Sense Organs:Eye/Ear

The eye and ear are sense organs, like skin, taste buds ,and olfactory regions(smell). They are receptors whose sensitive cells may be activated by energy or a stimulus in the external or internal environment . The cells respond by initiating a series of NERVE IMPULSES TO the brain! TO the brain is what kind of nerve cell? Afferent or efferent??

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Good! Who got that right? See its allll connected! Of our senses- What sense would you pick if you HAD to lose one? Which one would you pick if you could only have ONE?

Eyes        -ocular        ophthalmo-

The human eye has been called the most complex organ in our body. It's amazing that something so small can have so many working parts. But when you consider how difficult the task of providing vision really is, perhaps it's no wonder after all.

Anatomy of eye

Parts of the EYE

  • Pupil-the black circular opening in the iris that lets the light IN
  • The iris (the pigmented part) What color is your neighbors iris? Muscles of the iris constrict the pupil in bright light and dilate the pupil in dim light, regulating amount of light entering eye.
  • The conjunctiva is a membrane lining the inner surface of eyelids  and anterior part of eyeball over the white of eye. What is pink eye?

  • • The cornea (a clear dome over the iris) bends or refracts the light so they are focused properly/ avascular-what does that mean?
  • Lens is clear disk like structure helps focus light on retina, shape is controlled by ciliary  muscle so we can see things near and far.
  • • The sclera (the white part) Extends from cornea to optic nerve in back of the eye!  Its    the Outer layer that protects everything inside.
  • The choroid is a dark brown membrane inside sclera supplies nutrients to eyes.
  • The aqueous humor is fluid secreted by the ciliary body and maintains shape and
  •      nourishes the eye
  • The retina is the thin delicate NERVE layer of the eye and its receptor cells are called
  •        RODS and CONES. We have 6.5 million cones and 120 million rods in the retina
  • 1. RODS-function at low light levels and responsible for peripheral vision
  • 2. Cones-function in bright light, responsible for color and central vision/color blindness                    affects the cones responsible for that color.
  • All the messages  of light travel to our brain via the OPTIC NERVE.
  • Just another pic

    How do we SEE?

    How do we see an image?

    The lens focuses the image. It can do this because it is adjustable – using muscles to change shape and help us focus on objects at different distances. The automatic focusing of the lens is a reflex response and is not controlled by the brain.

    Once the image is clearly focused on the sensitive part of the retina, energy in the light that makes up that image creates an electrical signal. Nerve impulses can then carry information about that image to the brain through the optic nerve

    A video on how we see something!

    And what part of the cerebrum is responsible for vision? What lobe?

    Eye Diseases and Disorders

    Conjunctivitis

    Who has had this? Pink Eye!?

    Pink eye (conjunctivitis) is an inflammation or infection of the transparent membrane (conjunctiva) that lines your eyelid and covers the white part of your eyeball. When small blood vessels in the conjunctiva become inflamed, they're more visible. This is what causes the whites of your eyes to appear reddish or pink.

    Pink eye is commonly caused by a bacterial or viral infection, an allergic reaction, or — in babies — an incompletely opened tear duct. Very contagious! ANOTHER REASON TO KEEP YOUR HANDS OUT OF YOUR FACE! That is how pink eye is spread! Germ-x anyone?

    GROSS-Touch your eyes and you get it!!  Cooties

    Myopia

    Myopia (Nearsightedness)             

    Nearsightedness, or myopia,is a vision condition in which close objects are seen clearly, but objects farther away appear blurred. Nearsightedness occurs if the eyeball is too long or the cornea, the clear front cover of the eye, has too much curvature. As a result, the light entering the eye isn’t focused correctly and distant objects look blurred. Dr will

    prescribe eyeglasses or contact lenses that correct nearsightedness by bending the visual images that enter the eyes, focusing the images correctly at the back of the eye.

    How do we get this?

    heredity & visual stress

    Even though the tendency to develop nearsightedness may be inherited, its actual development may be affected by how a person uses his or her eyes. Individuals who spend considerable time reading, working at a computer, or doing other intense close visual work may be more likely to develop nearsightedness.

    Hyperopia

    What is farsightedness?

    Farsightedness, also known as hyperopia, is a common type of refractive error where distant objects may be seen more clearly than objects that are near.

