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Which Part Of The Eye Sends Signals To The Brain

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Frontal Lobe Higher And Human Function

The Human Eye and Its Parts – Sight – Senses for Children

Image: The frontal lobe is where higher human-like brain activity occurs

Where higher mental processes such as thinking, decision making, and planning. Highly developed in humans, the frontal lobe is also where our personality is formed and where we can carry out higher mental processes such as planning.

In addition, the frontal lobe is necessary to be able to speak fluently and meaningfully.

The Medulla Or Medulla Oblongata

Located directly above the spinal cord in the lower part of the brain stem. It controls many vital autonomic functions such as heart rate, breathing, and blood pressure.

Functions of the medulla are performed without thought. We would not be able to live without the medulla because the critical tasks it performs. These include regulating blood pressure and breathing.

The Cell Structure Of The Brain

The brain is made up of two types of cells: neurons and glial cells, also known as neuroglia or glia. The neuron is responsible for sending and receiving nerve impulses or signals. Glial cells are non-neuronal cells that provide support and nutrition, maintain homeostasis, form myelin and facilitate signal transmission in the nervous system. In the human brain, glial cells outnumber neurons by about 50 to one. Glial cells are the most common cells found in primary brain tumors.

When a person is diagnosed with a brain tumor, a biopsy may be done, in which tissue is removed from the tumor for identification purposes by a pathologist. Pathologists identify the type of cells that are present in this brain tissue, and brain tumors are named based on this association. The type of brain tumor and cells involved impact patient prognosis and treatment.

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The Brain And The Eye

The eye works like a camera. The iris and the pupil control how much light to let into the back of the eye, much like the shutter of a camera. When it is very dark, our pupils get bigger, letting in more light when it is very bright our irises constrict, letting in very little light.

The lens of the eye, like the lens of a camera, helps us to focus. But just as a camera uses mirrors and other mechanical devices to focus, we rely on eyeglasses and contact lenses to help us to see more clearly.

The focus light rays are then directed to the back of the eye, on to the retina, which acts like the film in a camera. The cells in the retina absorb and convert the light to electrochemical impulses which are transferred along the optic nerve to the brain. The brain is instrumental in helping us see as it translates the image into something we can understand.

The eye may be small, but it is one of the most amazing parts of your body. To better understand it, it helps to understand the different parts and what they do.

ChoroidA layer with blood vessels that lines the back of the eye and is between the retina and the sclera .

Ciliary BodyThe muscle structure behind the iris, which focuses the lens.

CorneaThe very front of the eye that is clear to help focus light into the eye. Corrective laser surgery reshapes the cornea, changing the focus to increase sharpness and/or clarity.

FoveaThe center of the macula which provides the sharp vision.

ScleraThe white outer coating of the eyeball.

What Is Normal Vision

Vision: It all Starts with Light

To understand how certain problems can affect your child’s vision, its important to know how normal vision happens. For children with normal vision, the following things happen in this order:

  • Light enters the eye through the cornea. This is the clear, dome-shaped surface that covers the front of the eye.

  • From the cornea, the light passes through the pupil. The iris, or the colored part of your eye, controls the amount of light passing through.

  • From there, it then hits the lens. This is the clear structure inside the eye that focuses light rays onto the retina.

  • Next, light passes through the vitreous humor. This is the clear, jelly-like substance that fills the center of the eye. It helps to keep the eye round in shape.

  • Finally, the light reaches the retina. This is the light-sensitive nerve layer that lines the back of the eye. Here the image is inverted.

  • The optic nerve is then responsible for carrying the signals to the visual cortex of the brain. The visual cortex turns the signals into images .

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    What Part Of The Brain Is Responsible For Vision

    As soon as the information passes from the optic nerve to the remainder of the brain, it is sent to the occipital lobe, where vision is processed. The occipital lobe is located in the back of the brain, above the cerebellum, and forms the center of the visual perception system, according to the Centre for Neuro Skills. Each hemisphere has its own occipital lobe therefore, each occipital lobe processes the information sent to that particular hemisphere. The occipital lobe controls how an individual views sight, so damage to this brain section can result in visual field cuts, and problems identifying color or movement of a things.

    Visual Cortex

    The last part of the brain associated with vision is the visual cortex, where sensory and motor info is incorporated with vision. The Canadian Institutes of Health Research states that several visual pathways are included. For instance, the ventral visual path controls how an individual identifies items, while the dorsal visual path manages an individuals visual-motor action to things. To puts it simply, the visual cortex enables you to understand that youre taking a look at a plate, for example, and then permits you to choose it up.

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    An Inside Look At The Eye

    The outer covering of the eyeball consists of a relatively tough, white layer called the sclera .

    Near the front of the eye, in the area protected by the eyelids, the sclera is covered by a thin, transparent membrane , which runs to the edge of the cornea. The conjunctiva also covers the moist back surface of the eyelids and eyeballs.

