communications Flashcards
define accomodation
eye changes shape of the lens to achieve a focused image of either distant or nearby objects
define aqueous humor
is the liquid between the lens and the cornea that is responsible for refracting light
define auditory nerve
transmits electrical messages from ear to brain so that sound can be interpreted
define cataract
clouding of the lens
what does the cerebellum do ?
regulates coordination
define choroid
a layer between the sclera and the retina, provides oxygen and nourishment
define colour blindness
inability to detect particular colours caused by a lack of specific colour cone cells
define cone cells
light sensitive cell found on the retina of the eye, particularly important in colour perception- concentrated @ the fovea
define cornea
transparent layer at the front of the eye, refracts incoming light
define effector
a muscle or gland that produces a response to a stimulus
define fovea
point on the retina with the greatest account and the greatest number of cone cells (6.5 million)
define incus
one of the three small bones in the middle ear
define ion
a charged atom or group of atoms
define iris
coloured part of the eye, controls the amount of light entering the eye
define labyrinth
organ in the inner ear that is responsible for balance
define lateral line
a visible line along the head and body of fish and amphibians, senses low frequency sound
define malleus
first of three small bones in the middle ear
define acuity
sharpness of vision
define axon
an extension on a neurone that takes the impulse away from the cell body
define binocular
involving the use of two eyes with overlapping field of view resulting in depth perception
define bioluminescence
the production of light by living organismss
define blind spot
the place on the retina where the opt nerve leaves the eye, contains no light sensitive cells
define ceteceans
order of marine mmala
define ciliary body
contains the suspensory ligaments and the ciliary muscles in the eye
define ciliarymuscles
small musclesattatched to the lens that change the shape of the lens to focus on near and far objects
define mechanoreceptors
a receptor that responds to sound, pressure, such and position
define medulla oblongata
involuntaryactions