Physiol Lab Quiz 2: Labs 3&4 Flashcards
What is somatic reflex?
- Fast
- Effector - skeletal muscles
What is visceral reflex?
- Slower than somatic
- Effector - smooth m., cardiac m., and glands
What is monosynaptic reflex?
- only have “ONE synapse” between the afferent and motor neuron
— Total of two neurons; No interneuron needed
What is polysynaptic reflex?
- have more than one synapse
- have at least three neurons (afferent/sensory neuron, at least one interneuron, and an efferent/motor neuron)
What is innate reflex?
- reflexes that we have naturally/born with
What is learned reflex?
- reflexes we learned
What is withdrawal reflex?
- reflex that withdraws away from a painful stimulus
- an example of polysynaptic neuron, contains at least one interneuron
What is crossed extensor reflex?
- builds upon the withdrawal reflex and has the contralateral side involved by having the opposing muscles contract or relax to help keep balance
Name the brain structure referred to as the primary motor cortex
Precentral gyrus
Determine the number of neurons usually involved in a stretch reflex
TWO neurons (afferent and efferent neuron)
- aka monosynaptic
Determine the function & if it is considered phasic or tonic for the following receptors: free nerve ending
Free nerve endings - phasic
* detect warm temperature by warm receptors
AND
* detect cold temperature by cold receptors
Determine the function & if it is considered phasic or tonic for the following receptors: nociceptor
Nociceptors - tonic
* detect nociception/pain
Determine the function & if it is considered phasic or tonic for the following receptors: hair receptor
Hair receptors - phasic
* detect hair movement
Determine the function & if it is considered phasic or tonic for the following receptors: tactile disc/Merkel disc
Tactile disc/Merkel disc - tonic
* for light touch
Determine the function & if it is considered phasic or tonic for the following receptors: bulbous corpuscle/Ruffini corpuscle
Bulbous/Ruffini corpuscle - tonic
* for pressure, stretch and joint movement
Determine the function & if it is considered phasic or tonic for the following receptors: Tactile corpuscle/Meissner’s corpuscle
Tactile corpuscle/Meissner’s corpuscle - tonic
* for light touch
Determine the function & if it is considered phasic or tonic for the following receptors: lamellar corpuscle/Pacinian corpuscle
Lamellar corpuscle/Pacinian corpuscle - phasic
* for deep pressure, tickle, vibration
Define sensory adaptation
how the sensory neuron adapts to prolonged stimulus
- not exclusive for general senses
Distinguish phasic vs. tonic receptors
— Phasic receptors: fast adapting so with prolonged stimuli, there is a quick burst of action potential but decreases soon after
— Tonic receptors: adapt slowly and so generates signals more uniformly
Name the location where the information on general senses gets relayed to after reaching the thalamus
Postcentral gyrus/ Primary somatosensory cortex
Name the brain structure referred to as the primary somatosensory cortex
Postcentral gyrus
What are the 3 properties of a reflex?
Fast, involuntary, and stereotypical
What are the components of a reflex arc? Draw an example.
- Stimulus
- Sensor/ receptor
- Afferent/sensory neuron
- Integrating center
- Efferent/motor neuron
- Effector
- Response
The reflex arc is an example of which type of feedback loop? Why?
Negative feedback loop; response is opposite from the stimulus
What are the different types of muscle fibers and how are they different?
- Intrafusal fibers:
* Contains muscle spindles (detects length of muscles and proprioception)
* Sends signals to the CNS through afferent/sensory neurons, whenever length of muscle changes
* Still able to contract by gamma motor neurons - Extrafusal fibers
* For contraction
* Innervated by efferent/motor neurons = alpha motor neurons
What type of motor neurons innervates each of these different muscle fibers?
Intrafusal fiber - innervated by gamma motor neurons
Extrafusal fiber - innervated by alpha motor neurons
What are muscle spindles and where are they found?
