Development of ear
•Download as PPTX, PDF•
15 likes•4,430 views
Ear is the anatomical unit serving both hearing and equilibrium. Understanding of the developmental of ear and its clinical anatomy is fundamental in the learning of embryology.
Report
Share
Report
Share
Recommended
Embryology of ear8
The ear develops from three main embryonic structures:
1. The external ear develops from swellings around the first and second pharyngeal arches.
2. The middle ear develops from the first pharyngeal pouch which forms the auditory tube and tympanic cavity. The ossicles develop from the first and second pharyngeal arches.
3. The inner ear develops from the otic placode which invaginates to form the otic vesicle. The vesicle then divides to form the structures of the inner ear including the cochlea, utricle and saccule.
Anatomy of inner ear by Dr. Aditya Tiwari
The document summarizes the anatomy and development of the inner ear. It describes how the inner ear develops from the otic placode and otocyst in the early embryo. It then discusses the detailed structures within the inner ear, including the bony and membranous labyrinths, semicircular canals, cochlea, vestibule, and organ of Corti. The organ of Corti contains hair cells and supporting cells that detect sound vibrations and transmit signals to the auditory nerve.
Embryology 18 ear
The ear develops from three parts - the external, middle, and inner ear. The inner ear develops from thickenings in the ectoderm called otic placodes around 22 days. These placodes invaginate to form the otic vesicles which divide into dorsal and ventral components forming the structures of the inner ear. The middle ear develops from the first pharyngeal pouch and cleft, giving rise to the tympanic cavity and auditory tube. The ossicles develop from the surrounding cartilage. The external ear develops from swellings near the pharyngeal arches which fuse to form the auricle and the external auditory meatus develops from the dorsal cleft.
Development of ear
The external ear, middle ear, and internal ear all develop from thickenings and pouches of ectoderm and mesoderm that form early in embryonic development. The external ear develops from six hillocks that fuse to form the auricle, while the external auditory meatus develops from the first pharyngeal cleft. The middle ear forms from the first pharyngeal pouch and cleft, and contains the tympanic cavity and three ossicles that develop from cartilage. The internal ear forms from the otic placode and vesicle, which give rise to the membranous labyrinth and its sensory structures for hearing and balance.
Otoacoustic emission
Otoacoustic emissions are low-intensity sounds generated by the inner ear that can be measured in the ear canal. They are produced by the outer hair cells' electromotility in response to sound stimulation. There are two main mechanisms that produce otoacoustic emissions - nonlinear distortion, attributed to outer hair cell action, and linear reflection from impedance mismatches in the cochlea. Measuring otoacoustic emissions can reveal the integrity of outer hair cell function. The different types of otoacoustic emissions include spontaneous, transient-evoked, distortion product, and stimulus frequency emissions.
Physiology Of Hearing
The document discusses the physiology of hearing. It covers topics like acoustics, properties of sound, the external ear, middle ear, inner ear, bone conduction, and the auditory pathway. The middle ear functions to transmit sounds from the air to the inner ear fluid through a transducer mechanism involving the vibrations of the tympanic membrane, ossicles, and oval window. Sound waves in the inner ear cause motion of hair cells and generation of nerve impulses that travel through the auditory pathway to the brain.
Acoustic Reflex (AR) and Tone decay (TDT)
This document discusses acoustic reflex and tone decay testing. It defines acoustic reflex as a decrease in tympanic membrane compliance in response to sound stimulation that is measured using immittance testing. Acoustic reflex can be tested ipsi-laterally, stimulating and measuring the same ear, or contra-laterally, stimulating one ear and measuring the opposite ear. Tone decay measures the relaxation of the stapedius muscle between contractions in response to sustained tones and can help localize lesions. Abnormal decay at low frequencies suggests lesions of the auditory nerve or brainstem while decay at high frequencies suggests cochlear lesions.
Middle ear anatomy
This document provides an anatomical overview of the structures of the middle ear and mastoid region. It describes the development, features, and contents of the eustachian tube, tympanic cavity, mastoid air cells, and related structures. Key structures discussed include the ossicles, muscles, nerves, blood supply, and the walls, openings and recesses of the middle ear cavity. Comparisons are made between adult and infant anatomy.
Recommended
Embryology of ear8
The ear develops from three main embryonic structures:
1. The external ear develops from swellings around the first and second pharyngeal arches.
2. The middle ear develops from the first pharyngeal pouch which forms the auditory tube and tympanic cavity. The ossicles develop from the first and second pharyngeal arches.
3. The inner ear develops from the otic placode which invaginates to form the otic vesicle. The vesicle then divides to form the structures of the inner ear including the cochlea, utricle and saccule.
Anatomy of inner ear by Dr. Aditya Tiwari
The document summarizes the anatomy and development of the inner ear. It describes how the inner ear develops from the otic placode and otocyst in the early embryo. It then discusses the detailed structures within the inner ear, including the bony and membranous labyrinths, semicircular canals, cochlea, vestibule, and organ of Corti. The organ of Corti contains hair cells and supporting cells that detect sound vibrations and transmit signals to the auditory nerve.
Embryology 18 ear
The ear develops from three parts - the external, middle, and inner ear. The inner ear develops from thickenings in the ectoderm called otic placodes around 22 days. These placodes invaginate to form the otic vesicles which divide into dorsal and ventral components forming the structures of the inner ear. The middle ear develops from the first pharyngeal pouch and cleft, giving rise to the tympanic cavity and auditory tube. The ossicles develop from the surrounding cartilage. The external ear develops from swellings near the pharyngeal arches which fuse to form the auricle and the external auditory meatus develops from the dorsal cleft.
Development of ear
The external ear, middle ear, and internal ear all develop from thickenings and pouches of ectoderm and mesoderm that form early in embryonic development. The external ear develops from six hillocks that fuse to form the auricle, while the external auditory meatus develops from the first pharyngeal cleft. The middle ear forms from the first pharyngeal pouch and cleft, and contains the tympanic cavity and three ossicles that develop from cartilage. The internal ear forms from the otic placode and vesicle, which give rise to the membranous labyrinth and its sensory structures for hearing and balance.
Otoacoustic emission
Otoacoustic emissions are low-intensity sounds generated by the inner ear that can be measured in the ear canal. They are produced by the outer hair cells' electromotility in response to sound stimulation. There are two main mechanisms that produce otoacoustic emissions - nonlinear distortion, attributed to outer hair cell action, and linear reflection from impedance mismatches in the cochlea. Measuring otoacoustic emissions can reveal the integrity of outer hair cell function. The different types of otoacoustic emissions include spontaneous, transient-evoked, distortion product, and stimulus frequency emissions.
