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Fertilization and normal embryonic and early fetal development
Published in Hung N. Winn, Frank A. Chervenak, Roberto Romero, Clinical Maternal-Fetal Medicine Online, 2021
Asim Kurjak, Ritsuko K. Pooh, Aida Salihagic-Kadic, Iva Lausin, Lara Spalldi-Barisic
The 3D power Doppler image presents early vascular anatomy on the base of the skull with branches evolving laterally to the mesencephalon and cephalic flexure. Pulsed Doppler signals are initially characterized by the absent enddiastolic velocities. Continuous pan-diastolic flow emerges at the gestational age of 9 to 10 weeks. A significant decrease in impedance was observed in intracranial vessels with advancing gestational age, being more pronounced than that in the other parts of the fetal circulation (12,22).
Formation of the Cranial Base and Craniofacial Joints
Published in D. Dixon Andrew, A.N. Hoyte David, Ronning Olli, Fundamentals of Craniofacial Growth, 2017
The adult cranial base shows a higher degree of flexure than in any other animal (Scott, 1958). From the beginning, the chrondrocranium is never flat in its longitudinal plane for, as it develops caudo-rostrally, it acquires the C-shaped curvature of the head-fold of the embryo that carries the cardiogenic area ventral to the foregut and somewhat caudal to the rapidly enlarging forebrain. In the 4th week, the brain anlagen bends sharply in a ventral direction at the future mesencephalon, as the cephalic flexure, with the prosencephalon immediately rostral and the rhombencephalon caudal to it. The initial condensations of mesenchymal cells, that signify the parachordal segment of the chondrocranium, mass on either side of the notochord beneath the rhombencephalon.
Cerebellopontine angle epidermoid with ipsilateral external ear atresia: an embryological association or a coincidence?
Published in British Journal of Neurosurgery, 2023
Khursheed Alam Khan, Rashim Kataria, Mohnish Grover, Virendra Deo Sinha
There are various theories for the origin of epidermoids; these include embryonic inclusions,9 trauma and differentiation from multipotential cell rests10 and epithelial remnants. The cysts have also been postulated to be neuro-ectodermal in origin11 or to arise from pial tissues in the plexus tufts.12 “Gacek”13 argued that epidermoids originate from epithelial cells from Seesels pouch, which may become encased within the fibrocartilage of the foramen lacerum during cephalic flexure, while others state that their capsules consist of a thickening of arachnoid mater14 and develop within it.