A textbook of obstetrics . he pedicle of the allantois. That por-tion of the allantois that remains within the abdominal cavity ofthe fetus forms the bladder and urachus. The umbilical cord atterm measures about cm. (20 in.) in length and about cm. (1/3 to y2 in.) or more indiameter, the latter measurementbeing irregular, from the fact thatthe arteries are coiled around thevein, usually from right to left,giving a twisted appearance tothe cord, and also because thegelatin of Wharton is depositedirregularly, being in some placesquite thick, and forming thus theso-called false kno
A textbook of obstetrics . he pedicle of the allantois. That por-tion of the allantois that remains within the abdominal cavity ofthe fetus forms the bladder and urachus. The umbilical cord atterm measures about cm. (20 in.) in length and about cm. (1/3 to y2 in.) or more indiameter, the latter measurementbeing irregular, from the fact thatthe arteries are coiled around thevein, usually from right to left,giving a twisted appearance tothe cord, and also because thegelatin of Wharton is depositedirregularly, being in some placesquite thick, and forming thus theso-called false knots of the the arteries and theveins of the cord have walls ofalmost the same thickness, andboth are provided with semi-Lunar and circular valves. The caliber of the vein is greater than that of the arteries. Accordingto Leopold,1 it measures normally 2 to 4 mm. ( too. 1 57 in.)in diameter, but at a point about 8 to 10 cm. ( 5 to in.) fromthe placental insertion there occurs a physiological Fig- 99-—Cross-section of an um-bilical cord at term, magnified abouttwelve diameters: V, Remnant of theallantois; V, umbilical vein; A,A,umbilical arteries (from Minot). Aichiv f. Gyn., Bd. viii, S. 221. 154 PREGNANCY. Anomalies of the Cord.—The cord may be abnormallylong, measuring rarely as much as ~o inches (178 cm.),1 or itmay be naturally or artificially too short ; and it may be absentaltogether. The cord is artificial!) shortened in those adhesiveinflammations of the amnion which result in the gluing togetherof the coils or in their attachment to the fetal skin or amnion. Exaggerated Torsion.—The cord maybe so twisted upon itslongitudinal axis that the vessels are nearly or quite obliterated,
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Keywords: ., bookcentury1800, bookdecade1890, bookidtex, booksubjectobstetrics
