Test 6 A&P
what causes conjunctivitis?
- infection agents - irritants
The sclera_________
- is made of dense connective tissue - provides for eye shape
which structures are part of the vestibular complex
- saccule - semicircular ducts - utricle
what are basic test sensations
- sour - umami - sweet
tactile disc
-Expanded nerve terminal that synapses with Merkel cell -Sensitive to fine touch
Place the structures of the eye in order from superficial to deep
1. Choroid 2. Photoreceptors 3. Horizontal cells 4. Bipolar cells
Place the three layer of of the eye in order from superficial to deep.
1. fibrous tunic 2. vascular tunic 3. retina
Order these structures in the order that tears travel through them
1. lacrimal puncta 2. lacrimal canaliculus 3. lacrimal sac 4. nasolacrimal duct
Place the structures of CN II in order from anterior to posterior
1. optic nerve 2. optic chiasm 3. optic tract
gustatory cells have a lifespan of
7-10 days
what disorder is caused by unequal curvatures of the lens and cornea
Astigmatism
when the _______ membrane moves, the _______ on the spiral organ hair cells distort because they are anchored
Basilar, stereocilla
A ________ shaped lens is used to treat hyperopia and a __________ shape lens is used to treat myopia
Convex - hyperopia Concave - myopia
the eye is spherical, measuring about 5 centimeters in diameter, and most of it is receded into the orbit of the skull
False
a detached retina is more likely to occur if a person is
Myopia ( nearsightedness)
The medial, inferior, and superior rectus muscles, as well as the inferior oblique, are all innervated by
Oculomotor nerve, CN III
The superior oblique eye muscle is innervated by
Trochlear nerve, CN IV
Why is visceral pain sometimes localized incorrectly?
Visceral sensory neurons travel along the same pathway as many somatic sensory neurons - therefore pain signals may be interpreted as originating from the wrong location.
the semicircular ducts are involved in detecting _________ acceleration
angular
What chamber is between the iris and cornea?
anterior chamber
what eye disorder causes "milky" vision
cataracts
what structure is filled with pigment from melanocytes
choroid
what is the name of the "snail shaped" structure of the inner ear
cochlea
what type of photoreceptors detect color
cones
which events occur during bright light adaptation?
cones gradually adjust, rods become inactive, and pupils constrict
as we adjust to low light, our ______ become nonfunctional and it may take ______ for rhodopsin to become generated sufficiently so that you can see well in low-light conditions.
cones, 20-30 minutes
when light hits the eye, the pupil ________ in bright or _________ in dim lights
contracts, expands
the limbus is the junction between the sclera and _______
cornea
the optic disc is associated with
cranial nerve II ( optic nerve)
what is the name of the gelatinous dome with embedded stereocilia of the semicircular canal
cupula
the primary function of the ___ is to prevent large objects from contacting the eye
eyelashes
hyperopia
farsightedness
the lens is ________ when we are viewing far away objects
flattened
when the bipolar cells release their neurotransmitter, the ___ cells propagate a nerve signal along the ___ nerve
ganglion, optic
which may result in symptoms such as reduced field of vision, dim vision or halos around lights
glaucoma
as a consequence of the dark current, ____ channels in the photoreceptor open
glutamate
when rhodopsin is split by light stimulation, the calcium and sodium channels are also closed and this blocks the release of the neurotransmitter called _______
glutamate
When you travel in an elevator (which moves linearly in space), the ___________ detect when the elevator is accelerating or decelerating.
hair cells covered by an otolithic membrane
sensory receptors in the utricle detect the position of the _________
head
the term equilibrium refers to our awareness and monitoring of our ______ position
head
the vitreous body is also called the vitreous _______
humor
light causes the photoreceptor plasma membranes to _____
hyperpolarize
the ______ segment of the photoreceptors connect directly to the cell body
inner
gustatory sensations travel to the ________ of the brain
insula
Specific types of receptors called ______ detect stimuli in the internal organs
interoceptors
where are tears created?
lacrimal apparatus
The suspensory ligaments connect the ______ to the ciliary muscles.
