Shade eye from sunlight
Eyebrows
Keep debris out of eye
Also called palpebrae;
thin, skin-covered folds
Eyelids
that protect eye
anteriorly
Transparent mucous
Accessory functions of
membrane that
the eye
Conjunctiva
produces a lubricating
mucous secretion
Consists of lacrimal
gland and ducts that
Lacrimal apparatus
drain into nasal cavity
Six straplike extrinsic
Extrinsic eye muscles
eye muscles
Opaque posterior
Vision
Sclera
region
Outermost layer; dense
avascular connective
Fibrous layer
Taste
tissue
Transparent anterior
one-sixth of fibrous
Cornea
Special senses
layer
Supplies blood to all
Hearing
Choroid
layers of eyeball
Smell
Equilibrium
Consists of smooth
muscle bundles, ciliary
muscles, that control
Ciliary body
Middle pigmented layer
Vascular layer
of eye, also called uvea
shape of lens
Olfactory epithelium:
Structure of eyeball
organ of smell
In order to smell
Colored part of eye that
lies between cornea and
lens, continuous with
Physiology of smell
Iris
volatile
The eye and vision
ciliary body
Smell
Absorbs light and
Vision receptors for
bright light
Dim light, peripheral
vision receptors
Odorant binds to
receptor, activating a G
pigmented layer
prevents its scattering
protein
Retina originates as an
Inner layer
outpocketing of brain
Cones
Photoreceptors, bipolar
cells, ganglion cells
substance, it must be
G protein activation
causes cAMP (second
neural layer
Smell transduction
Rods
messenger) synthesis
cAMP opens Na+ and
Ca2+ channels
Opsin and 11-cis retinal
combine to form
Pigment synthesis
Na+ influx causes
rhodopsin in dark
depolarization and
impulse transmission
When rhodopsin
surrounding ear canal
pigment captures
absorbs light, 11-cis
isomer of retinal
shell-shaped structure
process by which
Pigment bleaching
changes to all-trans
Capturing light
photon of light energy,
which is converted into
Auricle
Phototransduction
sound waves into
auditory canal
A&P Ch. 15
a graded receptor
isomer
that functions to funnel
potential
Short, curved tube lined
All-trans retinal
converted back to 11-cis
with skin bearing hairs,
Pigment regeneration
sebaceous glands, and
isomer
External ear
Both rods and cones are
strongly stimulated
glands
meatus
Light
Transmits sound waves
to eardrum
Pupils constrict
Light and dark
adaptation
Cones stop functioning
in low-intensity light
External acoustic
ceruminous (earwax)
Tympanic membrane
(eardrum)
Boundary between
external and middle
ears
Dark
Pupils dilate
Malleus
Equilibrium is response
Vestibular apparatus:
to various movements
equilibrium receptors in
of head that rely on
semicircular canals and
input from inner ear,
vestibule
eyes, and stretch
The ear and hearing
Equilibrium
the “hammer” is
secured to eardrum
Major areas of the ear
Middle ear
made up of auditory
ossicles
receptor
Incus
Stapes
Vestible
the “anvil”
the “stirrup” base fits
into oval window
Central egg-shaped
cavity of bony labyrinth
Three canals oriented in
Inner ear
Also referred to as the
labyrinth (maze)
Semicircular canals
three planes of space:
anterior, lateral, and
posterior
A small spiral, conical,
Cochlea
bony chamber, size of a
split pea