🥇 Anatomía del OJO 3/3 - Medios de Refracción, Cámaras del Ojo, Humor Acuoso, Cuerpo Vítreo

Summary

This video concludes a series on the anatomy of the eyeball, focusing on its refractive structures. It explains the role of the cornea, lens, vitreous body, aqueous humor, and vitreous humor in refraction. The script delves into the lens's structure, the eye's chambers, and the importance of the aqueous humor's production and reabsorption. It also touches on cataracts and glaucoma, emphasizing the eye's intricate mechanisms for clear vision.

Takeaways

• 👁️ The video discusses the refractive structures of the eye, focusing on the cornea, lens, vitreous body, aqueous humor, and vitreous humor.
• 🌐 The cornea is the most important refractive structure due to its high refractive power and is part of the anterior segment of the eye.
• 🔍 The lens, located behind the iris, is suspended by the suspensory ligaments and is responsible for fine-tuning the focus of the eye.
• 👀 The iris divides the eye into the anterior and posterior chambers, with the anterior chamber situated between the cornea and iris, and the posterior chamber between the iris and lens.
• 💧 The aqueous humor is a liquid produced by the ciliary processes and iris blood vessels, filling the anterior and posterior chambers and providing nutrients to the cornea and lens.
• 🔬 The lens has a convex shape and is made up of a capsule, cortex, and a hard nucleus, which allows it to change shape for focusing.
• 👁️‍🗨️ The vitreous body is a gelatinous structure that occupies the posterior segment of the eye and is in contact with the retina.
• 🧬 The vitreous humor, rich in hyaluronic acid, fills the vitreous body and has a consistency similar to the aqueous humor but with more polysaccharides.
• 📏 The distances between the anterior face of the lens and the cornea, and from the lens to the retina, are crucial for understanding eye focusing mechanisms.
• 🚫 Cataracts are a condition where the lens becomes cloudy, affecting its transparency and potentially impairing vision.
• 🌡️ Increased intraocular pressure due to issues with aqueous humor production or reabsorption can lead to glaucoma, a serious eye condition.

Q & A

What are the three main refractive structures of the eye mentioned in the video?

The three main refractive structures of the eye mentioned in the video are the cornea, the lens, and the vitreous body.

Why is the cornea considered the most important refractive structure?

The cornea is considered the most important refractive structure because it has the greatest refractive power among the eye's refractive structures.

What is the iris and how does it relate to the anterior and posterior chambers of the eye?

The iris is the colored part of the eye that surrounds the pupil. It divides the eye into the anterior chamber, which is in front of the iris, and the posterior chamber, which is behind the iris.

What is the function of the suspensory ligaments of the lens?

The suspensory ligaments of the lens, also known as the ciliary zonula, hold the lens in place and allow it to change shape, which is crucial for focusing on objects at different distances.

Describe the structure and location of the vitreous body in the eye.

The vitreous body is a gelatinous structure located in the posterior segment of the eye, behind the lens. It occupies most of the volume of the eye and is in contact with the retina.

What is the aqueous humor and where is it located within the eye?

The aqueous humor is a liquid that bathes the anterior segment of the eye, specifically in the anterior chamber in front of the lens and the posterior chamber behind the iris.

How does the lens change its shape to focus on objects at different distances?

The lens can elongate, stretch, and become less wide in an anteroposterior sense, adopting its main shape according to the eye's focusing needs, facilitated by the action of the suspensory ligaments.

What is the approximate diameter and central thickness of the lens?

The lens has an approximate diameter of one centimeter and a central thickness of about 5 millimeters.

What is the condition known as cataracts and how does it affect the lens?

Cataracts is a condition where the lens becomes cloudy or opaque, affecting its transparency and causing a decrease in vision clarity. It is often associated with aging and can be treated with surgery.

What is the role of the hyaloid membrane and vitreous humor in the eye?

The hyaloid membrane, also known as the vitreous membrane, covers the eye and is in contact with the retina. The vitreous humor, inside the vitreous body, has a gel-like consistency and is rich in polysaccharides, especially hyaluronic acid, providing structural support to the eye.

How is the aqueous humor produced and reabsorbed within the eye?