    Light enters the eye through the cornea, the clear, curved layer in front of the iris and pupil. The cornea serves as a protective covering for the front of the eye and also helps focus light on the retina at the back of the eye.

    After passing through the cornea, light travels through the pupil .

    The iristhe circular, colored area of the eye that surrounds the pupilcontrols the amount of light that enters the eye. The iris allows more light into the eye when the environment is dark and allows less light into the eye when the environment is bright. Thus, the pupil dilates and constricts like the aperture of a camera lens as the amount of light in the immediate surroundings changes. The size of the pupil is controlled by the action of the pupillary sphincter muscle and dilator muscle.

    Behind the iris sits the lens. By changing its shape, the lens focuses light onto the retina. Through the action of small muscles , the lens becomes thicker to focus on nearby objects and thinner to focus on distant objects.

    Cones are responsible for sharp, detailed central vision and color vision and are clustered mainly in the macula.

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    Are Toydarians Immune To Mind Tricks

    The mind trick was said to work only on the weak-minded, and there were certain species, including Toydarians and Hutts, that were either highly resistant or immune to it. Additionally, as exemplified by Prime Minister Almecs Mandalorian Guards, it was also possible to train individuals to resist mind tricks.

    Unexpected Link Between Posture And Your Eyes

    How fast does your brain send messages to your body?

    As an infant, you learned about the relationship between your body parts through trial and errorreaching out and making contact. As a child, maybe you recited your facial features as fast as you could or sang a ditty to remember that your neck bone connects to your head bone.

    Anatomical links affect more than the way you learnthey can change and, even, dictate your health. In this blog, youll discover the link between your posture, or how you stand, and your eyes.

    Understanding the Link

    To use the link between the position of your spine and your optic health to your advantage, you first must understand how the connection works.

    Eyes to Brain

    Your eyes represent a complex part of your central nervous system, connected directly to the brain. To see the way you do, your eyes accept light beams. These beams hit the photoreceptors, known as rods and cones, located in your retina at the back of your eyeball.

    The signals the retina receives translate into electrical impulses, which travel on the optic nerve into the brains visual cortex.

    Brain to Spine

    When impulses reach the visual cortex, your brain interprets them and uses them to determine how the body should respond. The brain sends messages down the spinal cord to tell the rest of your body how to react to what the eyes see.

    Eyes to Spine

    Results of This Connection

    Blurred vision or difficulty focusing the eyes Decreased circulation which causes numbness and muscle strength issues Eye strain or fatigue

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    Pressure On The Optic Nerve

    As the tumour grows, or there is a build-up of cerebrospinal fluid in the brain, it can squeeze normal healthy brain tissue including the main cranial nerves within the brain. The resulting pressure can alter how well the nerve works, and if this happens to the optic nerve, your vision can be affected.

    Tongue And Taste Buds

    The sense of taste is transduced by taste buds, which are clusters of 50-100 taste receptor cells located in the tongue, soft palate, epiglottis, pharynx, and esophagus. The tongue is the main sensory organ of the gustatory system. The tongue contains papillae, or specialized epithelial cells, which have taste buds on their surface. There are three types of papillae with taste buds in the human gustatory system:

    • fungiform papillae, which are mushroom-shaped and located at the tip of the tongue
    • foliate papillae, which are ridges and grooves toward the back of the tongue
    • circumvallate papillae, which are circular-shaped and located in a row just in front of the end of the tongue.

    Each taste bud is flask-like in shape and formed by two types of cells: supporting cells and gustatory cells. Gustatory cells are short-lived and are continuously regenerating. They each contain a taste pore at the surface of the tongue which is the site of sensory transduction. Though there are small differences in sensation, all taste buds, no matter their location, can respond to all types of taste.

    Taste Buds: A schematic drawing of a taste bud and its component pieces.

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    What Happens If The Occipital Lobe Is Damaged

    The most obvious effect of damage to the occipital lobe is blindness, but occipital lobe damage can have other surprising effects:

    • Epilepsy: Some seizures occur in the occipital lobe, and occipital lobe damage increases vulnerability to seizures.
    • Difficulties with movement: Even if you are still able to move, changes in depth perception and vision can lead to inappropriate movements and difficulty navigating the visual field.
    • Difficulties perceiving colors, shape, dimension, and size.
    • Difficulty recognizing familiar objects or faces.
    • Hallucinations

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    The Seat Of Consciousness: High Intellectual Functions Occur In The Cerebrum


    The cerebrum is the largest brain structure and part of the forebrain . Its prominent outer portion, the cerebral cortex, not only processes sensory and motor information but enables consciousness, our ability to consider ourselves and the outside world. It is what most people think of when they hear the term grey matter. The cortex tissue consists mainly of neuron cell bodies, and its folds and fissures give the cerebrum its trademark rumpled surface. The cerebral cortex has a left and a right hemisphere. Each hemisphere can be divided into four lobes: the frontal lobe, temporal lobe, occipital lobe, and parietal lobe. The lobes are functional segments. They specialize in various areas of thought and memory, of planning and decision making, and of speech and sense perception.