Physiology Of Hearing
The document discusses the physiology of hearing. It covers topics like acoustics, properties of sound, the external ear, middle ear, inner ear, bone conduction, and the auditory pathway. The middle ear functions to transmit sounds from the air to the inner ear fluid through a transducer mechanism involving the vibrations of the tympanic membrane, ossicles, and oval window. Sound waves in the inner ear cause motion of hair cells and generation of nerve impulses that travel through the auditory pathway to the brain.
Acoustic Reflex (AR) and Tone decay (TDT)
This document discusses acoustic reflex and tone decay testing. It defines acoustic reflex as a decrease in tympanic membrane compliance in response to sound stimulation that is measured using immittance testing. Acoustic reflex can be tested ipsi-laterally, stimulating and measuring the same ear, or contra-laterally, stimulating one ear and measuring the opposite ear. Tone decay measures the relaxation of the stapedius muscle between contractions in response to sustained tones and can help localize lesions. Abnormal decay at low frequencies suggests lesions of the auditory nerve or brainstem while decay at high frequencies suggests cochlear lesions.
Middle ear anatomy
This document provides an anatomical overview of the structures of the middle ear and mastoid region. It describes the development, features, and contents of the eustachian tube, tympanic cavity, mastoid air cells, and related structures. Key structures discussed include the ossicles, muscles, nerves, blood supply, and the walls, openings and recesses of the middle ear cavity. Comparisons are made between adult and infant anatomy.
Eustachian tube, anatomy, test and disorders, dr.vijaya sundarm, 20.03.17
The document discusses the anatomy, physiology, and disorders of the Eustachian tube. It describes the Eustachian tube's embryological development and details its adult anatomy including measurements, parts, musculature, and blood supply. Regarding function, it ventilates the middle ear and drains secretions. Dysfunctions include tubal blockage from various mechanical or functional causes like adenoids, cleft palate, or barotrauma. Tests to evaluate Eustachian tube function include Valsalva, Toynbee, and tympanometry. Disorders include tubal blockage, retraction pockets, and a patulous tube.
Middle ear
The document summarizes the anatomy of the middle ear. It describes the structures derived from the pharyngeal pouches and arches that make up the middle ear, including the ossicles, muscles, nerves and openings. It provides details on the walls, contents, blood supply and clinical relevance of the middle ear.
Development of ear ppt
The ear develops from three germ layers into three main structures - the inner, middle, and outer ear. The outer ear develops from hillocks in the mandibular and hyoid arches, which fuse to form the pinna. The external auditory canal develops from the first branchial groove. The middle ear cavities develop from outpouchings of the first and second pharyngeal pouches. Ossicles develop from the first and second branchial arches. The inner ear develops from the otic placode, forming the fluid-filled cochlea and vestibular system. The facial and acoustic nerves also develop during this period to innervate the ear structures.
Anatomy of inner ear
The inner ear consists of two parts - the bony labyrinth within the temporal bone, and the membranous labyrinth contained within. The bony labyrinth includes the cochlea, vestibule and semicircular canals. The membranous labyrinth contains the cochlear duct, utricle, saccule and semicircular ducts filled with endolymph. These structures contain specialized sensory cells that detect sound (cochlear hair cells) and linear/angular acceleration (vestibular hair cells), transmitting signals to the brain.
Physiology of hearing ppt
The document discusses the physiology of hearing. It covers the key components required for normal hearing including sound conduction through the ear canal, middle ear, and inner ear. The middle ear acts as an impedance matcher and sound intensity transducer. The cochlea contains hair cells that transduce sound waves into neural signals. The basilar membrane varies in width and stiffness along its length to allow different frequencies to stimulate separate regions of the cochlea.
Physiology of Hearing
The document provides information on the physiology of hearing. It discusses how sound waves are conducted through the ear to the inner ear, where they are transduced into neural signals. Key points include:
- Sound waves are collected by the pinna and focused through the external auditory canal to the tympanic membrane.
- Vibrations are transmitted through the ossicles to the oval window, matching impedances between air and fluid environments.
- In the cochlea, vibrations of the basilar membrane lead to stimulation of hair cells and transduction of sound into neural signals.
- These signals travel through the auditory pathway to the brain for perception of sound.
Tests like pure
HIS 120 Embryology of the Inner Ear
The inner ear first appears as auditory placodes that form hollow otocysts on the 24th day of embryo formation. By the 7th week, the otocyst has developed into the membranous labyrinth containing the semicircular canals and a single turn cochlea. By the 12th week, the adult form of the inner ear is nearly complete, with the membranous labyrinth suspended in perilymph within the developing bony labyrinth. A full understanding of inner ear embryology is important for treating hearing issues that result from prenatal development problems or cochlear damage in adulthood.
Physilogy of phonation by Dr.Ashwin Menon
This document discusses the physiology of phonation, or voice production. It defines phonation as the rapid opening and closing of the vocal cords due to the separation and apposition of the vocal folds, accompanied by breath under lung pressure, which creates vocal sound. It describes the anatomy involved in voice production including the lungs, diaphragm, larynx, throat, mouth and nose. It discusses theories of voice production and covers topics like pitch, volume, quality, vocal registers, vocal disorders, vocal injury, and video stroboscopy.
Anatomy of external ear
This document summarizes the anatomy of the external ear. It describes the pinna (auricle), which is made of elastic cartilage covered in skin. It is attached to the skull by ligaments and muscles supplied by the facial nerve. The external auditory canal extends from the bottom of the concha to the tympanic membrane. The outer third is cartilaginous while the inner two thirds are bony. The tympanic membrane separates the external ear from the middle ear. It consists of the pars tensa and pars flaccida and is innervated by the auriculotemporal, vagus, and glossopharyngeal nerves.
Auditory brainstem response (ABR)
The document discusses auditory brainstem response (ABR) testing, which is used to evaluate hearing in newborns. ABR testing uses electrodes to measure electrical activity in the brainstem in response to auditory clicks or tones. It is an effective screening tool for detecting hearing loss, with a high sensitivity and specificity. ABR testing can identify abnormalities in the auditory nerve or brainstem that may indicate conditions like acoustic neuromas. It provides objective information about hearing thresholds and neural conduction in the auditory pathway.
Baha & active middle ear implants
The document summarizes bone conduction hearing aids and the BAHA (Bone Anchored Hearing Aid) system. It discusses indications for BAHA, the surgical procedure, outcomes, advantages over conventional hearing aids, and limitations. BAHA provides an alternative for those who cannot use air conduction hearing aids due to ear canal issues or single-sided deafness. The surgery attaches a fixture to the skull bone which integrates and allows mounting of a sound processor externally on an abutment.
