Special Senses (visual system) Flashcards
What does this system include
Vision Hearing Balance Taste Olfaction
___ is our dominant sense
Vision
This lobe is involved with vision, perception, interpretation of images
Occipital
5 components of visual system
Lacrimal apparatus Palpebrae (eye lids) Conjunctiva Glands Extrinsic eye muscles
Short coarse hair that help shade eyes from sunlight, prevent sweat from dripping into eyes, aid in keeping larger particles from reaching the eye
Eye brows
This protects eye and keeps them from drying out
Eye lid (palpebrae)
Space between upper and lower lids
Palpebrae fissure
What do follicles of eye lashes have that make eye blink if anything touches the eye lash?
Sensory receptora
Commissure that contains sebaceous and sweat glands and produces whitish secretion “sandmans eye sand”
Lacrimal caruncle/ medial commissure
Thinnest skin of body supported by CT that serves as an anchoring point for orbicularis oculi and levator palpebrae superioris muscles
Tarsal plates
Which glands are embedded in the tarsal plates which open at edge of eyelid? They secrete oil preventing eyelids of sticking together
Tarsal/ Meibomian glands
Gland that creates a red sty when blocked by oil
Ciliary gland
Zeis
Transparent mucus membrane lining the eyelids (palpebrael conjunctiva) and anterior surface of the eyeball (bulbar conjunctiva)
Conjunctiva
Why are blood vessels underneath the eye visible when eye Is irritated
What is a special name for this irritated eye
Because conjunctiva is so thin
Blood shot
Gland that drains tears to nasal cavity
Lacrimal
What produces tears and is sent all the way through to the nasal cavity or down to your eye?
Lacrimal apparatus
Nerve that secretes tears mediated by the parasympathetic fibers
Cranial nerve 7
Allows us to follow a moving object and provides external support that helps maintain the shape of the eyeball and hold in the orbit
Extrinsic eye muscles
What makes up the extrinsic eye muscles, they flow into a ring.
4 rectus muscles (inferior superior lateral and medial) 2 oblique (superior oblique and tendon)
Muscles runs along medial wall of orbit, makes right then angle, passes through trochlea, innervates trochlear nerve
DEPRESSES AND LATERALLY
Superior oblique muscle
Muscle that runs laterally and inserts on inferolateral
ELEVATES AND moves LATERALLY
Inferior oblique
Has high axon to muscle fiver ratio
8-12 muscle cells for these motor units
Moves laterally
Nerve: VI abducens
Lateral rectus
Moves eye laterally
Nerve- III oculomotor
Medial rectus
Elevates eye
Nerve- III oculomotor
Superior rectus
Depresses eye
Nerve-III oculomotor
Inferior rectus
Chambers of eye contain fluid called
Aqueous humor
Lens is suspended by ciliary body by tiny filaments called
Suspensory ligaments
Or ciliary zonule
Clear gel like material in posterior segment, supports shape of eyeball from inside
Vitreous humor
We’re optic nerve leaves eye
Optic disk
Junction if retina with ciliary body
Ora serrata
photoreceptors aka
Cones
Site of attachment for muscles
Sclera
What secretes the aqueous humor
Ciliary processes
Muscles that extend out radially and make eye dilate
Pupillary dilator muscles
Muscles contract eye
Pupillary constrictor
Pupillary constrictor muscles stimulated by
Parasympathetic
Pupillary dilatory stimulated by
Sympathetic
Eyes medically rotate toward subject
Converge
Work in dim light
Best at detecting movement and peripheral vision
120 million in retina
Rod
10 million in retina Bright light Color vision High acuity vision Located in maxilla lures Central fovea only contains this
Cones
Diff between rods and cones
Rods- work at night/ dim light
Cones- work during day or in bright light
Visual pigment of rods
Rhodopsin (it’s color is deep purple)
Gradual loss of the accommodation reflex with age
Presbyopia
Nearsightedness
Myopia
Far sighted ness
Hyperopia
Blurry images
Astigmatism
Clouding of the lens
Like looking through glass
Cataract
Failure to drain the eye results in excessive pressure in anterior chamber which compresses retina and optic nerve
Glaucoma
