. Cunningham's Text-book of anatomy. Anatomy. EXTERNAL ACOUSTIC MEATUS. 831 The lumen of the pars cartilaginea is influenced by the movements of the mandible, being increased when that bone is depressed. This can be easily verified by inserting a â a. Pars ossea of external acoustic meatu Recessus epitympanicus Malleus Cochlea Cavum tympani Membrana tympani Internal carotid artery Crus antihelicis inferior =~ Cyrnba conchse Crus helicis Pars cartilaginea of external acoustic meatus Cavum conchse Lower boundary of incisura intertragica Fig. 707. Frontal Section of Eight Ear : Anterior Half of S
. Cunningham's Text-book of anatomy. Anatomy. EXTERNAL ACOUSTIC MEATUS. 831 The lumen of the pars cartilaginea is influenced by the movements of the mandible, being increased when that bone is depressed. This can be easily verified by inserting a â a. Pars ossea of external acoustic meatu Recessus epitympanicus Malleus Cochlea Cavum tympani Membrana tympani Internal carotid artery Crus antihelicis inferior =~ Cyrnba conchse Crus helicis Pars cartilaginea of external acoustic meatus Cavum conchse Lower boundary of incisura intertragica Fig. 707. Frontal Section of Eight Ear : Anterior Half of Section, viewed from behind (natural size). finger into the meatus, and then alternately opening and shutting the mouth. The condyle of the mandible lies in front of the pars ossea, while between the condyle and the pars cartilaginea a portion of the parotid gland is sometimes present. Behind the pars ossea, and separated from it by a thin plate of bone, are the mastoid air-cells. Structure of the Meatus.âThe cartilage of the meatus, directly continuous with that of the auricula, is folded on itself to form a groove, opening upwards and backwards, the margins of which are connected by fibrous tissue. The medial end of the cartilaginous tube is firmly fixed to the lateral margin of the bony meatus, whilst its lateral extremity is continuous with the cartilage of the tragus (p. 829). Two fissures exist in the anterior portion of the pars cartilaginea, and are filled by fibrous tissue. In> the lateral part of the meatus the cartil- age forms about three- fourths of the circum- ference of the tube; but, near the medial end of the pars cartil- aginea the cartilage forms merely a part of the anterior and lower boundaries of the canal. Condyle of mandible Parotid gland. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1914
