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The tympanic membrane: the tympanic membrane is oval in shape, with an area of about 50-90 mm2 and a thickness of about 0.1 mm. It is not a flat membrane, but is funnel-shaped with its apex facing the middle ear. It is not a flat membrane, and is funnel-shaped with its apex facing the middle ear. It is medially connected to the stalk of the malleus, which is located between the fibrous and mucous layers of the tympanic membrane, and terminates at the center of the tympanic membrane from the anterior superior to the inferior. The tympanic membrane, much like the diaphragm in a telephone receiver, is a pressure-carrying device with a better frequency response and less distortion, and its shape facilitates the transmission of vibrations to the hammertone shank at the tip of the funnel.
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Nasal cavity:Nasal cavity is a cavity located between the two sides of the face and skull, based on the bony nasal cavity and cartilage, the surface is lined with mucous membranes and skin and constitute. Nasal cavity is narrow at the top and wide at the bottom, anterior and posterior diameters greater than the left and right sides of the irregular long and narrow cavity, the front from the anterior nostril, after the end of the posterior nostril through the nasopharynx. Nasal cavity by the nasal septum is divided into the left and right two cavities, the front through the nostrils to the outside world, the rear through the posterior nasal aperture to the pharyngeal cavity. Each side of the nasal cavity can be divided into two parts: the nasal vestibule and the intrinsic nasal cavity.
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Olfaction:The mucous membrane of the olfactory region of the nasal cavity is mainly distributed in the inner side of the upper turbinate and its corresponding part of the nasal septum, and a small part of it can be extended to the inner side of the middle turbinate and its corresponding part of the nasal septum. The mucosa of the olfactory region consists of sensory cells, supporting cells, and basal cells. Sensory cells receive olfactory stimuli, and their synapses converge to form olfactory nerve fibers, which pass through the olfactory bulb to reach the olfactory center. The olfactory glands contained in the lamina propria, whose secretions can dissolve odor-containing particles reaching the olfactory region, stimulate the olfactory hairs to produce impulses, which are transmitted to the olfactory region of the brain to produce olfaction. Obstruction of the olfactory groove, mucosal atrophy of the olfactory region, fracture of the anterior cranial fossa, or lesions involving the olfactory pathway can lead to hyposmia or loss of olfaction.
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Tonsils: The palatine tonsils are lymphatic epithelial organs composed of lymphoid tissue and epithelium in close association. Before the age of 6 years old, the development of fast, after puberty began to atrophy, in old age only a small amount of lymphatic tissue. Palatine tonsil is flat ovoid, located in the palatoglossal arch and brow pharyngeal arch between the tonsil fossa, the upper part of this fossa is not filled with tonsil space called tonsil fossa, foreign bodies often stay in this, palatine tonsil medial side of the two mucous folds, palatine tonsil in addition to the medial side of the rest of the connective tissue by the tonsillar capsule package unity.
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Pharynx, vocal cords: laryngopharynx, also known as hypopharynx, anterior to the laryngeal cavity, the lower end in the plane of the lower edge of the cricoid cartilage connected to the esophagus. The vocal cords are located below the ventricular girdle, one on each side, consisting of the acoustic ligament, acoustic muscle and mucous membrane, because of the lack of submucosal layer, containing few blood vessels, in the indirect laryngoscopy is a white band, and its free edge is thin and sharp.
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Hearing: reference value of 16 a 24000 Hz (times / sec), the human auditory production is quite complex, mainly relying on the conduction function of the outer ear and the middle ear, as well as the inner ear, the auditory nerve and the auditory center of the sensory sound function to achieve. The human ear hears sound by two routes into the inner ear, namely, air conduction and bone conduction. Air conduction transmits sound waves to the hearing center in people with normal hearing, and bone conduction plays a very weak role; it is only when the air conduction route is impaired that bone conduction is utilized. All bone conduction is like an alternate conduction route.