#SummarysaReport #TheEar: the ear consists of the external ear; the middle ear, or tympanic cavity; and the internal ear, or labyrinth, which contains the organs of hearing and balance. External ear:The external ear has an auricle and an external auditory meatus. The auricle: Has a characteristics shape and collects air vibrations. The external auditory meatus: is a curved tube that leads from the auricle to the tympanic membrane. Outer third of meatus: provided with hairs and sebaceous and ceruminous glands. (researcher: pakiresearch unsay pulos or functions sa mga naka bold na words,then e include sa ppt.) The hairs and the wax: provide a sticky barrier that prevents the entrance of foreign bodies. The sensory nerve supply of the lining skin: is derived from the auriculotemporal nerve and the auricular branch of the vagus nerve. (clinical notes: tympanic membrane examination; nasa book) Middle Ear (tympanic cavity): The middle ear is an air-containing cavity in the petrous part of the temporal bone and is lined with mucous membrane. Auditory ossicles: whose functions is to transmit the vibrations of the tympanic membrane (eardrum) to the perilymph of the internal ear. (if pwd any picture ani sa ppt) (Figure 11-27 A,B,C) (Figure 11-28 A,B) (Figure 11-29 A,B) (Figure 11-30 A,B,C) (ayaw lng pud ipasunod ni tanang pictures) The middle ear has a: roof,floor,anterior wall,posterior wall, lateral wall and medial wall. The roof:is formed by a thin plate of bone, the tegmen tympani, which is part of the petrous temporal bone. (researcher: pakiresearch unsay pulos or functions sa mga naka bold na words,then e include sa ppt.) The floor: is formed by a thin plate of bone, which may be partly replaced by fibrous tissue. The anterior wall:is formed below a thin plate of bone that separates the tympanic cavity from the internal carotid artery. The posterior wall: has in its upper part a large, irregular opening, the aditus to the mastoid antrum. (researcher: pakiresearch unsay pulos or functions sa mga naka bold na words,then e include sa ppt.) The lateral wall: is largely formed by the tympanic membrane. (Figs.11-27 and 11-29) The medial wall: is formed by the lateral wall of the inner ear. *promontory: the greater part of the wall shows a rounded projection. *Fenestra vestibule: it lies above and behind the promontory, which is oval shaped and closed by the base of the stapes. *Fenestra cochlea: it lies below the posterior end of the promontory,which is round and closed by the secondary tympanic membrane. The Processus cochleariformis: Its posterior end is curved upward and forms a pulley. The Prominence of the facial nerve canal: a rounded ridge runs horizontally backward above the promontory and the fenestra vestibule. The tympanic membrane: is a thin, fibrous membrane that is pearly gray. (researcher: pakiresearch unsay pulos or functions sa mga naka bold na words,then e include sa ppt.) Auditory Ossicles: are the malleus, incus, and stapes (Figs. 11-28 and 11-29) The mallues:is the largest ossicle and possesses a head, a neck, a long process or handle, an anterior process and a lateral process. The head: is rounded and articulates posteriorly with the incus. The neck: is the constricted part below the head. The handle: is firmly attached to the medial surface of the tympanic membrane. The anterior process: is a spicule bone that is connected to the anterior wall of the tympanic cavity by a ligament. The lateral process: projects laterally and is attached to the anterior and posterior malleolar folds of the tympanic membrane. The incus: posses a large body and two processes. Figs. 11-29: picture sa ppt before ani na topic) The body:is rounded and articulates anteriorly with the head of the malleus. The long process: descends behind and parallel to the handle of the malleus. The short process: projects backward and is attached to the posterior wall of the tympanic cavity by a ligament. The stapes: has a head, a neck, two limbs and a base (Figs. 11-28: picture sa ppt before ani na topic) The head: is small and acticulates with the long process of the incus. The neck: is a narrow and receives the insertion of the stapedius muscle. The two