Muscles spindles: sensors that detect the length of the muscles and helps us with proprioception (body position awareness)
— Location: found within skeletal muscle
What is reciprocal inhibition? Give an example of this.
Reciprocal inhibition/reciprocal innervation: occurs along with the reflex, which inhibits the antagonistic muscles, causing the response to be more exaggerated
— EX: Patellar reflex
* When the afferent neuron sends signals to the spinal cord that the quadriceps are being stretched, one place it will synapse is at the motor neuron going to the quadriceps, making this a monosynaptic reflex.
* Another location the afferent neuron synapses on is an interneuron. This interneuron is depolarized and sends an inhibitory post-synaptic potential (IPSP) to a separate motor neuron that will innervate the hamstrings, which are the antagonistic muscles of the quadriceps.
— By inhibiting this motor neuron, it causes relaxation of the hamstrings, which will allow the quadriceps to contract without the hamstrings opposing them, allowing the kick to be more exaggerated than when the hamstrings are contracted.
What does ipsilateral mean? Give an example.
When the neuron, stimuli and response, occur on the same side of the body
— EX: Right hand and right leg
What does decussation mean?
Decussation: Cross over the midline
What does contralateral mean? Give an example.
Contralateral: When a stimulus occurs on one side of the body, but the brain on the opposing side from the stimulus picks up that sensory information
— EX: withdrawal reflex and crossed extensor reflex
* If one were to step on a sharp object with their right foot, they would react by lifting the right foot but also balance on their left leg. This occurs because sensory information is sent to the CNS, where the sensory neurons and interneurons will synapse and the interneuron will then cross over to contralateral interneurons, which will then cause the left leg to balance.
How are ascending tracts different from descending tracts?
Ascending tracts: Carry sensory information UP the white matter of the spinal cord to the brain
Descending tracts: Motor signals from the brain going DOWN the spinal cord
Where in the brain are most sensory information sent prior to reaching their respective cortex?
Thalamus
Which part of the brain is for general senses? Which part of the brain makes sense of general senses?
- Thalamus - for general senses
- Postcentral gyrus / primary somatosensory cortex - makes sense of general senses
Which part of the brain plans voluntary movements? Which part of the cerebral cortex helps carries out these voluntary movements?
- Premotor cortex/motor association area (frontal lobe of the brain) - plans voluntary movement
- Primary motor cortex/precentral gyrus - carry out these voluntary movements by sending signals down the spinal cord until it synapses with an alpha motor neuron.
What do the stretch reflexes test for?
Purpose: test if the nerves that innervate the muscles and the spinal cord where the synapse occurs are functioning properly
Determine the nerve(s) tested, muscle(s) contracted, muscle relaxed, and the patient’s response for the following reflex: Patellar reflex
Patellar Reflex
Nerve(s) tested - Femoral nerve
Muscle(s) tested - Quadriceps
Muscle(s) relaxed - Hamstrings
Patient’s response - Knee extends
Determine the nerve(s) tested, muscle(s) contracted, muscle relaxed, and the patient’s response for the following reflex: Biceps reflex
Biceps reflex
Nerve(s) tested - Musculocutaneous nerve
Muscle(s) tested - Biceps brachii
Muscle(s) relaxed - Tricep
Patient’s response - Flexion of the forearm
Determine the nerve(s) tested, muscle(s) contracted, muscle relaxed, and the patient’s response for the following reflex: Triceps reflex
Triceps Reflex
Nerve(s) tested - Radial nerve
Muscle(s) tested - triceps brachii
Muscle(s) relaxed - Bicep
Patient’s response - Extension of the forearm
Determine the nerve(s) tested, muscle(s) contracted, muscle relaxed, and the patient’s response for the following reflex: Ankle jerk reflex
Ankle Jerk reflex
Nerve(s) tested - Sciatic and tibial nerves
Muscle(s) tested - Calf muscles (gastrocnemius and soleus)
Muscle(s) relaxed - Tibialis anterior
Patient’s response - Plantar flexion
What is the difference between a positive and negative Babinski sign?
