Temporal Lobe. The temporal lobe is divided by superior and inferior temporal sulci into superior, middle, and inferior temporal gyri. The sulci run backward and slightly upward, in the same…

SUPEROLATERAL SURFACE On the superolateral surface, two sulci, the lateral and the central, can be easily identified. The lateral (sylvian) sulcus has a short stem between the orbital surface of…

After a normal pregnancy and delivery, early development is apparently normal through age 6 months; however, retrospectively, subtle deviant patterns occur, including deceleration of acquired head growth. Developmental progress stalls…

CLINICAL PRESENTATION The most severe of these disorders, autistic disorder, is characterized by markedly abnormal development in communication and social interaction and a markedly restricted range of activity and interests….

Because the primary deficit in developmental dyslexia is in reading and writing, the abnormality is usually not identified until the first few years of grade school, the time when children…

Defective Proliferation. A decrease in neuronal number may lead to microcephaly (microencephaly vera), whereas an increase may result in megalencephaly. Prenatal influences, including familial factors, are paramount in each abnormality….

The earliest-born neurons of the cortex itself migrate through the preplate, splitting it into the marginal zone and subplate, thus constituting layer 6 of the cortex. Each successive cortical neuron…

Once these interactions have progressed, the prosencephalic vesicle expands so that there are two telencephalic vesicles. Based on their proximity to anteromedial and anterior sonic hedgehog and FGF signals or…

Brachial birth palsy is believed to be secondary to a stretching of the plexus by traction, with the nerve roots being anchored by the spinal column and cord. In less…

Another type of cell, which is derived from both the neural crest and the wall of the neural tube and which participates in covering the neurons of the PNS, is…