CHAPTER I. THE ORGANS OF GENERATION.
"Man is fearfully and wonderfully made."
In studying the subject of obstetrics it is important to understand something of the anatomy of the pel- vis, its adaption to childbirth, and the organs of gen-
Fig-. 1 — Female pelvis. (Dickerson.)
eration. The pelvis or bony frame work of the lower
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part of the body, so called from its resemblance to a basin. It is composed of four bones. The two os in-
Fig. 2 — Female pelvis with ligaments viewed from above. (Dickerson.)
nominata or hip bones, consisting" of the two ilia, two ischie and one pube, forming the sides and front, and
Fig. 3 — Female pelvis with ligaments viewed from below.
the sacrum and coccyx completing it behind. The pelvis is a bony basin without a bottom. The lower
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opening is the inferior strait or outlet through which the child is propelled and finally expelled. These bones expand under pressure and during the greater part of the child bearing period there is more or less elasticity of the joints capable of being utilized dur-
Fig. 4 — Female pelvis with bones separated.
ing childbirth. Like other parts of the body, the pel- vis is often deformed which unfits a woman for ma- ternity. This deformity may be hereditary or due to injury or mode of living. The higher we go in civi- lization the more often do we find deformity present. Crooked bones and pelvic deformity may not serious- ly interfere otherwise with its relations with the rest of the body. But such a woman should not marrv, she cannot bring a child through a deformed pelvis without great danger to both herself and child.
THE ORGANS OF GENERATION.
The organs of generation are the two ovaries, the
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two fallopian tubes, the uterus or womb, the vagina, the vulva, and the two mammary glands.
Fig. 5 — Female organs of generation. (Beigel.) A, portio vaginalis; B, corpus uteri; C, fundus; D, Fallopian tubes; E, fimbriae; F. ovaries; G, parovaria; H, round ligaments: J, vagina; K, labia majora; L, labia minora; M, clitoris: N. hy- men. (Beigel.)
The Ovaries.
The ovaries are two small bodies, white in color, situated in the pelvic cavity, on each side of the uterus, on the posterior surface, just below the fallopian tubes. They are the size and shape of a flattened pigeons eg-g\ They are composed of small vesicles called the graffican follicles, which contain a smaller vesicle called the ovum, from which the whole body is developed when the ovum is fecundated. The rip- ened human ovum is a highly developed spherical cell about 1-125 of an inch in diameter. It is enclosed in a thick membrane called the A'etalline membrane. Within the membrane or cell wall is the protoplasm of the cell, filled with fatty and albumious granules, and is called the vitellus or yoke. Imbedded in the
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vitellus is a transparent nucleus (the germinal vesi- cle). In this germinal vesicle is a small nucleus, the germinal cell. Remember a cell is a minute portion of living substance called protoplasm. At the mo- ment of rupture the ovum is discharged into the ovary. After the ovum reaches certain stages of development it is discharged from the ovary into the fallopian tubes, and passing through this canal it is conveyed to the uterus. If the ovum is impreg- nated it is retained within the uterus, and the moment the ovum is impregnated by the male cell, life takes place. Upon the arrival of the ovum in the uterus it is grafted upon the mucus membrane. It usually lodges upon the upper surface of the side of the uterus, between two folds of mucus membrane. When the ovum passes from the fallopian tubes to the uterus it finds the mucus membrane prepared by certain changes t o receive it. The m u c u s membrane becomes thick a n d soft and furnishes the mem- brane known as the Fig"- 6-Formation of the decidua. decidua. About the third month there develops be-
Fig-. 7 — Formation of the decidua completed.
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tween the fetal sack and the wall of the uterus, the placenta. It is formed for the protection of the em- bryo.
