ABSTRACT
The microangioarchitecture of hippocampus was studied with the replica scanning electron microscope in rats and infants. Typical arteries and their branches were observed in the dorsal and ventral hippocampus of infants. Interarterial, intervenous and arteriovenous anastomoses were seen. Veins and their branches, capillary network and its anastomoses were also observed. A capillary divided into two branches and then they were together with each other like a fried dough twist shape. A vascular unit was observed which consisted of one vein situated centrally and three to four arterioles peripherally. Imprints of precapillary sphincters and postcapillary sphincters wene seen in human hippocampus. Morphology of the hippocampus vessels in rats was not completely similar to men. The diameter of branches which originated from arterioles suddenly changed from the larger to the smaller. There were a lot of impressions of smooth muscles in larger arterioles and their furcations.
ABSTRACT
51 dried skulls and 30(60 halves) cranial specimens were used for investigation. Special attention was given to anatomical features and relations between nerves and blood vessels surrounding spenoid sinus which is important to the transsphenoidal surgical approach. The results are as follows: 1)According to pneumatization of the sinus, the sphenoid sinus can be subdivided into four types. They are conchal(25%), prescllar (14.8%), infrasellar (33.3%)and postsellar(49.4%). Most of the sinus observed belong to sellar and postsellar types, in which the transsphenoidal surgical approach is easy to be done. 2)The septum of sphenoid sinus can be found in the majority of the cases(91.4%). Among them, the septum is situated in the midline in 13.5%cases, deviated to the left in 38.3% of the cases and deviated to the right in 39.5% cases. There is no septum in 8.6% of the cases observed. In addition to sagittal septum, there are accessory septa in the sphenoid sinus lying in frontal or horizontal position The cavity of the sinus may be subdivided into three parts(14.8%)or four parts(8.6%). 3)The average distance from ostium of sphenoid sinus to the anterior wall of sellar is 14.5mm in cranial specimens and 14.7mm in dried skulls. 4)The roof and posterior wall of sphenoid sinus were measured respectively. The anterior wall and floor of sella are the thinnest parts, the average thickness is less than 1.0mm. 5)In all cases observed, a clear prominence, optic canal prominence, can be seen on the lateral wall of the sphenoid sinus. Carotid prominence is another prominence arround sella, which can be divided into three segments, that is presellar Infrasellar and retrosel lar. The third prominence, maxillary nerve prominence, is on the inferior part of the lateral wall of sphenoid sinus. The length and width of each prominence and the distance between two same prominences on both sides were measured. The thickness of bony wall of each prominence was also measured, the avarage thickness is less than 0.5 mm.
ABSTRACT
The authors observed fifty petrosal veins in twenty five adult specimens with surgical microscope under ten times magnification.Special attentionwas paid to the microsurgical anatomical features of the petrosal vein andthe relations between these features and some aspects of the posterior rhi-zotomy of the trigeminal nerve. There is only one petrosal vein in each half of the specimen in themajority of the cases observed. All petrosal veins can be subdivided into three types: 1 ) single-trunk type; 2 ) two-trunk type; 3 ) three-trunktype. The micro-anatomical features of the vein are as follows: 1 ) in adeep position; 2 ) with a thinnest wall; 3 ) with a thicker and shortertrunk; 4 ) in a free and suspended manner during traversing the subarachnoidspace. During operation, the petrosal vein covered with a thin layer ofarachnoid can be seen. The method of how to sever the vein is different because the formationof it is different. Most of petrosal veins are located at a position superiorlateral to the teminal root, so they can be used as a guidance of looking for the nerve root.
ABSTRACT
Two methyl methacrylate corrosion casts prepared from the intra-microvascular system of human brain-stem were used for the observation of morphological features of the system. Arterioles, venules and capillaries have their own morphological features respectively, so it is not difficult to distinguish one from others. Besides different forms of impressions formed by the endothelial cells nuclei on the surface of larger arterioles and venules, there are semicir cular impressions formed by the smooth muscle cells on the surface of larger venules and the majority of larger venules take a looplike shape on their way to pass forward. All these characteristics could be used to distinguish the larger venules. There are anastomoses between arterioles and between venules, with some A-V communicating branches between arterioles and venules.