Exam 3-Toth-Ocular & Otic Systems

what is perception of images based on the light reflected or emitted by objects?

vision

What is the characteristics of vitreous humor?

-its is jelly-like -irreplaceable -holds retina against the choroid

Function of lacrimal glands:

-secretes tears that lubricate -nurture (deliver O2 and nutrients) -protect (wash away foreign particle -prevent infection with a bacterial lysozyme) the eye's anterior surface

photosensitive pigments

-transmembrane protein: opsin -detachable, vitamin A derivative: retinal aka rhodopsin

The middle ear contains

3 auditory ossicles: malleus, incus, stapes and auditory tube (Eusctachian tube)

Functions of ciliary body:

Contains: muscles, ligaments, glands: -produces aqueous humor into the posterior chamber -regulates suspensory ligaments to the lens --> critical in the process of accommodation to the sight of close objects

T/F: Rods and cones are scattered around the retina. Rods provide B/W vision and cones provide color vision.

False; rods are scatterd and do provide B/W vision BUT cones are concentrated in the fovea centralis and do provide color vision

T/F: Iris is the aperture of the eye.

True

If the focal plane for the lens/cornea is on the retina, the image will be in focus is known as ______. a. emmetropia b. hyperopia c. myopia d. presbyopia e. astigmatism

a. emmetropia

Which are true of the cornea? (select all that apply) a. specialized region on anterior surface b. transparent and admits light into the eye c. part or the middle layer of eye d. a continuation of the sclera e. both the corneal epithelium and corneal stroma are repairable

a. specialized region on anterior surface b. transparent and admits light into the eye d. a continuation of the sclera (its in outer layer; only the corneal epithelium is repairable)

The two divisions of the lumens:

anterior chamber - betw. cornea and lens posterio chamber - betw. lens and iris (*These communicate thru the pupil via aqueous humor to ensure proper ditance between chambers bc the fluid is not compressible)

the middle ear is responsible for _____ and is connected to _____.

auditory ossicles conduct sound from the tympanic membrane onto the oval window of the cochlea in the inner ear connected to the nasopharynx (throat) by the eustachian tube (equalizes pressure on the 2 sides of the tympanic membrane)

Outer ear contains

auricle, auditory canal and tympanic membrane

The degeneration of the optic disc is known as: a. macular degeneration b. glaucoma c. cataracts d. presbyopia

b. glaucoma

Why does your nose run when you cry?

bc tears enter the lacrimal punctum, travel down the lacrimal canal and nasolacrimal duct that opens in your nose in the infereior meatus of the nasal cavity

middle layer

choroid + ciliary body + iris

The outer ear is responsible for

conduct sound waves to tympanic membrane

inner ear is responsible for

contains receptors cells (hair cells) for hearing and balance; cochlea (organ of corti) + semicircular ducts (crista ampullaris) + verticular apparatus (urtricles and saccules)

parasympathetic stimulation of the pupil causes:

contraction of the circular muscle of the iris --> constriction of the pupil (miosis)

sympathetic stimulation of the pupil causes:

contraction of the radial muscle of the iris --> dilation of the pupil (mydriasis)

sensorineural hearing loss

damage to the receptors or neural pathway of hearing ex: noise trauma

What are the eyebrows mainly used for?

expression (but limited protection)

pupil

hole in the center of the iris

Where is the location of the primary visual cortex?

occipital lobe

Basic 3 areas in the anatomy of the ear

outer ear middle ear inner ear

What are the main layers of the eye? Which has the primary neural function? which admits and focuses light?

outer, middle and inner; inner; outer and middle

Two types of conjunctiva:

palpebral - inside eyelid - inferior and superior bulbar - covers tissues of eye (sclera)

The ____ gland sits under the optic chaisma and only affects the nerves that corss there. These nerves detect the vision from the temporal/nasal fields.

pituitary; temporal (lateral)

What are the eyelids used for?

protection, sleeping, blinking

inner layer

retina + optic nerve (blind spot, macula)

cochlea is made of 3 fluid filled ducts...

scala vestibule (perilymph Na+ rich) scala tympani (perilymph Na+ rich) cochlear duct (endolymph K+ rich)

The outer layer of the eye consists of?

sclera + cornea

Why is it important for the sclera to be white and fiberous?

to ensure light doesn't enter there and only enters the cornea so it can be focused on the retina

The image produced on the retina is ____ and ____.

upside down and backwards

T/F: There are lots of photoreceptors in the optic disc.

False; there are NO photoreceptors in the optic disc only a collection of axons and ganglionic nerve cells

The 3 ways adaptation mechanisms of light intensity:

1. pupil diameter (constrict in light; dilate in dark) 2. neural circuitry (interpretation) 3. photorecept physiology

Parasympathetic stimulation to the eye causes does NOT cause which of the following: 1. miosis 2. mydriasis 2. relaxation of suspensory ligaments 3. increased lacrimation

2. mydriasis

what wavelengths are visible?

400-700 nm

T/F: Circularly arranged ciliary muscles allows accommodation to change the lens to help you focus.

