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Questions and Answers
five senses that keep us in touch with what is going on in the external world:
five senses that keep us in touch with what is going on in the external world:
Touch, smell, sight, hearing, taste
How many percent of sensory receptors in the body are in the eyes
How many percent of sensory receptors in the body are in the eyes
70 percent
The adult eyes are measured about?
The adult eyes are measured about?
1 inch or 2.5 cm in diameter
_____ of the eye include the extrinsic
eye muscles, eyelids, conjunctiva, and lacrimal apparatus.
_____ of the eye include the extrinsic eye muscles, eyelids, conjunctiva, and lacrimal apparatus.
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In the anterior part of the eye, the eyes are protected by?
In the anterior part of the eye, the eyes are protected by?
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The eyelids will meet at what part of the eyes?
The eyelids will meet at what part of the eyes?
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The space between the eyelids in an
open eye is called the_____
The space between the eyelids in an open eye is called the_____
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Projecting from the boarder of each eyelids is called?
Projecting from the boarder of each eyelids is called?
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It is a modified sebaceous associated with eyelids edges?
It is a modified sebaceous associated with eyelids edges?
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These glands produce an oil that lubricates the eyes
These glands produce an oil that lubricates the eyes
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It is a
modified sweat glands, lie between the eyelashes
(cilium = eyelash), and their ducts open at the eyelash follicles
It is a modified sweat glands, lie between the eyelashes (cilium = eyelash), and their ducts open at the eyelash follicles
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On the medial aspect of each eye
is the____?, a raised area containing sebaceous and sweat glands that
produce an oily, whitish secretion that also lubricates the eye
On the medial aspect of each eye is the____?, a raised area containing sebaceous and sweat glands that produce an oily, whitish secretion that also lubricates the eye
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secretes mucus, which helps to lubricate the eyeball and keep it moist.
secretes mucus, which helps to lubricate the eyeball and keep it moist.
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consists of the lacrimal gland and a number of ducts that drain lacrimal secretions into the nasal cavity.
consists of the lacrimal gland and a number of ducts that drain lacrimal secretions into the nasal cavity.
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are located above the lateral
end of each eye. They continually release a dilute Salt solution (tears) onto the anterior surface of the eyeball through several small ducts.
are located above the lateral end of each eye. They continually release a dilute Salt solution (tears) onto the anterior surface of the eyeball through several small ducts.
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I sunod sunod ang giagian sa tears from the lacrimal glands include lacrimal glands sa answer
I sunod sunod ang giagian sa tears from the lacrimal glands include lacrimal glands sa answer
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an enzyme that destroys bacteria.
an enzyme that destroys bacteria.
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Inflammation of the conjunctiva, called____?
Inflammation of the conjunctiva, called____?
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its infectious form caused by bacteria or viruses, is Highly contagious
its infectious form caused by bacteria or viruses, is Highly contagious
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How many extrinsic muscles do we have?
How many extrinsic muscles do we have?
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These muscles produce gross eye movements and make it possible for the eyes to follow a moving object. gives the names, locations, actions, and cranial nerve serving each of these muscles.
These muscles produce gross eye movements and make it possible for the eyes to follow a moving object. gives the names, locations, actions, and cranial nerve serving each of these muscles.
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is a hollow sphere. Its wall is composed
of three tunics, or layers, and its interior is filled with fluids called humors that help to maintain its shape.
is a hollow sphere. Its wall is composed of three tunics, or layers, and its interior is filled with fluids called humors that help to maintain its shape.
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What fluid that fills the interior of our eyeball
What fluid that fills the interior of our eyeball
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it is the main focusing apparatus of
the eye, is supported upright within the eye cavity, dividing it into two chambers.
it is the main focusing apparatus of the eye, is supported upright within the eye cavity, dividing it into two chambers.
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What are the three layers of eyeball?
What are the three layers of eyeball?
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It is the outermost layer of the eyeball
It is the outermost layer of the eyeball
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It consist the protective sclera and transparent cornea
It consist the protective sclera and transparent cornea
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is seen anteriorly as the “white of the eye.”
is seen anteriorly as the “white of the eye.”
