Muscle groups

Typically, in order for motion to occur, several muscle sets must work together to perform even the simplest movements. The bicep is a two-muscle set the tricep is a three-muscle set. Each set works in tandem. Within each muscle group, muscle fibers obey the aU. or none principle, ie, aU. muscle fibers contract or none contract. Therefore, if the muscle fibers of a muscle group are stimulated enough by nerve impulses to contract, they contract to the maximum. 

Among the most significant adverse reactions associated with the antipsychotic dm are the extrapyramidal effects. The term extrapyramidal effects refers to a group of adverse reactions occurring on the extrapyramidal portion of the nervous system as a result of antipsychotic drains. This part of the nervous system affects body posture and promotes smooth and uninterrupted movement of various muscle groups. Antipsychotics disturb the function of the extrapyramidal portion of the nervous system, causing abnormal muscle movement. Extrapyramidal effects include Parkinson-like symptoms (see Chap. 29), akathisia, and dystonia (see Display 32-1). 

Cimetidine and ranitidine may be administered by the intramuscular (IM) route. When administered via the IM route the nurse gives the drug deep into a large muscle group. 

The overall results and individual PBPK models for trichloroethylene are discussed in this section in terms of their use in risk assessment, tissue dosimetry, and dose, route, and species extrapolations. Several PBPK models have been developed for inhaled trichloroethylene. In an early model by Fernandez et al. (1977), the human body was divided into three major compartments or tissue groups the vessel-rich group (VRG), muscle group (MG), and adipose tissue (fat) group (FG). The distribution of trichloroethylene in these... 

MS patients usually have upper motor neuron spasticity. This type of spasticity cannot be treated with muscle relaxants such as carisoprodol. MS patients must be treated with agents specific for upper motor neuron spasticity (Table 26—8).48 MS spasticity is classified as focal or generalized. If the spasticity primarily involves only one muscle group, it is focal and may benefit from botulinum toxin administration.11 Systemic medications are used for generalized spasticity. No clear conclusion can be reached regarding the superiority in efficacy of one antispasticity agent over another medication selection is usually based on adverse effects (see Table 26-8).11,48... 

Tonic-clonic Characterized by a sudden loss of consciousness accompanied by tonic extension and rhythmic clonic contractions of all major muscle groups. The duration of the seizure is usually 1 to 3 minutes. These seizures are often described as grand mal. ... 

Myoclonic Single and very brief jerks of all major muscle groups. Patients with these may not lose consciousness, due to the seizure lasting less than 3 to 4 seconds. Patients may describe these seizures as shoulder shrugs or spinal chills. Myoclonic seizures may cluster and build into a generalized tonic-clonic seizure. 

E. F. Evans, J. D. Proctor, M. J. Fraktin, J. Velandia, and A. J. Wasserman, Blood flow in muscle groups and drug absorption, Clin. Pharmacol. Ther, 17, 44-47 (1975). 

During exercise or voluntary hyperventilation, expiration becomes an active process. Under these conditions, a larger volume of air must be exhaled more rapidly. Therefore, two muscle groups are recruited to facilitate this process. The most important muscles of expiration are the muscles of the abdominal wall. Contraction of these muscles pushes inward on the abdominal contents and increases abdominal pressure. As a result, the diaphragm is pushed upward more rapidly and more forcefully toward its preinspiration... 

In patients with myoglobinuria, renal insufficiency is a possible life-threatening complication. Physical examination between episodes of myoglobinuria may be completely normal or show some degree of weakness and, occasionally, wasting of some muscle groups. 

In a study in which female Harlan Wistar rats were exposed for 8 hours to a phenol aerosol at a concentration of 234 ppm, Flickinger (1976) observed a slight loss of coordination with spasm of the muscle groups at 4 hours. By 8 hours, frank tremors were observed leading to a severe loss of coordination however, all animals were normal by post-exposure day 1, and no abnormal lesions were observed upon gross autopsy. 

In order to assess the MT effect in different skeletal muscle groups, several experiments have been performed on whole body units as described in the next section exemplarily. 

IMCL-content of both muscle groups showed a negative correlation with insulin sensitivity, i.e., the higher the IMCL-content, the lower the GIR. ... 

Fig. 24. Spectra of TA (a) and SOL (b) of a 34-year-old male insulin sensitive volunteer (left row) with low IMCL content, and a 32-year-old male insulin resistant volunteer (right row) with markedly higher IMCL in both muscle groups.

Fig. 26. Spectra recorded from TA of a 32-year-old male volunteer before (left row) and after (right row) short term diets, (a) After high caloric diet (HC) there is a marked increase in IMCL, whereas IMCL content is nearly unchanged after normal caloric diet (NC) as shown in (b). (c) Relative changes of IMCL from baseline after the dietary intervention in the two muscle groups (12 subjects data are given as mean SD).

The convulsant toxins, tetanus toxin (cause of wound tetanus) and strychnine diminish the efficacy of interneuronal synaptic inhibition mediated by the amino acid glycine (A). As a consequence of an unrestrained spread of nerve impulses in the spinal cord, motor convulsions develop. The involvement of respiratory muscle groups endangers life. 

In an early study in rats, subcutaneous injections of triphenyl phosphite caused two distinct stages of neurotoxic action. The early, rapidly developing stage was characterized by fine or coarse tremor, usually involving the large muscle groups. The tremor disappeared in surviving animals within a few hours. The... 

Musculoskeletal - Skeletal muscle palsies, myopathy, or neuromyopathy leading to progressive weakness and atrophy of proximal muscle groups, depression of tendon reflexes, and abnormal nerve conduction. 

Sndden diminntion in muscle tone affecting isolated muscle groups or loss of all muscle tone may have extremely brief loss of conscionsness... 

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