Aids to obstetrics / by Samuel Nall.

  • Nall, Samuel.
Date:
1913
Catalogue details

Licence: In copyright

Credit: Aids to obstetrics / by Samuel Nall. Source: Wellcome Collection.

Provider: This material has been provided by The University of Leeds Library. The original may be consulted at The University of Leeds Library.

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    Moulding of the Fcetal Head.—Owing to the pre- sence of the sutures and fontanelles, and also to the flexibility of the cranial bones, the head can undergo considerable change in shape during its passage through the pelvis in labour. Measurements of the Foetal Sead. Occipito-frontal, from occiput to root of nose, 4h inches. Sub-occipito-frontal, from nape of neck to a point midway between the root of the nose and the anterior fontanelle, 4 inches. Sub-occipito-bregmatic, from nape of neck to the centre of the anterior fontanelle or bregma, 3I inches. Mento-vertical, from the chin to the vertex, 5]- inches. Mento-frontal, from the chin to the bregma, 4 inches. Biparietal, between the two parietal eminences, 3f inches. Bi-temporal, between the two extremities of the coronal suture, inches. The movements of the foetal head on the spinal column are of wider range than in the adult, thus allowing of considerable twisting. The Diameters of the Trunk are— Bisacromial, widest diameter of shoulders, 4^ inches. Bitrochanteric, widest diameter of hips, 4 inches. Nutrition of the Foetus.—The early embryo is nourished partly by the yolk and partly by absorption through the chorionic villi; after the third month the placenta is the medium through which it is nourished. The Fcetal Circulation—Peculiarities.—(i) There is a direct communication between the right and left auricles by means of the Foramen Ovale. (2) Passing from the pulmonary artery to the aorta is a communi- cating vessel, the Ductus Arteriosus, which joins the
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