G.+Sensory+System

__**Application**__
== Christine- The sensory organs are one of the first things we check on a patient. During our initial assessment we check to see if a patient has dilated or constricted pupils, can follow commands (in other words can they hear what we want them to do), and if they can feel pain or pressure. We check to see whether a patient's eyes are dilated or constricted because it is often a sign of brain function and whether or not we have a problem. Pain and pressure are also very good indicators in how the patient is doing. If the patient has been in a trauma we often check to see if they can feel different areas and we also want to know what their pain level is. We would be concerned if the patient was in a traumatic injury and didn't really have much pain. This could possibly mean that the nerves have been damaged or they could be going into shock. ==

==Kalli- Without the sensory system, no one not even a professional would be able to tell what was wrong with someone. As an OTA, I will work with patients who know exactly what is wrong, and with those who have no idea. However, if they are able to tell me what hurts, where is hurts, what movements they can't do, and things they can't feel, I will be able to help them recover a little better from what traumatic incident put them in therapy anyway. Without the sensory system, there is no way to actually define pain if you can't feel it. Sensory perception is important to everyone, for we could not do without seeing bright blue skies, smelling things like the ocean, feeling the softness of rose petals, tasting the best chocalate in the world, or hearing your favorite song on the radio. We as humans have no idea what it's like to no be able to do those things, until we can't do them anymore.==

== Meagan-This unit was very intersting to me. It seems like most people take their senses for granted. People don't realize how important their senses are until they don't have them anymore. To me, my vision is my most valuable sense. My grandma had Macular Degeneration for as long as I can remember. It was extremely hard for her to see almost anything. She had to bring items close to her face to be able to tell what they were. Watching her have to deal with Macular Degeneration was one of the worst things I have seen. So I value my vision because I know that my grandma couldn't use hers to its full potential. As an OTA, I will be working with a variety of individuals with sensory impairments. It is important for me to understand how the sensory system works so I will better be able to provide treatment to my clients. The sensory system can impair other parts of a person. For example, if a person may have trouble seeing so they may become depressed and I will have to address the vision and the depression. I try not to take my senses for granted anymore! ==

7. Cutaneous receptors
==** 1. Chemoreceptors respond to chemicals in the external environment (producing sensations of smell and taste) and internal environment (producing reflex responses to blood carbon dioxide, pH, and oxygen). **==

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** 2. Thermoreceptors respond to heat and cold (temperature changes). **
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==** 3. Mechanoreceptors respond to stimuli that respond to deform the plasma membrane or the receptor cell. These produce sensations of touch and pressure in the skin. Mechanoreceptors are present in the inner ear where they are responsible for equilibrium and hearing. **== picture- []

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5. Nociceptors respond to pain.
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6. Proprioceptors are receptors in our muscles, joints, tendons, and ligaments.
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7. Cutaneous receptors are sensory receptors in the skin. They respond to touch, pressure, heat, cold, and pain.
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Information on sensory receptors came from Fundamentals of Human Physiology book Ch. 7 Sensory system page 158.

2. The outer ear channels sound waves to the middle ear.
==== The outer ear consists of the pinna (auricle) which transmits sound wavesinto the external auditory meatus. The sound waves cause vibrations of the tympanic membrane (ear drum). The middle ear is the cavity between the tympanic membrane an the cochlea. The 3 middle-ear ossicles, which are little bones, include the malleus (hammer), incus (anvil), and the stapes (stirrup) are located in the middle ear. There is a footplate on the stapes which is attached to a small membrane in the cochlea called the oval window. The movements of the stapes produces vibrations of the oval window. Since the tympanic membrane is much larger than the oval window, the vibrations in response to sound by the tympanic membrane are greatly magnified in the vibrations of the oval window. ====

Information came from Fundamentals of Human Physiology book Ch. 7 Sensory system page 167-168.

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3. The lens changes shape to keep the image focused on the retina.
==== The refraction of light by the cornea and lens focuses an image on the retina. Accomadation is the ability of the eyes to keep the image focused on the retina as the distance between the eyes and the object changes. This is achieved by changing the shape and thickness of the lens, which occurs by changing the tension exerted on the lens by the ciliary muscle. This circular muscle surrounds the lens. When ciliary muslces relax, its circle widens and puts more tension on the lens. The lens gets stretched into a thinner shape. When the ciliary muscles contract, the circle narrows and puts less tension on the lens. This allows the lens to assume a thicker, more round shape. ====

==== When we view an object 20 feet or more from our eyes, the ciliary muslces are relaxed and our lenses thin, allowing the object to be focused on the retinas. As we move closer to the object, our ciliary muscles contract, allowing the lenses to become increasingly thick. This maintains the focus on our retinas. The closer we are to an object, the thicker the lenses become. The closest that we can focus is known as the near point of vision. ====

Information came from Fundamentals of Human Physiology book Ch. 7 Sensory system page 173-174.

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__**Why does Grandpa ignore Grandma?**__
1. What is the general purpose of the sensory nervous system and the specific purpose of the auditory system?

The general purpose of the sensory nervous system is to regulate homeostasis. The specific purpose of the auditory system is to onvert sound waves into nerve impulses. These impulses are then perceived and interpreted by the brain as sound

2. Trace the path of sound from the outer ear to interpretation by the brain, detailing what happens at each step in the pathway. 3. What are the environmental factors that might have prevented Grandpa Carl from hearing Grandma Marie? Some environment factors that might have prevented Grandpa Carl from hearing Grandma Marie include the TV volume being too loud, too much distance between Grandpa and Grandma, Grandma not speaking clearly, too many distractions going on in the house, and because football is more interesting than taking out the trash.

4. Why was Bob able to hear Grandma Marie when Grandpa Carl could not.

Grandpa was not able to hear Grandma because he could have damage to one or more parts of his ear, loss of hair cells, or over exposure to loud noises over a long period of time.

5. Provide a precise definition of presbycusis and identify the classic types of the disorder. Presbycusis is the loss of hearing that gradually occurs in most individuals as they grow older. The classic types of presbycusis are sensory, neural, metabolic, and mechanical.

6. What does the data suggest might be the likely cause of Grandpa Carl’s hearing problems? The cause of Grandpa's hearing problems could be age and over exposure to loud noises over time. 7. What are the physiological mechanisms that might lead to this hearing loss? There are problems with the sound reaching the inner ear. Since the sound travels there via conduction, this is called conductive hearing loss. It's the far less common mechanism of hearing loss. Much more common is sensorineural hearing loss.This is often called nerve deafness, but this is a misnomer, because the auditory nerve is almost never the cause. The problem is usually in the hair cells of the cochlea.

8. What, if any, possible treatments could improve Grandpa Carl’s hearing?

Possible treatments include hearing aids, assistive listening devices, alerting devices, and other communication aids.