Umbilical cord

“ Occasionally water may form between the three membranes, and during labor the chorion may rupture [Pg 174] and not the amnion, and the waters between them be discharged. In like manner, water which has formed between the decidua and the chorion may come away. These, then, are two sources of fluid which may be discharged from the vagina in labor when the amnion is intact.
Umbilical Cord.—The organ by which the fetus is attached to the uterus is a whitish, glistening structure which springs from the fetus at the center of the abdomen, and passes to the internal aspect of the placenta. ”

“ As this membrane is more and more filled, it presses back the exterior liquid and thereby condenses it until the amnion comes in contact with the chorion. And since it adheres to the abdominal parietes of the fœtus, it furnishes as it extends a membranous sheath to the allantoid and umbilical vesicle, and these vessels, and all parts thus enclosed constitute the umbilical cord. ”

“ The inside lining of the whole is the amnion, from the upper and lateral portion of which hangs an umbilical cord of three quarters of an inch in length, with an imperfect fœtus the size of half a wasp, in which however the rudiments of the abdominal extremities are quite distinct. The whole Ovum measures four inches vertically, and three inches transversally. ”

“ Circulation in Fetus.—In the fetus there is direct communication between the two auricles through the foramen ovale, which normally closes at birth, though occasionally it remains open. There is also communication between the pulmonary artery and the arch of the aorta through the ductus arteriosus. The freshly oxidized blood comes to the fetus through the placenta, from which it is brought along the umbilical cord in the umbilical vein to the liver and thence to the inferior vena cava, where it mixes with the blood from the lower extremities. ”

“ During gestation the unborn infant has been supplied with air and nourishment by the mother. An organ called the Placenta, a spongy growth of [16] blood vessels, develops on the inner point of the womb. To this organ the growing foetus is moored by a species of cable, the Umbilical Cord. This cord, also made up mainly of blood vessels, carries the blood of the foetus to and from the Placenta, absorbing it through the thin walls which separate it from the mother's blood. Only through her blood can the mother influence the child, since the Umbilical Cord contains no nerves. ”

“ Mature human foetus (at the end of pregnancy, in its natural position, taken out of the uterine cavity) . On the inner surface of the latter (to the left) is the placenta, which is connected by the umbilical cord with the child's navel. (From Bernhard Schultze.) )
Of the three vesicular appendages of the amniote embryo which we have now described the amnion has no blood-vessels at any moment of its existence. But the other two vesicles, the yelk-sac and the allantois, are equipped with large blood-vessels, and these effect the nourishment of the embryonic body. ”

“ If, as sometimes happens, the cord, which attaches the child from its navel to the placenta in the mother's womb, should be wrapped around the baby's neck when his head and neck appear, try to slip it quickly over his head so that he will not strangle. ”

“ A very striking condition of the cord has frequently attracted my attention—lack of embryonic tissue, the gelatin of Wharton, with excessive torsion; the cord flat, thin, in parts thread-like, and usually very much twisted; the embryo retarded in development as compared to the size of the ovum, no other cause being at the same time discernible, neither disease of the uterus nor affection of the system. The torsion is secondary, often wanting, the cord being very thin and thread-like in places, consisting of the amniotic sheath and the vessels, obliterated entirely or in part. ”

“ If the disturbance causing the abortion has been of rapid progress, the cavity is large, the embryo approximating in development the period of expulsion; whilst if the changes have taken place slowly, the walls are thick, the cavity small, and the embryo may appear merely as a small mass pendent from the navel-string, or may have entirely disappeared, and can be traced only by the fine detritus in the amniotic fluid, the cord itself perhaps only in part remaining, and even this may have disappeared. ”

“ The cord is longer than the uterine cavity and must fall in coils toward the bottom of it. Now, since the fetus is free to move it enters and withdraws from these loops, many times, in the course of pregnancy. Finally, when it takes up a position head downward, as it nearly always does, the head is the part of the fetus which passes through the coil, should one happen to lie in its path. After the head is delivered the physician always feels about the neck to discover whether a loop of cord is there. ”

“ As to the point at which we divide the cord—whether at a half an inch or an inch and a half from the abdomen—every one must be his own judge. It is an old woman’s notion, both in this country and in the old, which was derived from the physiology of the ancients, and which requires that the cord should be cut very near the umbilicus if the child was a girl, and very far from it if it is a boy ”

“ Very often the person who performs the delivery removes the blood, mucus and vernix from the baby’s body, as soon as the cord is tied, by sponging it thoroughly with albolene or olive oil; wraps the cord stump with a sterile, dry or alcohol sponge and applies the abdominal binder while an assistant holds the baby by the feet, head down. It is also very common simply to oil the baby with unsterile lard, oil or vaseline, cover the cord with sterile gauze and leave the bath, cord-dressing and binder to be attended to later. ”

“ Many mothers do not understand the dual mission of the belly-band. They have the erroneous idea that it must be fastened very tightly over the navel to prevent rupture both before and after the cord comes off. This is a grave mistake, and leads to unnecessary suffering for many children. [Pg 153] The belly-band supports the abdomen while the baby is very young and tender, and it protects the bowels from abrupt changes in temperature. It is not a truss nor a surgical instrument, but a protection to the baby’s very delicate organs and system immediately after birth. ”

“ The life of the fetus, therefore, is absolutely contingent upon an uninterrupted, two-way flow of blood through the cord.
The Fetus. In tracing the development of the ovum after its implantation in the uterine lining, we begin, as previously stated, with a shaggy-looking vesicle, containing fluid, with a clump of cells hanging toward the centre from their point of attachment on the inner surface of the sac. This clump develops into the embryo. ”

