While a digital arteriovenous anastomosis (Hoyer-Grosser's organ, Masson's glomus) is a well-known structure, photographic evidence of communication between arterial and venous lumens might not be demonstrated in routine histological or immunohistochemical analysis. Abundant clusters of so-called glomera were found in semi-serial sections of the distal aspect of 14 fingers obtained from 7 donated elderly cadavers. Two to six round or oval clusters were observed in each longitudinal section (over 0.
View Article and Find Full Text PDFEarly development of veins and sinuses at and around the posterior cranial fossa seemed not to be shown by photographs except for our recent study (Ann Anat, 2020). Examination of histological sections of 38 fetuses at 10-16 weeks gestational age (GA) demonstrated that: (1) the superior petrosal sinus passed posterosuperiorly through the tentorium cerebelli and, distant and lateral to both the cerebellum and internal ear, drained into the transverse sinus; (2) the superior sagittal sinus was underdeveloped, and the inferior sagittal sinus was not yet evident; (3) the straight sinus (STS) originated from a joining of the bilateral pial veins from the lateral ventricular choroid plexus, passed through the inferoposterior part of the falx cerebri, reached the initial confluens sinuum, and then divided into the bilateral transverse sinuses. The STS origin was immediately behind the pineal body, and near the inferoposterior end of the third ventricle.
View Article and Find Full Text PDFThe embryonic occipital bone and odontoid process of the axis are attached and connected by the notochord, but become separated in later development and growth. With special attention to the process of separation, we examined sagittal sections of the craniocervical junction in 18 human fetuses at 8-16 weeks and 22 fetuses at 31-37 weeks. At 8-9 weeks, the anterior arch of atlas was always seen overriding the occipital basal part.
View Article and Find Full Text PDFThere seems to be no complete demonstration of the suboccipital fascial configuration. In 30 human fetuses near term, we found two types of candidate myodural bridge: (1) a thick connective tissue band running between the rectus capitis posterior major and minor muscles (rectus capitis posterior major [Rma], rectus capitis posterior minori [Rmi]; Type 1 bridge; 27 fetuses); and (2) a thin fascia extending from the upper margin of the Rmi (Type 2 bridge; 20 fetuses). Neither of these bridge candidates contained elastic fibers.
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