Correlation of electrical and contractile activities of the cricopharyngeus muscle in the cat. Am J Physiol 1997 Aug;273(2 Pt 1):G470-9
Date
08/01/1997Pubmed ID
9277427DOI
10.1152/ajpgi.1997.273.2.G470Scopus ID
2-s2.0-0030870531 (requires institutional sign-in at Scopus site) 29 CitationsAbstract
We correlated the electrical and contractile activities of the cricopharyngeus (CP) to better understand the function of the CP and the upper esophageal sphincter (UES). In 40 decerebrate cats, we recorded resting and active tension of the CP and CP force and electromyographic (EMG) activity simultaneously during electrical stimulation of the pharyngoesophageal (PE) nerve, esophageal distension, or swallowing. In six intact cats, the change in diameter of the UES during food swallows was determined in two planes using videofluoroscopy. We found that resting tension of the CP developed quickly with stretch, and the strain-energy function, y = 6.5e3.4(z-1), fit (r = 0.94 +/- 0.06) this relationship. Active tension peaked at 1.68 +/- 0.03 times resting length, which is greater than the maximum distension during swallowing. Activation and relaxation of the CP occurred in approximately 50 and 120 ms, respectively. PE nerve stimulation bilaterally caused a force equal to approximately 90% of the summed force generated by separate stimulation of each PE nerve. The magnitude of the EMG response of the contralateral CP was approximately 18% of the ipsilateral response to unilateral PE nerve stimulation. We conclude that the CP exhibits tension throughout its physiological range of stretch. The CP functions more like a bilateral than a single contiguous muscle, and more like cardiac than striated muscle with regard to its passive elastic properties.
Author List
Medda BK, Lang IM, Dodds WJ, Christl M, Kern M, Hogan WJ, Shaker RAuthors
Ivan M. Lang DVM, PhD Adjunct Professor in the Medicine department at Medical College of WisconsinBidyut K. Medda PhD Associate Professor in the Medicine department at Medical College of Wisconsin
Reza Shaker MD Assoc Provost, Sr Assoc Dean, Ctr Dir, Chief, Prof in the Medicine department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsCats
Deglutition
Electric Stimulation
Electromyography
Electrophysiology
Esophagogastric Junction
Esophagus
Female
Male
Muscle Contraction
Nervous System Physiological Phenomena
Pharyngeal Muscles
Physical Stimulation