Special Senses Flashcards
How many layers of fluid-filled sphere does the eye have?
3
List the structural features of the eye
-fibrous tunic
-vascular tunic
-nervous (sensory) tunic
-lens
-anterior segment
-posterior segment
What are the parts of the fibrous tunic?
sclera (white)
cornea (transparent)
conjunctiva
what part of the vascular tunic contains melanin and is highly vascular?
choroid
what is the coloured part of the eye?
iris
What focuses the lenses?
ciliary body
What is the hole in the iris?
pupil
What are the three layers of neurons in the eye?
Photoreceptors
Bipolar cells
Ganglion cells
What are the two types of photoreceptors?
Rods- black + white
Cones- colour
what part of the eye is the area of greatest visual acuity and is where the light focuses?
fovea centralis
this has no rods NOR cones, and is where the optic nerve exits the eye
optic disc
are lens vascular?
no
what are cataracts?
clouding of lens
what part of the eye contains aqueous humor and is anterior to the lens
anterior segment
posterior segment contains what kind of humor?
vitreous humor which is gel-like
What part of the ear conducts sound?
external, middle, and inner ear
what are the parts of the external ear (3)
auricle (pinna) = elastic cartilage covered with skin
external auditory canal (meatus)
tympanic membrane (eardrum)
What are the parts of the ear?
External Ear
Middle Ear
Inner Ear (labyrinth)
Cochlea
Receptors in Inner ear
What are the parts of the inner ear?
bony labyrinth
membranous labyrinth
what does the bony labyrinth contain? the membranous labyrinth?
perilymph, endolymph
IN ORDER
What are the parts of the bony labyrinth? What are their functions?
semicircular canals = equilibrium
vestibule = equilibrium
cochlea = hearing
what are the parts of the membranous labyrinth? where are they located?
semicircular ducts = inside canals
utricle + saccule = inside vestibule
cochlear duct = inside cochlea
What are the 3 channels of the coils found in the cochlea?
scala vestibuli = upper; perilymph
scala tympani = lower; perilymph
cochlear duct = middle; endolymph
What are the three membranes of the cochlea?
vestibular membrane = b/w cochlear duct and scala vestibuli
basilar membrane = b/w cochlear duct and scala tympani
tectorial membrane = covers hair cells
what do hair cells that synapse with neurons do?
send impulses to the brain via cranial nerve VIII
where do cilia that extend into endolymph embedded?
tips are embedded in tectorial membrane for stability
