Eye and Ear Flashcards
(26 cards)
the chemicals in “food depolarize”chemoreceptors in the taste buds that are located on the surface of the tongue.
Taste (Gustation)
the chemicals (odorants) in the “air depolarize” chemoreceptors in the upper part of the nasal passages (olfactory bulb).
Smell (Olfaction)
a “photoreceptor”, the eye can be divided into three layers: The Sclera, Choroid Layer, Retina.
Vision
the ear (a mechanoreceptor for both hearing and balance) is divided into three main parts: Outer Ear, Middle Ear, Inner Ear
Hearing
the semicircular canals are responsible for detecting motion changes (dynamic equilibrium)
Balance
the outer white layer of the eye that protects and provides shape
Sclera
the transparent covering that protects and “refracts/bends” light towards the pupil.
Cornea
the “middle layer” containing blood vessels supplying the eye with nutrients and oxygen, and a dark pigment prevents the reflection of light.
Choroid
the “fluid behind the cornea” that supplies the cornea and lens with nutrients; refracts light and cushions.
Aqueous Humor
the muscular, colourful part of the eye, which “regulates the amount of light entering the “pupil” (the opening into the eyeball). In bright light, the iris contracts making the pupil constrict (smaller)
Iris
“focuses an image on the retina” that is upside down and reversed due to its shape
Lens
a jelly like material that maintains the shape of the eye.
Vitreous Humor
“innermost layer of the eye” containing the two types of photoreceptor cells.
Rods and Cones
Retina
“specialized for vision in dim light”; used to discriminated between shades of gray, used to see shapes and movement. Rods contain Rhodopsin, which contains vitamin A, and a large protein molecule called Opsin.
Rods
specialized for colour vision and sharp detail; activated by bright light; less numerous than the rods. Color Blindness is related to defective cones
Cones
a small and highly sensitive part of the retina responsible for detailed central vision. High concentration of cones.
Fovea Centralis
is the area at the back of the eye containing no rods or cones, the location of the optic nerve (carries information to the visual cortex of the occipital lobe).
Blind Spot
adjustments of the pupil (and iris) to different light intensities.
Pupillary Reflex
adjustments of the lens for near and distant images.
Accommodation Reflexes
the image focuses in front of the retina therefore distant objects are not clearly seen. Caused by a too long of an eyeball or a lens that can’t flatten enough. Corrected by wearing a concave lens or surgery.
Near Sightedness (myopia)
the image focuses behind the retina so near objects are out of focus. Caused by the eyeball being to short or the lens being to stiff. Corrected by wearing a convex lens or surgery.
Far Sightedness (hyperopia)
clouding of the lens so that it becomes opaque and restricts light from entering the eye.
Cataract
caused by an “uneven curvature” of the cornea or lens. Creates blurred vision, headaches etc.
Astigmatism
Is commonly found in older people and results in high intraocular pressure due to a build-up of a fluid in the aqueous humor.
Glaucoma
