Upgrade to remove ads
Only $35.99/year

Special Senses - Eye

Terms in this set (71)

Retina
light-sensitive inner lining of the back of the eye
Cornea
clear front surface of eye, part of the eye that primarily focuses light
Iris
functions like diaphragm of a camera, controls amount of light reaching the back of the eye by adjusting the size of the pupil
Anterior chamber
space between cornea and iris
Lens
located directly behind the pupil and focuses light
Posterior chamber
region behind the iris
Ciliary body
controls ciliary muscle, controls shape of lens and ciliary epithelium
aquaeous humor
slightly alkaline liquid that occupies the anterior and posterior chambers of the eye
Suspensory ligaments
ligament that supports a body part
Vitreous humor
transparent, colorless, gelatinous mass that fills the space between the lens of the eye and the retina lining the back of the eye
Sclera
"white part of eye", fibrous, protective, outer layer of eye made of collagen and elastic fibers
Optic disc
raised disk on retina at point of entry of optic nerve, lacks visual receptors and creates a blind spot
Choroid coat
vascular layer of the eye lying between the retina and the sclera
protect eye
spread tears
Function of eyelid
Eyelids
protect eye from dirt, dust, bright light, and foreign matter
spread tears over surface of eye
Cornea
Light rays enter the eye through the _________, the clear front "window" of the eye.
Refractive power
Pupil
The cornea's ____________ bends the light rays in such a way that they pass freely through the ________ the opening in the center of the iris through which light enters the eye.
Extrinsic Eye muscles
Some of the fastest contracting and most precisely controlled skeletal muscles in the human body

Function as Agonist & Antagonists pairs to move the eyeball
Accommodation
the process by which the eye's lens changes shape to focus near or far objects on the retina

Lens helps the eye automatically focus on near and approaching objects, like an autofocus camera lens.
Refraction
change in direction of propagation of any wave as a result of its traveling at different speeds at different points along the wave front.
measurement of the focusing characteristics of an eye or eyes.
Eyeglasses lens
correct refractive errors by focusing light directly on the retina. The type of lens depends on the type and severity of the refractive error.
Diopters
The strength of a lens (i.e., its refractive power) is measured in optical units called?

This measurement indicates how much refractive power the lens must have to focus images directly on the retina.

The higher it is, the stronger the lens.
Photoreceptors (rods or cones)
Retina contains visual receptors called?
Outer - photoreceptors
Middle - bipolar neurons
Inner - ganglion cells
Layers of retina
Ganglion and bipolar neurons
Light passes through this before reaching photoreceptors
Periphery
Central
Rods are abundant in the ______ of the retina whereas cones are found more frequently in ______ areas
Phototransduction
Conversion of light stimuli into neural signals
Right half
______ interprets image from left eye and vice versa
Photopigment absorbs lights and breaks down to two components
Hyperpolarizes rods and cones
Decrease in release of inhibitory neurotransmitters
Phototransduction process
Lacrimal apparatus
Produces tears
Outer ear
Middle ear
Inner ear
Sense of hearing three parts
Hearing
Equilibrium
Ear functions as sense of?
Pinna
External auditory canal
eardrum (tympanic membrane)
Parts of outer ear
Auditory ossicles
Middle ear cavity
Oval Window
Eustachian tube
Parts of middle ear
Labyrinth
Semicircular canals
Cochlea
Round Window
Spiral Organ (Organ of Corti)
Inner ear parts
Auricle or pinna
Funnel-shaped elastic cartilage that funnels sound and protects entry of ear.

Helps collect sound waves traveling through the air and directs them into the external acoustic meatus.

Funnel like structure
External Acoustic meatus or External Auditory Canal
canal which extends into head from the base of the auricle.

As sound waves enter they change
the pressure on the eardrum.

S-shaped tube
eardrum (tympanic membrane)
a thin membrane, which sound waves vibrate

Cone shaped

Sometimes considered part of middle ear

Semitransparent membrane covered by a thin layer of skin on its outer surface and a mucosa membrane in the inside

Has an oval margin and cone-shape with the cone apex pointing inward.
Malleus
Incus
Stapes
auditory ossicles
Oval window
Opening of tympanic cavity that leads to inner ear
Auditory Tube or Eustachian Tube
Connects middle ear to nasal cavity
Auditory Ossicles
Tiny ligaments attach bones to wall of tympanic cavity

Bridge the ear drum and the inner ear

Help increase (amplify) the force of vibrations from eardrum to oval
window
Labyrinth
Complex system of communicating chambers
Osseous
Membranous
Two parts of labyrinth
Osseous labyrinth
Bony canal in temporal bone
Membranous labyrinth
Similar shape of osseous labyrinth
Found within osseous labyrinth
Perilymph
Fluid between labyrinths is called _______ which is secreted by
cells in the walls of the bony canal
Endolymph
Fluid within Membranous is called?
Semicircular canal
Part of labyrinth
Provide sense of equilibrium
Cochlea
Functions in hearing

Has bony core and thin bony shelf that winds around the core like the threads of a screw
Upper and lower compartment
Shelf divides the osseous labyrinth of
cochlea into?
Upper compartment or Scala Vestibuli
Leads from oval window to apex of spiral
Lower compartment or Scala Tympani
Extends from Apex to round window
Round window
Opening in the wall of inner ear
Cochlear Duct
Part of membranous labyrinth
Lies between to bony compartments and ends as a closed sac at the apex
Vestibular membrane (Reissner's membrane)
Basilar membrane
Cochlear Duct is
Separated from scala vestibuli by?
Separated from Scala Tympani by?
Organ of Corti
Spinal organ is also known as?
Hearing receptors
Spinal organ contains?
Receptor cells
AKA Hair cells
Function somewhat like neurons
Move back and forth depending on pitch of sound
20-20000
2,000-3,000
Young person Detect sound waves ranging from _________ or more
vibrations per second

_________ is the range of greatest sensitivity
Temporal lobe
Vestibulocochlear cranial nerve
Interprets hearing (lobe)
It follows what cranial nerve?
Static - vestibule
Dynamic - semicircular canal
2 sense of equilibrium and what part
Static
Sense position of head
Maintain stability and posture when head is still
Dynamic
Sudden movement or rotation of head
Aid in maintaining balance
Vestibule
Bony chamber
between SCC and Cochlea
Utricle
Saccule
Macula
Vestibule contains?
Macula
Each of utricle and saccule have tiny hair like structures called?
Head bending forward, backward, or to one side stimulate hair cells
Crista ampularis
Rapid turns of head stimulate?
SCC move with head but fluid stays stationary
Eyes
Joints in neck
Other organs that help maintain balance
Cerebellum
Part of the brain that interprets impulses from SCC
Ampulla
Houses sensory organs called crista ampularis contain a number of sensory hair cells and supporting cells
Students also viewed