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It is the central anterior portion of the fibrous layer is crystal clear.
This “window” is the_____?
It is the central anterior portion of the fibrous layer is crystal clear. This “window” is the_____?
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What transparent layer of the eye that is well supplied with nerve endings? That if you it, it will increase the tears.
What transparent layer of the eye that is well supplied with nerve endings? That if you it, it will increase the tears.
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It is the most exposed part of the eye and it is vulnerable to damage
It is the most exposed part of the eye and it is vulnerable to damage
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the only tissue in the body that is transplanted from one person to another without the worry of rejection.
Because it has no blood vessels, it is beyond the reach of immune system
the only tissue in the body that is transplanted from one person to another without the worry of rejection. Because it has no blood vessels, it is beyond the reach of immune system
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It is the middle layer of the eyeball
It is the middle layer of the eyeball
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Most posterior of vascular layer a bloodrich nutritive tunic that contains a dark pigment. The pigment prevents light from scattering inside
the eye
Most posterior of vascular layer a bloodrich nutritive tunic that contains a dark pigment. The pigment prevents light from scattering inside the eye
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What are the two muscle structure of choroid?
What are the two muscle structure of choroid?
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ciliary body, which is attached to the lens by a suspensory ligament called____?
ciliary body, which is attached to the lens by a suspensory ligament called____?
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it regulates the amount of light entering the eye so that we can see as clearly as possible in the available light
it regulates the amount of light entering the eye so that we can see as clearly as possible in the available light
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the _____ through which light passes. Circularly and radially arranged smooth muscle fibers form the iris, which acts like the diaphragm of a camera.
the _____ through which light passes. Circularly and radially arranged smooth muscle fibers form the iris, which acts like the diaphragm of a camera.
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The innermost sensory layer of
the eye is the delicate two-layered ___?which extends anteriorly only to the ciliary body.
The innermost sensory layer of the eye is the delicate two-layered ___?which extends anteriorly only to the ciliary body.
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The outer ____ layer of the retina is omposed of pigmented cells that, like those of the choroid, absorb light and prevent light from scattering inside the eye. They also act as phagocytes to remove dead or damaged receptor cells
and store vitamin A needed for vision.
The outer ____ layer of the retina is omposed of pigmented cells that, like those of the choroid, absorb light and prevent light from scattering inside the eye. They also act as phagocytes to remove dead or damaged receptor cells and store vitamin A needed for vision.
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What is the transparent layer of retina
What is the transparent layer of retina
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They are called PHOTORECEPTORS because they respond to light
They are called PHOTORECEPTORS because they respond to light
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Electrical signals pass from the photoreceptors via a two-neuron chain called_____?
Electrical signals pass from the photoreceptors via a two-neuron chain called_____?
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list in sequence the neural layer in retina which is the first step is the rods and cones which is the photoreceptors and then?
list in sequence the neural layer in retina which is the first step is the rods and cones which is the photoreceptors and then?
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The blind spot in our vision
The blind spot in our vision
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this photoreceptors allow us to see in gray tones in dim light, and they
provide our peripheral vision.
this photoreceptors allow us to see in gray tones in dim light, and they provide our peripheral vision.
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Anything that interferes with rod function hinders our ability to see at night. This condition, called_____?
Anything that interferes with rod function hinders our ability to see at night. This condition, called_____?
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is one of the building blocks of the pigments the photoreceptor cells need to respond to light
is one of the building blocks of the pigments the photoreceptor cells need to respond to light
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are discriminatory receptors that allow
us to see the details of our world in color under right light conditions. They are densest in the center of the retina and decrease in number toward
the retinal edge.
are discriminatory receptors that allow us to see the details of our world in color under right light conditions. They are densest in the center of the retina and decrease in number toward the retinal edge.