    It is mainly cause by two reasons-

    • Low converging power of eye lens because of weak action of ciliary muscles.
    • Eyeball being too short because of which the distance between eye lens and retina decreases

    Common signs and symptoms of farsightedness include:

    • Headaches
    • Eyestrain
    • Squinting
    • Blurry vision, especially for close objects

    Farsightedness can be corrected with eyeglasses, contact lenses, or surgery.

    Presbyopia

    Presbyopia              Presby/o-old age          - opia--vision condition

    Presbyopia usually occurs beginning at around age 40, when people experience blurred near vision when reading, sewing or working at the computer.

    What Causes Presbyopia?

    Presbyopia is caused by an age-related process. This differs from astigmatism, nearsightedness and farsightedness, which are related to the shape of the eyeball and are caused by genetic and environmental factors. Presbyopia generally is believed to stem from a gradual thickening and loss of flexibility of the natural lens inside your eye.

    Retinal Detachment

    Retinal detachment itself is painless, but retinal detachment warning signs and symptoms almost always appear before it occurs or has advanced. Retinal detachment symptoms may include:

    • The sudden appearance of many floaters — small bits of debris in your field of vision that look like spots, hairs or strings and seem to float before your eyes
    • Sudden flashes of light in the affected eye
    • A shadow or curtain over a portion of your visual field that develops as the detachment progresses
    • Different causes example: diabetic problems, injury, etc
    • Retinal Tears will usually need to be treated with laser treatment or cryotherapy (freezing), to seal the retina to the back wall of the eye again. ...
    • Detached Retina. Retinal detachments may require surgery to return the retina to its proper position in the back of the eye.

    TREATMENTS

    LASIK eye surgery is the most common type of refractive surgery. Refractive surgery changes the shape of the dome-shaped transparent tissue (cornea) at the front of your eye.

    Lasik Surgery

    Cataracts

    A cataract is a clouding of the eye's natural lens, which lies behind the iris and the pupil.

    Cataracts are the most common cause of vision loss in people over age 40 and is the principal cause of blindness in the world

    Glaucoma

    What is Glaucoma?     Gluac/o-gray          -oma- mass or collection of fluid

    Glaucoma is a group of diseases that damage the eye’s optic nerve and can result in vision loss and blindness. However, with early detection and treatment, you can often protect your eyes against serious vision loss.

    At first, open-angle glaucoma has no symptoms. It causes no pain. Vision stays normal. Glaucoma can develop in one or both eyes.

    Without treatment, people with glaucoma will slowly lose their peripheral (side) vision. As glaucoma remains untreated, people may miss objects to the side and out of the corner of their eye. They seem to be looking through a tunnel. Over time, straight-ahead (central) vision may decrease until no vision remains.

    Normal vision

    View if you have glaucoma

    Can glaucoma be cured?

    No. There is no cure for glaucoma. Vision lost from the disease cannot be restored.

    Glaucoma treatments include medicines, laser trabeculoplasty, conventional surgery, or a combination of any of these. While these treatments may save remaining vision, they do not improve sight already lost from glaucoma.

    Eye and Cornea Donation:


    By registering to be a donor, you can transform the lives of dozens of people—including giving the gift of sight.

    • Eyes can help restore sight to people with cornea problems (the clear part of the eye). Damage can be caused by eye disease or injury, or defects from birth. The white part of the eye (the sclera) can be used in operations to rebuild the eye.
    • A corneal transplant involves replacing a diseased or scarred cornea with a new one. Since 1961, more than 1,000,000 men, women, and children ranging in age from nine days to 100+ years, have had their sight restored.
    • Over 95 percent of all corneal transplant operations successfully restore the corneal recipient’s vision.
    • With corneal tissue, everyone is a universal donor. Your blood type does not have to match. It doesn’t matter how old you are, what color your eyes are or how good your eyesight is. Aside from those suffering from infections or a few highly communicable diseases such as HIV or hepatitis, most people are suitable donors.

    Tissue donation must be initiated within 24 hours of death.

    Tests and Diagnosing

    Visual acuity test

    The visual acuity test is used to determine the smallest letters you can read on a standardized chart (Snellen chart) held 20 feet away.