lens
presbyopia occurs when the _____ loses elasticity
lens
acrimal fluid prevents bacterial infection because it contains an antibacterial enzyme called
lysozyme
macular degeneration occurs when the _______ degenerates
macula lutea
tactile receptors are a type of __________
mechanoreceptor
lacrimal caruncle is on the _________ side of the eye
medial - its located on the inner corned of the eye ( small pink section)
Where are end bulbs located?
oral and naval cavities
the ______ segment of each photoreceptor is composed of hundreds of discs containing photopigments that are capable of absorbing light energy
outer
eyelids are also called
palpebrae
the portion of the conjunctiva on the inside of the eyelid is called the:
palpebral conjunctiva
accommodation is controlled by the ______ division of the nervous system
parasympathetic
a sensation experienced by someone who has had a limb amputated but still feels like the limb is there
phantom pain
As tears drain, through the lacrimal caruncle, they enter small holes called the lacrimal _______
puncta
the parasympathetic nervous system controls ____________
pupil contraction
the sympathetic nervous system controls ____________
pupil dilation
the black hole in the eye is called the __________ and it is surrounded by the colorful ________
pupil, iris
some individuals experience pain in their left shoulder during a heart attach. this is an example of
referred pain
light rays are ______ when they pass through the lens and the cornea
refracted
what structure makes up the posterior 5/6 of the fibrous tunic
sclera
Order these structures from superficial to deep: choroid, sclera, pigmented layer of retina, neural layer of retina.
sclera ( outermost) choroid pigmented layer of retina neural layer of retina (inner most)
receptors for general senses are distributed throughout the ____ and viscera
skin and viscera
the ciliary muscles are made of _________ muscle
smooth muscle
axons from the optic tract project to the _____ colliculi
superior
reflexive movements of the head, eyes, and neck are coordinated by the _________
superior colliculi
tactile cells are associated with________
tactile discs
The dendritic ending of each gustatory cell is formed by a slender gustatory microvillus, sometimes called a
taste hair
upon exposure to light the rental straightens out and reconfigured into a form called ________-retinal
trans-retinal
in cones, the bleaching reaction occurs as cis-retinal transforms to trans-retinal
true
the conjunctiva is
vascular
which layer of the eye contains the blood and lymph vessels
vascular tunic
in the eye, the ______ humor is gelatinous
vitreous
free nerve endings are terminal branches of
dendrites
photoreceptors are _____ when it is completely dark
depolarized
The auricle has ________ cartilage that supports its structure.
elastic
the dissociation of ____ into its two components is called the bleaching reaction
rhodopsin
the cis-retinal, in the processor regeneration, is transported back to the ______ where it associated with the opsin and reforms the ______
rod, rhodospin
the lens is _______ when we are viewing close-up objects
rounded
which chamber is most superior
scala vestibuli
Our brain perceives different colors because each cone responds to a different wavelength on the visual spectrum.
false - There are only three different types of cones. Each cone responds to a range of wavelength. The combination of stimulation to different cones results in the perception of different colors.
rods are essentially nonfunctional in bright light because:
in bright light rhodopsin will bleach as fast as it is reformed
some of the axons from the cochlea project directly to the _______ colliculus of the midbrain
inferior
Which disorder of refraction is corrected with a concave lens?
myopia - Myopia (near-sightedness) is corrected with a concave lens that will bend the light rays less to land on the retina
myopia
nearsightedness
emmetropia
normal vision
optic tracts ultimately are directed to the primary visual cortex in the _______ lobe
occipital
in phototransduction, the _______ responds to light stimulation by changing its resting membrane potential, resulting in a change in the neurotransmitter it releases
photoreceptor
what is conjunctivitis
pink eye; inflammation of the conjunctiva
the apparent distortion of the spoon in the water glass is due to the phenomenon known as
refraction
root hair plexuses are usually found in the _________
reticular layer of the dermis
the ora serrata extends anteriorly from the
retina
in hearing, secondary neurons can go one of two pathways; they can go directly to the inferior colliculus or go to the _______ _______ nucleus before they go to the inferior colliculus
superior olivary
What color is the macula lutea
yellowish, the rest of the retina is red