Part 43

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DISEASES OF THE GENERATIVE ORGANS. DESCRIPTION OF PLATES.

PLATE XII. Fetal calf within its membranes (at mid term). The uterus is opened on the left side. In the uterus the fetus is surrounded by several membranes which are known as the amnion or inner layer, the allantois or central layer, and the chorion or outer layer. The amnion is nearest the fetus and forms a closed sac around it filled with a fluid known as liquor amnii, in which the fetus floats. The allantois is composed of two layers, which form a closed sac in connection with the urachus, or the tube which extends from the fetal bladder through the umbilical cord. The one layer of the allantois is spread over the outer surface of the amnion and the other over the inner surface of chorion. The allantois also contains a fluid which is known as the allantoid liquid. The chorion is the outer envelope or membrane of the fetus, completely inclosing the fetus with its other membranes. On the outer surface of this membrane are found the fetal placentulÊ, or cotyledons, which, through their attachment to the maternal cotyledons, furnish the fetus with the means of sustaining life. The relation of the fetal and maternal cotyledons to each other is illustrated on the following plate.

PLATE XIII. Pregnant uterus with cotyledons.

Fig. 1. Uterus of the cow during pregnancy, laid open to show the cotyledons (d) on the internal surface of uterus (c). The ovary (a) is shown cut across, and the two halves are laid open to show the position of the discharged ovum at a'.

Fig. 2 illustrates the relation of the fetal and maternal parts of a cotyledon. A portion of the uterus (A) is shown with the maternal cotyledon (BB) attached to it. The fetal portion (D) consists of a mass of very minute hairlike processes on the chorion (E), which fit into corresponding depressions or pits of the maternal portion. Each portion is abundantly supplied with blood vessels, so that a ready interchange of nutritive fluid may take place between mother and fetus.

PLATE XIV. Vessels of umbilical cord.

Fig. 1. Fetal calf with a portion of the wall of the abdominal cavity of the right side and the stomach and intestines removed to illustrate the nature of the umbilical or navel cord. It consists of a tube (1-1') into which pass the two umbilical arteries (3) carrying blood to the placenta in the uterus or womb and the umbilical vein (4) bringing the blood back and carrying it into the liver. The cord also contains the urachus (2') which carries urine from the bladder (2) through the cord. These vessels are all obliterated at birth. 5, liver; 5', lobe of same, known as the lobus Spigelii; 5'', gall bladder; 6, right kidney; 6', left kidney; 6'', ureters, or the tubes conducting the urine from the kidneys to the bladder; 7, rectum, where it has been severed in removing the intestines; 8, uterus of the fetus, cut off at the anterior extremity; 9, aorta; 10, posterior vena cava. (From F¸rstenberg-Leisering, Anatomie und Physiologie des Rindes.)

Fig. 2. Blood vessels passing through the umbilical cord in a human fetus. (From Quain's Anatomy, vol. 2.) L, liver; K, kidney; I, intestines; U C, umbilical cord; Ua, umbilical arteries. The posterior aorta coming from the heart passes backward and gives rise to the internal iliac arteries, and of these the umbilical arteries are branches. Uv, umbilical vein; this joins the portal vein, passes onward to the liver, breaks up into smaller vessels, which reunite in the hepatic vein; this empties into the posterior vena cava, which carries the blood back to the heart.

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PLATE XV. Normal position of calf in utero. This is the most favorable position of the calf or fetus in the womb at birth, and the position in which it is most frequently found. This is known as the normal anterior position. The back of the fetus is directly toward that of the mother, the forelegs are extended back toward the vulva of the mother, and the head rests between them. The birth of the calf in this position usually takes place without artificial assistance.

PLATE XVI. Abnormal positions of calf in utero. (Figs. 1, 2, 3, and 5 from Fleming's Veterinary Obstetrics; fig. 4 after St. Cyr, from Hill's Bovine Medicine and Surgery; fig. 6 from D'Arboval, Dictionaire de MÈdecine et de Chirurgie.)

Fig. 1. Anterior presentation; one fore limb completely retained. The retained limb must be reached if possible and brought forward joint by joint and the fetus then extracted.

Fig. 2. Anterior presentation; fore limbs bent at knee. The limbs must be extended before delivery can be accomplished.

Fig. 3. Anterior presentation; fore limb crossed over neck. The leg should be grasped a little above the fetlock, raised, drawn to its proper side, and extended in genital canal.

Fig. 4. Anterior presentation; downward deviation of head. The head must be brought into position seen in Plate XV before delivery can take place.

Fig. 5. Anterior presentation; deviation of the head upward and backward. Retropulsion is the first indication, and will often bring the head into its normal position.

Fig. 6. Anterior presentation; head presented with back down. The fetus should be turned by pushing back the fore parts and bringing up the hind so as to make a posterior presentation.

PLATE XVII. Abnormal positions of calf in utero. (Figs. 2 and 3 from Fleming; figs. 4, 5, and 6 from D'Arboval.)

Fig. 1. Anterior presentation, with hind feet engaged in pelvis. A very serious malpresentation, in which it is generally impossible to save the fetus if delivery is far advanced. The indications are to force back the hind feet.

Fig. 2. Thigh and croup presentation, showing the fetus corded. The cord has a ring or noose at one end. The two ends of the cord are passed between the thighs, brought out at the flanks, and the plain end passed through the noose at the top of the back and brought outside the vulva. The fetus must be pushed back and an attempt made to bring the limbs properly into the genital passage.

Fig. 3. Croup and hock presentation. The indications in this abnormal presentation are the same as described for Fig. 2.

Fig. 4. Posterior presentation; the fetus on its back. Turn the fetus so as to make a normal anterior presentation.

Fig. 5. Sterno-abdominal presentation. The fetus is on its side with limbs crossing and presenting. The limbs least eligible for extraction should be forced back into the uterus.

Fig. 6. Dorso-lumbar presentation; the back presenting. The fetus must be turned so that one or the other extremity can enter the passage.

PLATE XVIII. Abnormal positions of the calf in utero. Surgical instruments and sutures.

Fig. 1. Twin pregnancy, showing the normal anterior and posterior presentations. (From Fleming.)