    How the Test is Performed

    This test may be done in a health care provider's office, a school, a workplace, or elsewhere.

    You will be asked to remove your glasses or contact lenses and stand or sit 20 feet from the eye chart. You will keep both eyes open.

    You will be asked to cover one eye with the palm of your hand, a piece of paper, or a small paddle while you read out loud the smallest line of letters you can see on the chart. Numbers or pictures are used for people who cannot read, especially children.

    Visual acuity is expressed as a fraction.

    • The top number refers to the distance you stand from the chart. This is usually 20 feet.
    • The bottom number indicates the distance at which a person with normal eyesight could read the same line you correctly read.

    For example, 20/20 is considered normal. 20/40 indicates that the line you correctly read at 20 feet away can be read by a person with normal vision from 40 feet away.

    Even if you miss one or two letters on the smallest line you can read, you are still considered to have vision equal to that line.

    What Abnormal Results Mean

    Abnormal results may be a sign that you need glasses or contacts. Or it may mean that you have an eye condition that needs further evaluation by a health care provider.

    More tests

    Ophthalmoscopy     ophthalm/o-eye    scopy-visual exam

    Ophthalmoscopy is a test that allows a doctor to see inside the back of the eye and other structures using a magnifying instrument (ophthalmoscope) and a light source. It is done as part of an eye exam and may be done as part of a routine physical exam.

    Next Awesome Sense Organ:

    EARS!-HUH?
    Did you say something?
    Your talking in my bad ear.
    Your on my deaf side.

    The main purpose of the ear is to turn sound waves from the air into electrical signals that are interpreted by the brain.

    The ear is made up of three parts: the outer, middle, and inner ear. All three parts of the ear are important for detecting sound by working together to move sound from the outer part through the middle and into the inner part of the ear. Ears also help to maintain balance.

    Parts to know

    The outer ear includes:

    • auricle (cartilage covered by skin placed on opposite sides of the head)PINNA
    • auditory canal (also called the ear canal)
    • eardrum outer layer (also called the tympanic membrane)


    The outer part of the ear collects sound. Sound travels through the auricle and the auditory canal, a short tube that ends at the eardrum.

    The middle ear includes:

    • eardrum
    • cavity (also called the tympanic cavity)
    • ossicles (3 tiny bones that are attached)
      • malleus (or hammer) – long handle attached to the eardrum
      • incus (or anvil) – the bridge bone between the malleus and the stapes
      • stapes (or stirrup) – the footplate; the smallest bone in the bod

    The inner ear includes:

    • semicircular ducts – filled with fluid; attached to cochlea and nerves; send information on balance and head position to the brain
    • cochlea – spiral-shaped organ of hearing; transforms sound into signals that get sent to the brain
    • auditory tube – drains fluid from the middle ear into the throat behind the nose

    When the stapes moves, it pushes the oval window, which then moves the cochlea. The cochlea takes the fluid vibration of sounds from the surrounding semicircular ducts and turns them into signals that are sent to the brain by nerves.

    What you said?

    What is the Pathway of Sound?

    From the speaker to my brain?  Hello...is there anybody in there?  Pink Floyd...anyone?

    Why am I Deaf? I know why I am!(mh)

    Hearing loss can happen for many reasons.

    Some people may be born with hearing loss while others may lose their hearing slowly over time. There are diseases, infections and cancers that affect specific parts of the ear and can lead to hearing loss in children and adults.

    Listening to loud music a lot can cause the same kind of damage, especially if headphones or ear buds are used. Some famous musicians and Mrs. Hudecek have suffered hearing loss and developed tinnitus — a real problem for someone who needs to hear to make and enjoy music. That's why now you might notice that some of your favorite musicians wear hearing protection while they're playing. And Mrs. Hudecek saying "huh" a lot.

    Otitis Media

    Infections of the middle ear are one of the most common reasons for children to see a doctor. Three out of 4 children experience ear infection (otitis media) by the time they are 3 years old. Children are more likely to have ear infections like otitis media that come from bacteria or viruses than adults because of their developing ear anatomy. The middle ear is connected to the back of the nose by the auditory tube (also called the eustachian tube) and its location allows easier access to germs. This may lead to a buildup of fluid and pressure, painful infections. Usually follows a URI.