Positive Babinski sign - the flaring of the toes and extension of the hallux
Negative Babinski sign - the toes curling and slight plantar flexion
What is considered a normal response for an infant vs. an adult regarding the Babinski sign? Why is there a difference?
- Normal response for infant - Positive Babinski sign (flaring of toes and extension of hallux)
- Normal response for adults - Negative Babinksi sign (toes curling and slight plantar flexion)
- The difference occurs when infants begin to learn how to walk, descending tracts will start to develop to cause plantar flexion instead to help keep our balance, due to inhibition by descending tracts as we mature.
What is considered abnormal for an adult regarding the Babinski sign? Why might this occur?
- Abnormal response for adults - Positive Babinksi sign
- If the adult has CNS damage, whether along the spinal cord or the brain, the inhibition by the descending tracts will no longer function properly, causing the positive sign of the Babinski reflex, since the plantar reflex is a spinal reflex.
Explain why the room temperature water bath felt different after placing your hands at different temperatures?
— Since thermoreceptors are phasic receptors, they will first give a burst of action potential for their particular temperature.
— After time, they will quickly ADAPT to the temperature by sending FEWER action potentials to the CNS. The warm receptors of the skin will decrease the number of action potentials it generates.
— When we change that temperature, they are LESS sensitive to the temperature that they are adapted to, so it feels more like the opposing temperature. When the hand from the warm water is placed in room temperature water, it will feel cold because the warm receptors is still sending fewer action potentials to the CNS, while on the contrary the cold receptors will be sending more frequent action potentials to the CNS, giving us the perception of coldness, even though the water is not actually colder than room temperature.
What is a receptive field?
the area of the skin that contains receptors for a particular sense and is inversely proportional to the density of the sensory receptors in that area
What happens to the receptive field if you increase the amount of receptors and vice versa? Give examples to locations of the body.
— If you have more receptors in a given area, each receptor has a smaller receptive field, allowing more sensitivity when being touched
* EX: Fingertip
— Areas of the skin that have fewer sensory receptors have larger receptive field
* EX: Back
What is two-point touch threshold?
Two-point touch threshold: the minimum distance between two points that we perceive as two points
- Helps us figure how large the receptive fields are and how sensitive our sense of touch is
Determine the Normal Two-Point Discrimination for the following location: Index fingertip
1-5 mm
Determine the Normal Two-Point Discrimination for the following location: Palm of hand
5-10 mm
Determine the Normal Two-Point Discrimination for the following location: Anterior side of forearm
35-40 mm
Determine the Normal Two-Point Discrimination for the following location: Posterior side of calf
45-50 mm
What are dermatomes?
Spinal nerves that come off the spinal cord will innervate organs and that same spinal nerve that innervates that organ will also innervate a region of the skin
What is referred pain? Give an example.
Referred pain is when pain is felt from a certain location on one’s body, however this pain signal comes from a visceral organ, located at a different area than where the pain is actually felt.
— An example of referred pain is myocardial infarction (heart attack). Some people may experience pain down their left arm, which can indicate a heart attack occurring.
Name the photopigment found in rods
Rhodopsin
Name the 2 molecules that form from the photopigment in rods vs. cones after light hits the photopigment
Rods - retinaldehyde (retinene or retinal) and an opsin
Cones - retinaldehyde and a photopsin
Describe the optic disc & name the cells that are missing
Optic disc - “Blind spot”
- where all the ganglion cells’ axons exit the eye (via optic nerve)
- NO photoreceptors
Define accommodation & describe the change to the following structures (ciliary muscles, suspensory ligaments & lens) when you look at something near vs. far
Accommodation: how our eye keeps an image focused on the retina when the object we are looking at varies in distance
* Lens changes shape to focus on objects that are near or far with the help of the ciliary body and suspensory ligaments
Looking at something near:
- Ciliary bodies contract; loosening the suspensory ligaments
= Lens become wider/thicker (MOST convex)
Looking at something far:
- Ciliary bodies relax; tightening the suspensory ligaments
= Lens become thinner (LEAST convex)
Define visual acuity? (What structure of the eye plays a role in this?)
