Neuroanatomy - 15 Visual Motor Systems

cornea, sclera

the fibrous layer of the eye contains the _________ and the __________

cornea

the __________ contains pain receptors, has minimal blood supply, and has a lack of immune response to transplant because of lack of lymphatic drainage

sclera

the ________ is the lateral margin of the cornea, continuous with the dura mater of the optic nerve

choroid, ciliary body, iris

the vascular layer of the eye contains the ________, ________, and ________

choroid

the _______ is pigmented to absorb light rays and prevent scattering; located just under the sclera and has a high vascular supply

ciliary body

the ___________ secretes fluid to bathe the cornea and iris, has suspensory ligaments to the lens, and drains into the canal of schlemm

iris

the _____ is the colored part of the eye that contains 2 muscles for dilation and constriction of the pupil

lens

the ______ of the eye refracts the light entering the eye and focuses it on the retina

convex

the lens of the eye is a ________ lens

cataracts

_______ are abnormal clumps of crystalline proteins that are naturally occuring in the lens

vitreous body

the __________ is between the lens and the retina, and transmits light rays to the retina, as well as supporting the layers of the retina. it helps prevent changes in pressure within the eye when extraocular muscles contract

retinal pigment epithelium, neural retina

the two layers of the retina are the _____________ and the ______________

neural retina

the retinal pigment epithelium supplies the __________ with nutrition in the form of glucose and essential ions

retinal photoreceptors

the retinal pigment epithelium protects _____________ from potentially damaging levels of light by absorbing some

photoreceptors, light

the neural retina contains __________ and associated neurons of the eye and is specialized for sensing ________ and processing the resultant informations

quanta of light (photons), electrical signal, retinal neurons

the photoreceptors absorb _________________ and convert this input to an ____________ which is then processed by ____________

opposite

the directional path of light into the retina and the directional path of neural outflow are in the (same/opposite) parallel direction

rods, cones

the two types of photoreceptors are _______ and _______

rods

______ help see dim light vision in the dark, sense contrast, motion, black and white/grayscale

rhodopsin

rods use a chemical called _________

photopsin

cones use a chemical called ___________

peripherally

rods are located more (peripherally/centrally) in the retina

centrally

cones are located more (peripherally/centrally) in the retina

cones

______ sense bright light, color vision, visual acuity, edges and shapes

cones

the macula contains only (cones/rods)

macula lutea

the ____________ is a yellowish spot where retinal cells thin out and only cones are present, which allows maximum light to reach the cones and help with best acuity

fovea centralis

the center of the macula lutea is called the __________

optic disc

the _______ is where axons from ganglion cells pierce the choroid and sclera to form the optic nerve

T

T/F: vessels penetrate at the optic disc

F; OPTIC DISC causes this

T/F: the fovea centralis causes a functional blind spot

ICA, ophthalmic, posterior ciliary and central retinal

the pathway of blood to the eye is mainly from the _________ artery, to the ________ which then splits to the __________ artery and the ___________ artery

conjunctiva

the __________ is a thin clear membrane that covers the sclera; bacteria or virus can cause inflammation

tarsal plates

the levator palpebrae superioris and orbicularis oculi attach at the _____________

away from

abduction of the eyeball is (away from/towards) the midline of the nose

toward

adduction of the eyeball is (away from/towards) the midline of the nose

up

elevation of the eyeball is looking (up/down)

down

depression of the eyeball is looking (up/down)

towards

intorsion: eye rotates along itself — the top of the eye rotates (away from/towards) the nose

away from

extorsion: eye rotates along itself — the top of the eye rotates (away from/towards) the nose

extraocular, intraocular, facial eye

the 3 classes of eye muscles are _________, __________, and _________

control movement of the eye

the function of the extraocular eye muscles is _____________

pupil accommodation and reaction to light

the function of the intraocular eye muscles is ________________

open and close eyelid

the function of the facial eye muscles is _____________

• lateral rectus

• medial rectus

• inferior rectus

• superior rectus

• superior oblique

• inferior oblique

the extraocular eye muscles are: (6)

