. Cunningham's Text-book of anatomy. Anatomy. TYMPANIC CAVITY OR MIDDLE EAE. 835 anterior and posterior malleolar plicae. The small triangular portion of the membrane (Fig. 710) situated above these folds is thin and lax, and constitutes the pars flaccida ( membrane of Shrapnell); the main portion of the membrane is, on the other hand, tightly stretched and termed the pars tensa. A small orifice, sometimes seen in the pars flaccida, is probably either a pathological condition or has been produced artificially during manipulation. The manubrium mallei is firmly fixed to the medial surface o
. Cunningham's Text-book of anatomy. Anatomy. TYMPANIC CAVITY OR MIDDLE EAE. 835 anterior and posterior malleolar plicae. The small triangular portion of the membrane (Fig. 710) situated above these folds is thin and lax, and constitutes the pars flaccida ( membrane of Shrapnell); the main portion of the membrane is, on the other hand, tightly stretched and termed the pars tensa. A small orifice, sometimes seen in the pars flaccida, is probably either a pathological condition or has been produced artificially during manipulation. The manubrium mallei is firmly fixed to the medial surface of the membrana tympani, the central portion of which is drawn towards the tympanic cavity so that its lateral surface is concave. The deepest part of this concavity corresponds with the lower end of the manubrium of the malleus, and is named the umbo membranae tympani. The membrana tympani consists of three layers: (1) a lateral, the stratum cutaneum; (2) an intermediate, the membrana propria; (3) a medial, the stratum mucosum. The stratum cutaneum is continuous with the skin of the meatus, and consists of a thin layer of cutis covered with epidermis. The cutis is thickest near the circumference; the epidermis, on the other hand, is thickest near the centre of the membrane. The membrana propria consists of two sets of fibres: (a) a lateral, the stratum radiatum, situated immediately under the stratum cutaneum, and radiating from the manubrium of the malleus to the annulus fibrocartilaginous; (h) a medial, the stratum circulare, the fibres of which are numerous near the circumference, but scattered and few in number near the centre of the membrane (Fig. 710). Both radial and circular fibres are absent from the pars flaccida, which consists only of the cutaneous and mucous strata. Gruber pointed out that, in addition to the radial and circular fibres, there exists, next the stratum mucosum, a series of dendritic or branched fibres, which are best developed in the posterior part o
Size: 1636px × 1527px
Photo credit: © Central Historic Books / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1910, booksubjectanatomy, bookyear1914
