Peripheral organ systems

Acetylcholine (Ach) is an ester of acetic acid and choline with the chemical formula CH3COOCH2CH2N+ (CH3)3. ACh functions as a chemical transmitter in both the peripheral nervous system (PNS) and central nervous system (CNS) in a wide range of organisms, humans included. Neurotransmitter involved in behavioral state control, postural tone, cognition and memory, and autonomous parasympathetic (and preganglionic sympathetic) nervous system. 

The adrenergic system is an essential regulator that increases cardiovascular and metabolic capacity during situations ofstress, exercise, and disease. Nerve cells in the central and peripheral nervous system synthesize and secrete the neurotransmitters noradrenaline and adrenaline. In the peripheral nervous system, noradrenaline and adrenaline are released from two different sites noradrenaline is the principal neurotransmitter of sympathetic neurons that innervate many organs and tissues. In contrast, adrenaline, and to a lesser degree noradrenaline, is produced and secreted from the adrenal gland into the circulation (Fig. 1). Thus, the actions of noradrenaline are mostly restricted to the sites of release from sympathetic nerves, whereas adrenaline acts as a hormone to stimulate many different cells via the blood stream. 

Calretinin is homologous to calbindin D28k- It is abundantly expressed in the central and peripheral nervous system and other organs. The protein contains four EF-hand domains homologous to the first four of calbindin D28k-... 

Triiodothyronine (3, 5,3-L-triiodothyronine, T3) is a thyroid hormone. It is producedby outer ring deiodination of thyroxine (T4) in peripheral tissues. The biologic activity of T3 is 3-8 times higher than that of T4. T3 is 99.7% protein-bound and is effective in its free non-protein-bound form. The half-life of triiodothyronine is about 19 h. The daily tur nover of T3 is 75%. Triiodothyronine acts via nuclear receptor binding with subsequent induction of protein synthesis. Effects of thyroid hormones are apparent in almost all organ systems. They include effects on the basal metabolic rate and the metabolisms of proteins, lipids and carbohydrates. 

There is a second type of cholinesterase called butyrylcholinesterase, pseudocholinesterase, or cholinesterase. This enzyme is present in some nonneural cells in the central and peripheral nervous systems as well as in plasma and serum, the liver, and other organs. Its physiologic function is not known, but is hypothesized to be the hydrolysis of esters ingested from plants (Lefkowitz et al. 1996). Plasma cholinesterases are also inhibited by organophosphate compounds through irreversible binding this binding can act as a detoxification mechanism as it affords some protection to acetylcholinesterase in the nervous system (Parkinson 1996 Taylor 1996). 

Animal behavior has been dehned by Odnm (1971) as the overt action an organism takes to adjnst to its environment so as to ensure its survival. A simpler definition is the dynamic interaction of an animal with its enviromnent (D Mello 1992). Another, more elaborate, one is, the outward expression of the net interaction between the sensory, motor arousal, and integrative components of the central and peripheral nervons systems (Norton 1977). The last dehnition spells out the important point that behavior represents the integrated function of the nervous system. Accordingly, disruption of the nervous system by neurotoxic chemicals may be expected to cause changes in behavior (see Klaasen 1996, pp. 466-467). 

Clancy A.N., Schoenfeld T., Forbes W. and Macrides F. (1994). The spatial organization of the peripheral olfactory system of the hamster, II receptor surfaces and odorant passageways within the nasal cavity. Brain Res Bull 34, 211-241. 

Peripheral nervous system Nicotine, organic phosphates... 

Describe the organization of the nervous system including the central nervous system and the peripheral nervous system... 

Babel, J., Bischoff, A. and Spoendlin, H. Ultrastructure of the peripheral nervous system and sense organs. In Atlas of Normal and Pathologic Anatomy. St Louis Mosby, 1970, pp. 1-171. 

Since OPC block ChE selectively in every cholinergic structure (bland N-cholinoreceptive systems), practically all physiological systems and organs can be involved in a pathological process. At that, changes in activity of the central and peripheral nervous systems as well as the resulting impairments in respiratory and cardiac activities have a critical influence on an outcome of the poisoning. 

Despite the obvious expression of GABAb receptors in many peripheral organs, such as heart, spleen, lung, liver, intestine, stomach, and urinary bladder, no overt peripheral phenotype has been described for GABAB(1)-deficient mice. However, as in the central nervous system (CNS), knockout studies demonstrate that the GABAB(i) subunit is an essential requirement for GABAb receptor function in the enteric and peripheral nervous system (PNS) (66). 

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