Term
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Definition
| Helps to equalize pressure on both sides of the tympanic membrane. |
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Term
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Definition
| Elastic cartilage covered with skin, shaped to direct sound. |
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Term
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Definition
| Curved tube of cartilage and bone leading into temporal bone. |
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Term
| Ceruminous Glands (Functions) |
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Definition
| Produce cerumen (ear wax). Keeps out bugs, repels water, and keeps tympanic membrane dry. |
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Term
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Definition
| Epidermis, collagen and elastic fibers. Simple cuboidal epith. 20x larger than oval window. |
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Term
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Definition
| Tube that extends from the middle ear to the larynx. Helps to equalize pressure. |
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Term
| Pitch vs. Loudness Definitions |
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Definition
Pitch: The frequency at which parts of the ear vibrate. *20 to 20,000 Hz*
Loudness: Perception of intensity of sound energy. *How much air molecules are compressed in decibles* |
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Term
| Pitch vs. Loudness Determinations |
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Definition
Pitch: Depends on which part of basilar membrane is vibrated at peak amplitude of standing wave.
Membrane is narrow and stiffer at basal end because of collagen. Brain interprets signals from IHC basal end as high pitched, distal ends is low pitched. |
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Term
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Definition
1. Auricle collects sound waves
2. Tympanic membrane vibrates (slow vibrations for low sounds, fast for high sounds)
3. Ossicles vibrate.
4. Stapes pushes on oval window producing fluid pressure waves on scala vestibuli and tympani.
5. Pressure fluctuations inside cochlear duct move the hair cells against the tectorial membrane.
6. Microvilli are bent producing receptor potentials. |
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Term
| Auditory Projection Pathway |
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Definition
1. Superior olivary nucleus compares sounds from both sides by CN V111 to identify direction.
2. Inferior colliculus helps locate origin of sound in space, process fluctuations in pitch in speech and produces startled responses of head turning towards loud noises.
3. Temporal lobe is site of conscious perception.
4. Primary auditory cortex to association area. (If language is involved it will be sent to Wernike's)If not it will stay in memory. |
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Term
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Definition
Nerve deafness is caused by damage to hair cells from antibiotics, high pitched sounds, anticancer drugs. The louder the sound the quicker the hearing loss.
Conduction deafness
Perforated Eardrum
Otosclerosis |
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Term
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Definition
| Sounds caused by shortening and lengthening of outer hair cells in response to signals from motor neurons. Vibration that travels backwards toward eardrum. |
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Term
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Definition
| CSF due to it's high sodium content and low potassium content. |
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Term
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Definition
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Term
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Definition
| Perilymph and oval window |
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Term
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Definition
| Perilymph and round window |
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Term
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Definition
1. Outer hair cells contract in response to motor stimuli reducing the basilar membrane's freedom to vibrate
1.2 Fewer signals go to brain from that area allowing the brain to better distinguish active and less active areas.
2. Pons also have inhibitory fivers that synapse near the base of the inner hair cells inhibiting firing of sensory fibers.
2.1. This increases contract between regions of cochlea. |
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Term
| Stereocilia are high in _______ creating ______ |
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Definition
K+ concentration (in endolymph).
Electrochemical gradient from tip to base. |
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Term
| IHC are in what orientation to the tectorial membrane in comparison to the OHC. What frequencies do they typically deal with? |
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Definition
IHC- Further away from tectorial membrane as they are used for high pitched sounds which are easier to transduce.
OHC- Have tips embedded in tecorial membrane which is anchored. For low pitched sounds that are more difficult to transduce. |
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Term
| Explain transduction from a gated potential to an action potential. |
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Definition
1. As microvilli are bent, mechanically-gated channels in the membrane let in K+.
2. This depolarization spreads and causes voltage-gated Ca+2 channels at the base of the cell to open.
3. This triggers the release of neurotransmitter onto the first order neuron. |
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Term
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Definition
| Set of tube like cavities in temporal bone. Filled with perilymph. This surrounds membranous labyrinth. |
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Term
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Definition
| Set of membranous tubes containing sensory receptors for hearing and balance and is filled with endolymph. |
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Term
| Components and function of Organ of Corti |
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Definition
1. 16000 hair cells that have 30 to 100 stereocilia (microvilli)
