+ Site Statistics
References:
52,654,530
Abstracts:
29,560,856
PMIDs:
28,072,755
+ Search Articles
+ Subscribe to Site Feeds
Most Shared
PDF Full Text
+ PDF Full Text
Request PDF Full Text
+ Follow Us
Follow on Facebook
Follow on Twitter
Follow on LinkedIn
+ Translate
+ Recently Requested

The parasympathetic control of muscle tonus



The parasympathetic control of muscle tonus



Arch Neurol & Psychiatry 22(2): 265-281



A review is given of the facts which bear on Frank's hypothesis that tonic impulses are conveyed to the muscles antidromically over parasympathetic fibers in the dorsal roots. Antidromic vasodilation and the pseudomotor phenomenon are probably both brought about by the fine dorsal root fibers that accompany the blood vessels. Although the pseudomotor phenomenon and acetylcholine contrac-ture are inhibited by epinephrine, they are not inhibited by large doses of scopolamine and atropine. Hence the pharmacologic evidence is against the reactions falling definitely in the parasympathetic class. On the other hand, the favorable action of atropine and scopolamine on the Parkinsonian rigidities must not be forgotten. The importance of the dorsal roots for muscle tonus has been overstated. Contrary to the usual belief, deaffer-ented muscle does not remain permanently atonic, but recovers some of its tone and may for a time become hypertonic. Decerebrate rigidity, tonic crossed extensor reflexes and labyrinthine tonic reflexes can be obtained from deafferented muscle. This shows that whatever role the dorsal roots may play in tonus, the fibers of the ventral roots are sufficient in themselves to produce tonic contractions. It remains an open question whether or not there are any efferent fibers in the dorsal roots. There is no histologic evidence that dorsal root fibers have any endings on the muscle fibers in the limbs of mammals other than the endings in the muscle spindles.

(PDF emailed within 1 workday: $29.90)

Accession: 025877972

Download citation: RISBibTeXText


Related references

Blighted ovum and tubal pregnancy: a rare form of heterotopic pregnancy: case report. Bmc Research Notes 11(1): 242-242, 2018

Parasympathetic predominance in the shock patient and its aggravating interference. (Dominant vasodilating tonus in finger-nail microcirculation as a sign of parasympathetic predominance). Minerva Anestesiologica 34(7): 835-838, 1968

Parasympathetic prevalence present in the patient at the moment of shock and its aggravating interference. Vasodilatory tonus in the digito-ungual microcirculation as a sign of parasympathetic prevalence. Minerva Medica 59(98): 5376-5378, 1968

Muscle Tonus. Physiological And Physiopathological Aspects. Ii. The Neurologist In Relation To Muscle Tonus. La Presse Medicale 72: 2213-8 Concl, 1964

Muscle Tonus. Physiological And Physiopathological Aspects. I. The Physiologist In Relation To Muscle Tonus. La Presse Medicale 72: 2107-12 Contd, 1964

Studies on muscle tonus IV The r61e of the sympathetic nervous system in muscle tonus. 1926

On the tonus and its nervous regulation of the sphincter muscle of Anodonta cygnea II Relationship between tonus and tetanus. 1941

Role of parasympathetic tonus in vasomotor rhinitis. Turk Tip Cemiyeti Mecmuasi 33(2): 117-123, 1967

Tracheobronchial muscle tonus and its reflex control. Archives Internationales de Physiologie et de Biochimie 97(4): A15-A35, 1989

Alpha and beta adrenergic control of muscle tonus. Bollettino Della Societa Italiana di Biologia Sperimentale 49(9): 427-432, 1973

Influence of an enhanced parasympathetic tonus on exercise mediated cardiovascular effects. Naunyn-Schmiedeberg's Archives of Pharmacology 357(4 SUPPL): R161, 1998

Parasympathetic nervous control of airway smooth muscle. Annals of the New York Academy of Sciences 221: 99-102, 1974

Anterior trunk surface thermograms in patients with different tonus of the sympathetic and parasympathetic nervous systems. Fiziologicheskii Zhurnal (Kiev) 35(2): 57-61, 1989

Cholinergic and noncholinergic parasympathetic control of airway smooth muscle. Zaagsma, Johan , Reprint Author, Meurs, Herman , Reprint Author, Roffel, Ad F Muscarinic receptors in airways diseases: 1-24, 2001

Parasympathetic neural control of canine tracheal smooth muscle. Tokai Journal of Experimental and Clinical Medicine 29(4): 143-149, 2005