[Anatomic and clinical evidence of intrapelvic pudendal nerve and its relation with striated sphincter of the urethra].

Objective: To demonstrate that somatic innervation of the urethrae striate sphincter is intrapelvic and not through an internal pudendal nerve, an extrapelvic nerve in its entire path. To study the relationship of the pelvic plexus with genito-urinary organs and its surgical implications.

Methods: 6 embryos and 2 fetuses, sliced and stained with techniques suitable for nervous structures were studied.

Anastomosis between both hypoglossal nerves in a 30 mm human embryo.

In this paper we present the first description of an anastomosis between both hypoglossal nerves during the embryonic period, a very uncommon anatomical variation. This was observed in a 30 mm crown-rump (C-R) length human embryo (Carnegie stage 23) from the Bellaterra Collection (Prof. Doménech Mateu), stained for nerve fibers.

An unusual clinical presentation of bilateral schizencephaly.

We present a case with a characteristic magnetic resonance image (MRI) of bilateral open-lipped schizencephaly and atypical clinical presentation. The patient is still alive and in good health in her forties, she has never presented seizures, and although the motor dysfunction is well correlated with cerebral lobe involvement, neurobehavioral dysfunction is not proportional to the MR image of the cerebral malformation.

Prenatal development of the rat sinuatrial node.

In order to study the origin and mode of differentiation of the cells which make up the sinuatrial node, samples of the sinuatrial junction of rat embryos of different ages were studied by transmission electron microscopy. From a seemingly morphologically homogeneous cell population at 11 days, an ultrastructural differentiation occurs from day 12. So, one could see: a) irregular-shaped cells with dark nucleus and medium-sized contractile apparatus which we have identified as ordinary ("working") atrial myocardiocytes and, b) pale cells with a clear spheroidal nucleus and cytoplasm containing few organelles and fine myofibrils which we have classified as nodal cells.