Term
| What are the layers of the olfactory organs called? |
|
Definition
| Olfactory epithelium and lamina propria |
|
|
Term
| What does the olfactory epithelium contain? |
|
Definition
| Olfactory receptor cells, supporting cells, and regenerative basal cells. |
|
|
Term
| What does the lamina propria contain? |
|
Definition
| Areolar tissue, numerous blood vessels, nerves and olfactory glands. |
|
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Term
|
Definition
| Dissolved compounds that stimulate olfactory receptors |
|
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Term
| Steps involved in smelling |
|
Definition
1. The binding of an odorant to its receptor protein (G-protein receptors) leads to the activation of adenylyl cyclase, the enzyme that converts ATP to cAMP.
2. The cAMP opens sodium ion channels in the plasma membrane, which then begins to depolarize.
3. If sufficient depolarization occurs, an action potential is triggered in the axon, and the information is relayed to the CNS. |
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Term
|
Definition
| Taste receptors and specialized epithelial cells on the tongue, pharynx, and larynx. |
|
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Term
|
Definition
| Variously shaped epithelial projections on the tongue |
|
|
Term
| 4 types of lingual papillae |
|
Definition
1. Filiform papillae: provide friction, do not contain taste buds.
2. Fungiform papillae: small, contain about 5 taste buds
3. vallate papillae: large, contain as many as 100 taste buds
4. Foliate papillae: folds found on the lateral margins of the posterior tongue |
|
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Term
| Taste buds are innervated by which cranial nerves? |
|
Definition
| CN VII (facial), CN IX (glossopharyngeal), and CN X (vagus). |
|
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Term
| Where do the sensory afferent fibers carried by the cranial nerves synapse? |
|
Definition
| In the solitary nucleus of the medulla oblongata. |
|
|
Term
| Where does information about the texture of food, along with taste related sensations such as "peppery" or "burning hot" come from? |
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Definition
| It comes from sensory afferents in the trigeminal cranial nerve (V). |
|
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Term
|
Definition
| A pleasant savory taste due to the presence of free glutamates in food |
|
|
Term
| Olfactory glands (Bowman's glands) |
|
Definition
| Secretions coat surfaces of olfactory organs (mucus) |
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Term
|
Definition
| Taste-provides information about the foods we eat and drink |
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Term
| Taste buds contain _______. |
|
Definition
Basal (stem) cells which divide, differentiate, and mature
Gustatory receptor cells (mature cells) |
|
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Term
|
Definition
Extends microvilli (taste hairs) through a taste pore.
Survives for about 10 days before being replaced. |
|
|
Term
| How is the taste of water detected? |
|
Definition
| By the water receptors in the pharynx |
|
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Term
|
Definition
Protein complexes that use second messengers to produce their effects.
