It is painless, but may lead to spasm or inertia of the uterus, and thus induce grave results. Besides, it is not the same in every part of the organ.
It is best marked in the fundus and in the body, and almost nil in the cervix; hence the gravity of hemorrhage in placenta prrevia.
Dithinished, weakened or exhausted, by great distension of the uterus, it may be reinduced by cold, massage and direct excitation of the uterus; but its action ends immediately after delivery, and, as Pajot says, it is not retractility which brings the uterus back to its normal state, but a pro cess of absorption and atrophy, which processes depend upon the health of the woman, since the first effect of puerperal disease is to suspend this work of absorption.
3d. irritability. —This may be called an impressionability of the uterus which varies in different patients, and shows itself by a more or less prompt tendency to contract, to react against the exciting causes. It is marked in some women, and absent in others: hence the frequency of abortion from insignificant causes in the former, and the incredible re sistance of pregnancy in the latter.
4th. Elasticity, Extensibility.—While Pajot leans toward the admission
that elasticity is the result of combined retractility and extensibility, Tarnier and Chantreuil confound the terms elasticity and extensibility.
Whatever be its name, it is from this property that the uterus can be distended by the ovum, preserving that suppleness which is so different from flaccidity. Except in great distension (twins, and dropsy of the amnion), extensibility and elasticity never attain their maximum; hence the child can move in utero either spontaneously, or when version is at tempted.
5th. Sensibility.—This is slightly developed in an empty uterus, and the cervix may even be burnt with red-hot iron without the woman having any pain; but it increases during pregnancy, although to no great extent. It is more marked in the body than in the cervix, and the child moving, as well as uterine contraction, causes pain. It varies in different women; and, except in primiparte, increases with age. Our observations lead to the conclusion that the pains of labor are much severer and far more ill-borne by primipane who are over thirty, than by young women.