Embryology of the ear
The document discusses the development of the ear. It begins with the formation of the otic placode which develops into the otic pit and then the otic vesicle. The otic vesicle then forms the endolymphatic duct and sac as well as the utricular and saccular portions. The cochlea also develops from the otic vesicle. The middle ear develops from the tubotympanic recess which forms the tympanic cavity and Eustachian tube. The auditory ossicles also develop in the tympanic cavity. The external ear develops from the first branchial groove which forms the external acoustic meatus. Congenital anomalies that can result include deafness and end
Development of Ear
The document discusses the development of the ear, including the external, middle, and internal ear structures. It describes how the otic placode invaginates to form the otic vesicle, which then develops into the membranous labyrinth. The ventral part forms the saccule and cochlear duct, while the dorsal part forms the semicircular ducts and utricle. The first pharyngeal pouch develops into the middle ear cavity and auditory tube, while the first pharyngeal cleft forms the external acoustic meatus. Various congenital deformities of the external ear are also mentioned.
Anatomy of inner ear
The inner ear is composed of a bony labyrinth that houses the membranous labyrinth. The membranous labyrinth contains the cochlea, three semicircular canals, and two otolith organs (the utricle and saccule). The semicircular canals contain cristae that detect rotational head movements while the utricle and saccule contain maculae that detect linear accelerations and gravity. Endolymph fills the membranous labyrinth and perilymph fills the space between the bony and membranous labyrinths. The vestibular portion detects head movements and maintains balance.
Evaluation of deaf child
Evaluation of a deaf child for cochlear implantation. complete workup of a bilateral congenital snhl child for cochlear implantation
VEMP (PPT) Dr.dr.HR Yusa Herwanto, MKed(ORL-HNS), Sp.THTKL(K)
VEMP testing provides a method to evaluate otolith function in the inner ear by measuring electromyographic responses from the sternocleidomastoid (cVEMP) and inferior oblique ocular muscles (oVEMP) elicited by sound stimulation. cVEMP assesses the saccule and vestibular nerve pathway while oVEMP assesses the utricle pathway. VEMP testing is useful in clinical diagnosis of various vestibular disorders including neuritis, Meniere's disease, vestibular schwannoma, and more. Standardization of stimulation and recording methods is still needed for VEMP to be effectively utilized in clinical practice.
Anatomy of the inner ear
The inner ear consists of a membranous labyrinth encased within the bony labyrinth of the temporal bone. The membranous labyrinth contains the cochlea for hearing and the vestibular system for balance. In the cochlea, sound vibrations are transduced into neural signals by hair cells located along the basilar membrane. The vestibular system contains semicircular canals and otolith organs that sense head movement and position. Sensory information from the inner ear is transmitted to the brainstem and cortex via the vestibulocochlear nerve.
Physiology of Hearing and Equilibrium
The organ of Corti contains outer and inner hair cells that transmit auditory stimuli through afferent pathways to the brain. Sound is conducted through the outer, middle, and inner ear before stimulating the hair cells. The vestibular system contains semicircular canals and otolith organs that detect head movement and gravity. It transmits signals through vestibular ganglia and nuclei to mediate reflexes for balance and eye movement. Both auditory and vestibular systems integrate sensory information in the brain to process sound and maintain equilibrium.
Cochlear implant 1
Cochlear implants are surgically implanted devices that provide a sense of sound to those who are profoundly deaf or hard of hearing. They work by bypassing the damaged portions of the ear and directly stimulating the auditory nerve. The first modern cochlear implant was developed in 1961 and they have since become smaller and more advanced, allowing for implantation in younger children. Cochlear implants require extensive preoperative testing and evaluation to determine candidacy as well as postoperative programming and mapping to optimize hearing outcomes for each individual recipient.
Mucosal folds of the middle ear
The document discusses the mucosal folds of the middle ear, which develop as the primitive tympanic cavity expands into the middle ear cleft between 3-7 months of fetal development. This forms four primary sacs that enlarge and replace the mesenchyme, with their walls becoming the mucosal lining of the middle ear. Mucosal folds are the planes of contact between neighboring sacs and carry ligaments and blood vessels to the ossicles. There are 10 important mucosal folds described, including the anterior and posterior malleal folds, lateral malleal ligamental fold, and tensor tympani fold. The folds divide the epitympanum (attic) and orient the progression of
Physiology of ear
The ear consists of three main parts - the outer, middle, and inner ear. Sound waves enter the outer ear and cause the tympanic membrane in the middle ear to vibrate. These vibrations are amplified by the ossicles and transmitted through the oval window to the cochlea of the inner ear. Within the cochlea, vibration of the fluid causes movement of hair cells which stimulate nerves for sound perception. The vestibular system detects head movement and maintains balance.
Senses ppy
The document summarizes the structure and function of the human ear, eye, and associated sensory systems. It describes the three main parts of the ear - outer, middle, and inner ear. Sound waves are collected by the outer ear and transmitted through the middle ear via the auditory ossicles to the inner ear, where they are converted to nerve impulses. The inner ear also contains structures for balance. Similarly, it outlines the three layers of the eye - outer fibrous layer, middle vascular layer, and inner nervous layer. Light enters through the cornea and lens, stimulating photoreceptors in the retina which transmit signals to the brain via the optic nerve. Both sensory systems provide vital functions of hearing, balance,
More Related Content
What's hot
Eustachian tube, anatomy, test and disorders, dr.vijaya sundarm, 20.03.17
The document discusses the anatomy, physiology, and disorders of the Eustachian tube. It describes the Eustachian tube's embryological development and details its adult anatomy including measurements, parts, musculature, and blood supply. Regarding function, it ventilates the middle ear and drains secretions. Dysfunctions include tubal blockage from various mechanical or functional causes like adenoids, cleft palate, or barotrauma. Tests to evaluate Eustachian tube function include Valsalva, Toynbee, and tympanometry. Disorders include tubal blockage, retraction pockets, and a patulous tube.
Middle ear
The document summarizes the anatomy of the middle ear. It describes the structures derived from the pharyngeal pouches and arches that make up the middle ear, including the ossicles, muscles, nerves and openings. It provides details on the walls, contents, blood supply and clinical relevance of the middle ear.
Development of ear ppt
The ear develops from three germ layers into three main structures - the inner, middle, and outer ear. The outer ear develops from hillocks in the mandibular and hyoid arches, which fuse to form the pinna. The external auditory canal develops from the first branchial groove. The middle ear cavities develop from outpouchings of the first and second pharyngeal pouches. Ossicles develop from the first and second branchial arches. The inner ear develops from the otic placode, forming the fluid-filled cochlea and vestibular system. The facial and acoustic nerves also develop during this period to innervate the ear structures.
Anatomy of inner ear
The inner ear consists of two parts - the bony labyrinth within the temporal bone, and the membranous labyrinth contained within. The bony labyrinth includes the cochlea, vestibule and semicircular canals. The membranous labyrinth contains the cochlear duct, utricle, saccule and semicircular ducts filled with endolymph. These structures contain specialized sensory cells that detect sound (cochlear hair cells) and linear/angular acceleration (vestibular hair cells), transmitting signals to the brain.