Respond to sweet, bitter, and umami receptors |
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Term
| Accessory structures of the eye |
|
Definition
Palpebrae (eyelids)
Superficial epithelium
The lacrimal apparatus |
|
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Term
|
Definition
| The gap that separates the free margins of the upper and lower eyelids |
|
|
Term
| Medial and lateral canthus |
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Definition
| Where the two eyelids are connected |
|
|
Term
| Tarsal glands (Meibomian glands) |
|
Definition
| Secrete lipid-rich product that helps keep eyelids from sticking together |
|
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Term
|
Definition
| Mass of soft tissue, contains glands producing thick secretions, contributes to gritty deposits after good night’s sleep |
|
|
Term
|
Definition
| A cyst that results from an infection of a tarsal gland |
|
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Term
|
Definition
| Muscle that closes the eyelids |
|
|
Term
| Levator palpebrae superioris muscle |
|
Definition
| Muscle that raises the upper eyelid |
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Term
|
Definition
| Epithelium covering inner surfaces of eyelids (palpebral conjunctiva) and outer surface of eye (ocular conjunctiva) |
|
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Term
|
Definition
| A transparent part of the outer fibrous layer of the eye |
|
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Term
|
Definition
| An inflammation of the conjunctiva |
|
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Term
|
Definition
Keeps conjunctival surfaces moist and clean
Reduce friction
Remove debris
Prevent bacterial infection
Provide nutrients and oxygen to conjunctival epithelium |
|
|
Term
| Lacrimal apparatus consists of |
|
Definition
A lacrimal gland with associated ducts
Paired lacrimal canaliculi
A lacrimal sac
A nasolacrimal duct |
|
|
Term
| Functions of the lacrimal apparatus |
|
Definition
| Produces, distributes, and removes tears |
|
|
Term
|
Definition
| A pocket created where the palpebral conjunctiva joins the ocular conjunctiva |
|
|
Term
|
Definition
Secretions contain lysozyme, antibacterial enzyme & antibodies
Its secretions provide nutrients and oxygen to the corneal cells by diffusion. |
|
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Term
|
Definition
| Where the tears accumulate in the medial canthus |
|
|
Term
|
Definition
| Two small pores that drain the lacrimal lake |
|
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Term
|
Definition
| Small canals that the lacrimal punta empty into. |
|
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Term
|
Definition
| Leads from the lacrimal canaliculi, tears flow into the nasolacrimal duct |
|
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Term
|
Definition
| Delivers tears to the nasal cavity-runny nose when a person cries |
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|
Term
| Eyeball is hollow- divided into two cavities: |
|
Definition
Large posterior cavity
Smaller anterior cavity- anterior & posterior chambers |
|
|
Term
|
Definition
| A clear watery fluid that fills the anterior cavity of the eye |
|
|
Term
|
Definition
| A gelatinous substance that fills the posterior cavity of the eye and helps to stabilize the shape of the eye |
|
|
Term
|
Definition
1. Outer fibrous tunic
2. Middle vascular tunic
3. Inner layer (retina) |
|
|
Term
| Fibrous tunic consists of: |
|
Definition
| The sclera and the cornea. |
|
|
Term
| Functions of the Fibrous layer |
|
Definition
1. Supports and protects
2. Serves as an attachment site for the extrinsic eye muscles
3. Contains structures that assist in focusing |
|
|
Term
| Sclera (white of the eye) |
|
Definition
Dense, fibrous connective tissue containing both collagen and elastic fibers.
Covers most of the ocular surface
The 6 extrinsic eye muscles insert on the sclera |
|
|
Term
|
Definition
Transparent, avascular
Cornea very sensitive, limited ability to repair itself |
|
|
Term
| Vascular layer (uvea) functions |
|
Definition
Provides route for blood vessels and lymphatics that supply tissues of eye
Regulates amount of light entering eye
Secretes and reabsorbs aqueous humor that circulates within chambers of eye
Controls shape of lens, which is essential to focusing |
|
|
Term
| The vascular layer (uvea) contains: |
|
Definition
The iris, ciliary body, and choroid
Numerous blood vessels, lymphatic vessels, and the intrinsic (smooth) muscles of the eye |
|
|
Term
|
Definition
Extends posteriorly to level of ora serrata:
Serrated anterior edge of thick, inner portion of neural tunic
Contains ciliary muscle, covered by ciliary processes (folds of epithelium) that attach to suspensory ligaments of lens |
|
|
Term
|
Definition
Contains blood vessels, pigment cells, pupillary muscles
Pupillary constrictor muscles- forms series of concentric circles around pupil, contract pupil decreases
Pupillary dilator muscles- extend radially away from edge of pupil, contract pupil enlarges |
|
|
Term
|
Definition
Vascular layer that separates fibrous and neural tunics posterior to ora serrata
Delivers oxygen and nutrients to retina
Also contains melanocytes |
|
|
Term
| Inner layer (retina) consists of: |
|
Definition
Pigmented part: a thin, outer layer
Neural part: a thick, inner layer |
|
|
Term
|
Definition
| absorbs light that passes through neural part, preventing light from bouncing back through neural part |
|
|
Term
|
Definition
| Contains visual receptors and associated neurons preliminary processing & integration of visual information |
|
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Term
|
Definition
Outermost layer of cells closest to pigmented layer contains photoreceptors- cells that detect light
Rods and cones are types of photoreceptors:
Rods: allow you to see in dim light
Do not discriminate among colors of light
Highly sensitive to light
Cones: allow you to see color
3 types of cones
Sharper, clearer image than rods, require more light
Densely clustered in fovea, at center of macula lutea
Macula lutea- area where visual image arrives after passing through cornea & lens |
|
|
Term
|
Definition
The area where a visual image arrives after it passes through the cornea and lens
It has no rods |
|
|
Term
|
Definition
the center of the macula, where the hightest concentration of cones is
The site of sharpest vision
Establishes visual axis |
|
|
Term
|
Definition
A circular region just medial to the fovea.
