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Anatomy: Senses

Terms in this set (129)

what is conjunctiva and conjunctivitis
a delicate membrane; likes the eyelids and covers part of the outer surface of the eyeball; ends edge of the cornea by fusing with corneal epithelia; secreted mucus-->makes moist// inflammation of the conjunctiva; reddened, irritated eyes "pink eye"
what are lysozymes (not lysosomes)
an enzyme that destroys bacteria; cleanses and protects eye
located above the lateral end of each eye; release tears
lacrimal glands
...
excretory ducts of lacrimal glands
where the tears are flushed across the eye
lacrimal canaliculus
tear ends up here and is emptied into the nasal cavity
nasolacrimal duct
tears spill into here after coming out of eyelids
inferior meatus of nasal cavity
formed by the choroid; two smooth muscle structures; lens is attached to this by suspensory ligament
ciliary body
the suspensory ligament that attaches lens to ciliary body
ciliary zonale
in the fibrous layer; transparent " window" where light enters the eye; well supplied with nerve endings
cornea
the pigment iris' rounded opening; light passes through
pupil
anterior segment to the lens contains this clear watery fluid
aquenous humor
light entering the eye is focused on the retina by this which is flexible biconvex crystal- like structure; held upright in the eye by a suspensory ligament; the ciliary zoncale, attached to the ciliary body
lens
gel like substance that filled the posterior segment
vitreous humor
pigment with round opening
iris
thick; glistening white connective tissue, seen anteriorly as the "white of the eye"
sclera
a blood rich nutritive tunic that contains a dark pigment
choroid
delicate, two layered, extends anteriorly only to the ciliary body
retina
lateral to each blindspot, a tiny pit that contain s only cones
fovea centrals
composed of ganglion cell axon; nerve of the eye
optic nerve
...
central artery and vein of the retina
what is night blindness? what is the most common cause?
anything that interferes with rod function hinders our ability to see at night; prolonged vitamin
compare total color blindness to partial color blindness
total: lack of all three cone types, blue light, green light and green/red
parietal: lack of one cone light
cataracts cause and effects
cause--> age lens become hard and opaque;diabetes mellitus, frequent exposure to intentness sunlight and heavy smoking
effect--> vision to become hazy and distorted and they eventually cause blindness in the affected eye
glaucoma cause and effect
cause--> aqueous drainage is blocked and pressure increases and compress the delicate retina and optic nerve
effect--> pain, blindness unless detected early, common cause of elderly blindness; little to no symptoms "vision going gray"
what is meant by 'binocular vision' and what type of vision does it allow us to have
"two eyed vision" provides for depth perception aka "3D" vision, as our visual cortex fuses the 2 slightly different images delivered by the 2 eyes
hyperopia; when parallel light rays from distant objects are focused behind the retina; for can see far away objects clearly
far sided
mytopia; when the parallel light rays from distant objects fail to reach the retina and instead are focuses in front of it; distant objects blurry, see near objects clearly and need connective lenses to focus distant objects
near sided
unequal curvatures in different parts of the cornea/ lens; blurry images occur bc points of light are focused not as points on the retain but as lines
astigmatism
when the eyes are suddenly exposed to bright light, the pupils immediately constrict; prevents excessively bright light from damaging the delicate photoreceptors
photopupillary reflex
what are the two main categories of sensory receptors
general and special senses
what is sensory adaption
the ability of our nervous system to become less responsive to stimulus that we are steadily under
how do pain receptors protect us
damaged tissue stimulates these pain receptors to warn us
what are the accessory organs
eyelids, lacrimal apparatus and extrinsic muscles in the eye
what is conjunctiva; conjunctivitis
conjunctiva-mucus membrane that covers inside of eye lid and eyeball
conjunctivitis-"pink eye" infection of conjunctiva
what does the lacrimal gland secrets
it secretes tears
why does our nose run when we cry
tears come out of tear glands under eyelids and drain through tear ducts that empty into our nose
why do we need all of that fluid in our eyes
(aqueous humor) flows and nourishes lens and cornea to support and maintain the shape of the eye
why is the cornea transparent
contains very few cells and no blood vessels, most exterior part, as it goes further behind the eye it becomes sclera
from what is our optic nerve attached
brain
What are chemoreceptors
the receptors for taste and olfactory; respond to chemicals in solution
What are olfactory receptors?