The aqueous humor is produced by the ciliary processes and blood vessels of the iris. It circulates through the posterior and anterior chambers, and is reabsorbed at the Schlemm's canal located at the corneoscleral iridium angle.

What is the normal intraocular pressure range and what can cause it to increase?

The normal intraocular pressure range is 5 to 21 millimeters of mercury, with an average of 15. An increase in this pressure can be caused by overproduction of aqueous humor or issues with its reabsorption, potentially leading to glaucoma.

Outlines

00:00

👁️ Eyeball Refraction and Structure Overview

This paragraph introduces the third and final video in a series about the human eye, focusing on the refraction process. It discusses the cornea's significant role due to its high refractive power and the lens's position behind the iris, suspended by the suspensory ligaments. The vitreous body and the aqueous and vitreous humors are also mentioned as key refractive structures. The video promises to delve into the details of these structures, including the lens's anatomy and function, and the eye's chambers, which are crucial for understanding the eye's refraction capabilities.

05:05

🔍 Detailed Examination of the Lens and Eye Chambers

The second paragraph provides a deeper look into the lens, describing its central location, dimensions, and shape, including the equator and its convex anterior and posterior faces. It explains the lens's transparency and the yellowing that occurs with age, as well as cataracts, which impair its clarity. The paragraph also covers the lens's ability to change shape for focusing and the distances between the lens, cornea, and retina. It then describes the eye's anterior and posterior chambers, their dimensions, and how they are separated by the iris. The role of the aqueous humor in these chambers and its production and reabsorption cycle is also explained, highlighting the risk of glaucoma if there is an imbalance in this process. The paragraph concludes by mentioning related videos on the channel that cover additional aspects of eye anatomy.

Keywords

💡Eyeball

The 'eyeball' refers to the organ of sight in humans and other animals, consisting of various structures that work together to process light and allow vision. In the video's context, the term is used to describe the overall anatomy of the eye, including its layers and refractive structures, which are essential for understanding how the eye functions in vision.

💡Refraction

Refraction is the bending of light as it passes from one medium to another with different optical densities. In the video, refraction is discussed in relation to the eye's structures, such as the cornea and lens, which bend light to focus it onto the retina, a critical process for clear vision.

💡Cornea

The 'cornea' is the clear, front part of the eye that covers the iris, pupil, and anterior chamber. It is highlighted in the script as the most important refractive structure due to its significant role in bending light entering the eye. The cornea's shape and transparency are crucial for proper vision.

💡Lens

The 'lens' is a transparent, biconvex structure located behind the iris that focuses light onto the retina. The video explains that the lens changes shape to adjust focus, a process known as accommodation. Its elasticity and ability to change shape are vital for the eye's ability to see objects at various distances.

💡Vitreous Body

The 'vitreous body' is a gel-like substance that fills the large space behind the lens in the eye. The script mentions it as a structure that, along with the vitreous humor, contributes to the eye's overall shape and helps maintain its firmness while allowing light to pass through to the retina.

💡Aqueous Humor

The 'aqueous humor' is a clear fluid that circulates in the anterior and posterior chambers of the eye, in front of the lens. As described in the script, it provides nutrients to the cornea and lens and helps maintain intraocular pressure. Its balance is crucial for eye health, and any disruption can lead to conditions like glaucoma.

💡Vitreous Humor

The 'vitreous humor' is a gelatinous substance that fills the vitreous body and is similar in consistency to the aqueous humor but richer in polysaccharides. The script explains that it plays a role in maintaining the shape of the eye and allowing light to pass through to the retina.

💡Suspensory Ligaments

The 'suspensory ligaments,' also known as the 'ciliary zonula,' are fibers that connect the lens to the ciliary body. As mentioned in the script, these ligaments are responsible for holding the lens in place and allowing it to change shape, which is essential for focusing on objects at different distances.

💡Anterior Chamber

The 'anterior chamber' is the space between the cornea and the iris, filled with aqueous humor. The video script describes it as part of the eye's refractive system, where the distance between the cornea and the lens is crucial for the eye's focusing mechanism.

💡Posterior Chamber

The 'posterior chamber' is the space between the iris and the lens, also filled with aqueous humor. The script explains its role in the eye's anatomy, noting that it is separated from the anterior chamber by the iris and is important for the circulation of aqueous humor.