Visual acuity: is the sharpness of our vision, which is due to the cones within the macula lutea and fovea centralis
Distinguish myopia vs. hyperopia vs. emmetropia vs. astigmatism vs. presbyopia
- Myopia: (nearsightedness) eye is too elongated in shape; making focal point of the image to be IN FRONT of the retina
- Hyperopia: (farsightedness) eye is too short; causing focal point of image to be BEHIND the retina
- Emmetropia: normal vision or 20/20 vision
- Astigmatism: deformed shape of the cornea or lens; which prevents the light rays from different planes to be focused properly on the retina
- Presbyopia: as we age, the lens becomes less and less flexible, which makes it harder for us to focus on objects that are nearer to us
List the structures, in correct order, as light enters the eye, including the retinal cells that light passes through.
- Cornea
- Aqueous humor of the anterior cavity
- Anterior cavity - Pupil
- Iris: pigmented portion that controls the amount of light entering, radial and circular smooth m. - Lens: helps focus the light rays onto the retina
- Ciliary bodies
- Suspensory ligaments - Vitreous humor of the posterior cavity:
- Posterior cavity: - Retina: the layer of the eye that contains neurons that detects the light
- Ganglion cells
- Bipolar cells
- Photoreceptors - Choroid
What type of photopigment is in rods and what is it made of? What about the cones?
Rods - Rhodopsin (retinaldehyde + opsin)
Cones - retinaldehyde + photopisn
List all the structures, in correct order, that visual nerve impulses pass through.
Structures that conduct visual nerve impulses to the brain once light is detected by the photoreceptors
1. Photoreceptors
2. Bipolar cells
3. Ganglion cells
4. Optic nerve
5. Optic chiasma
6. Optic tract
- Superior colliculi
OR
- Thalamus
* Optic radiations
* Primary visual cortex
* Visual association area
What is the optic nerve and what information does it sends ipsilaterally vs contralaterally?
Optic nerve (CNII) : sends information of the medial field of vision/visual field IPSILATERALLY, while the lateral field of vision will continue CONTRALATERALLY by decussating at the optic chiasma
What is the superior colliculi?
Superior colliculi of the midbrain : part of the corpora quadrigemina or tectal plate and is the location where visual reflexes occur (pupillary reflex, blinking, focusing).
What chart is used to test visual acuity?
The Snellen chart
What is myopia? Why does this occur?
Myopia (nearsightedness) : the eye is too elongated in shape, making the focal point of the image to be IN FRONT of the retina
How do you correct myopia?
With CONCAVE lens
What is hyperopia? Why does this occur?
Hyperopia (farsightedness) : when the eye is too short causing the focal point to be BEHIND the retina
How do you correct hyperopia?
With CONVEX lens
What is astigmatism? What tests for this in our lab?
Astigmatism: caused by a deformed shape of the cornea, which prevents the light rays from different planes to be focused properly on the retina
- Astigmatism chart: contains a set of three parallel lines on different planes
* People with normal cornea curvature - will see all the lines clearly
* People with astigmatism - will see certain sets of three lines blurry, while others are clear
What is your visual acuity? What type of vision do you have?
20/13; Emmetropia
Describe the causes of astigmatism
caused by a deformed shape of the cornea
Interpret the readings from the Snellen chart & determine a patient’s type of vision based on the readings
Patient is placed 20 ft. away from the chart and their vision is compared to what people with normal visual acuity can see at a certain distance
* Emmetropia: 20/20 - at 20 feet you can see the letters, which people with normal visual acuity can see at 20 feet
* Myopia: 20/30 - at 20 feet you can see the line of letters, which people with normal visual acuity can see at 30 feet
What two muscles are found in the iris and what do they do, and which autonomic nerve are they innervated by?