Physiology of hearing ppt
The document discusses the physiology of hearing. It covers the key components required for normal hearing including sound conduction through the ear canal, middle ear, and inner ear. The middle ear acts as an impedance matcher and sound intensity transducer. The cochlea contains hair cells that transduce sound waves into neural signals. The basilar membrane varies in width and stiffness along its length to allow different frequencies to stimulate separate regions of the cochlea.
Physiology of Hearing
The document provides information on the physiology of hearing. It discusses how sound waves are conducted through the ear to the inner ear, where they are transduced into neural signals. Key points include:
- Sound waves are collected by the pinna and focused through the external auditory canal to the tympanic membrane.
- Vibrations are transmitted through the ossicles to the oval window, matching impedances between air and fluid environments.
- In the cochlea, vibrations of the basilar membrane lead to stimulation of hair cells and transduction of sound into neural signals.
- These signals travel through the auditory pathway to the brain for perception of sound.
Tests like pure
HIS 120 Embryology of the Inner Ear
The inner ear first appears as auditory placodes that form hollow otocysts on the 24th day of embryo formation. By the 7th week, the otocyst has developed into the membranous labyrinth containing the semicircular canals and a single turn cochlea. By the 12th week, the adult form of the inner ear is nearly complete, with the membranous labyrinth suspended in perilymph within the developing bony labyrinth. A full understanding of inner ear embryology is important for treating hearing issues that result from prenatal development problems or cochlear damage in adulthood.
Physilogy of phonation by Dr.Ashwin Menon
This document discusses the physiology of phonation, or voice production. It defines phonation as the rapid opening and closing of the vocal cords due to the separation and apposition of the vocal folds, accompanied by breath under lung pressure, which creates vocal sound. It describes the anatomy involved in voice production including the lungs, diaphragm, larynx, throat, mouth and nose. It discusses theories of voice production and covers topics like pitch, volume, quality, vocal registers, vocal disorders, vocal injury, and video stroboscopy.
Anatomy of external ear
This document summarizes the anatomy of the external ear. It describes the pinna (auricle), which is made of elastic cartilage covered in skin. It is attached to the skull by ligaments and muscles supplied by the facial nerve. The external auditory canal extends from the bottom of the concha to the tympanic membrane. The outer third is cartilaginous while the inner two thirds are bony. The tympanic membrane separates the external ear from the middle ear. It consists of the pars tensa and pars flaccida and is innervated by the auriculotemporal, vagus, and glossopharyngeal nerves.
Auditory brainstem response (ABR)
The document discusses auditory brainstem response (ABR) testing, which is used to evaluate hearing in newborns. ABR testing uses electrodes to measure electrical activity in the brainstem in response to auditory clicks or tones. It is an effective screening tool for detecting hearing loss, with a high sensitivity and specificity. ABR testing can identify abnormalities in the auditory nerve or brainstem that may indicate conditions like acoustic neuromas. It provides objective information about hearing thresholds and neural conduction in the auditory pathway.
Baha & active middle ear implants
The document summarizes bone conduction hearing aids and the BAHA (Bone Anchored Hearing Aid) system. It discusses indications for BAHA, the surgical procedure, outcomes, advantages over conventional hearing aids, and limitations. BAHA provides an alternative for those who cannot use air conduction hearing aids due to ear canal issues or single-sided deafness. The surgery attaches a fixture to the skull bone which integrates and allows mounting of a sound processor externally on an abutment.
Embryology of the ear
The document discusses the development of the ear. It begins with the formation of the otic placode which develops into the otic pit and then the otic vesicle. The otic vesicle then forms the endolymphatic duct and sac as well as the utricular and saccular portions. The cochlea also develops from the otic vesicle. The middle ear develops from the tubotympanic recess which forms the tympanic cavity and Eustachian tube. The auditory ossicles also develop in the tympanic cavity. The external ear develops from the first branchial groove which forms the external acoustic meatus. Congenital anomalies that can result include deafness and end
Development of Ear
The document discusses the development of the ear, including the external, middle, and internal ear structures. It describes how the otic placode invaginates to form the otic vesicle, which then develops into the membranous labyrinth. The ventral part forms the saccule and cochlear duct, while the dorsal part forms the semicircular ducts and utricle. The first pharyngeal pouch develops into the middle ear cavity and auditory tube, while the first pharyngeal cleft forms the external acoustic meatus. Various congenital deformities of the external ear are also mentioned.
Anatomy of inner ear
The inner ear is composed of a bony labyrinth that houses the membranous labyrinth. The membranous labyrinth contains the cochlea, three semicircular canals, and two otolith organs (the utricle and saccule). The semicircular canals contain cristae that detect rotational head movements while the utricle and saccule contain maculae that detect linear accelerations and gravity. Endolymph fills the membranous labyrinth and perilymph fills the space between the bony and membranous labyrinths. The vestibular portion detects head movements and maintains balance.
Evaluation of deaf child
Evaluation of a deaf child for cochlear implantation. complete workup of a bilateral congenital snhl child for cochlear implantation
VEMP (PPT) Dr.dr.HR Yusa Herwanto, MKed(ORL-HNS), Sp.THTKL(K)
VEMP testing provides a method to evaluate otolith function in the inner ear by measuring electromyographic responses from the sternocleidomastoid (cVEMP) and inferior oblique ocular muscles (oVEMP) elicited by sound stimulation. cVEMP assesses the saccule and vestibular nerve pathway while oVEMP assesses the utricle pathway. VEMP testing is useful in clinical diagnosis of various vestibular disorders including neuritis, Meniere's disease, vestibular schwannoma, and more. Standardization of stimulation and recording methods is still needed for VEMP to be effectively utilized in clinical practice.
Anatomy of the inner ear
The inner ear consists of a membranous labyrinth encased within the bony labyrinth of the temporal bone. The membranous labyrinth contains the cochlea for hearing and the vestibular system for balance. In the cochlea, sound vibrations are transduced into neural signals by hair cells located along the basilar membrane. The vestibular system contains semicircular canals and otolith organs that sense head movement and position. Sensory information from the inner ear is transmitted to the brainstem and cortex via the vestibulocochlear nerve.
Physiology of Hearing and Equilibrium
The organ of Corti contains outer and inner hair cells that transmit auditory stimuli through afferent pathways to the brain. Sound is conducted through the outer, middle, and inner ear before stimulating the hair cells. The vestibular system contains semicircular canals and otolith organs that detect head movement and gravity. It transmits signals through vestibular ganglia and nuclei to mediate reflexes for balance and eye movement. Both auditory and vestibular systems integrate sensory information in the brain to process sound and maintain equilibrium.