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The area of the retina with the greatest concentration of cones( your area focus…. you test it’s functionality when you read the Eye chart)
The area of the retina with the greatest concentration of cones( your area focus…. you test it’s functionality when you read the Eye chart)
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is a condition in which the lens of the eye is warped. The warped lens will cause images to appear out of focus on the retina.
is a condition in which the lens of the eye is warped. The warped lens will cause images to appear out of focus on the retina.
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This is a condition in which distant objects are seen more clearly than are object that are nearby. This is because light is focused behind the retina rather than on it.
This is a condition in which distant objects are seen more clearly than are object that are nearby. This is because light is focused behind the retina rather than on it.
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This is a condition in which objects that are nearby are seen clearly while objects in the distance are out of focus. This is because the light is focused in front of the retina rather than on the retina.
This is a condition in which objects that are nearby are seen clearly while objects in the distance are out of focus. This is because the light is focused in front of the retina rather than on the retina.
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is one of the major causes of blindness. High pressure builds in the eye and damages the optic nerve. Any vision that is lost is not repairable.
is one of the major causes of blindness. High pressure builds in the eye and damages the optic nerve. Any vision that is lost is not repairable.
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are when the clear transparent lens of the eye develops a cloudy or milky covering. It prevents the eye from being able to see. Although it can happen to young people, it is mostly found in the elderly.
are when the clear transparent lens of the eye develops a cloudy or milky covering. It prevents the eye from being able to see. Although it can happen to young people, it is mostly found in the elderly.
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this humor helps prevent the eyeball from collapsing inward by reinforcing it internally.
this humor helps prevent the eyeball from collapsing inward by reinforcing it internally.
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Aqueous humor is reabsorbed
into the venous blood through the?
Aqueous humor is reabsorbed into the venous blood through the?
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is a common cause of
blindness in the elderly
is a common cause of blindness in the elderly
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the pressure inside the
eye. It also provides nutrients for the avascular
lens and cornea
the pressure inside the eye. It also provides nutrients for the avascular lens and cornea
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It is an instrument that is used to measure the intraocular pressure, which should be tested yearly in people over 40.
It is an instrument that is used to measure the intraocular pressure, which should be tested yearly in people over 40.
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is an instrument that illuminates the interior of the eyeball, allowing the retina, optic disc, and internal
blood vessels at the fundus, or posterior wall of the eye, to be viewed and examined
is an instrument that illuminates the interior of the eyeball, allowing the retina, optic disc, and internal blood vessels at the fundus, or posterior wall of the eye, to be viewed and examined
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What is the posterior wall of
the eye
What is the posterior wall of the eye
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When light passes from one substance to another substance that has a different density, its speed changes and its rays are bent, or
When light passes from one substance to another substance that has a different density, its speed changes and its rays are bent, or
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The image formed on the retina as a result of the light-bending activity of the lens is a____?
The image formed on the retina as a result of the light-bending activity of the lens is a____?
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This ability of the eye to focus specifically for close objects (those less than 20 feet away) is called ____?
This ability of the eye to focus specifically for close objects (those less than 20 feet away) is called ____?
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is the loss of the same side of the visual field of both eyes, which results from damage to the visual cortex on one side only
is the loss of the same side of the visual field of both eyes, which results from damage to the visual cortex on one side only
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thee eye that focuses images correctly on the retina is said to have
emmetropia, literally, “harmonious vision.
thee eye that focuses images correctly on the retina is said to have emmetropia, literally, “harmonious vision.
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occurs when the parallel light rays from distant objects fail to reach the retina
and instead are focused in front of it;
occurs when the parallel light rays from distant objects fail to reach the retina and instead are focused in front of it;
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What lenses should you use if you have myopic eye?
What lenses should you use if you have myopic eye?
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usually results from an eyeball that is too short or from a “lazy” lens
usually results from an eyeball that is too short or from a “lazy” lens
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occurs when the parallel light rays from distant objects are focused behind the retina—at least in the resting eye, in
which the lens is flat and the ciliary
muscle is relaxed
occurs when the parallel light rays from distant objects are focused behind the retina—at least in the resting eye, in which the lens is flat and the ciliary muscle is relaxed
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What lens should you use if you have hyperopia?