💡Glaucoma

Glaucoma is a group of eye conditions that damage the optic nerve, often due to increased pressure in the eye. The script mentions it in the context of the eye's aqueous humor dynamics, where an overproduction or impaired reabsorption can lead to increased intraocular pressure, potentially causing glaucoma.

Highlights

Introduction to the third and final video on the anatomy of the eyeball, focusing on the means of refraction.

Explanation of the cornea as the most important refractive structure due to its high refractive power.

Description of the iris as a part of the eye, but not a means of reflection.

Introduction of the lens as the next refractive structure located behind the iris.

Details on the lens's location, size, and its importance in the eye's refractive process.

Mention of the vitreous body, a gelatinous structure occupying most of the posterior segment of the eye.

Discussion on the aqueous humor and its role in bathing the corneal structure.

Introduction of the vitreous humor, its consistency, and composition.

Identification of the refractive structures of the eye: cornea, lens, vitreous body, aqueous humor, and vitreous humor.

Explanation of the anterior and posterior chambers of the eye and their division by the iris.

Description of the lens's shape, equator, and its transparency that changes with age.

Information on cataracts, a disease affecting the lens's transparency.

Details on the lens's structure, including its capsule, cortex, and nucleus.

Function of the lens's ability to change shape for focusing, facilitated by the suspensory ligaments.

Distance measurements between the lens, cornea, and retina, important for understanding eye anatomy.

Role of the vitreous body and hyaloid membrane in the eye's structure.

Explanation of the aqueous humor's production, circulation, and reabsorption, and its relation to intraocular pressure.

Mention of the Schlemm's duct and its importance in the reabsorption of aqueous humor.

Discussion on glaucoma, a pathology related to increased intraocular pressure.

Conclusion of the video with an invitation to subscribe and watch related content for a comprehensive understanding of eye anatomy.

Transcripts

Welcome to the third and last eyeball video, we already talked about the three layers of the

eyeball in the previous videos, now we are going to talk about the means of refraction,

now in the means of reflection and we talked first about the most important one, which was the cornea

because it has the greatest refractive power, this analogy that I gave you here was the

complete eyeball with its three layers and what you see here would basically be the iris, which is not

a means of reflection, until now the only means The expression that speaks to them or names them

is the cornea; The next means of reflection in order from anterior to posterior is the lens.

Remember that the lens is located behind the iris and is suspended

through the suspensory ligaments of the lens. There, in that central position behind

the lens, we find the vitreous body. which is a more gelatinous structure that

is occupied where most of what is the eyeball is behind the lens and

then we have two liquids or a liquid rather, which is the aqueous humor that is in front of

the lens, It is what bathes all that coneal structure, that chamber that is in front of

the lens and then we have the vitreous humor, which is the one inside the vitreous body

that has the gelatinous shape or consistency, these five structures are

the ones that we We call the refractive structures of the eye. Now we will also touch on this

video what the cameras of the eye are, remember that the eyes have two large chambers,

an anterior chamber and a posterior chamber, that is, everything that is in front of the lens

is a camera, but what is going to tell me dividing anterior from posterior is really the iris,

the one in front of the iris would be the anterior chamber and the one posterior to the iris would be

the posterior chamber. Let's then elucidate each of these means of refraction except

the cornea, which we touch in the number one video, don't get away from the video

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and don't forget to like the video. It is very important then that you subscribe to the

channel, here in the lower right corner you click and you are automatically subscribed to the

channel, we already talked about the cornea as I told you in video one, we are going to talk then the

following structure of these means of reflection which is the lens, which is the crystal of the eye,

this lens is a structure that is located in the center of the eye that has an

approximate diameter of one centimeter and has a central thickness that is a greater thickness of 5 millimeters

and In this view, which would be more or less a superior view of the lens, we are going to see that it obtains

a convex shape, this would be its anterior face, this would be its posterior face and it has a

central area that is the most pronounced area, called the equator of the lens. crystalline,

it has a fairly transparent color but as we grow, when we

are over 35 or 40 years old it becomes more and more yellowish and as time progresses it

becomes even more yellowish. There is also a disease that is We call cataracts

, which are, so to speak, a stain that occurs or that is covering what is the

transparent power that the lens has. It will have two limits or two points, one

would be the anterior pole and the other would be the posterior pole, if we make a histological section we see

that on the outside it is already covered by a capsule, inside the capsule we find a cortex

and we find a nucleus in the center, contrary to what we would think, it becomes increasingly

harder. The closer you get to the nucleus, in fact the hardest part of the lens

is the nucleus and as you look towards the periphery, towards the cortex it becomes softer and

softer, it has the ability to elongate, stretch and become less wide. in an

anteroposterior sense and adopt its main shape according to what the eye needs, at that point

we are now going to talk about what the anterior face of the lens is, the distances

between the anterior face of the lens and what it is. The posterior surface of the cornea is