Cochlear implant 1
Cochlear implants are surgically implanted devices that provide a sense of sound to those who are profoundly deaf or hard of hearing. They work by bypassing the damaged portions of the ear and directly stimulating the auditory nerve. The first modern cochlear implant was developed in 1961 and they have since become smaller and more advanced, allowing for implantation in younger children. Cochlear implants require extensive preoperative testing and evaluation to determine candidacy as well as postoperative programming and mapping to optimize hearing outcomes for each individual recipient.
Mucosal folds of the middle ear
The document discusses the mucosal folds of the middle ear, which develop as the primitive tympanic cavity expands into the middle ear cleft between 3-7 months of fetal development. This forms four primary sacs that enlarge and replace the mesenchyme, with their walls becoming the mucosal lining of the middle ear. Mucosal folds are the planes of contact between neighboring sacs and carry ligaments and blood vessels to the ossicles. There are 10 important mucosal folds described, including the anterior and posterior malleal folds, lateral malleal ligamental fold, and tensor tympani fold. The folds divide the epitympanum (attic) and orient the progression of
What's hot (20)
Eustachian tube, anatomy, test and disorders, dr.vijaya sundarm, 20.03.17
Eustachian tube, anatomy, test and disorders, dr.vijaya sundarm, 20.03.17
VEMP (PPT) Dr.dr.HR Yusa Herwanto, MKed(ORL-HNS), Sp.THTKL(K)
VEMP (PPT) Dr.dr.HR Yusa Herwanto, MKed(ORL-HNS), Sp.THTKL(K)
Similar to Development of ear
Physiology of ear
The ear consists of three main parts - the outer, middle, and inner ear. Sound waves enter the outer ear and cause the tympanic membrane in the middle ear to vibrate. These vibrations are amplified by the ossicles and transmitted through the oval window to the cochlea of the inner ear. Within the cochlea, vibration of the fluid causes movement of hair cells which stimulate nerves for sound perception. The vestibular system detects head movement and maintains balance.
Senses ppy
The document summarizes the structure and function of the human ear, eye, and associated sensory systems. It describes the three main parts of the ear - outer, middle, and inner ear. Sound waves are collected by the outer ear and transmitted through the middle ear via the auditory ossicles to the inner ear, where they are converted to nerve impulses. The inner ear also contains structures for balance. Similarly, it outlines the three layers of the eye - outer fibrous layer, middle vascular layer, and inner nervous layer. Light enters through the cornea and lens, stimulating photoreceptors in the retina which transmit signals to the brain via the optic nerve. Both sensory systems provide vital functions of hearing, balance,
Embryology and anatomy of external ear
It describes the embryology and anatomy of the human external ear according to the various books used for reference
functional anatomy of the ear.ppt
The document summarizes the anatomy and function of the ear. It describes the three main divisions of the ear - the outer, middle and inner ear. The outer ear collects sound waves. The middle ear contains the ossicles that transmit vibrations from the eardrum to the inner ear. The inner ear converts vibrations to neural signals via hair cells in the cochlea and balances functions in the semicircular canals. The ear detects sound and maintains equilibrium through these specialized structures that work together to transmit physical vibrations to the brain for processing.
Ear development
The document summarizes the development of the ear from the early stages of formation through maturation. It describes:
- The formation of the otic placode from surface ectoderm, which then invaginates to form the otic vesicle.
- How the otic vesicle develops into the inner, middle, and outer ear structures. The inner ear forms from regionalization of the vesicle directed by homeobox genes.
- The development of the middle ear bones and structures from the pharyngeal arches. The external ear develops from auricular hillocks that fuse to form the pinna.
- Key processes like differentiation of hair cells and formation of the bony labyrinth that
The Ear, Anatomy, Physiology, Clinical diseases, and pathology, hearing tests
Ear is composed of three parts: External ear, middle ear, and the Inner ear.
Hearing tests (Rinne's and Weber's tests).
Most important hearing and ear diseases are included.
embryology of inner ear.pptx
The ear develops from three parts - the external ear, middle ear, and inner ear. The external ear develops from swellings around the first pharyngeal cleft. The middle ear develops from the first pharyngeal pouch. The inner ear develops from thickenings of surface ectoderm that invaginate to form the otic vesicles. These vesicles give rise to the membranous labyrinth containing the saccule, utricle, semicircular canals and cochlear duct. The ossicles of the middle ear develop from cartilage of the pharyngeal arches. Congenital deafness and abnormalities of the external ear can result from abnormal development and are often associated with other malformations
EAR AND BALANCE.pptx
The document summarizes the structure and function of the human ear. It describes the ear as having three main parts: the outer, middle, and inner ear. The outer ear collects sound waves and directs them through the auditory canal to the middle ear, where the vibrations are transmitted through three small bones to the inner ear. In the inner ear, fluid waves stimulate hair cells to generate nerve impulses that travel to the brain for hearing and balance. The ear detects sound properties like pitch from frequency and volume from amplitude to enable hearing perception.
Ears
The ear has three main sections - the outer, middle, and inner ear. The outer ear collects and directs sound waves through the external auditory meatus to the eardrum. The middle ear contains the auditory ossicles that transmit vibrations through to the inner ear. The inner ear senses both hearing and equilibrium, containing the cochlea which detects sounds and the vestibular system that monitors movement and orientation. Receptors in the cochlea and vestibular system of the inner ear enable the senses of hearing and balance.
sense of hearing.pptx
The document discusses the special senses of vision, hearing, balance, taste and smell. It focuses on the anatomy and physiology of hearing and balance. Key points include:
- The ear is divided into external, middle and inner sections. Sound waves cause the eardrum and ossicles to vibrate, transmitting vibrations to the cochlea.
- The cochlea contains the organ of Corti with hair cells that transduce vibrations into nerve impulses. Different hair cell regions respond to different frequencies.
- Loudness is determined by vibration amplitude and number of activated hair cells. Reflexes protect from loud noises.
- The vestibular system detects head position
development of ear & eye.pptx
The development of the eye begins around day 22 of gestation with the formation of optic grooves on either side of the forebrain, which then invaginate to form optic vesicles. The optic vesicles continue to develop into double-walled optic cups with inner and outer layers. Simultaneously, surface ectoderm thickens to form lens placodes which then invaginate to form lens vesicles. The optic cups and lens vesicles continue to develop throughout weeks 4-8 of gestation, with structures such as the iris, ciliary body, retina, choroid, and sclera deriving from the optic cup layers and the lens developing from the lens vesicle. By week 8, the basic structures of the eye
HEARING - MECHANISM, DYSFUNCTION AND TREATMENT
The document discusses the biochemical and molecular mechanisms of hearing. It describes the various parts of the ear involved in sound conduction including the outer ear, middle ear with the ossicles, and inner ear cochlea. It explains how sound is transduced by the hair cells in the cochlea into nerve impulses. Dysfunctions like deafness and treatments using hearing aids or cochlear implants are also summarized.
