Muscle physiological function

General types of physiological functions attributed to quaternary ammonium compounds are curare action, muscarinic—nicotinic action, and ganglia blocking action. The active substance of curare is a quaternary that can produce muscular paralysis without affecting the central nervous system or the heart. Muscarinic action is the stimulation of smooth-muscle tissue. Nicotinic action is primary transient stimulation and secondary persistent depression of sympathetic and parasympathetic ganglia. 

Nature has created a diverse array of plant and animal toxins that act at mammalian muscle and ganglionic nAChRs or invertebrate nAChRs because the critical physiological functions of these receptors make them prime targets for defensive or predatory strategies. More recently, the perceived validity of neuronal nAChR as therapeutic targets has prompted the generation of new synthetic ligands. Examples are listed in Table 1. 

The rapid and relatively recent determination of the structures of so many nematode neuropeptides has resulted in a huge disparity between available structural and functional data indeed, currently the physiological function of any of the known nematode neuropeptides remains unknown. Most of the accumulated data on nematode neuropeptide activities have been obtained using muscle strips of A. suum and, as a result, only provide a glimpse of the putative role for many of the peptides involved. 

Molecular basis and physiological functions of dynamic Ca2+ signalling in smooth muscle cells... 

Muscle makes up 40-50% of body mass. It is the tissue which allows one to move the limbs, which is utilized in articulating the joints of the skeleton. On closer examination all the muscles in the human body show biochemical specialization allowing them to perform their particular physiological functions the muscles in the back and buttocks evolved for continuous heavy lifting where fuel economy is important. The eyeballs are steered by extraocular muscles when reading they must contract quickly and precisely. The hollow viscera often require a slow steady squeeze to function properly. The heart muscle must provide continuous circulation of blood for transport of oxygen and nutritive substances. The different muscles in the body can be divided in three main types, which are described in the following. 

The response in sepsis depends on the extent of infection. If severe, the loss of skeletal muscle can be large enough to impair physiological function and this increases mortality, for reasons given in Chapter 16. The loss can be as much as 150-200 g per day, despite adequate enteral or parenteral nutrition. Because this is detrimental to the recovery of the patient, there is considerable emphasis on development of treatments that could reduce this loss provision of... 

Serotonin mediates many central and peripheral physiological functions, including contraction of smooth muscle, vasoconstriction, food intake, sleep, pain perception, and memory, a consequence of it acting on several distinct receptor types. Although 5-HT may be metabolized by monoamine oxidase, platelets and neurons possess a high-affinity mechanism for reuptake of 5-HT. This mechanism may be inhibited by the widely prescribed antidepressant drugs termed selective serotonin re-uptake inhibitors (SSRl), e.g. fluoxetine (Prozac ), thereby increasing levels of 5-HT in the central nervous system. 

Nitric oxide has recently been found to be important messenger molecule mediating critical physiological functions such as neurotransmission and muscle relaxation. The nitroprusside ion, which is clinically used as a vasodilator, functions by releasing NO in vivo. The reactivities of these molecules are surveyed with a view toward the development of metallonitrosyls as pharmaceutical... 

The physiological function of heparin is not completely understood. It is found only in trace amounts in normal circulating blood. It exerts an antihpemic effect by releasing lipoprotein lipase from endothehal cells heparinlike proteoglycans produced by endothelial cells have anticoagulant activity. Heparin decreases platelet and inflammatory cell adhesiveness to endothelial cells, reduces the release of platelet-derived growth factor, inhibits tumor cell metastasis, and exerts an antiproliferative effect on several types of smooth muscle. 

Contemporary anesthetic management requires (1) rapid loss of consciousness, which eliminates awareness, memory of pain, anxiety, and stress throughout the surgical period (2) a level of analgesia sufficient to abohsh the reflex reactions to pain, such as muscular movement and cardiovascular stimulation (3) minimal and reversible influence on vital physiological functions, such as those performed by the cardiovascular and respiratory systems (4) relaxation of skeletal muscle to facilitate endotracheal intubation, provide the surgeon ready access to the operative field, and reduce the dose of anesthetic required to produce immobihty (5) lack of... 

Children have special physiological and pathological characteristics. As their internal organs, muscles and bones are delicate and their physiological functions are not fully developed, children become ill more easily than adults, and their diseases develop quickly. Therefore, the proper formula with suitable dosages of herbs should be given at the appropriate time. 

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