“ The internal cavity is laid open so as to exhibit an embryo in each half of the Ovum, the one being double the size of the other. The smaller embryo is about as large as a good-sized house-fly. The cord of the largest embryo is nearly an inch and a half long, sacculent, and expanding towards the abdomen so as to form the only covering of that cavity. The cord of the smaller embryo is half an inch in length and filiform. ”

“ Acardiac and Acranial Monsters.—It sometimes happens in a twin pregnancy that one of the embryos fails to develop a heart and a complete vascular system of its own, depending for its nourishment upon blood derived from the placenta of its well-formed twin by means of its umbilical vessels. It grows into a more or less shapeless mass, in which all traces of the human form may be lost. Other viscera besides the heart will be wanting, and no head distinguishable; the most likely parts to keep the line of development are the lumbar region (with the kidneys) , the pelvis, and the lower limbs. ”

“ It then consists of a vein and two arteries, the urachus, a species of gelatine of a ropy nature, called the gelatine of Wharton, a portion of the intestinal canal, (larger in proportion as the embryo is younger,) the vesicula umbilicalis, in part, and the omphalo-mesenteric vessels, the whole enveloped by a sheath proceeding from the involucra of the ovum already described. The last three constituent elements of the cord, however, become obliterated or disappear after the third or fourth month of gestation—the others remain permanent throughout that period. ”

“ Excessive or insufficient length of the cord, which may seriously complicate labor at term, in no way affects the development of the ovum; in the third or fourth month the length of the cord is naturally much greater than that of the embryo, and the resulting coils and knots seem in no way to endanger its existence. ”

“ Hence in the embryo, there is almost no use for the liver, but the umbilical vein passes directly through, a foramen or an anastomosis existing from the vena portae. The blood returns from the intestines of the foetus, not through the liver, but into the umbilical vein mentioned, and flows at once into the heart, mingled with the natural blood which is returning from the placenta; whence also it is that in the development of the foetus the liver is one of the organs that is last formed. ”

“ Because of the body flexure and large size of the embryo the head was amputated, in the plane a-b, and cut sagitally, while the body was cut transversely in the direction shown by the section planes. In the present figure the outline of the embryo, including the eye, appendages, and umbilical stalk, is shown by fine dotted lines; the outlines of the lungs and liver are shown by heavier, broken lines; while the outlines of the enteron proper and the trachea are shown in solid lines, filled in which fine stippling. For the sake of simplicity only one lung and one bronchus are shown. ”

“ Anderson to speak to one point in particular in closing the discussion, viz., would there not be great danger if the placenta was separated at a time when the child was still partly in the uterus?
Dr. F. C. Wilson: The only point I wish to bring out in connection with the case is the possibility of detecting the fact that the cord is around the neck of the child before delivery, and being on our guard for it. Encircling of the cord around the neck of the child ought to give rise to a funic bruit. You can hear very plainly a funic bruit, a bruit which is synchronous with the fetal heart sounds. ”

“ Whatever part of the womb the ovum attaches itself to is stimulated to intense activity, to growth. Numerous bloodvessels begin to grow and that part of the lining membrane with its numerous bloodvessels constitute the placenta, or as it is commonly called afterbirth, because it comes out after the birth of the child. From the placenta there is also reflected a membrane over the ovum, so as to give it additional protection. That membrane forms a complete bag over the fetus ”

“ Though the latter be formed in the uterus, even when the embryo is lodged, by aberration, in some other part of the abdomen, its presence must not be deemed, on that account, unessential to the embryo; for a vascular membrane, as nearly alike to it in texture as can be, has invariably been found to connect, by blood-vessels, the embryo to some vital part nearest to where that embryo has been casually deposited, that part having, at the same time, its circulation and vascularity greatly increased, and becoming, in fact, the parent of the connecting vascular membrane in question. ”

“ The veins of the cord are marked at various places by knots or varices, resembling vesicles filled with blood; this is a contrivance of nature to prevent the blood rushing too violently to the fœtus. From the number of these knots superstitious midwives are accustomed to predict the number of the future offspring; and if none can be seen at all they pronounce that the woman will be ever after barren: they also absurdly prophesy by the distance between the knots about the interval to take place between the birth of each child, and also of its sex from their colour. ”

“ In the region of the brain the medullary cord is so thick that it gives rise, as in Teleostei, to a projection of the whole body of the embryo towards the yolk. Posteriorly it is flatter. The mesoblast (Me) in the trunk has the form of two plates, which thin out laterally. The hypoblast (hy) is a single layer of cells, and is nowhere folded in to form a closed alimentary canal. The hypoblast is separated from the neural cord by the notochord (Ch) , which throughout the greater part of the embryo is a distinct structure. ”

“ This muscular tube is lined throughout its entire length with mucous membrane, which, though continuous, changes somewhat in character along its course. The epithelial cells of the lining of the tubes and body of the uterus have hair-like projections, cilia, which maintain a constant waving motion from above downward. The effect of this sweeping current is to carry down toward the outlet any object or secretion which may be upon the surface of the lining of the tubes or uterine cavity. The unfertilized ovum is thus swept down to meet the germ cell of the male and become fertilized. ”

“ On the formation of the body cavity of the embryo a central axial portion of the placenta becomes separated from a peripheral layer; and a channel is left between them which leads from a maternal blood sinus into the embryonic body cavity. The peripheral layer of the placenta is formed of cells continuous with the epiblast of the embryo; while the axial portion is constituted of a disc of cells adjoining the embryo, with a column of fibres attached to the maternal side. ”