    Small tubes placed inside of childrens' ears help fluid drainage and relieve pressure in the ears so that hearing improves.

    Otosclerosis

    What is otosclerosis?

    Otosclerosis is a term derived from oto, meaning “of the ear,” and sclerosis, meaning “abnormal hardening of body tissue.

    Tinnitus           NOT -ITIS!!!          -itus

    Tinnitus (TIN-ih-tus) is noise or ringing in the ears. A common problem, tinnitus affects about 1 in 5 people

    Tinnitus isn't a condition itself — it's a symptom of an underlying condition, such as age-related hearing loss, ear injury or a circulatory system disorder.

    Although bothersome, tinnitus usually isn't a sign of something serious.

    Vertigo

    Whats that? Sensation of irregular or whirling motion of oneself or external objects

    Testing & Diagnosing Ear Problems

    Who do you see for this? EENT

    EYES/EARS/NOSE/THROAT

    Otoscopy

    Otoscopy is an examination that involves looking into the ear with an instrument called an otoscope. This is performed in order to examine the 'external auditory canal' – the tunnel that leads from the outer ear (pinna) to the eardrum

    Do you see the pearly gray normal eardrum? Did you really see it in nursing school? No but I said I did when we tested out!

    Audiometry

    An audiometry exam tests your ability to hear sounds. Sounds vary based on their loudness (intensity) and the speed of sound wave vibrations (tone).

    Tuning fork test

    There are many ways of testing hearing in the office. Bedside testing may be used as a screening procedure. While formal audiometry is preferable, for reasons of expense or access, it may not always be possible. In bedside testing, tuning forks are often used to test frequencies.

    Treatments

    Otoplasty- surgical repair of ear----mike tyson--anyone--eeewwww!!

    Cochlear Implants

    A cochlear implant is a small, complex electronic device that can help to provide a sense of sound to a person who is profoundly deaf or severely hard-of-hearing. The implant consists of an external portion that sits behind the ear and a second portion that is surgically placed under the skin

    There is controversy around this! Not everyone needs a CI!

    Adults who have grown up deaf can find the implants ineffective or irritating. This relates to the specific pathology of deafness and the time frame.

    Adults who are born with normal hearing and who have had normal hearing for their early years and who have then progressively lost their hearing tend to have better outcomes than adults who were born deaf. This is due to the neural patterns laid down in the early years of life, which are crucially important to speech perception.

    Cochlear implants cannot overcome such a problem. Daily exercises such as side by side tracking, listening to audio books while reading a print book, synthetic training, and analytic training can improve the efficacy of an implant through practice.

    Hearing aides too

    My ears like rock yours like hip-hop
    HOW?

    “Despite our idiosyncrasies in listening, the brain experiences music in a very consistent fashion across subjects,”

    Daniel Abrams, researcher at Stanford University School of Medicine. Participants in the study, who had no formal musical training, listened to symphonies, while undergoing an MRI brain scan. They found that among all the participants, the music had an almost identical effect in their brains; it activated brain regions that are involved in movement, planning, attention, and memory — which means:

    that when we listen to music, we aren’t just simply processing sound, like background noise or the sound of a car engine. Music is more meaningful to our brains than just any sound: It's repetitive, melodious, organized.

    There isn't a single music center of the brain, in large part because listening to even very simple music combines a bunch of distinct neurological processes. Let's first look at the more strictly mechanical aspects of listening to music, the auditory cortex is an important part of processing the sound of music. Part of the temporal lobe, the auditory cortex takes in information from the ear and assesses the pitch and volume of the sound.

    Other parts of the brain deal with different aspects of music. Rhythm is only connected in a relatively minor way to the auditory cortex.

    A lot goes into keeping even relatively simple, regular beats - tapping along to something as basic as a 1:2 rhythm brings in the left frontal cortex, left parietal cortex, and right cerebellum, and more unusual rhythms bring in still more areas of the cerebral cortex and cerebellum.

    Sorry but that was perfect after you all just rocked the nervous system!

    Love me a celebration! Thanks Ms Woods!

    The reason I have presbycusis-what is that?

    Word parts:

    Opti-                       op-

    oto-                        auro-

    -sclerosis              ophthalmo-