• 2 in iris — sphincter pupillae, dilator pupillae

• 1 in ciliary body — ciliary muscle

the intraocular eye muscles are: (3)

orbicularis oculi, levator palpebrae superioris

the facial eye muscles are: (2)

abducts, abducens

the lateral rectus m _________ the eye and is innervated by the __________ nerve

adducts, oculomotor

the medial rectus m _________ the eye and is innervated by the __________ nerve

medial rectus, lateral rectus

the only 2 extraocular muscles that act in the X axis are the ___________ and the ___________ muscles

depresses & adducts, oculomotor

the inferior rectus m _________ the eye and is innervated by the __________ nerve

depresses & abducts, trochlear

the superior oblique m _________ the eye and is innervated by the __________ nerve

elevates & adducts, oculomotor

the superior rectus m _________ the eye and is innervated by the __________ nerve

elevates & abducts, oculomotor

the inferior oblique m _________ the eye and is innervated by the __________ nerve

sphincter pupillae

the ___________ muscle constricts the pupil, limiting light to the iris

sphincter pupillae

the ___________ muscle is involved in the pupillary light reflex

oculomotor

the sphincter pupillae is innervated by the ___________ n

sympathetic fibers from superior cervical ganglion

the dilator pupillae is innervated by the _______________ n

dilator pupillae

the ____________ muscle increases the size of the pupil to allow more light to enter the eye

ciliary

the ___________ muscle changes the shape of the lens when focusing on a near object, accommodation

oculomotor

the ciliary muscle is innervated by the _____________ nerve

closes

the orbicularis oculi ________ the eyelid

retracts and elevates

the levator palpebrae superioris ________ the eyelid

oculomotor

the levator palpebrae superioris muscle is innervated by the ___________ n

facial

the orbicularis oculi muscle is innervated by the ____________ n

• vestibulo-ocular reflex (VOR)

• corneal reflex

• pupillary light reflex

the three eye reflexes are: (3)

eye movement of equal velocity and opposite direction to head movement

the purpose of the VOR reflex is to provide ____________

extraocular, vestibular

the VOR reflex requires coordination between the _________ nuclei and the _________ nuclei

oculomotor, abducens

the efferent motor nerves involved in the VOR reflex are the _________ and _________

medial rectus, lateral rectus

the main two muscles involved in the VOR reflex are the _________ and _________

close eyelid when cornea is touched

the purpose of the corneal reflex is to __________

T

T/F: the corneal reflex is bilateral

trigeminal

the afferent portion of the corneal reflex uses the __________ nerve

facial

the efferent portion of the corneal reflex uses the __________ nerve

bright light

the pupillary light reflex occurs when the eye is exposed to __________

pretectal nucleus

in the pupillary light reflex, the optic tract sends neural impulses to the ____________ in the midbrain

optic tract

after the optic chiasm, the optic nerve is called the __________

BOTH accessory oculomotor nerve

in the pupillary light reflex, the pretectal nucleus stimulates _______________ nuclei

short ciliary nerves

in the pupillary light reflex, the oculomotor nucleus sends an impulse to the ________________

sphincter pupillae

in the pupillary light reflex, the _____________ contracts to constrict pupil limiting light to the iris

visual field

the _________ is the part of the world seen when patient has both eyes open and looking straight ahead

binocular

the _________ zone of the visual field is the broad central region seen by both eyes

right monocular

the _________ zone of the visual field is the small zone seen only by the right eye

left monocular

the _________ zone of the visual field is the small zone seen only by the left eye

nasal

the _____ retina is the portion of the retina closer to midline

temporal

the _____ retina is the portion of the retina more lateral

cornea and lens, retina

the light ray coming into the eye is bent/refracted by the __________ so that the image is focused on the _______

temporal, nasal

in the binocular zone, the right visual field information hits the:

• _______ retina of the left eye

• _______ retina of the right eye

nasal, temporal

in the binocular zone, the left visual field information hits the:

• _______ retina of the left eye

• _______ retina of the right eye

DOES NOT

the information from the temporal retina (does/does not) cross the optic chiasm

does

the information from the nasal retina (does/does not) cross the optic chiasm

ipsilateral

the information from the temporal retina travels on the (ipsilateral/contralateral) optic tract

contralateral

the information from the nasal retina travels on the (ipsilateral/contralateral) optic tract

lateral geniculate

information from both the temporal and nasal retinas go through the _____________ nucleus

ipsilateral

the information from the temporal retina is headed to the (ipsilateral/contralateral) visual cortex

contralateral

the information from the nasal retina is headed to the (ipsilateral/contralateral) visual cortex

F; each eye contributes to BOTH visual fields

T/F: each eye contributes to one of the visual fields, left or right

strabismus

_________ is a condition where the eyes are misaligned, which can lead to diplopia, eventually failing to focus one of the eyes

diplopia

________ is double vision, seeing 2 images of the same object

amblyopia

__________ is a condition also called lazy eye, due to abnormal visual inputs early in lift; the brain favors the stronger eye, and the good eye has access to visual cortex

myopia, far away

______ is nearsightedness, objects ______ appear blurry