The Placental Sack. — The child is enveloped in a sack with a double wall. The amnion inside, the cho- non outside. This sack resembles a flat cake. The umbilicus cord is inserted on one side and the other side of the placenta is attached to the inner surface of the uterus. The mother's blood flows in and around the placenta. After the birth of the child the placenta is separated from the wall of the uterus and expelled. It is about seven inches in diameter and one inch in thickness, weighing* about sixteen ounces. The Placental blood vessels are the two Umbilical arteries, and one umbilical vein which extend from the placenta through the umbilicus cord and are continuous with the circulatory system of the fetus.
The Umbilicus Cord. — The umbilicus cord is com- posed principally of these vessels, namely, the two umbilicus arteries and one umbilicus vein and a pe- culiar substance known as the jell}- of Y\ narton. It is about tAventy inches long and a half an inch thick.
The Amniotic Fluid. — The placental sack contains a fluid known as the amniotic fluid. In this fluid the fetus floats during its intrauterine life. It is formed for its protection. It protects it from sudden jars and shocks. The origin of the amniotic fluid is not known, the most probable supposition being that it is simply exuded from the tissues of the fetus. After the for- mation of the placenta, a capillary network, connect- ed with the vessels of the umbilicus cord, is developed just beneath the amnion in that portion of the chor- ion which covers the placenta. From these vessels a transudation of serum takes place into the cavity of
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the amnion. The increased amount of fluid in the am- nion in the later months of gestation is possibly due to the accumulation of urine which the fetus passes from time to time during intrauterine existence. The amniotic fluid contains in addition to water, albu- men, urea and salts which are found in serum and urine. This fluid is a great tactor in the first stages of labor. First it dilates the cervix and the vagina gently and eA^enly. It protects the baby from injuri- ous pressure on any one part. When the uterus contracts the pressure on the fetal sack is even, and after rupture it lubricates the passage, making the child descend with less effort, and if there is infec- tion in the vagina it washes it out, and prevents it get- ting into the baby's eyes.
The Fallopian Tubes. — The fallopian tubes are two in number, situated on each side above the ovary. They are of reddish glistening color, resembling a trumpet, the expanded end over the ovary, and the other at the upper end of the uterus. They are hol- low muscular canals, about three inches long which every month convey the ovum into the uterus.
The Uterus. — The uterus is a muscular flattened pear-shaped organ, two and a half inches long, one and a fourth inches wide, and three fourths of an inch thick, weighing from two to two and a half ounces. Situated in the middle of the pelvic cavity, behind the bladder and in front of the rectum. The small in- testine rest upon it. It is held in position, mainly, by two large folds of peritoneum called the broad ligaments, and two rounded fibro-muscular cords called the round ligaments, and the tissues below. It is freely movable in all directions. The upper angles are called the horns or cornea, and receive the
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fallopian tubes. The lower part is called the neck or cervix. A portion of this protudes into the vagina and presents an orifice called the os, which leads into a cavity in the interior of the uterus.
In the virgin it is a very tense organ, weighing about two ounces, but when pregnant it increases im- mensely in size and capacity.
The Vagina. — The vagina is a curved muscular membranous canal situated in the pelvis, extending from the vulva to the uterus, and is very dilatable. Its walls are composed of mucus membrane and mus- cular fibrous coats, and it is supplied with lymphat- ics, blood vessels and nerves.
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The Vulva. — The vulva is the external orifice of the female organ:
Fig. 8 — Mammary glands. Mammary gland. a, nipple, the central which is retracted; b, areola; c, c, c, c, c, lobules ottne sinus or dilated portion of one of the lactiferous ducts: 2 ities of the lactiferous ducts. (Liegeois.)
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portion
of
i, extrem-
rland
The Mammary Glands. — The mammary glands are the large racemose glands which secrete the milk.
Thus we will see how closely connected, and how important the function of each organ is. The ovary furnishes the ovum or germ from which the new crea- ture is created, the fallopian tubes receives this germ and convey it to the uterus, and in the uterus the germ obtains the nutritive material necessary for its life, growth and development.