Has no photoreceptors, light striking here goes unnoticed
Blind spot
The origin of the optic nerve. |
|
|
Term
|
Definition
Neurons that rods and cones synapse with
Bipolar cells then synapse with another layer of neurons- ganglion cells |
|
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Term
|
Definition
| Extend across the neural part of the retina at the level of the synapses between photoreceptors and bipolar cells |
|
|
Term
|
Definition
| A layer of cells that occur where bipolar cells synapse with ganglion cells. |
|
|
Term
| Where does the aqueous humor go? |
|
Definition
| It circulates within the anterior cavity. It passes from the posterior chamber to the anterior chamber through the pupil. It also freely diffuses through the posterior cavity and across the surface of the retina. |
|
|
Term
|
Definition
Fluid circulates within eye, resembles composition of CSF
Important route for nutrient & waste transport
Fluid cushion
Diffuses through walls of anterior chamber into canal of Schlemm (scleral venous sinus)
Intraocular pressure- fluid pressure in aqueous humor, helps retain eye shape |
|
|
Term
|
Definition
In the posterior cavity of the eye.
Gelatinous mass
Helps stabilize eye shape and supports retina
Formed during development of the eye- not replaced |
|
|
Term
|
Definition
Posterior to cornea, held in place by suspensory ligaments
Primary function- focus the visual image on photoreceptors by changing its shape
Consists of concentric layers of cells, covered by fibrous capsule (elastic)
Cells in interior of lens- lens fibers, no nuclei or organelles
Filled with crystallins, provide clarity & focusing power to lens |
|
|
Term
|
Definition
| A condition in which the lens has lost its transparency |
|
|
Term
|
Definition
Transparent proteins that give the lens its clarity and focusing power.
They remain intact and functional for a lifetime. |
|
|
Term
|
Definition
The light is bent when it passes from one medium to another medium with different density.
The greatest amount of refraction occurs when light passes from the air into the corneal tissues.
Additional refraction occurs when the light passes from the aqueous humor into the lens |
|
|
Term
|
Definition
The distance between the center of the lens and its focal point.
