. Anatomy, descriptive and applied. Anatomy. 1120 THE OBGANS OF SPECIAL SENSE INSERTION -antihelix; this bifurcates above and forms the crura (crura anthelicis), which en- close a triangular depression, the fossa of the antihelix (fossa triangularis [auric- ulae]). The narrow curved depression between the helix and antihelix is called the fossa of the helix or the scaphoid fosSa (scapha); the antihelix describes a curve around a deep, capacious cavity, the concha auriculae, which is partially divided into two parts by the crus of the helix (crus helicis), or the commencement of the helix; the
. Anatomy, descriptive and applied. Anatomy. 1120 THE OBGANS OF SPECIAL SENSE INSERTION -antihelix; this bifurcates above and forms the crura (crura anthelicis), which en- close a triangular depression, the fossa of the antihelix (fossa triangularis [auric- ulae]). The narrow curved depression between the helix and antihelix is called the fossa of the helix or the scaphoid fosSa (scapha); the antihelix describes a curve around a deep, capacious cavity, the concha auriculae, which is partially divided into two parts by the crus of the helix (crus helicis), or the commencement of the helix; the upper part is termed the cymba conchae, the lower part the cavum conchae. In front of the concha, and projecting back- ward over the meatus, is a small pointed eminence, the tragus, so called from its being generally covered on its under surface with a tuft of hair resembling a goat's beard. Opposite the tragus, and separated from it by a deep notch (incisura intertragica), is a small tubercle, the antitragus. Below this is the lobule (lohulus auricu- lae), composed of tough areolar and adipose tissue, wanting the firmness and elas- ticity of the rest of the pinna. Sometimes the lobule does not hang freely, but is adherent. CARTILAGE ? EXTERNAL AUDITORY MEATUS. TRANSVERSE AURICULAR MUSCLE iFiG. 839.—The cartilage of the right pinna, isolated, with the muscles, viewed from the inside. (Spalteholz.) Where the helix turns downward a small tubercle, tubercle of Darwin (hiberculum auriculae 'IDarwiniJ), is frequently seen. This tubercle is very evident about the sixth month of fetal life; at this stage the human pinna has a close resemblance to that of some of the adult monkeys. The cranial surface of the pinna presents elevations which correspond to the depressions on its outer surface and after which they are named, e. g., 'eminentia conchae, eminentia fossae triangularis, etc. Structure.—The pinna is composed of a thin plate of yellow fibrocartilage, covered with integument a
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1913