What lens should you use if you have hyperopia?
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In this condition, blurry images occur
because points of light are focused
not as points on the retina but as
lines
In this condition, blurry images occur because points of light are focused not as points on the retina but as lines
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What lenses should you use if you have astigmatism
What lenses should you use if you have astigmatism
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is the reflexive movement of the eyes medially when we view close objects.
When convergence occurs, both eyes are aimed toward the near object being viewed
is the reflexive movement of the eyes medially when we view close objects. When convergence occurs, both eyes are aimed toward the near object being viewed
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When the eyes are suddenly exposed to bright light, the pupils immediately constrict; this is the___? What reflex?
When the eyes are suddenly exposed to bright light, the pupils immediately constrict; this is the___? What reflex?
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long periods of reading tire the eyes and often result in what is commonly called ____?
long periods of reading tire the eyes and often result in what is commonly called ____?
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Which of the following correctly describes the pathway of light passing through the eye to the retina?
Which of the following correctly describes the pathway of light passing through the eye to the retina?
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Study Notes
Sensory Receptors and the Eye
- Approximately 70% of sensory receptors in the body are concentrated in the eyes.
- Adult eyes measure about 1 inch in diameter.
- Extrinsic eye muscles, eyelids, conjunctiva, and lacrimal apparatus compose the exterior structures of the eye.
- The anterior part of the eye is protected by eyelids that meet at the medial and lateral canthi.
- The space between the eyelids in an open position is called the palpebral fissure.
Eyelid Structure and Function
- Projections from the border of each eyelid are called eyelashes.
- Modified sebaceous glands located at the eyelid edges secrete an oil that lubricates the eyes.
- Modified sweat glands situated between the eyelashes have ducts opening at the follicle bases.
Tear Production and Function
- The lacrimal caruncle, found on the medial aspect of each eye, produces an oily secretion for lubrication.
- The lacrimal apparatus consists of the lacrimal gland and ducts, draining tears into the nasal cavity.
- Lacrimal glands continuously release a saline solution (tears) onto the eyeball's surface.
- Lysozyme, an enzyme found in tears, destroys bacteria.
Conjunctivitis and Eye Muscles
- Inflammation of the conjunctiva, known as conjunctivitis, can be highly contagious and caused by bacteria or viruses.
- There are six extrinsic muscles that facilitate gross eye movements and tracking of moving objects.
Anatomy of the Eyeball
- The eyeball is hollow, with three tunics forming its walls and filled with fluids known as humors.
- The anterior chamber of the eye is separated from the posterior chamber by the lens, which is the primary focusing structure.
- Three layers (tunics) of the eyeball are: fibrous, vascular, and sensory (retina).
Fibrous Layer
- The outermost layer consists of the protective sclera and transparent cornea.
- The sclera appears as the “white of the eye,” while the cornea serves as the clear front part, highly innervated and vulnerable to damage.
Vascular Layer (Uvea)
- The middle layer contains the choroid, which is the most posterior and blood-rich, preventing light scattering.
- The ciliary body, attached to the lens via the suspensory ligament, regulates light entering the eye.
- The iris, made of smooth muscle fibers, functions like a camera diaphragm to control light passage.
Retina and Photoreception
- The innermost sensory layer of the eye consists of a two-layered retina that extends to the ciliary body.
- The retinal structure includes a pigmented outer layer that absorbs light, preventing scattering, and acts as a phagocyte for receptor cells.
- Photoreceptors (rods and cones) respond to light; rods detect dim light and provide peripheral vision, while cones allow for color vision in bright light conditions.
Neural Pathway and Vision Conditions
- Electrical signals generated by photoreceptors travel through a two-neuron chain in the retina.
- The blind spot is the region lacking photoreceptors where the optic nerve exits the eye.
- Night vision difficulties due to rod disruption are called nyctalopia, indicating the importance of Vitamin A for photoreceptor function.
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Description
Test your knowledge about the five senses that help us interact with the external world. This quiz will cover the details of each sense and their functions in perception. Explore how these senses are essential for our daily experiences.