2. Microvilli make contact with tectorial membrane.
3. Basal sides of inner hair cells synapse with 1st order sensory neurons whose cell body is in spiral ganglion. |
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Term
| Hair cells responsible for hearing or transducing the sound we perceive. |
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Definition
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Term
| Hair cells responsible for adjusting cochlear responses to different frequencies increasing precision. |
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Definition
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Term
| Resonance and it's relation to the basiliar membrane. |
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Definition
| Resonance are pressure waves. Resonance in the basiliar membrane will cause cochlear tuning. |
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Term
| Static equilibrium vs. Dynamic equilibrium and where their receptors are located. |
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Definition
Static - Maintain body position relative to the force of gravity. Macula receptors within saccule and utricle.
Dynamic - Maintain body position during sudden movement of any type. Crista receptors within ampulla of semicircular ducts. |
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Term
| Within the saccule and utricle and cell types within this area does. |
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Definition
| Macula- Hair cells with stereocilia and one cilia known as kinocilium. As well as supporting cells that secrete gelatinous layer. |
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Term
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Definition
| Otolithic organs which are sheets of hair cells. Hair cells stick out into a gelatinous mass called the otolithic membrane. |
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Term
| Otolithic membrane contains |
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Definition
| Otoliths which are ear stones that move in response to gravity. |
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Term
| What is the Crista Ampulla and what is it's function. |
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Definition
| A small elevation within each of the semicircular ducts. It's function is to release neurotransmitter upon stimulation. |
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Term
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Definition
| Gelatinous material that covers hair cells. When movement occurs, fluid in canal bends cupula, stimulating the hair cells that release neurotransmitter. |
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Term
| The names of the 3 semicircular ducts |
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Definition
Anterior - Straight
Horizontal - Around
Posterior - Lateral |
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Term
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Definition
Perception of light emitted or reflected from objects in the enviornment
Electromagnetic Radiation |
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Term
| Visible lights for people |
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Definition
| 400 to 750nm, anything over 750 causes damage |
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Term
| Purpose of Eyebrows and Eyelids |
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Definition
Eyebrows: Facial expression, protection from glare and perspiration
Eyelids: Block foreign objects, assist in sleep, and blink to moisten. Also contain tarsal glands that secret oil that reduces tear evaporation. Eyelashes to help keep debris from eye. |
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Term
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Definition
Transparent mucous membrane lines the eyelids and covers anterior surface of eyeball aside from cornea.
Richly innervated and vascular, so it heals quickly |
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Term
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Definition
| Tears flowing across eyeball to help wash away foreign particles, helps with diffusion of oxygen and co2 and contains bactericidal lysozymes. Which help breakdown bacterial cell walls. |
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Term
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Definition
Helps to focus light (astigmatism)
3 layers. Nonkeratinized stratified squamous. Collagen fibers and fibroblasts. Simple Squamous epithelium.
Has no blood vessels to obtain o2 and co2 so it relies on diffusion.
Nourished by aqueous humor. |
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Term
| Fibrous tunic consists of.. |
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Definition
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Term
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Definition
"White" of eye.
Dense irregular CT. Collagen and Fibroblasts.
Provides shape and support.
At the junction of sclera and cornea is an opening known as the scleral venous sinus. |
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Term
| Vascular Tunic consists of.. |
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Definition
| Choroid. Ciliary body. Iris. Pupil. Lens. Muscles. Suspensory ligament. |
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Term
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Definition
Pigmented epithilial cells (melanocytes) and blood vessels.
Provides nutrients to retina. Black pigment in melanocytes absorb scattered light |
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Term
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Definition
1. Ciliary processes
1.2 Folds on ciliary body
1.3 Secrete aqueous humor
2. Ciliary muscle.
2.1. Smooth muscle that alters shape of lens. |
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Term
| Ciliary muscle, suspensory ligament and lens. |
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Definition
| When muscle is contracting the lens bulges. When muscle is relaxing the lens flattens. Bulges is up close. Flattens is far away. |
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Term
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Definition
Colored portion of eye.