Anatomy of the ear (ecture 2) by dr, noura 2018
Lectures of Anatomy by Dr. Noura El -Tahawy . Assist. prof. of Anatomy, Faculty of Medicine, Port Said University; Egypt 2018,
Vestibular and auditory apparatus-Dr.B.B.Gosai
Functional anatomy of Vestibular and Auditory apparatus presentation by Dr.B.B.Gosai
More presentations on https://www.drbbgosai.com/
Ear
The document provides an overview of the anatomy and physiology of the ear in 3 parts. It discusses the 5 parts of the temporal bone, the external, middle, and inner ear. The middle ear contains the ossicular chain and eustachian tube. The inner ear contains the bony and membranous labyrinth. It also discusses the auditory and vestibular systems, embryology, and some common congenital anomalies of the ear.
Anatomy of external and middle ear by dr. faisal rahman
This includes anatomy of external and middle ear with their clinical co relations. Embryology is also discussed here. Pinna, External auditory canal, Tympanic membrane, Middle ear Cleft, Mastoid and Auditory tube topics are included.
Human Ear
The document discusses the structure and function of the human ear. It is divided into three main parts:
1. The external ear collects sound waves and channels them through the auditory canal to the eardrum.
2. The middle ear contains three small bones that transmit vibrations from the eardrum to the inner ear.
3. The inner ear contains the cochlea, which converts sound waves into nerve signals that are sent to the brain, allowing us to perceive sound. The inner ear also contains semicircular canals that help maintain balance.
Special senses ear ppt
The document summarizes the anatomy and physiology of the human ear and balance system. It describes the outer, middle, and inner ear structures and their functions in hearing and balance. Specialized sensory receptors in the cochlea and vestibular system detect sound vibrations and head position, transmitting nerve impulses to the brain for hearing and maintaining equilibrium.
Ear anatomy (1)-1.pptx
The document summarizes the anatomy and physiology of the ear. It is divided into three main parts: the external ear, middle ear, and inner ear. The external ear collects sound waves and directs them through the external auditory canal to the tympanic membrane. The middle ear contains three small bones (ossicles) that transmit sound vibrations from the tympanic membrane to the inner ear. The inner ear, or labyrinth, contains the cochlea for hearing and semicircular canals for balance. It converts sound vibrations into neural signals that are sent to the brain.
Similar to Development of ear (20)
The Ear, Anatomy, Physiology, Clinical diseases, and pathology, hearing tests
The Ear, Anatomy, Physiology, Clinical diseases, and pathology, hearing tests
Anatomy of external and middle ear by dr. faisal rahman
Anatomy of external and middle ear by dr. faisal rahman
More from Haritha RK
Epidemiological Trends of Oral Diseases in India
A brief look at the recent epidemiological trends of dental caries, periodontal disease, oral cancer and malocclusion in India as of available research in March 2021
COVID-19 & Dentistry: Recent Updates
With the widespread transmission of COVID-19, & the dental healthcare professionals at an increased risk of contracting the infection or being potential carriers, it is essential that we know about the recent protocols suggested by CDC, Ministry of Health and Family Welfare, FDI, WHO & constantly update our knowledge in par with the current research of COVID-19
Occupational hazards in dentistry: An introduction
Occupational hazards are seen in every profession, and we as dentists have our own set of occupational hazards which needs to be understood, prevented & handled with best recent research available.
Oral Health Policy: Needs, Barriers & Strategies in India
This document summarizes India's national oral health policy, including its need, goals, and initiatives. It discusses the oral health burden in India, including high rates of dental caries, periodontal disease, and tooth wear. It outlines barriers to oral health promotion such as a lack of prioritization, resources, and public health expertise. The national oral health policy was established in 1986 and aims to improve access to care. Key initiatives discussed include the National Oral Health Care Program launched in 1995, fluoride mapping from 2002-2003, and targets set for 2010 including reducing DMFT scores in children. More recent programs discussed are a 2017 pit and fissure sealant pilot project and an oral health helpline. The document concludes by
Orofacial syndromes
Orofacial syndromes are rare but not uncommon, knowledge about these various syndromes aids in early detection, genetic counselling, symptomatic & aesthetic management. The pediatric dentist especially play a pivotal role in assessing & managing such patients for improving the quality of life in such long standing diseases.
Diagnosis of ulcerative, vesicular and bullous lesion
Ulcers, vesicles and bullous lesions are seen in the oral cavity as well. They sometimes are the first signs of skin diseases and is essential to diagnose them early for better prognosis.
Diagnosis of pigmented lesions of oral cavity
This document provides a summary of different types of pigmented lesions that can occur in the oral mucosa. It describes the clinical features of freckles, oral melanotic macules, oral melanoacanthomas, melanocytic nevi, malignant melanoma, drug-induced melanosis, smoker's melanosis, postinflammatory hyperpigmentation, melasma, and melanosis associated with systemic or genetic diseases such as Cushing's syndrome or vitamin B12 deficiency. For each type of lesion, it outlines characteristics such as appearance, location, risk factors, distinguishing clinical features, and potential causes. The document serves as a guide for clinically diagnosing different pigmented lesions of the oral mucosa.
Diet and dental caries: human studies
Relationship between the type of food, frequency of intake and various cariogenic and non-cariogenic factors which influence initiation and progression of caries have been studied over the years.
Bevels in Dental Restorations
Any abrupt incline between the two surfaces of a prepared tooth or between the cavity wall and the cavo-surface margins in the prepared cavity
Diabetes and oral health
Diabetes doesn't just effect our systemic health but also affects the oral cavity which is of significance in oral hygiene maintenance, incidence, treatment planning and prognosis of the disease.
Cardiovascular complications in dentistry
Common cardiovascular diseases like hypertension, MI, congestive cardiac failure, valvular diseases etc and their management in dental set up
For more content check out my blog www.rkharitha.wordpress.com - "a little about everything dental"
Dental caries
Dental caries is the most common microbial disease affecting the tooth. Even through extensive studies over the years, the pathogenesis remains questionable. Hence a fundamental understanding of caries and its theories is essential as data from the past serves as the most vital evidence in the unavoidable quest to figure out the pathogenesis.
For more content check out my blog www.rkharitha.wordpress.com - "a little about everything dental"
HIV and oral manifestations
HIV causes immunosupression leading to many oral diseases. These oral diseases are sometimes the first sign of the disease. Hence dentists play a vital role in identifying these lesion.
Life cycle of ameloblast
Ameloblast are the enamel forming cells. Understanding of life cycle of ameloblast aids in the understanding of various developmetal anomalies in particular and various other oral pathologies.
