.
It consists of three concentric layers: an elastic capsule, a simple epithelium, and the bulk of the lens made of elongated cells (lens fibres).
The lens fibres make up the majority of the lens and provide its refractive power.