Shape of flat donut suspended between cornea and lens.
Function is to regular amount of light entering eye.
Autonomic reflexes causes circular muscle fibers to contract in bright light to shrink the pupil. Radial muscle fibers contract in dim light to enlarge pupil. |
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Term
| What muscle fibers of the iris are innervated by parasympathetic fivers and sympathetic fibers? |
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Definition
Constrictor pupillae - para
Dilator pupillae-symp
The response varies in different levels of light |
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Term
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Definition
Avascular
Cystallin proteins arranged like layers in onion
Clear capsule and perfectly transparent
Lens held in place by suspensory ligaments
Focuses light on fovea |
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Term
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Definition
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Term
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Definition
Posterior 3/4 of eyeball
Optic Disc (optic nerve exiting back of eyeball)
Central retina BV (Fan out to supply nourishment to retina)(visible for inspection-hypertension-diabetes)
Detached retina can be caused by trauma. |
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Term
| Detached retina can be caused by.. What are the symptoms. |
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Definition
Trauma to the head.
Insufficient vitreous body.
Can cause blurry areas in field of vision.
Will lead to blindness due to disruption of blood supply. |
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Term
| Canal of Schlemm (Venous sinuses) |
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Definition
Drains aqueous humor from eye to bloodstream.
Opening in white of eye at junction of cornea and sclera.
If canal is blocked it can lead to a build up of aqueous humor known as Glaucoma. |
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Term
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Definition
Is produced by ciliary body
Replaced every 90 minutes
Provides nutrients
Flows from posterior chamber to anterior through pupil. |
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Term
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Definition
Anterior Chamber. Between cornea and iris.
Postierior Chamber. Between Iris and Lens.
Filled with aqueous humor. |
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Term
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Definition
Posterior to Lens.
Formed during embryonic life.
Floaters are debris in vitreous of older individuals. |
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Term
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Definition
Bending of light as it passes from one substance (air) into a 2nd substance with a different density(cornea)
In eye, light is refracted by anterior and posterior surfaces of the cornea and the lens.
Bending of light rays occurs when light passes through substance with different refractive index at any angle other than 90 degrees. |
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Term
| Refraction by the Cornea vs. Lens |
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Definition
Image focused on retina is inverted and reversed from left to right.
75% of refraction is done by cornea, rest is by the lens.
Light rays from greater that 20' are nearly parallel and only need to bend enough to focus on retina
Light rays from less that 6' are more divergent and need more refraction. (The extra process to get additional bending of light is called accommodation) |
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Term
| Marijuana's affect on eyes |
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Definition
| Causes vasodialation of blood vessels and opens up canal of schelmm. |
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Term
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Definition
| Absorb excess photons of light |
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Term
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Definition
Sclera
Choroid
Pigmented Epithelium
Rod and cone outer segments
Bipolar cells
Ganglion Cells
Nerve fibers to optic nerve
Vitreous body |
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Term
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Definition
Shades of gray in dim light
120 million rod cells
Discriminates shapes and movements
Distributed along peiphery |
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Term
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Definition
Sharp, color vision, resolution
6 million
Fovea of macula lutea (This is a densely packed region for cones. At exact visual axis of eye. 2nd cells do not cover cones. Sharpest resolution of acuity.) |
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Term
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Definition
Helps cones increase level of contract
Bilateral vision.
Cone sending strongest signal acts as dendrite, sends signals to other cones turning them off, so only one cone sends a signal. |
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Term
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Definition
Rods
Rods summate onto a single bipolar cell. Amacrine cells will summate bipolar cells together then to a singular ganglion cell. |
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Term
| Pathway of Nerve Signal in Retina |
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Definition
Light penetrates retina.
Rods and cones transduce light into action potentials.
Rods and cones excite bipolar cells
Bipolar cells excite ganlion cells
Axons of ganglion cells form optic nerve leaving the eyeball to the thalamus and then the primary visual cortex. |
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