Life cycle of ameloblast
Amelogenesis is the formation of enamel. During amelogenesis, the ameloblast (enamel-forming cells) undergo various stages i.e the life cycle of ameloblast.
For more content check out my blog: www.rkharitha.wordpress.com "a little about everything dental"
Newer techniques in local anesthesia delivery systems
The document discusses several newer techniques for local anesthesia delivery systems including vibrotactile devices, computer-controlled delivery systems, jet injectors, and devices for intraosseous anesthesia. It describes technologies like the Dental Vibe device that stimulates sensory receptors to reduce pain, as well as computer-controlled systems like the Wand/Compudent system that allow consistent flow rates. Jet injectors like the Syrijet and Med-Jet H III use high pressure liquid to pierce tissue rather than needles. Devices for intraosseous anesthesia discussed are the Stabident, X-Tip, and Intra Flow, with the Intra Flow allowing one-step entry, injection, and withdrawal. The document concludes by mentioning potential
Composite resins
This document discusses the specifications and properties of dental composite materials according to ADA specification no. 27. It outlines the major and minor constituents of composites including the resin matrix, filler particles, and coupling agents. It also describes the advantages and disadvantages of composites, their mechanical properties, modes of curing, and factors that affect properties such as polymerization shrinkage, thermal expansion, water sorption, and radiopacity.
More from Haritha RK (17)
Occupational hazards in dentistry: An introduction
Occupational hazards in dentistry: An introduction
Oral Health Policy: Needs, Barriers & Strategies in India
Oral Health Policy: Needs, Barriers & Strategies in India
Diagnosis of ulcerative, vesicular and bullous lesion
Diagnosis of ulcerative, vesicular and bullous lesion
Newer techniques in local anesthesia delivery systems
Newer techniques in local anesthesia delivery systems
Recently uploaded
Dehradun #ℂall #gIRLS Oyo Hotel 8107221448 #ℂall #gIRL in Dehradun
Dehradun #ℂall #gIRLS Oyo Hotel 8107221448 #ℂall #gIRL in Dehradun
Integrating Ayurveda into Parkinson’s Management: A Holistic Approach
Explore the benefits of combining Ayurveda with conventional Parkinson's treatments. Learn how a holistic approach can manage symptoms, enhance well-being, and balance body energies. Discover the steps to safely integrate Ayurvedic practices into your Parkinson’s care plan, including expert guidance on diet, herbal remedies, and lifestyle modifications.
Adhd Medication Shortage Uk - trinexpharmacy.com
The UK is currently facing a Adhd Medication Shortage Uk, which has left many patients and their families grappling with uncertainty and frustration. ADHD, or Attention Deficit Hyperactivity Disorder, is a chronic condition that requires consistent medication to manage effectively. This shortage has highlighted the critical role these medications play in the daily lives of those affected by ADHD. Contact : +1 (747) 209 – 3649 E-mail : sales@trinexpharmacy.com
Top Effective Soaps for Fungal Skin Infections in India
Swisschem Dermacare has mentioned the List of The Best Antifungal Soap In India 2022. All of these soaps are trusted by various Dermatology Experts.
Hemodialysis: Chapter 4, Dialysate Circuit - Dr.Gawad
- Video recording of this lecture in English language: https://youtu.be/kqbnxVAZs-0
- Video recording of this lecture in Arabic language: https://youtu.be/SINlygW1Mpc
- Link to download the book free: https://nephrotube.blogspot.com/p/nephrotube-nephrology-books.html
- Link to NephroTube website: www.NephroTube.com
- Link to NephroTube social media accounts: https://nephrotube.blogspot.com/p/join-nephrotube-on-social-media.html
Histololgy of Female Reproductive System.pptx
Dive into an in-depth exploration of the histological structure of female reproductive system with this comprehensive lecture. Presented by Dr. Ayesha Irfan, Assistant Professor of Anatomy, this presentation covers the Gross anatomy and functional histology of the female reproductive organs. Ideal for students, educators, and anyone interested in medical science, this lecture provides clear explanations, detailed diagrams, and valuable insights into female reproductive system. Enhance your knowledge and understanding of this essential aspect of human biology.
Novas diretrizes da OMS para os cuidados perinatais de mais qualidade
Novas diretrizes da OMS para os cuidados perinatais de mais qualidadeProf. Marcus Renato de Carvalho
Recomendações da OMS sobre cuidados maternos e neonatais para uma experiência pós-natal positiva.
Em consonância com os ODS – Objetivos do Desenvolvimento Sustentável e a Estratégia Global para a Saúde das Mulheres, Crianças e Adolescentes, e aplicando uma abordagem baseada nos direitos humanos, os esforços de cuidados pós-natais devem expandir-se para além da cobertura e da simples sobrevivência, de modo a incluir cuidados de qualidade.
Estas diretrizes visam melhorar a qualidade dos cuidados pós-natais essenciais e de rotina prestados às mulheres e aos recém-nascidos, com o objetivo final de melhorar a saúde e o bem-estar materno e neonatal.
Uma “experiência pós-natal positiva” é um resultado importante para todas as mulheres que dão à luz e para os seus recém-nascidos, estabelecendo as bases para a melhoria da saúde e do bem-estar a curto e longo prazo. Uma experiência pós-natal positiva é definida como aquela em que as mulheres, pessoas que gestam, os recém-nascidos, os casais, os pais, os cuidadores e as famílias recebem informação consistente, garantia e apoio de profissionais de saúde motivados; e onde um sistema de saúde flexível e com recursos reconheça as necessidades das mulheres e dos bebês e respeite o seu contexto cultural.
Estas diretrizes consolidadas apresentam algumas recomendações novas e já bem fundamentadas sobre cuidados pós-natais de rotina para mulheres e neonatos que recebem cuidados no pós-parto em unidades de saúde ou na comunidade, independentemente dos recursos disponíveis.
É fornecido um conjunto abrangente de recomendações para cuidados durante o período puerperal, com ênfase nos cuidados essenciais que todas as mulheres e recém-nascidos devem receber, e com a devida atenção à qualidade dos cuidados; isto é, a entrega e a experiência do cuidado recebido. Estas diretrizes atualizam e ampliam as recomendações da OMS de 2014 sobre cuidados pós-natais da mãe e do recém-nascido e complementam as atuais diretrizes da OMS sobre a gestão de complicações pós-natais.
O estabelecimento da amamentação e o manejo das principais intercorrências é contemplada.
Recomendamos muito.
Vamos discutir essas recomendações no nosso curso de pós-graduação em Aleitamento no Instituto Ciclos.
Esta publicação só está disponível em inglês até o momento.
Prof. Marcus Renato de Carvalho
www.agostodourado.com
Part II - Body Grief: Losing parts of ourselves and our identity before, duri...