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    The Functioning Of The Eyes

    Your eyes play a crucial role in almost everything you do. Here are some of the main functions that help the eye make clear, single images.

    Seeing – Eyes take in light and convert it into electrical impulses that are sent to the brain, which processes these signals to form the images we see.

    Moving – The six extraocular muscles control the movement of the eye. Four move the eyeball up, down, left and right two adjust the eyes to counterbalance head movement. If your eyes don’t move together you will see double.

    Blinking – Every time you blink, a salty secretion from your tear gland is swept over the surface of the eye, keeping your eyeballs moist and clean. We really appreciate this in dusty / windy conditions. Tears are also bactericidal so they help prevent infections.

    Crying – Tears are salty fluid containing protein, water, mucus and oil are released from the lacrimal gland in the upper, outer region of the eye. Reflex tears protect the eye from irritants like smoke, dust and wind. Emotional tears are a response to sadness or joy.

    Protecting – The eyes are recessed into sockets in the skull to protect them from injury. Eyelashes and eyelids keep out dust and dirt. Eyebrows are arched in shape to divert sweat away from your eyes.

    Glossary / Anatomy Of The Eye

    The cornea is the eye’s outermost layer. It is the clear, dome-shaped surface that covers the front of the eye.
    AMD-Dry Form
    The dry form of age-related macular degeneration occurs when the light-sensitive cells in the macula slowly break down, gradually blurring central vision in the affected eye. Over time, as less of the macula functions, central vision is gradually lost in the affected eye.
    AMD-Wet Form
    The wet form of age-related macular degeneration occurs when abnormal blood vessels behind the retina start to grow under the macula. These new blood vessels tend to be very fragile and often leak blood and fluid. The blood and fluid raise the macula from its normal place at the back of the eye. Damage to the macula occurs rapidly.
    Floaters are tiny spots, specks, flecks and “cobwebs” that drift aimlessly around in your field of vision.
    The lens is the clear part of the eye that helps to focus light, or an image, on the retina.
    The macula is the part of the eye that allows you to see fine detail. The macula is located in the center of the retina.
    Optic Nerve

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    Importance Of Routine Eye Exams

    Routine eye exams are an easy and important way to make sure your vision is in tip-top shape. During an eye exam, your eye doctor can assess the health of your optic nerve and evaluate any symptoms you may be experiencing.

    If the eye doctor sees a problem related to the optic nerve, they may refer you to a neuro-ophthalmologist for more specialized treatment.

    Schedule an exam

    Which Part Of The Brain Deals With Sight

    The Human Eye and Its Parts – How Vision Works – Compilation Video – Senses for Kids

    Interestingly enough, vision is controlled by the part of the brain which is furthest away from the eyes themselves the occipital lobe. It is located in the back of your head above the brain stem, the part of our brain that controls breathing.

    The occipital lobe also has two hemispheres. The left hemisphere processes information from the right eye and vice versa.

    The primary visual cortex gets raw information from the eyes and sends them to the secondary visual cortex for further processing. The secondary visual cortex is made out of the ventral stream and dorsal stream. Visual stimuli are processed in the temporal lobe as well.

    Its important to keep the brain healthy and to challenge it with new tasks on a daily basis. That way, we can keep our brains strong and functioning well.

    Thanks to Brocas area we can share our thoughts and ideas with people around us. What thoughts would you like to share with us below?

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    The Coordinated Balance System

    The human balance system involves a complex set of sensorimotor-control systems. Its interlacing feedback mechanisms can be disrupted by damage to one or more components through injury, disease, or the aging process. Impaired balance can be accompanied by other symptoms such as dizziness, vertigo, vision problems, nausea, fatigue, and concentration difficulties.

    The complexity of the human balance system creates challenges in diagnosing and treating the underlying cause of imbalance. The crucial integration of information obtained through the vestibular, visual, and proprioceptive systems means that disorders affecting an individual system can markedly disrupt a persons normal sense of balance. Vestibular dysfunction as a cause of imbalance offers a particularly intricate challenge because of the vestibular systems interaction with cognitive functioning,2 and the degree of influence it has on the control of eye movements and posture.

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    Rods are on the dark side

    The retinas rod cells arent part of the cone coloring system. They work when light levels are low. Instead of photopsins, rods have a different pigment-protein pair: rhodopsin . Rods produce images only in shades of grey. But they are much more sensitive to light than cones are. They are so sensitive that a rod cell can detect a single photon of light the smallest possible particle.

    In the dark, we rely on our rods. But light inactivates these cells. It stimulates them so much that they become unresponsive. Thats all right, cones are there to take over. They require much more light to function. So we rely on cones in the light.

    When they detect certain wavelengths of visible light, the photoreceptors trigger electrical signals. Rods and cones will send these signals through nerves that reach into the brain. They head for the occipital cortex, right up against the back of the skull. There, the brain interprets these signals to make sense of what were looking at.

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