Cell bodies, nervous system

Polyunsaturated fats are known as essential fats. Like vitamins they are essential for hfe, they cannot be made in the body and must be obtained from the diet. These good fats have actually been shown to counter the effects of bad fats in our blood and are important for maintaining good health of our hearts, cells and nervous systems. In contrast to saturated and mono-unsaturated fatty acids, PUFAs have at least two double bonds, a feature which crucially affects their structural, physical and chemical properties. 

The human body has more than 600 muscles. The body s movement is performed by muscle contractions, which are stimulated by the nervous system. This system links muscle tissue to the spinal cord and brain. The network of nerve cells which carries the brain s signals directs the flow of muscular energy. Most muscular activity occurs beyond the range of the conscious mind. The body, working through the neuromuscular network, manages... 

The nigrostriatal tract is one of the four main dopaminergic pathways in the central nervous system. About 75% of the dopamine in the brain occurs in the nigrostriatal pathway with its cell bodies in the substantia nigra, whose axons project in the corpus striatum. Degeneration of the dopaminergic neurons in the nigrostriatal system results in Parkinsons disease. 

The mechanism whereby the bacteria produce the disease with its attendant symptoms is often due to the cells ability to produce specific poisons, toxins or aggressins (Chapter 14). Many of these are tissue-destroying enzymes which can damage the cellular structure ofthe body or destroy red blood cells. Others (neurotoxins) are highly specific poisons ofthe central nervous system, for example the toxin produced by Clostridium botulinum is, weight for weight, one ofthe most poisonous substances known. 

Dahlstrom, A and Fuxe, K (1964) Evidence for the existence of monoamines containing neurons in the central nervous system. 1. Demonstration of monoamines in the cell bodies of brainstem neurons. Acta Physiol. Scand. 62 (Suppl 232) 1-55. 

Figure 9.1 The distribution of 5-HT neurons in the brain. The cell bodies are clustered in nuclei (B1-B7) in the pons/upper medullary regions of the brainstem. The rostral cluster ( superior group ) project mainly to forebrain areas while the caudal ( inferior ) group projects mainly to the medulla and spinal cord. Collectively, these neurons innervate most regions of the central nervous system...

Steinbusch, H.W.M. Distribution of serotonin-immunoreactivity in the central nervous system of the rat—Cell bodies and terminals. 

The transport of information from sensors to the central nervous system and of instructions from the central nervous system to the various organs occurs through electric impulses transported by nerve cells (see Fig. 6.17). These cells consist of a body with star-like projections and a long fibrous tail called an axon. While in some molluscs the whole membrane is in contact with the intercellular liquid, in other animals it is covered with a multiple myeline layer which is interrupted in definite segments (nodes of Ranvier). The Na+,K+-ATPase located in the membrane maintains marked ionic concentration differences in the nerve cell and in the intercellular liquid. For example, the squid axon contains 0.05 MNa+, 0.4 mK+, 0.04-0.1 m Cl-, 0.27 m isethionate anion and 0.075 m aspartic acid anion, while the intercellular liquid contains 0.46 m Na+, 0.01 m K+ and 0.054 m Cl-. 

Hydroxy tryptamine, or serotonin, is a neurotransmitter in the central nervous system (CNS). The nerve-cell bodies of the major serotoninergic neurones are in the midline raphe nuclei of the rostral pons, and ascending fibers innervate the basal ganglia, hypothalamus, thalamus, hippocampus, limbic forebrain, and areas of the cerebral cortex. The serotoninergic system plays an important role in the control of mood and behavior, motor activity, hunger, thermoregulation, sleep, certain hallucinatory states, and some neuro-endocrine mechanisms. 

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