- Radial muscles: cause pupillary dilation
- Circular muscles: cause pupillary constriction
- Both innervated by the oculomotor nerve (CNIII)
Which part of the autonomic nervous system controls which smooth muscle of the iris?
- Radial muscles - sympathetic nervous system
- Circular muscles - parasympathetic nervous sytem
What is consensual light reflex? What coordinates this?
Consensual light reflex/pupillary light reflex: shine light into 1 eye, both pupils constrict
* Coordinated by superior colliculi of midbrain
Describe the pathway of the pupillary reflex
- Stimulus - Increase or decrease in light that enters the eye
- Sensor/receptor - Rods and cones of the retina that detects the light and sends signals…
- Afferent neuron - Optic nerve (formed by a series of cells), then send signals to…
- Integrating center - Superior colliculi; determines whether the light being received is close to the set point. If not, it will send signals to…
- Efferent neuron - Oculomotor nerve, will continue to send signals to…
- Effector - to the radial or circular smooth muscles of the iris
- Response - Iris will pupillary dilate OR pupillary constrict
- If there is an INCREASE in light, the circular smooth muscles of the iris will cause pupillary constriction, decreasing the amount of light entering the eye.
- If there is a DIMMING of light, the radial smooth muscles of the iris will cause pupillary dilation, increasing the amount of light entering the eye.
* Even though you shine the light into one of the eyes, both irises will undergo pupillary constriction.
What types of cones are there and what are they sensitive to?
- Short-wavelength (S) cones: are sensitive to 420 nm of light, which responds to the color purple
- Medium-wavelength (M) cones: are sensitive to 531 nm of light, which responds to green
- Long-wavelength (L) cones are sensitive to
558 nm of light, which responds to red
What is red-green color blindness? What are they lacking?
Red-green color blindness: One cannot distinguish the color red or green from each other
- Individual lacks either L or M cones
What type of trait is red-green color blindness? Who is more susceptible in getting red-green color blindness? Why?
Sex-linked recessive trait:
- Males tend to have this type of color blindness than females
* Males only have one X chromosome, while females have two X chromosomes
What is used to test red-green color blindness?
Ishihara test: has dots of different colors that make an image of a number or symbol
- Those who cannot see the number or symbol have red-green color blindness
Distinguish the function, and the nerve that innervates the following extrinsic eye muscle: Medial Rectus
Function: Moves eye medially
Innervated by: Oculomotor Nerve (C.N. III)
Distinguish the function, and the nerve that innervates the following extrinsic eye muscle: Inferior Rectus
Function: Moves the eye downward
Innervated by: Oculomotor Nerve (C.N. III)
Distinguish the function, and the nerve that innervates the following extrinsic eye muscle: Superior Oblique
Function: Moves the eye laterally and inferiorly
Innervated by: Trochlear nerve (C.N. IV)
Distinguish the function, and the nerve that innervates the following extrinsic eye muscle: Superior Rectus
Function: Moves the eye upward
Innervated by: Oculomotor Nerve (C.N. III)
Distinguish the function, and the nerve that innervates the following extrinsic eye muscle: Inferior Oblique
Function: Moves the eye laterally and superiorly
Innervated by: Oculomotor Nerve (C.N. III)
Distinguish the function, and the nerve that innervates the following extrinsic eye muscle: Lateral Rectus
Function: Moves the eye laterally
Innervated by: Abducens nerve (C.N. VI)
What is the spiral organ/Organ of Corti?
Spiral organ/Organ of Corti: On the basilar membrane, it contains the hair cells that detect the vibrations due to its hairs/stereocilia being bent within the tectorial membrane and transduce the vibrational signals into electrical signals to be sent to the brain. The remaining vibrations will be sent to the perilymph of the scala tympani.