neurons equipped with olfactory hairs
Why does sniffing the air give you a more intensified smell than taking a deep breath?
cause more air to flow across olfactory receptors intensifies the sense of smell
Why do they give us such long lasting memories?
olfactory nerves are tied with limbic system
What is anosmia and what could cause it?
anosmia- loss of sense of smell caused by cold-only temporary/partial
About what percentage of what we perceive as taste is actually due to the sense of smell?
75%
What kind of senses are smell and taste?
chemical senses
What are odorants?
airborn odor molecules
Be able to trace or sequence an odorant to the brain cortex
nasal passage--> dissolve in mucus--> cilia on olfactory hairs--> stimulate olfactory nerves--> olfactory bulb---> brain cortex
What is the first pair of cranial nerves?
olfactory nerves
Why does the sense of smell more than any other invoke memories?
olfactory nerves are tied with the limbic system
Why can you not 'smell yourself' or your house?
nasal passage is filled with particular odorants--> can't speak to that certain nerve..in other words it used to it
Why could astronauts not taste their food?
without gravity to pull the fluids down astronaut sinuses get clogged and they can't taste
In what physical condition must an odor be in order for it to be perceived and interpreted?
they must be vaporized or turned to liquid
Why can we not smell when we have a cold?
nasal cavities are clogged with mucus---> can't dissolve odors if the odorant can not be vaporized (liquified) it cannot reach olfactory nerves
What are the two chemical senses?
taste & smell
What are papillae?
on tongue surface- covered in taste buds
What are gustatory cells?
taste cells-replaced every ten cells
In what physical condition must food be to be tasted?
must be in liquid form
What is meant by "most of taste is smelling"?
in order to taste, the olfactory nerves must vaporized the odorant/food
Why can we not taste our food when we have a cold?
it can't be vaporized bc of all the mucus
Name the three parts of the ear:
outer, middle, inner
Other than hearing, for what else do we need the ear?
equilibrium/ balance
For what do we need the pinna/auricle?
designed to catch sound waves
What is the purpose of the external auditory canal/meatus?
meatus actually means canal
Where does it terminate?
temporal bone to eardrum
What is the purpose of the ceruminous glands?
has ceruminous glands which secrete yellow waxy material
What is the tympanic membrane/eardrum?
thin membrane/eardrum
What are your ossicles? Name them:
malleus, incus, and stapes- 3 smallest bones in our body
What is their main purpose?
is to intensify and magnify sounds waves
These bones create a bridge between what two parts?
hearing receptors and eardrum
The malleus attaches to the:
eardrum and incus
The malleus then causes the __________ to vibrate and then what?
bone; incus--> stapes--> oval window - hearing receptors
What is the last of the ossicles to receive the vibrations? Where does it send those vibrations?
stapes--> hearing receptors
What are the last cells to receive the vibrations in this series?
(text me the answer to this if u have my number and know it please)
The auditory tube links the middle ear with the ___________________ close to the nasopharynx.
throat
What is its purpose?
helps maintain equal air pressure on both sides of the eardrum
How does otitis media start in the auditory tube?
mucous membranes in throat if infected could spread through this canal to the inner ear causing an ear infection called media
Why is it called a labyrinth?
complex system of communicating chambers
What are the three parts of the labyrinth?
cochlea- organ of hearing; vestibule; semicircular canal
Of the three, which is the organ of hearing?
cochlea
What is the receptor organ for hearing located in this part called?
