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37 Cards in this Set
- Front
- Back
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Sensory receptors
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—neurons specialized to detect certain types of stimuli.
Exteroceptors interoceptors |
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Exteroceptors
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detect stimuli from outside the body. (taste, smell, vision, hearing, & somatosenses)
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Interoceptors
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detect stimuli from inside the body.
* Changes in blood pressure. * Changes in blood volume. * Changes in pH of the blood |
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How Sensation Occurs:
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• Sensation occurs when nerve impulses arrive
at the cerebrum. • Perception, which also occurs in the cerebrum, is an interpretation of the meaning of sensation. |
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Touch
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-somatosenses of the dermis
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Cutaneous receptors
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make the skin sensitive to touch (mechanoreceptors), pressure (mechanoreceptors), pain (chemorecptors), and temperature (thermoreceptors).
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Gustation or Taste/ taste receptors
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Taste receptors (chemoreceptors)
— sensitive to molecules in the food we eat. (sweet, salty, sour, bitter, and umami) |
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Olfaction or Smell/smell receptors
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• Smell receptors (chemoreceptors) —sensitive to molecules in the air we breathe.
• Greater than 10,000 different types of olfactory receptors (80-90% of taste sensation is actually due to our sense of smell) |
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Vision- photoreceptors
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Vision- photoreceptors
-respond to light energy -rods- for black and white vision -cones- for color vision |
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Sclera
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(white of the eye)
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Choroid
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(middle layer of cells)
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Retina
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(contains photoreceptors) where image is produced—upside down.
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• Cornea
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(transparent sclera) covers and protects the pupil.
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Lens
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(transparent, flexible, concave) focuses light rays on the retina.
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Pupil
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(hole in the eyeball) allows light to enter the eyeball.
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Ciliary muscles
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(smooth muscles) change the shape of the lens in order to focus on near and distant objects.
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Fovea centralis
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(lot of cones & no rods) sharpest vision.
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The visual pathway
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begins in the retina & passes through the thalamus before reaching the primary visual area in the occipital lobe of the brain.
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Optic nerve
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(cranial nerve) carries impulses to the brain to be interpreted.
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Blind spot
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(where optic nerve attaches to the retina) no vision.
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Nearsightedness
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—you can see up close but not far away. (eyeball too long)
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Farsightedness
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—you can see far away but not up close. (eyeball too short)
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Macular Degeneration
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-majority of cases are in people over 55
specific spot in eye where cells are dying vision is fuzzy and unclear |
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Cataract-
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clouding of the lens
-major cause of blindness worldwide -most cases due to aging, but also can be related to diabetes, ocular infection, excessive UV exposure, and glaucoma |
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Color blindness
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- inability to distinguish a full range of colors
-usually due to a deficient number of a particular type of cone -often inherited |
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-red-green color blindness
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is a X-linked recessive trait more common in men than women
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Glaucoma-
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aqueous humor in the anterior chamber of the eye is not draining properly due to a blockage
-increase in pressure can destroy cells in the retina and optic nerve -edges of vision get dark -unclear -can be result of age |
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• Outer ear- 2 parts
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pinna and auditory canal
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Pinna (ear flap)
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—catches sound waves.
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Auditory canal
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-directs sound waves to the tympanic membrane (eardrum).
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Tympanic membrane (eardrum)
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—picks up and
amplifies sound waves. |
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Small bones of the middle ear
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—pick up and amplify sound waves.
(Malleus, Incus, and Stapes) |
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Eustachian tube (connects middle ear to the throat)—
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equalizes pressure to keep the ear clear
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Cochlea
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—converts vibrations into nerve
impulses. |
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Vestibule
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—gravitational equilibrium.
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Semicircular canals
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—rotational equilibrium.
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Middle ear infection (ottis media) -
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usually occurs in children under 5
blockage of auditory tube |