List the structures, in correct order, for the pathway for auditory nerve impulses
Because of sound, the vibrations on the basilar membrane causes the stereocilia embedded in the tectorial membrane to move, causing the following to activate…
1. Hair cells: activated sending signals to the…
2. Cochlear branch of the vestibulocochlear nerve (cranial nerve VIII): the branch of the cranial nerve that carries auditory senses. The impulses will eventually continue onto to the…
3. Inferior colliculi of the corpora quadrigemina/tectal plate: part of the midbrain for auditory reflexes, like when something loud drops and you reflexively look towards that sound. Unlike the visual nerve impulses which either go to the superior colliculi OR the thalamus, all auditory nerve impulses will go from the inferior colliculi and continue to the…
4. Thalamus: which is the relay center that sends the auditory impulses to the…
5. Primary auditory cortex: superior portion of the temporal lobe where we perceive sound. After perceiving the sound, signals go to the…
6. Auditory association area: inferior portion of the temporal lobe to make sense of the sounds and to help us recognize words and music.
What is the inferior colliculi and its function?
Inferior colliculi: part of the midbrain for auditory reflexes; when something loud drops and you reflexively look towards that sound
— ALL auditory nerve impulses will go from the inferior colliculi and continue to the thalamus
What is the primary auditory cortex and where is it found?
Primary auditory cortex: superior portion of the temporal lobe where we perceive sound
- Will then send signals to auditory association area
What is conductive hearing loss? What causes this?
Conductive hearing loss: when there is a decrease of sound transmission in the ear up to the oval window
— Can be caused by:
1. ear wax (cerumen)
2. a ruptured tympanic membrane
3. conditions that affect the auditory ossicles
What can help conductive hearing loss?
Hearing aids can be used to help amplify the sounds or conduct it through bone to correct this, or in other cases clearing the ear wax or allowing the tympanic membrane to reform.
What is sensorineural/perception hearing loss? What causes this?
Sensorineural/perception hearing loss: when any of the structures mentioned within the pathway for auditory impulses is damaged
— Could be caused by: loud noises that damage hair cells or damage to the vestibulocochlear nerve
What may help sensorineural/perception hearing loss?
Using cochlear implants; that stimulate existing neurons to send electrical signals so sound can be perceived
What is the Rinne’s test and what does it test for?
Rinne’s test: tests for conductive hearing loss
— Use a tuning fork against the mastoid process of the temporal bone, the sound vibrations conducted across the bone is less sensitive than sound waves across air molecules
— Those with conductive hearing loss will be able to hear the sounds conducting through bone to be louder than those conducted through air
— When you stop hearing the vibration across the bone and are able to hear the tuning fork when placed next to the acoustic meatus, you have normal hearing. If not, something is preventing the air molecules from conducting it to the oval window, which means you have conductive hearing loss.
What is Weber’s test and what does it test for?
Weber’s test: tests for both conductive and sensorineural hearing loss
— Is usually done after the Rinne’s test; after finding out whether or not the person has conductive deafness, you will use a tuning fork at the top of the head
* Normally, the amplitude of sound should be the same bilaterally or in both ears
* If the person has conductive hearing loss after the Rinne’s test, the one side that sounds louder is the one that has conductive hearing loss
* If the person has normal hearing from the Rinne’s test, but still hears one side louder than the other, the person has sensorineural hearing loss
How is amplitude determined in the ear?
Amplitude of sound waves or loudness of sound is determined by the FREQUENCY OF ACTION POTENTIALS sent by the cochlear branch of the vestibulocochlear nerve (cranial nerve VIII) and by the AMOUNT OF HAIR CELLS being stimulated
— The louder the sound, the more frequency of action potentials are sent through cranial nerve VIII and the more hair cells are activated as well
How is low versus high pitch determined in the ear?
— The higher frequency of sound waves stimulates the hair cells at the base of the cochlea, giving us the perception of high pitch. —Lower frequency of sound travels further up the cochlea towards the helicotrema. Hair cells stimulated here will be perceived as low pitch
What happens to pitch when we age?