True

T/F: There is only brown pigment in the eye.

True; so the refractory elements of cornea and aqueous humor of eye determines the different colors of eye

conductive hearing loss

conditions interfere with transmitting vibrations to the inner ear ex: otitis media

Which is incorrectly paired? a. mydriasis - dilation of pupil b. miosis - contriction of pupil c. presbyopia - lens becomes stiffer with age d. astigmatism - cloudy lens

d. astigmatism - cloudy lens (astigmatism is no single focal plane due to irregularities on the cornea and lens) (cloude lens is cataracts)

Which is NOT true of the sclera? a. white part of eye b. contains collagen fibers c. connected to the cornea d. has 4 muscles attached to it for movement e. part of otuer layer

d. has 4 muscles attached to it for movement (it has 6 muscles inserted to allow for precise movement)

All of the following are true of dry eyes except: a. it is a multifactorial disease of the tears and ocular surface b. causes discomfort, visual disturbances, and tear film instability c. it can potentially damaging the ocular surface d. age increases risk >65yo e. male and white population is more at risk

e.male and white population is more at risk (female; asian/hispanic > black >white)

T/F: The conjunctiva has its own blood supply?

false; it depends on the lacrimal glands production of tears to lubricate and provide nutrients and O2 across bulbar conjunctiva

During transduction, light activated rhodopsin and results in __________ of the cell and a _____ in the release of neurotransmitter.

hyperpolarization; decrease

What is the choroid?

next layer after the sclera provides extra protection to ensure light doesn't get in (except through cornea) -pigmented to absorb light if some accidently gets in sclera -highly vascularized to provide nutrients to sclera

Where are the lacrimal gland located?

superolaterally

presbyopia occurs when _____? and what is the treatment?____

the lens becomes stiffer with age --> accommodation --> need for bifocals (top of lens for far vision, bottom of lens for near vision)

What are the steps in the visual pathway?

visual light in eye --> transduction to neuronal signals --> optic nerve --> brain

Is the aqueous ro vitreous humor between the lens and the retina?

vitreous

The bipolar cells are ______ cells and are in between the _____ and _____.

inihibitory cells; photoreceptor and ganglionic cell layers

What happens if the retina is not held against the choroid? (ie./retinal detachment)

its doesn't get nutrients and dies

transduction

light activates rhodopsin which results in hyperpolarization of the cell and a decrease in the release of NT

The inner ear contains

cochlea (shell), semicircular ducts (3 loops at right angles to each other), vesitbular apparatus (utricle and saccule), neural component (cranial nerve VIII)

To allow for close vision which is the correct mechanisms: a. ciliary muscles contract under parasymp. stim. and the suspensory ligaments relax --> lens becomes more spherical allows close vision b. ciliary muscles contract under parasymp. stim. and the suspensory ligaments contract --> lens becomes more spherical allows close vision c. ciliary muscles relax under symp. stim. and the suspensory ligaments contract --> lens becomes more spherical allows close vision d. ciliary muscles relax under symp. stim. and the suspensory ligaments relax --> lens becomes more flat allows close vision

a. ciliary muscles contract under parasymp. stim. and the suspensory ligaments relax --> lens becomes more spherical allows close vision

If a person is farsightedness, the focal plane is posterior to the retina. This is known as ______. a. emmetropia b. hyperopia c. myopia d. presbyopia e. astigmatism

b. hyperopia

When the conversion of trans back to cis is slowed down this is known as ____.

bleaching of photopigment

The optic disc (aka _____ _____) is where the _________, _____ and _____ leave/enter the eye.

blind spot; optic nerve; retinal central artery; central vein

Glaucoma is worsened

by excessive intraocular pressure which further damages optic disc and retina by squeezing off the body supply

Which of the following are NOT true during transduction? a. activated rhodopsin activates transducin (G-protein) b. G protein activates a phosphodiesterase to breakdown cGMP c. decrs. in cGMP closed the Na channels leads to depolarization d. decr. in NT rel. from photoreceptor to bipolar cells increases firing by ganglionic cells

c. decrs. in cGMP closed the Na channels leads to depolarization (hyperpolarizes)

The spot in the retina that has no blood vessels is known as _____. a. fovea centralis b. optic disc c. macula lutea d. ciliary body

c. macula lutea (its is located near fovea centralis)

If a person is nearsightedness, the focal plane is anterior to the retina. This is known as ______. a. emmetropia b. hyperopia c. myopia d. presbyopia e. astigmatism

c. myopia

What is the route of aqueous humor?

ciliary body glands produces into the posterior chamber-->flows to anterior chamber--> then excreted through Schlemm's canal (sclera venous sinus) via trabecular outflow mainly (some through uvelosclera outflow)

In the resting form, rhodopsin is in the ______-retinal form. When light comes in, it changes rhodopsin to the ____-retinal form and becomes hyperpolarized and will carry the signal to the optic nerve

cis; trans (after activation and signalling the trans form converts back to cis form in the dark.