inside the cochlea "organ of corti"
What are the hearing receptors?
hair cells
Once they are stimulated, where are the impulses sent?
transmitted along cochlear part of the vestibulocochlear nerve
Where does it go and what happens there?
to the auditory cortex in the temporal lobe for interpretation or hearing occurs
Read and listen to the summary. Don't memorize it all by numbers but do know what happens when to the extent it has been presented to you above.
sound waves--> auditory meatus--> pressure charge--> eardrum--> vibrate--> turn malleus--> vibrate--> incus--> stapes--> oval window--> organ of corti--> sensory impulses--> cochlear part of nerve--> auditory cortex= hearing
Equilibrium - Balance: As with hearing, we will be dealing with fluid and hair cells. Look in your book on page 296, Figure 8.13 (a)
...
Our sense of _______________________ responds every time we move our head.
equilibrium
The receptors of equilibrium are in the inner ear and are called:
vestibular appartus
On what does static equilibrium provide information?
on which way is up or down
When those calcium salts in the jellylike material pass over those small hairs, where are messages sent?
calcium salts roll over hairs sending message as to where you are in space to your cerebellum
With dynamic equilibrium, where are the receptor cells found?
in semicircular canals
To what do they respond?
to angular or rotary movements
Because of the way the canals are situated what will always be true?
receptor can detect and record it
ability to focus for close vision (under 20 feet)
accommodation
inability to focus well on close objects; farsightedness
hyperopia
clouding of the lens, resulting in loss of sight
cataract
nearsightedness; inability to see faraway objects
myopia
blurred vision, resulting from unequal curvatures of the lens or cornea
astigmatism
condition of increasing pressure inside the eye, resulting from blocked drainage of aqueous humor
glaucoma
inability to see well in the dark; often a result of vitamin A deficiency
night blindness
fluid that provides nutrients to the lens and cornea
aqueous humor
the "white" of the eyes
sclera
gel-like substance that helps to reinforce the eyeball
vitreous humor
heavily pigmented tunic that prevents light scattering within the eye
choroid
area of acute vision (cones only, sharpest vision)
fovea centralis
pigmented "diaphragm" of the eye
iris
a decrease ability to conduct the energy of sound waves through the external and middle ear to hearing receptors in the inner ear
conduction deafness
can be caused by ear, wax building up, damage to tympanic membrane or fusion of auditory ossicles
conduction deafness
can also be hardened as a result of disease
eardrum
damage to the cochlea, auditory nerve or auditory pathways
sensorineural hearing loss
loud sounds, tumors in the central nervous system, brain damage from strokes, use of certain drug
sensorineural hearing loss
Collectively called the ossicles:
Anvil (incus), Hammer (malleus), stirrups (stapes)
Structures composing the bony or osseous labyrinth:
Cochlea, Semicircular canals, vestibule
Ear structures involved with hearing; contain receptors for the sense of equilibrium:
Semicircular canals, vestibule
Allows pressure in the middle ear to be equalized with the atmospheric pressure; connects nasopharynx and the middle ear:
auditory tube
Vibrates as sound waves hit it; transmits the vibrations to the ossicles:
Tympanic Membrane
Contains the ogran of Corti:
Cochlea
Transmits the vibrations from the stirrup to the fluid in the inner ear:
Oval window
c/s can result from a bug wedged in the external auditory meatus.
conduction deafness
c/s can result from damage to the cochlear nerve.
sensorineural hearing loss
c/s often improved by a hearing aid.
conduction deafness
c/s can result from otitis media.
conduction deafness & sensorineural hearing loss
trace the path of sound, what happens at each part
mechanoreceptors
body adapts to stuff on u like clothes
sensory adaptation
made up of lacrimal gland
lacrimal apparatus
allows lens to change shape to facilitate focusing
accommodation
sensitive no blood cells
macula
5 taste buds
sweet, sour, bitter, salter, umami
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