How convenient is it for you to use this blog for your purpose?
Anything you want this blog to add or change?
Resources for Communication Problems
Monday, March 3, 2008
The human cranial nerves are the result of evolutionary modifications to a basic vertebrate pattern of CNS organization, constructed of ~40 bilaterally symmetrical repeating segments. During development, the first 2 nerves ( olfactory [ CN I] and optic [ CN II] ) became elaborated as the forebrain and involve the thalamus before reaching the cortex. The remaining 10 cranial nerves originate from the brainstem and innervate the muscles of the head, neck, face, larynx, tongue, and pharynx. These muscles serve speech, resonance, swallowing, facial expression, chewung, and phonation. Besides serving special senses such as vision, audition, smell, and taste, the cranial nerves regulate autonomic secretive functions of glands in the oral, nasal, and orbital cavities.
Some cranial nerves mediate only sensation, whereas others exclusively serve motor functions. However, most nerves have both sensory and mortor functions. Some cranial nerves serve only a single functional component, whereas others contain fibers to serve two or more functional components. Several mortor cranial nuclei receive corticobulbar projections from both sides of the mortor cortex. This bilaterality of projection has important clinical implications for the mortor speech processes.