Muscle innervation

Symptoms of intoxication in humans caused by accidental ingestion of Kou-Wen plants have been described as follows. The effect on the digestive system starts with loss of appetite and turn of the stomach, and continues to severe abdominal pain and intestinal bleeding. The effect on the respiratory system presents as breathing difficulties which finally lead to death by respiratory failure. The effect on muscle innervation usually results in generalized muscular weakness and paralysis of the limbs. The effect on the circulatory system starts with heartbeat disorders and a drop in blood pressure, but heart failure is not a common cause of death. In addition to dilation of pupils, a drop in body temperature and proliferation of white blood cells have also been obseryed (70). 

External urethral sphincter muscle probably has cholinergic and adrenergic autonomic innervation as well as cholinergic striated muscle innervation (Elbadawi and Schenk, 1974). This rhabdosphincter is unique when compared to other striated muscle in that it has a higher density of neural end-plates as well as blood vessel-independent neural plexuses. Efferent rhabdosphincter innervation is probably via the pudendal nerve while the lissosphincter efferents probably emanate from the pelvic plexus (Elbadawi and Schenk, 1974). 

Nicotinic receptors are part of a transmembrane polypeptide whose subunits form cation-selective ion channels (see Figure 2-9). These receptors are located on plasma membranes of postganglionic cells in all autonomic ganglia, of muscles innervated by somatic motor fibers, and of some central nervous system neurons (see Figure 6-1). 

Most vascular smooth muscle (innervated) Contraction... 

Q2 Patients with myasthenia gravis suffer from extreme muscle weakness and fatigue, particularly after repeated muscle contraction. A noticeable feature of myasthenia gravis is that the upper eyelids droop (ptosis) because of the unconscious and repeated use of the muscles involved in blinking, and these eyelid muscles show fatigue and weakness before any other skeletal muscle is affected. Weakness of other muscles innervated by the cranial nerves is usually also visible early, resulting in a loss of the person s normal facial expression. Their vision is affected, their jaw may drop and their speech may become slurred. The condition occurs mostly in women, with a peak incidence in the third decade. 

Myasthenia gravis is an autoimmime disease that affects the neuromuscular junction.A decrease in the number of available acetylcholine receptors due to circulating antibodies results in impaired neuromuscular transmission. This impairment manifests clinically as weakness and fatigability of volimtary musculature. Ocular and other muscles innervated by cranial nerves are most often involved. Although different treatment modalities are available, anticholinesterase drugs remain the mainstay of therapy. 

The pharmacologic treatment of myasthenia gravis is based on increasing the amount of available acetylcholine by use of oral cholinesterase inhibitors such as neostigmine or pyridostigmine. Pyridostigmine bromide (Mestinon) is used most often and effectively relieves myasthenic symptoms in small muscles innervated by cranial nerves, particularly those involved in ptosis. 

The toxicity of botuhnum toxins is due to their ability to attack nerves specifically and also to catalyse the degradation of selective pres)maptic proteins. The toxins bind specifically to the pres)maptic membrane of neurones, notably motoneurones (but also autonomic and sensory neurones). After binding to the nerve terminal the toxin gains access to the cytosol of the neurones to block the release of the neurotransmitter. The result is paralysis of the muscles innervated by those nerves. 

These four alkaloids stimulate smooth muscles innervated by postgan-ghonic cholinergic nerves. The first three act directly, but the action of physostigmine is an indirect one through cholinesterase inhibition. Moreover, the actions of physostigmine are more complex, and its effects, particularly in the intact animal, more difficult to predict. None of these alkaloids are of clinical importance as oxytocics. 

The eyeball is spherical and therefore free to turn in both the horizontal and vertical directions. Each eye is rotated by three pairs of mutually opposing muscles, innervated by the oculomotor nuclei in the brainstem. The eyes are coordinated as a pair in two useful ways turning together to find and follow objects and turning inward to allow adjustment for parallax as objects become closer. The latter is called convergence. 

Svanberg E, Ohlsson C, Hyltander A, Lundholm KG. The role of diet components, gastrointestinal factors, and muscle innervation on activation of protein synthesis in skeletal muscles following oral refeeding. Nutrition 1999 15 257. 

Struthers , which joins the anomalous bony process and the medial epicondyle. Clinically, this condition typically affects young sportsmen as a result of intense muscular activity in the elbow and forearm and may start with pain and numbness in the first three fingers and weakness of forearm muscles innervated by the median nerve (Sener et al. 1998). US can demonstrate the relationship of the median nerve with the anomalous bone and ligament. Although not yet reported in the radiological literature, displacement of the nerve by these structures may represent an indicator of entrapment. Therapy includes excision of the ligament of Struthers and ablation of the supracondylar process. The brachial artery can also be compressed by an anomalous insertion of the pronator teres muscle into the supracondylar process (Talha et al. 1987). 

DNLM 1. Electromyography-methods. 2. Extremities-innervation. 3. Muscles-innervation. WE500]... 

Following the sequence of clinical neurological examination there can be disturbances of lower cranial nerves difficulty in swallowing, nasal speech, atrophy and weakness of muscles innervated by the accessory nerve. Upper cervical nerves can be involved in a series syndromes of neck pain. This however is only occasionally encountered in transoral surgery. 

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