Spinal cord anatomy

Fig. 20.2. The spinal cord and cauda equina. The caudal spinal cord does not completely fill the caudal vertebral column. As a result, the dorsal and ventral roots of lumbar and sacral neurons are very long, spanning from the more rostral cell bodies to the more caudal exit points. Therefore, the dissected spinal cord resembles a horse s tail. The practical effect of this anatomy is that it becomes very hard to reliably determine the level of the spinal cord that is being studied in any given cross-section.

Relatively hydrophilic dmgs such as methotrexate (log P = -0.5) which do not cross the blood-brain barrier in significant amounts, have been infused intrathecally to treat meningeal leukaemia, and baclofen (log P =-1.0) to treat spinal cord spasticity. High lumbar CSF concentrates are achieved as a result. Figure 9.56 shows the anatomy of the epidural space and routes of dmg transport. The spinal CSF has a small volume (70 cm ) and a relatively slow clearance (20-40 cm h ) for hydrophilic dmgs. 

This section reviews basic principles of brain anatomy and function to provide a framework within which to discuss the effect of plants on the CNS. The human nervous system is exceptionally complex, it is the body s major communication system, and is divided into central and peripheral regions. The central nervous system consists of the brain and spinal cord, and the peripheral nervous system consists of all other nerves. Although thought processes and reason are most commonly associated with the CNS, almost every aspect of physiological function is affected by CNS activity. After all, Brain death is widely accepted as the definition of the end of human life 10). The follow description of CNS anatomy and physiology can be foimd in most text books on the and reviews on the subject 11, 17). 

Deficiency of an essential bone element anywhere in the body triggers a reaction in which one or more hormones signal the release of that element from bone to meet the need. If the intake of one or more of the bone elements has been chronically low, the continual borrowing of that element to meet body needs will weaken the bone.The body has a system of self-protective priorities. It will seemingly rob nutrients from a lower-priority part of the body to sustain a higher-priority part s need, even to the harm of that lower part. The highest-priority part of our anatomy is the central nervous system (brain and spinal cord). It would be the last part of the anatomy to suffer depletion in case of long-term starvation. 

Olfaction represents a subset of the sense of smell, which this chapter seeks to circumscribe by means of four propositions put forth as guidelines. Of these guidelines, the first is chemical, and the second is behavioral. The third guideline addresses the relationship between anatomy and behavior. Applying it requires that the organism possess a well developed eentral nervous system (CNS). The CNS of terrestrial vertebrates includes a spinal cord and a brain, from which emanates a set of cranial nerves. The first cranial nerve is often called the olfactory bulb. If the connections between the nose and the olfactory bulb are completely severed, the ability to sense and to discriminate among volatile stimuli do not necessarily vanish utterly. Those capabilities that are completely lost, however, include olfaction. 

Folate is involved in one-carbon unit transfer reactions during DNA synthesis, DNA methylation, and amino acid metabolism. Evidence to date shows that maternal dietary intake of folic acid is inversely associated with the risk of neural tube defect-affeeted pregnancies [9,10]. Neural tube defects (a term which includes spina bifida) are anatomieal birth anomalies affecting the brain and the spinal cord. As a result of these landmark findings, the first folic acid fortification program was introduced in the United States during 1998, in an attempt to reduce the prevalence... 

Fig. 24.1. Anatomy of feeding arteries of the spinal cord. 1 vertebral artery, 2 left subclavian artery, 3 posterior intercostal artery, 4 anterior spinal artery, 5 Adamkiewicz artery,...

Lasjaunias P, Berenstein A (1990) Functional vascular anatomy of brain, spinal cord and spine, 1st edn. Springer, Berlin Heidelberg, New York... 

Laslett, E.E.. and Warrington, W.B. (1898) The morbid anatomy of a case of lead paralysis. Condition of the nerves, muscles, muscle spindles and spinal cord. Brain 21, 224-231. 

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