The body of the Uterus is formed of a very dense, gray colored, muscular substance, possessing astonishing contractile power. The interior is lined, like the Vagina, with a mucus membrane, and the whole organ is plentifully supplied with arteries, veins, and nerves.
One of the most remarkable properties of the Womb is that of being able to distend to an extraordinary degree, and then retract again to nearly its original size. The force which it sometimes exhibits during its contraction is very great, being sufficient to separate, and even break, the bones of the mother's pelvis, and paralyze the hand of the operator when introduced. The Muscular Fibres on which this contractile force depends are most obvious during gestation; they then appear very numerous, and very curiously disposed, some of them ramifying in almost every direction, as will be seen by Plates V, VI. It is owing to this that the Womb contracts in every conceivable direction, and thus presses, during labor, on every part of the child's body.
PLATE V.
Figures 1 and 2.
Fig. 1. In this plate represents the Muscular Fibres a little exaggerated, so that they can be more distinctly seen.—a. a. are the orifices of the Fallopian Tubes.
Fig. 2. Represents the natural appearance, the fibres not being quite so distinct, though sufficiently obvious.—a. a. The orifices of the Fallopian Tubes.
In both Figures the Womb is supposed to be turned inside out, its peculiar structure being more readily seen interiorly than exteriorly.
Fig. 1 Fig. 2
Plate V.
The Muscular Fibres of the Womb.
PLATE VI.
Figures 1 and 2.
Fig 1. This represents the appearance of the Fibres externally, and shows how they terminate in the round ligament a. b.
Fig. 2. The lines a. b. represent the direction of the force of the Fundul Fibres; c. d. That of the Circular Muscles of the body of the Uterus; d. e. The combined force of the Muscles.
The dotted lines represent the force reflected by the liquor amnii. The dotted curved lines the direction of the circular fibres of the body of the Uterus.
Fig. 1
Fig. 2
Plate VI.
The Muscular Fibres of the Womb.
THE VAGINA.
The Vagina (c. Plate I.) is a membranous canal, lined with a mucus membrane like the Uterus. By its upper part it is attached to the neck of the Womb, at about two-thirds of its height—so that two-thirds of the neck hang within the Vagina. Below, it terminates in the Vulva, or external mouth. The upper part of the Vagina is much larger than the lower part, particularly in those who have borne children. It is capable of considerable distension, and after retraction, to allow of the child passing down it from the Womb. The external mouth is called the Vulva, and is usually partly closed, in the virgin state, by the membrane called the Hymen, (n. Plate I.) The length of the Vagina is from three to five inches, and its diameter from one inch to one and a half, or even two inches in those who have borne many children.
THE VULVA.
This is the external opening, or mouth of the Vagina, through which the child has to pass at the termination of delivery. The external and internal lips, with the muscular and membranous tissue surrounding it, are all capable of great distension, without injury, to allow of the passage of the child.
THE PERINEUM.
This is the part situated between the Vulva and the Rectum. (p. Plate I.) It is composed of a somewhat dense and firm substance, chiefly muscular, and, like all the other parts mentioned, is capable of great distension. It is important, in many of the manipulations during labor, to be well acquainted with it; and when the child's head is passing the perineum requires supporting, to prevent its being lacerated or broken through, an accident which often happens from want of due attention, and which leads to the most serious consequences.
THE PELVIS.
The Pelvis is that part of the bony structure, or skeleton, of the female, in which the generative organs are placed, and through which the process of parturition is effected. An acquaintance with its natural structure, and with the changes which may be produced in its form and size, by disease and other accidents, is indispensable to those who wish to practise or understand midwifery.
In early life the Pelvis is composed of several bones, many of which, after puberty, grow together. In the adult female it is customary to speak of but four bones, the sacrum, the coccygis, and the two innominata, or hip bones, (see Plates VII, VIII.) In the young female these are divided into several distinct parts.
PLATE VII.
Bones of the Pelvis.
The four principal bones, as found in Mature life.—A. A. The Ossa Ilii, or Ossa Innominata, commonly called the haunch, or hip bones.—B. The Os Sacrum, or lower part of the back bone.—C. The extreme termination of the back bone, called the Os Coccygis.
The divisions into parts, as in Early life.—The Ilium, A, on each side, is in three parts; the Ilium, properly so called, marked a. a.; the Pubis, marked b. b.; and the Ischium, marked c. c. The Sacrum is in five parts, marked 1, 2, 3, 4, 5.
d. Is the last bone of the spine, which joins the Sacrum.—e. e. Are the Sockets in which the upper parts of the thigh bones fit, forming the hip joints.—g. g. The two rings, formed by the bones of the Pubis and Ischium, each called the Foramen Magnum.
Plate VII.
Bones of the Pelvis.
PLATE VII.—a.
This represents the Male Pelvis, to show the difference in structure.
The letters correspond with those in Plate VII.
PLATE VIII.
Section of the Pelvis, to show the shape and connection of those parts not distinctly visible in the full view. The section is made down the middle of the back bone, and through the symphysis pubes, in front. The letters correspond with those in Plate VII.
A. The right Ilium.—B. The Sacrum.—C. The Coccygis.—b. The Os Pubis.—c. The Os Ischinum.—g. The Foramen Magnum.—o. shows the manner in which the coccygis is bent back through labor.
These