limbs: diverge the neck and are attached to the oval base. Muscles of the Ossicles (Nasa book ang table, kaw na bahala bhai) Movements of the Auditory Ossicles (dili naku masabtan sa book, taas pajud. Research nlng ani, kanang dali sabton). Or basi nay video ani.) Auditory tube: it connects the anterior wall of the tympanic cavity to the nasal pharynx. Mastoid Antrum: It lies behind the middle ear in the petrous part of the temporal bone. Relations of the Mastoid Antrum: These are important in understanding the spread of infection. (more research ani) Anterior wall is related to the middle ear and contains the aditus to the mastoid antrum (Picture sa fig. 11-30) Posterior wall separates the antrum from the sigmoid venous sinus and the cerebellum (Picture sa fig. 11-30) Lateral wall is thick and forms the floor of the suprameatal triangle. (naa ni sa page 838 sa book) Medial wall is related to the posterior semicircular canal (Picture sa fig. 11-30) Superior wall which is related to the meninges of the middle cranial fossa and the temporal lobe of the brain. (Picture sa fig. 11-30) Inferior wall is perforated with holes, through which the antrum communicates with the mastoid air cells. (Picture sa fig. 11-30) Mastoid air cells: it is a series of communicating cavities within the process that are continous above the antrum and the middle ear. Facial Nerve (pakiresearch, walay klaro sa book) Important Brances of the Intrapetrous Part of the Facial Nerve The greater petrosal nerve:arises from the facial nerve at the geniculate ganglion. The Nerve to the stapedius: arises from the facial nerve as it descends in the facial canal behind the pyramid. (Picture sa fig. 11-30) The chord tympani: arises the facial nerve just above the stylomastoid foramen (Picture sa fig. 11-29) . (Figure 11-31 A B C) Tympanic Nerve: arises from the glossopharyngeal nerve, just below the jugular foramen. Tympanic plexus: supplies the lining of the middle ear and gives off the lesser petrosal nerve. lesser petrosal nerve: which sends secretomotor fibers to the parotid gland via the otic ganglion. (clinical notes: infections,complications and otitis media: kaw bahala if apilon sa pp tang mga clinical notes) The internal ear or Labyrinth: is situated in the petrous part of the temporal bone, medial to the middle ear. (picture sa fig. 11-28) Bony Labyrinth: 3 Parts: the vestibule, the semicircular canals and the cochlea. The vestibule: it is the central part of the bony labyrinth, lies posterior to the cochlea and anterior to the semicircular canals. The 3 semicircular canals The superior semicircular canals: is vertical and placed at right angles to the long axis of petrous bone. The posterior semicircular canals: it is also vertical but is placed parallel with the long axis of the petrous bone. The lateral semicircular canals: is set in a horizontal position and it lies in the medial wall of the aditus to the mastoid antrum. The cochlea: it resembles a snail shell. It opens into the anterior part of the vestibule. (picture sa Fig. 11-30, e-include sa ppt after ani) Membranous Labyrinth: is lodge within the bony labyrinth. (picture sa Fig. 11-30, e-include sa ppt after ani) The utricle: it is indirectly connected to the saccule and the ductus endolymphaticus by the ductus ultriculosaccuralis. The saccule: is globular and is connected to the utricle. The semicircular ducts: although much smaller in diameter than the semicircular canals, have the same configuration. The ducts of the cochlea: is triangular in cross section and is connected to the saccule by the ductus renuines. Vestibulocochlear Nerve: On reaching the bottom of the internal acoustic meatis, the nerve divides into vestibular and cochlear portions. (picture sa fig. 11-28,sa ppt) The vestibular nerve: is expanded to form the vestibular ganglion. The cochlear nerve: divides into branches, which enter foramina at the base of the modiolus. The End. (pakimessage si shoti sa FB, tung iyang research daw sa mga trivia about sa ear) Pakitag sa ubang ka grupo. labaw na sa researchers and reporters. Godbless sa ato guys.
Posted on: Mon, 29 Sep 2014 05:25:21 +0000
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