Journal of anatomy
-
Dissection of 30 human vastus medialis muscles and their nerves has revealed a consistent bipartite nerve supply from the posterior division of the femoral nerve. One part, a short and slender nerve termed the lateral branch, supplies the upper lateral portion of the muscle. The other part, a medial branch, supplies the middle and lower portion of the muscle. ⋯ The lateral branch, which in some cases arises from the nerve that supplies the vastus intermedius, receives a similar spinal input to that of the vastus intermedius. Therefore, whereas the upper portion of the human vastus medialis muscle is closely aligned with the vastus intermedius, the lower third of the muscle has a richer innervation and also shows a distinct gross morphology that, among primates, may be unique to humans. The gross structure of the muscle, taken together with this evidence from the pattern of innervation, suggests that the human vastus medialis is functionally tripartite.
-
One day old rats had their right eyes removed and together with non-enucleated controls were raised in either 'light' or 'dark' (red light) conditions from birth until 39 days of age. This resulted in four groups of animals: light-reared enucleated, light-reared non-enucleated, dark-reared enucleated and dark-reared non-enucleated. All animals were killed by intracardiac perfusion with 2.5% sodium cacodylate-buffered glutaraldehyde at 39 days of age. ⋯ However, there was a suggestion of a differential effect between the right and left cortices in these enucleated, dark-reared animals. These results demonstrate the importance of light stimulation for the normal development of interneuronal connectivity of the visual cortex. They also show that the effects of unilateral enucleation for the visual cortex are not as great as those previously observed for the superior colliculi in the same animals, at least as far as synapse-to-neuron ratios are concerned.
-
Historical Article
Schmorl's nodes (intravertebral herniations of intervertebral disc tissue) in two historic British populations.
The herniation of the nucleus pulposus into the vertebral body produces ectopic deposit of disc material which are known as Schmorl's nodes. This prolapsed disc tissue leaves characteristic deformations on the surface of the vertebral body and hence the incidence of this lesion can be studied in skeletal remains. This report describes the occurrence of Schmorl's nodes in TV8-SV1 in two historic adult British populations, one from Aberdeen and the other from London. ⋯ The aetiology of Schmorl's nodes is unclear. Various hypothetical causal factors were appraised in relation to the findings of this study. It was suggested that anomalies in vascular and/or notochordal regression may be related to the development of the lesion.
-
Although clinically important, the lumbar epidural space is inconsistently described in textbooks of both anatomy and anaesthetics. This anatomical study of twelve cadavers was performed in an attempt to clarify the description of this region. ⋯ This contains the internal vertebral venous plexus and a posterior deposit of fat which lies in a recess between the ligamenta flava. These findings are discussed in relation to previous studies in an attempt to arrive at a cohesive description of the epidural region.
-
The L 1-4 dorsal rami tend to form three branches, medial, lateral, and intermediate, which are distributed, respectively, to multifidus, iliocostalis, and longissimus. The intertransversarii mediales are innervated by a branch of the dorsal ramus near the origin of the medial branch. ⋯ Each lumbar medial branch innervates two adjacent zygapophysial joints and ramifies in multifidus, supplying only those fascicles which arise from the spinous process with the same segmental number as the nerve. The comparative anatomy of the lumbar dorsal rami is discussed and the applied anatomy with respect to 'rhizolysis', 'facet denervation' and diagnostic paraspinal electromyography is described.