Most nerves are attached to the neuraxis by rootlets. The CNS-PNS transitional zone (TZ) is that length of rootlet containing both central and peripheral nervous tissue. The 2 tissues are separated by a very irregular but clearly defined interface, consisting of the surface of the astrocytic tissue comprising the central component of the TZ. Central to this, myelin sheaths are formed by oligodendrocytes and the supporting tissue is astrocytic. Peripheral to it, sheaths are formed by Schwann cells which are enveloped in endoneurium. The features of transitional nodes are a composite of those of central and peripheral type. The interface is penetrated only by axons. It is absent at first. It is formed by growth of processes into the axon bundle from glial cell bodies around its perimeter. These form a barrier across the bundle which fully segregates prospectively myelinated axons. Rat spinal dorsal root TZs have been used extensively to study CNS axon regeneration. The CNS part of the TZ responds to primary afferent axon degeneration and to regenerating axons in ways which constitute a satisfactory model of the gliotic tissue response which occurs in CNS lesions. It undergoes gliosis and the gliotic TZ tissue expands distally along the root. In mature animals axons can regenerate satisfactorily through the endoneurial tubes of the root but cease growth on reaching the gliotic tissue. The general objective of experimental studies is to achieve axon regeneration from the PNS through this outgrowth and into the dorsal spinal cord. Since immature tissue has a greater capacity for regeneration than that of the adult, one approach includes the transplantation of embryonic or fetal dorsal root ganglia into the locus of an extirpated adult ganglion. Axons grow centrally from the transplanted ganglion cells and some enter the cord. Other approaches include alteration of the TZ environment to facilitate axon regeneration, for example, by the application of tropic, trophic, or other molecular factors, and also by transplantation of cultured olfactory ensheathing cells (OECs) into the TZ region. OECs, by association with growing axons, facilitate their extensive regeneration into the cord. Unusually, ventral motoneuron axons may undergo some degree of unaided CNS regeneration. When interrupted in the spinal cord white matter, some grow out to the ventral rootlet TZ and thence distally in the PNS. The DRTZ is especially useful for quantitative studies on regeneration. Since the tissue is anisometric, individual parameters such as axon numbers, axon size and glial ensheathment can be readily measured and compared in the CNS and PNS environments, thereby yielding indices of regeneration across the interface for different sets of experimental conditions.

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Determined by anatomical dissection, we have described the ultrasound features of the thoracic paravertebral space and performed clinically successful ultrasound-guided paravertebral block.

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Anatomy is recognized to play a central role in the education and training of clinicians, healthcare professionals, and scientists. However, in recent years, the perceived decline in popularity of anatomy has led to a deficiency in the numbers of new anatomy educators. The tide is now turning with anatomy once again taking its rightful place in a wide of variety of disciplines, and therefore it is imperative that a new generation of anatomists is in place to meet this need. In response, the Anatomical Society of Great Britain and Ireland has made the training of the next set of anatomists, one of its strategic priorities, and in collaboration with the American Association of Anatomists has developed a dedicated Training Program. The overall aim of the Program is to provide trainees with the necessary knowledge, understanding, aptitudes, and attitudes in appropriate detail, sufficient to enable them to teach and examine Anatomy with full competence at the undergraduate and postgraduate level. The Program offers opportunities to consolidate knowledge and deepen understanding of anatomy, improve skills in teaching and communication with students, and be competent in preparing teaching materials and assessment modalities. The Program uses a distance‐learning approach with an incorporated Residential School and is particularly aimed at those undertaking a career in the biosciences. Early indications suggest that initiatives such as the development of this Training Program will help deliver the next generation of anatomists and ensure that anatomy continues to play a fundamental role in the education of clinicians, healthcare professionals, and scientists. Anat Sci Ed 2:119‐125, 2009 © 2009 American Association of Anatomists.