2 to 2.5 millimeters if we see the distance between the posterior surface of the cornea, excuse me

, from the lens to what is the retina, it is approximately 16 millimeters; So there are

some ligaments that hold the lens in place and they are the ones that can make

it elongate or, let's say, return to its original position, relax, these ligaments,

which are the ones you see here, are inserted mostly in what are the ciliary processes and are

called the suspensory ligaments of the lens, also called ciliary zonula,

both are synonyms, what is going to happen then? In the back part of the lens we find

what is the vitreous body. This vitreous body is made up of the vitreous membrane, also

called the hyaloid membrane, which is this entire structure that you see, which covers the

eye, which is the one that is in contact with the retina, that is what is called the hyaloid membrane and

inside it is the liquid that is the vitreous humor, this vitreous humor has a consistency

very similar to the aqueous humor that is in the chambers of the eye, but this is much

richer in polysaccharides, especially rich in a substance called hyaluronic acid,

in the center we see that there is a duct called the hyaloid duct which is nothing more than the place

where in fetal life the hyaloid artery was in the fetus, then the eye or The light

to pass through the eye has to pass through these aqueous media, it has to pass through

the cameras; We have an anterior chamber which is the one between the cornea and the iris and we have

a posterior chamber which is the one between the lens and the iris. We are going to start with this anterior chamber

, it measures approximately 2 to 2.5 millimeters, which is the same distance that

I told you just now that there was between the lens and the cornea, that anterior wall of the anterior chamber

is given by what is the face posterior of the cornea while its posterior wall, which

would be this towards the periphery, would be given by the iris, towards the center, which is why it is the pupil,

remember that it is nothing more than the hole left by the iris in the center and by the central portion

of the lens, that would be the posterior wall of the anterior chamber, its circumference, which is the,

let's say, widest place in the anterior chamber, is given by the angle between the iris and the cornea, which is the

corneal iridium angle, there was a missing i , is corneal iridium. Now the posterior chamber, which would be the

one behind the iris, has as its anterior limit what is the posterior face of the iris,

while its posterior wall is given towards the center by the lens and towards the periphery

by what are the suspensory ligaments. of the lens, which we already know is also

called the ciliary zonule, its circumference would be this one that you see here,

the smaller one, which is the free circumference of this posterior chamber, is given by the union between what

is the pupil, which is the same free edge of the iris and the central portion of the lens,

while its largest circumference, which would be the one you see towards the periphery,

the widest one is given by the ciliary processes. So all these chambers, the anterior and the

posterior, are bathed by a liquid that is the aqueous humor, very similar to the vitreous humor,

but without so much hyaluronic acid, this aqueous humor is a liquid that is largely produced

by the hilar processes and by the blood vessels that have the iris, now when

it is formed it passes through what is the posterior chamber and then through the pupil it bathes the entire

anterior chamber and it is in the anterior chamber at the level of the corneal iridium angle where

the schlemm duct that it is reabsorbed, that is why if an overproduction of aqueous humor were to occur

or its reabsorption in the schlemm duct were to occur,

the pressure inside the eye would increase, the normal intraocular pressure is 5 to 21 millimeters of

mercury on average is said to be 15, so when this pressure increases is when the

pathology called glaucoma occurs and this was then the entire video of refraction medium, I hope you liked it,

do not forget to subscribe to the little circle that appears here, like the video

if you liked it, I invite you to watch the previous videos carefully so that you can understand well

what is the anatomy of the eyeball and also the videos of tear glands and the

bone orbit video that is also on my channel, I will also make a special video about the

extra ocular muscles that are responsible for moving the eye, many thank you