As we age, the hair cells towards the base of the cochlea begin to die off, meaning that higher pitch sounds will not be heard
What type of hearing loss is it when we cannot hear higher pitches as we age?
An example of sensorineural/perception hearing loss
What structures are in the vestibule and what do they each detect?
Vestibule: made up of Utricle and Saccule, detects linear acceleration
— Utricle: detects horizontal acceleration, like accelerating or braking in a car
— Saccule: detects vertical acceleration, like going up or down an elevator
What are the different semicircular ducts and what do they each detect?
- Anterior semicircular ducts: detects sagittal rotational acceleration, similar to doing front and back flips
- Posterior semicircular ducts: detects coronal rotational acceleration, similar to doing cartwheels
- Lateral semicircular ducts: detects horizontal rotational acceleration, similar to spinning around in circles
What is the pathway for equilibrium impulses?
- Hair cells within the macula of the vestibule (urticle and saccule) and crista ampullaris of the semicircular ducts are activated when their stereocilia within the otolithic membrane or cupula bends. The bending of the stereocilia will send nerve impulses to the…
- Vestibular branch of the vestibulocochlear nerve (cranial nerve VIII), which then sends information to both the…
— Cerebellum to help coordinate with our skeletal muscles for balance.
— Superior colliculi which has the oculomotor center to control eye movement by the oculomotor nerve (cranial nerve III) to the extrinsic eye muscles.
If someone was doing cartwheels, which part of the vestibular apparatus is stimulated?
Posterior semicircular ducts
If someone starts to run, which part of the vestibular apparatus is stimulated?
Utricle
Name the structures that form the vestibular apparatus vs. vestibule
- Vestibular apparatus: vestibule (utricle and saccule), semicircular ducts (anterior, posterior, lateral)
- Vestibule: Utricle and saccule
What is vestibular nystagmus?
Vestibular nystagmus: When eyes drift then move back to the midline
When the patient was facing forward while being spun around, which specific structure was being stimulated
Lateral semicircular duct
When the patient was looking downwards while being spun around, which specific structure are we trying to stimulate?
Posterior semicircular duct
When the patient had their head tilted to the side (lateral flexion) while being spun around, which specific structure are we trying to stimulate?
Anterior semicircular duct
What is the pathway for hearing/sound?
- Pinna/auricle: funnels sound waves into the…
- Auditory canal / external acoustic meatus: a passageway that leads the sound waves to the…
- Tympanic membrane: vibrates due to the sound waves, causing the auditory ossicles to vibrate which consists of the…
- Malleus: first of the auditory ossicles to vibrate by the tympanic membrane
- Incus: second of the auditory ossicles to vibrate by the malleus
- Stapes: third of the auditory ossicles to vibrate by the incus. The stapes when vibrating will be attached to the…
- Oval window: an opening of the cochlea. The vibrations of the stapes are converted into fluid vibrations of the cochlea. The oval window vibrates the…
- Perilymph of the scala vestibuli: fluid within the superior chamber of the cochlea, which will then vibrate the…
- Vestibular membrane: membrane that separates the scala vestibuli and the scala media/cochlear duct. The scala media/cochlear duct contains…
- Endolymph of the scala media/cochlear duct: fluid within the scala media/cochlear duct that will then vibrate the…
- Basilar membrane: membrane that separates the scala media/cochlear duct and the scala tympani, and it contains the spiral organ/Organ of Corti. Since the basilar membrane is vibrating, it vibrates the…
- Spiral organ/Organ of Corti:
- Tectorial membrane: not directly part of the pathway of sound since this is part of the spiral organ - Perilymph of the scala tympani: the remaining waves will exit out of the ear by having these waves vibrate the fluid within the scala tympani and will exit the cochlea through the…
- Round window: where the remaining fluid vibrations exits the cochlea.
