special senses Flashcards
tarsal plate
mass of collagen and elastic fibers
skeleton of upper eyelid
cornea
covered by conjunctiva (epithelium tissue covered by tears to keep eye moist
anterior 1/6, fibrous coat
–ciliary body and iris (smooth muscle), pulpil
sclera
posterior 5/6 of fibrous coat
wall of eyeball middle layer
vascular coat deep in fibrous coat called choroid
wall of eyeball third layer
nervous layer-inner retina-where light translated to electrical impulse by photo receptors
anterior part=pigments behind lens
optic disk
makes start of optic nerve, no photoreceptors
ciliary body
when it contracts, suspensory ligaments become lose and you can look at near objects (parasympathetic)
when it relaxes, you are looking at far away things (sympathetic control)
what is the sphincter pupillae?
parasympathetically innervated circular sm layer that constricts pupil
dilator pupillae
radial muscle fibers, sympathetic innervation
what produces aqueous humor?
what is it?
ciliary body
posterior chamber filled–>flows to ant–>collected by small veins at corneal-scleral junction called canal of schlemm
what is glaucoma?
buildup of pressure in chambers that causes hazy cornea and dilated scleral vessels
lacrimal apparatus
produces tears to clean eyelid
tears collected in medial corner of eye in lacrimal canaliculi–>ducts–>lacrimal sac–>nasolacrimal duct–>nasal cavity
where does the external ear end?
ends at tympanic membrane
describe external ear parts
includes auricle-cartilage and external acoustic meatus
-w/ceruminous glad that produces earwax which disinfects the area
middle ear
tympanic cavity
how is sound passed from middle to inner ear?
3 ossicles malleus, incus, shapes connected by 2 windows to inner ear oval window-covered by shapes round window-covered by a mucosal membrane
which structures help to reduce vibration of the bones noise?
tensor tympani and stapedius
bony labarynth inner ear
3 semicircular canal, vestibule, and cochlea
membranous inner ear
in bony labyrinth filled with endo lymph fluid 3 semicircular ducts in semicircular canal utricle and saccule in bony vestible cochlear duct in cochlea
where are there cristae in the inner ear
ampulla (dilated part) at junction b/t semicircular duct and saccule
where is CSF filtered to produce endolymph fluid?
@ endolymphatic sac that passes through the bone INTO the cranial cavity
-extension of utricle and saccule