Focal distance determined by 2 factors:
1. the distance of the object from the lens- closer an object is to the lens the greater the focal distance
2. The shape of the lens- the rounder the lens, the shorter the focal distance. |
|
|
Term
|
Definition
| The automatic adjustment of the eye to give us clear vision. The lens becomes rounder to focus the image of a nearby object. The lens becomes flatter to focus the image of a distant object on the retina. |
|
|
Term
|
Definition
|
|
Term
|
Definition
| Basic unit of visible light |
|
|
Term
|
Definition
| Special organic compounds located in each photoreceptor's outer segment in flattened membranous plates called discs. |
|
|
Term
|
Definition
Light energy travels in waves with characteristic wavelength
Human eyes can detect visible light 400-700 nm
700 nm (violet) high energy, 400 nm (red) low energy
Rods- provide CNS with info about presence/absence of photons, regardless of wavelength
Cones- provide info about the arriving photons, color perception |
|
|
Term
| Anatomy of rods and cones |
|
Definition
Outer segment- contains hundreds of membranous discs
Rod- separate and elongated cylinder shape
Cone- infoldings of plasma membrane, cone shape
Inner segment- contains cellular organelles
Narrow stalk connects outer segment to inner segment
Inner segment releases neurotransmitters |
|
|
Term
|
Definition
|
|
Term
|
Definition
| derivatives of the compound rhodopsion, which consists of a protein, opsin, bound to the pigment retinal |
|
|
Term
| First step in photoreception |
|
Definition
| The absorption of photons by visual pigments |
|
|
Term
|
Definition
Blue cones
Green cones
Red cones
Each type has a different form of opsin and is sensitive to a different range of wavelengths. |
|
|
Term
|
Definition
|
|
Term
|
Definition
nearsightedness
The eyeball is too deep or the resting curvature of the lens is too great |
|
|
Term
|
Definition
Farsightedness
The eyeball is too shallow or the lens is too flat |
|
|
Term
|
Definition
| movement of Na+ into outer segment, on to inner segment, out of cell |
|
|
Term
| Step one of photoreception |
|
Definition
| Normally, the molecule is in the 11-cis form; on absorbing light it changes to the more linear 11-trans form. This change activates the opsin molecule. |
|
|
Term
| Step two of photoreception |
|
Definition
| Opsin activates transducin, which in turn activates PDE. (Transducin is a G protein, a membrane-bound enzyme complex) |
|
|
Term
| Step three of photoreception |
|
Definition
Cyclic GMP levels decline and gated sodium channels close.
The removal of cGMP from the gated sodium channels results in their inactivation. The rate of Na+ entry into the cytoplasm then decreases. |
|
|
Term
| Step four in photoreception |
|
Definition
Dark current is reduced and rate of neurotransmitter release declines.
Active transport continues to export Na+ from the cytoplasm. When the sodium channels close, the membrane potential drops toward -70mV. As the plasma membrane hyperpolarizes, the rate of neurotransmitter decreases, which signals the adjacent bipolar cell that the photoreceptor has absorbed a photon. |
|
|
Term
|
Definition
Rhodopsin molecule breaks down into retinal and opsin
Before retinal can combine with opsin, must be enzymatically converted to 11-cis
Requires ATP and time |
|
|
Term
|
Definition
Begin at photoreceptors, end at visual cortex of cerebral hemispheres
Message crosses two synapses before it heads toward brain
Photoreceptor to bipolar cell
Bipolar cell to ganglion cell |
|
|
Term
|
Definition
| monitor a specific portion of a field of vision |
|
|
Term
|
Definition
Ganglion cells that monitor rods, provide information about the general form of an object, motion, and shadows in dim lighting.
