ANATOMY OF THE FEMALE BONY PELVIS FETAL SKULL：女性的骨盆和胎儿颅骨解剖.ppt

FETAL SKULL The skull is formed of the face , the vault the base The bones that form the skull are : two frontal bones, two parietal bones, two temporal bones wings of the sphenoid occipital bone The bones of the face base are heavy fused The bones of the vault are 2 frontal ,2 parietal occipital The bones of the vault are not joined thus changes in the shape of the fetal head during labor can occur due to molding FETAL SKULL DEFINITIONS Bregma ? Ant fontanelle Brow ? lies between bregma root of the nose Face ? lies between root of the nose suborbital ridges Occiput ? boney prominence behind post fontanelle Vertex ? diamond shaped area between ant post fontanelles parietal eminences FETAL SKULL SUTURES Frontal suture ? between 2 frontal bones Sagittal suture ? between 2 parietal bones Coronal suture ? between parietal frontal Lambdoid suture ? between parietal occipital Temporal suture ? between inferior margin of the parietal temporal FETAL SKULL FONTANELLES Anterior fontanelle ? diamond shaped space between coronal sagittal suture 3 * 3 cm , ossifies at 18 months after birth Post font (lambda) ? triangle shaped space between sagittal lambdoid suture, closes at 6-8 weeks of life FETAL SKULL DIAMETERS Biparietal diameter 9.5 cm. ? between parietal eminences The greatest transverse diameter Suboccipitobregmatic 9.5 cm. ? middle of the bregma to undersurface of the occipital bone at the neck The presenting diameter of the well flexed head in labour Suboccipitofrontal 10.5 cm ? root of the nose to undersurface of the occipital bone at the neck The presenting diameter of the