Lab 10 Flashcards
Medial Rectus
Moves eye medially to nose
Lateral rectus
Moves eye laterally towards temples
Superior recuts
Moves eye upward/downward, helps rotating top of eye towards nose
Inferior rectus
Moves eye upward/downward, rotate top of eye away from nose
Superior oblique
Moves top of eye towards nose, moves eye in a downward and outward direction
Inferior oblique
Rotates top of eye away from nose and moves eye in an upwards and inwards direction
Anterior segments
Contains cornea, iris, lens
Controls the light coming into eye
Aqueous Humor
Clear liquid in the front part of eye
Nourishment, shape of eye
Choroid
BV rich, dark membrane
BV to nourish the outer layers of eye and the melanin absorbs excess light
Ciliary Body
Modification of the choroid that encircles the lens
Contains the ciliary muscles and the ciliary process
Ciliary muscle
Smooth muscle within ciliary body
Alters shape of lens with contraction and relaxation
Cones
Senses and interprets light in Retina
Interprets color
Cornea
Modified to form a transparent layer that bulges anteriorly, contains no BV
Forms clear window that is major light bending medium of eye
Continuous with sclera
Fovea centralis
Where light reaches, acts as screen of eye
Responsible for high-acuity vision, where the light hits and focuses at the back of eye in center of macula lutea
Iris
2 layers of pigmented smooth muscle (anterior vascular layer)
Controls amount of light entering eye
Lens
Convex layer of the eye, transmits light
Macula lutea
Yellow oval spot at center of retina, responsible for sharp, detailed, central vision
Optic Chiasma
Place in brain where some optic nerve fibers from one eye cross those of the other eye
Conducting visual info from eye to cornea
Optic Disk
Round spot on retina formed by passage of axons
Transfers signals from photoreceptors to optic nerve
Blind spot
Photoreceptors
Rods and cones
Special cells in retina responsible for converting light into signals sent to brain
Pigmented epithelium
Behind retina
Absorbs excess light so it is not reflected
Posterior segment
posterior 2/3 of eye
Encompass the vitreous humor, retina, choroid, and optic nerve
Pupil
Round central opening of the iris
Allows light to enter the eye
Retina
Back of eye, pigmented and neural
Transmits sensory light info to the brain
Rhodopsin
Light receptor
Initiates scotopic vision
Rods
Sense and interpret light
Detects black and white/brightness
Sclera
Opaque white CT
Maintains eye shape and attachment site for muscles
Vitreous Humor
Gel-like substance in posterior chamber
Structure/round shape of eye
Zonules
Sensory ligament
Connects lens to ciliary body
How does eye focus on objects near and far
For distance vision, ciliary muscles relax, the lense becomes thin, and the zonular fibers become stretched and taught.
For closer vision, ciliary muscles contract, the lens becomes thicker, and the fibers relax.
Why do we have a blind spot
There are no light sensitive cells in the place where the optic nerve connects so this part of the retina “can’t see”
Where in field of vision is blind spot
For the right eye, the blind spot is just to the right of the center of vision and vice versa for the left eye
Why don’t you notice your blind spot
Your brain fills the missing info based on what is going on around you
How come we only see one image but both eyes are getting a slightly different view
Brain combines the two images and puts it into a single 3D image
2 ways photoreceptors stimulated in absence of light and what causes this to occur
Electric stimuli and external pressure can both stimulate photoreceptors when there is no light. Electrical stimulation excites nervous tissue which makes an action potential and external pressure stimulates mechanical receptors which can generate an action potential.
Pinna
Outside of ear, protection
Malleus
Transfers auditory oscillation to the incus and stapes
Incus
Middle ear, transmits vibration to stapes
Semicircular canals
Inner ear, sense head rotations
Vestibular nerve
Tell brain about balance
Cochlear nerve
Communicate to brain about hearing
Cochlea
Inside temporal bone
Water ripples across small hairs
Eustachian tube
Connects nasopharynx to middle ear
Opens and closes to maintain pressure
Round window
Within mesotympanum at posterior basal turn of cochlea
transmission of sound
Stapes
Membrane covered opening that connects middle ear to inner ear
Sound conduction
Tympanic cavity
Between inner and middle ear, separates them
Tympanic membrane
Separates external ear canal from eustachian tube, vibrates with sound
External ear canal
Pinna to eardrum
Transmission of sound
Ear and eye structures
Label diagrams of both
Including cochlea and Crista Ampullaris