Relatively large |
|
|
Term
|
Definition
Ganglion cells that monitor the cones
Smaller and more numerous than M cells
Active in bright light, provide information about edges, fine detail, and color |
|
|
Term
|
Definition
| When almost all visual pigments have recovered from photobleaching, and the visual system is extremely sensitive. |
|
|
Term
|
Definition
| When the lights come on, the sensitivity decreases as bleaching occurs. Eventually, the rate of bleaching is balanced by the rate at which the visual pigments reassemble. |
|
|
Term
|
Definition
Excited by light arriving in center of their sensory field
Are inhibited when light strikes edges of their receptive field |
|
|
Term
|
Definition
Inhibited by light in central zone
Stimulated by illumination at edges |
|
|
Term
| Central processing of visual information |
|
Definition
Axons from ganglion cells converge on optic disc
Penetrate wall of eye
Proceed toward diencephalon as optic nerve (II)
Two optic nerves (one for each eye) reach diencephalon at optic chiasm
½ fibers stay same side
½ fibers cross to lateral geniculate nucleus on other side
From each lateral geniculate nucleus, visual information travels to the occiptal cortex
Optic radiation- bundle of projection fibers link lateral geniculate with visual cortex |
|
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Term
|
Definition
| The ability to judge depth or distance by interpreting the 3 dimensional relationships among objects in view |
|
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Term
|
Definition
Position of the head in space
by monitoring gravity, linear acceleration, and rotation. |
|
|
Term
|
Definition
| Enables us to detect and interpret sound waves |
|
|
Term
|
Definition
Both use mechanoreceptors- hair cells
Ear divided into external, middle, internal ear
External- collects, directs sound waves toward middle ear
Middle- collect sound waves, directs to inner ear
Inner ear- sensory organs for hearing & equilibrium |
|
|
Term
|
Definition
| A passageway (auditory canal) |
|
|
Term
|
Definition
| Protects the opening of the auditory canal and provides directional sensitivity |
|
|
Term
|
Definition
A thin, semi-transparent sheet that separates the external ear from the middle ear
The eardrum |
|
|
Term
|
Definition
| Integumentary glands along the external acoustic meatus that secrete a waxy material that helps keep out foreign objects or small insects. |
|
|
Term
|
Definition
| The slightly waxy secretion of the ceruminous glands, slows the growth of microorganisms and reduces the chance of infection |
|
|
Term
| Middle ear (tympanic cavity) |
|
Definition
An air-filled chamber separated from the external acoustic meatus by the tympanic membrane.
Communicates with:
Nasopharynx through the auditory tube
Mastoid air cells through a number of small connections |
|
|
Term
| Pharyngotympanic tube (Eustachian tube), auditory tube |
|
Definition
Consists of 2 portions:
First, near the connection to the middle ear, is narrow and supported by elastic cartilage.
Second, near the opening to the nasopharynx, is broad and funnel shaped
Equalizes pressure on either side of the tympanic membrane |
|
|
Term
| Middle ear has 3 auditory ossicles |
|
Definition
These connect the tympanic membrane with one of the receptor complexes of the inner ear.
These are called the malleus, the incus, and the stapes. |
|
|
Term
|
Definition
| attaches at 3 points to the interior surface of the tympanic membrane. |
|
|
Term
|
Definition
| Attaches the malleus to the stapes |
|
|
Term
|
Definition
| The edges of the base of the stapes are bound to the edges of the oval window |
|
|
Term
|
Definition
| An opening in the temporal bone that surrounds the internal ear. |
|
|
Term
| What does vibration of the tympanic membrane do? |
|
Definition
| Converts arriving sound waves into mechanical movements. |
|
|
Term
| What do the auditory ossicles do? |
|
Definition
| Conduct vibrations to the inner ear. |
|
|
Term
|
Definition
Stiffens the tympanic membrane to reduce the amount of movement possible.
Innervated by motor fivers of the mandibular branch of the trigeminal nerve (V) |
|
|
Term
|
Definition
Pulls the stapes reducing movement of the stapes at the oval window.
Innervated by the facial nerve (VII) |
|
|
Term
|
Definition
| Provides us with the sense of equilibrium and hearing |
|
|
Term
|
Definition
A layer of dense bone which forms the superficial contours of the internal ear.
Continuous with the surrounding temporal bone. |
|
|
Term
|
Definition
| A delicate, interconnected network of fluid-filled tubes where the receptors are found |
|
|
Term
|
Definition
| Between the bony and membranous labyrinths, a liquid that closely resembles CSF |
|
|
Term
|
Definition
| Inside the membranous labyrinth, a fluid with electrolyte concentrations that differ from those of typical body fluids. |
|
|
Term
| Subdivisions of the bony labyrinth |
|
Definition
Vestibule
The semicircular canals
cochlea |
|
|
Term
|
Definition
Consists of a pair of membranous sacs:
Saccule
Utricle
Receptors in these sacs provide sensations of gravity and linear acceleration. |
|
|
Term
|
Definition
Contain semicircular ducts
Receptors stimulated by rotation of head
Vestibule + semicircular canals = vestibular complex |
|
|
Term
|
Definition
A spiral-shaped bony chamber that contains the cochlear duct of the membranous labyrinth.