Learn about body grief and ways to cope with it. We will also explore methods to heal from this challenging experience.
Identification and nursing management of congenital malformations .pptx
Identification and nursing management of congenital malformations .pptxMGM SCHOOL/COLLEGE OF NURSING
Identification and nursing management of congenital malformations NVBDCP.pptx Nation vector borne disease control program
NVBDCP was launched in 2003-2004 . Vector-Borne Disease: Disease that results from an infection transmitted to humans and other animals by blood-feeding arthropods, such as mosquitoes, ticks, and fleas. Examples of vector-borne diseases include Dengue fever, West Nile Virus, Lyme disease, and malaria.
Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotes
A proprietary approach developed by bringing together the best of learning theories from Psychology, design principles from the world of visualization, and pedagogical methods from over a decade of training experience, that enables you to: Learn better, faster!
share - Lions, tigers, AI and health misinformation, oh my!.pptx
• Pitfalls and pivots needed to use AI effectively in public health
• Evidence-based strategies to address health misinformation effectively
• Building trust with communities online and offline
• Equipping health professionals to address questions, concerns and health misinformation
• Assessing risk and mitigating harm from adverse health narratives in communities, health workforce and health system
Top-Vitamin-Supplement-Brands-in-India List
Swisschem Dermacare provides the Top 10 Vitamin Supplement Brands in India. To know more about us give us call at our official number
Recently uploaded (20)
Dehradun #ℂall #gIRLS Oyo Hotel 8107221448 #ℂall #gIRL in Dehradun
Dehradun #ℂall #gIRLS Oyo Hotel 8107221448 #ℂall #gIRL in Dehradun
Integrating Ayurveda into Parkinson’s Management: A Holistic Approach
Integrating Ayurveda into Parkinson’s Management: A Holistic Approach
Muscles of Mastication by Dr. Rabia Inam Gandapore.pptx
Muscles of Mastication by Dr. Rabia Inam Gandapore.pptx
Top Effective Soaps for Fungal Skin Infections in India
Top Effective Soaps for Fungal Skin Infections in India
Hemodialysis: Chapter 4, Dialysate Circuit - Dr.Gawad
Hemodialysis: Chapter 4, Dialysate Circuit - Dr.Gawad
CHEMOTHERAPY_RDP_CHAPTER 6_Anti Malarial Drugs.pdf
CHEMOTHERAPY_RDP_CHAPTER 6_Anti Malarial Drugs.pdf
Novas diretrizes da OMS para os cuidados perinatais de mais qualidade
Novas diretrizes da OMS para os cuidados perinatais de mais qualidade
Part II - Body Grief: Losing parts of ourselves and our identity before, duri...
Part II - Body Grief: Losing parts of ourselves and our identity before, duri...
Identification and nursing management of congenital malformations .pptx
Identification and nursing management of congenital malformations .pptx
NVBDCP.pptx Nation vector borne disease control program
NVBDCP.pptx Nation vector borne disease control program
Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotes
Promoting Wellbeing - Applied Social Psychology - Psychology SuperNotes
share - Lions, tigers, AI and health misinformation, oh my!.pptx
share - Lions, tigers, AI and health misinformation, oh my!.pptx
Tests for analysis of different pharmaceutical.pptx
Tests for analysis of different pharmaceutical.pptx
Development of ear
- 2. INTRODUCTION Anatomical unit serving both hearing and equilibrium In the embryo 1. the external ear 2. the middle ear 3. the inner ear
- 3. INTERNAL EAR
- 4. Internal ear Approximately 22 days – first indication Optic placodes invaginate and form otic or auditory vesicles Each ventricle divides into 1. ventral component - saccule and cochlear duct 2. dorsal component – utricle, semicircular canals and endolymphatic duct
- 5. Saccule, Cochlea and Organ of corti Tubular outpocketing at its lower pole It penetrates the surrounding mesenchyme in spiral fashion. – 8 weeks, 2.5 turns. Differentiation into cartilage. Scala vestibuli and scala tympani are formed Vestibular memrane and basilar membrane
- 7. Saccule, Cochlea and Organ of corti Lateral wall – spiral ligament – surrounding cartilage Median angle – modiolus, the future axis of the bony cochlear Inner ridge – the future spiral limbus Outer ridge – hair cells, the sensory cells of the auditory system.
- 8. Organ of corti Sensory cells + tectorial membrane Impulses are transmitted to the spiral ganglion and then to the nervous system by the auditory fibres cranial nerve VIII
- 9. Utricle and semicircular canals During sixth week of development, semicircular canals appear as flattened outpocketings of the reticular part of the otic vesicle. Cels in ampulla – crista ampullaris containing sensory cells for maintenance of equilibrium. Maculae acusticae develop in the walls of the utricle and saccule.
- 11. Utricle and semicircular canals Impulses are carried to the brain by vestibular fibres of cranial nerve VIII Statoacoustic ganglion – small group of cells breaks away from its wall. Ganglion splits into cochlear and vestibular portions.
- 12. MIDDLE EAR TYMPANIC CAVITY AND AUDITORY MEATUS 1st pharyngeal pouch Contact with 1st pharyngeal cleft Distal part – primitive tympanic cavity Proximal part – auditory tube
- 13. Ossicles Malleus and incus - 1st pharyngeal pouch Stapes - 2nd pharyngeal pouch Remain embedded in the mesenchyme until 8th month Tympanic cavity becomes twice its original size Endoderm epithelium connects ossicles to the wall of the cavity in mesentary like fashion. Supporting ligaments of ossicles develop later.
- 14. Ossicles During late fetal life, by vacuolization of surrounding tissue form tymapnic antrum. After birth – pneumatization Later, most of the mastoid air sinus come in contact with the antrum and tympanic cavity – middle ear infection.
- 15. EXTERNAL EAR EXTERNAL AUDITORY MEATUS 1st pharyngeal cleft At the beginning of 3rd month – medial plug is formed In the 7th month – plug dissolves and epithelial lining of floor help in definitive eardrum formation
- 16. Eardrum or tympanic membrane Eardrum consists of a) An ectodermal epithelial lining b) An intermediate layer of mesenchyme c) An endodermal lining which form the fibrous strature.
- 17. Auricle Six mesenchymal proliferations These swellings, auricular hillocks later fuse and form the definitive auricle. Developmental abnormalities of the auricle are common Initially the external ears are in the lowerneck region but later ascend to the side of the head at the level of eye.
- 18. Clinical anatomy CONGENITAL DEAFNESS Usually associated with deaf mutism
- 19. Clinical anatomy EXTERNAL EAR DEFECTS They are common, they include minor and severe abnormalities
- 20. Clinical anatomy PREAURICULAR APPENDAGES AND PITS Pits indicate abnormal development of auricular hillocks Appendages indicate abnormal development of accessory hillocks