Receptors within the cochlear duct provide the sense of hearing.
The duct is sandwiched between a pair of perilymph-filled chambers |
|
|
Term
|
Definition
| A thin, membranous partition that separates the perilymph of the cochlear chambers from the air-filled middle ear |
|
|
Term
|
Definition
Formed of collagen fibers
Connected to base of stapes |
|
|
Term
|
Definition
Equilibrium sensations provided by receptors of vestibular complex
Semicircular canals- info about rotational movement of head
Saccule & utricle- info about position with respect to gravity & acceleration |
|
|
Term
|
Definition
Hair cells (sensory receptors) respond to rotational movements of the head
Ducts are continuous with utricle
Each duct contains
Ampulla- expanded region that contains receptors
Region in ampulla with hair cells- crista
Crista is bound to cupula- gelantinous structure extends full width of ampulla
Free surface of each hair cells has stereocilia (80-100)– resemble long microvilli:
Each hair cell has kinocilium – single, large cilium |
|
|
Term
|
Definition
Provide equilibrium sensations
Are connected with the endolymphatic duct, which ends in endolymphatic sac |
|
|
Term
|
Definition
Provide equilibrium sensations
Are connected with the endolymphatic duct, which ends in endolymphatic sac |
|
|
Term
|
Definition
Densely packed calcium carbonate crystals
Whole complex- Otolith (ear stone) = gel and statoconia |
|
|
Term
|
Definition
| Found at the boundary between the pons and the medulla oblongata |
|
|
Term
| Functions of the vestibular nuclei |
|
Definition
1. Integrating sensory information about balance and equilibrium that arrives from both sides of the head.
2. Relaying information from the vestibular complex to the cerebellum.
3. Relaying information from the vestibular complex to the cerebral cortex, providing a conscious sense of head position and movement.
4. Sending commands to motor nuclei in the brain stem and spinal cord. |
|
|
Term
|
Definition
| Directs the automatic movements of the eyes in response to sensations of motion |
|
|
Term
|
Definition
Located between vestibular duct & tympanic duct
Hair cells located in organ of Corti, sits on basilar membrane |
|
|
Term
|
Definition
Separates cochlear duct from tympanic duct
Hair cells arranged in longitudinal rows, lack kinocilia
Stereocilia in contact with overlying tectorial membrane
Tectorial membrane is attached to inner wall of cochlear duct |
|
|
Term
|
Definition
Waves of pressure conducted through a medium such as air or water.
In air, each pressure wave consists of a region where the air molecules are crowded together and an adjacent zone where they are further apart. |
|
|
Term
|
Definition
1. Sound waves arrive at the tympanic membrane.
2. Movement of the tympanic membrane causes displacement of the auditory ossicles.
3. Movement of the stapes at the oval window establishes pressure waves in the perilymph of the scala vestibuli.
4. The pressure waves distort the basilar membrane on their way to the round window of the scala tympani.
5. Vibration of the basilar membrane causes hair cells to vibrate against the tectorial membrane.
6. Information about the region and the intensity of stimulation is relayed to the CNS over the cochlear branch of CN VIII. |
|
|
Term
|
Definition
S-shaped curves, repeat in a regular pattern
Travel air ~768 mph |
|
|
Term
|
Definition
inversely related to frequency- number of waves (cycles) that pass a fixed reference point in a given time
Frequency of sound measured in terms of number of cycles per second (cps)- hertz (Hz) |
|
|
Term
|
Definition
intensity of sound wave
More energy- more amplitude
Sound energy is reported in decibels |
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|
