The topographical anatomy of the smooth muscle of the cat's nictitating membrane

1938 ◽  
Vol 71 (3) ◽  
pp. 297-311 ◽  
Author(s):  
George H. Acheson
Keyword(s):  
Smooth Muscle ◽  
Nictitating Membrane ◽  
Topographical Anatomy

Clinical topographical anatomy of the gastro-oesophageal junction in the cat

2017 ◽  
Vol 20 (4) ◽  
pp. 308-311 ◽  
Author(s):  
Agni Voutsinou ◽  
Lysimachos G Papazoglou ◽  
Ioannis Antonopoulos ◽  
Timoleon S Rallis
Keyword(s):  
Smooth Muscle ◽  
Gastric Mucosa ◽  
Abdominal Cavity ◽  
Muscle Thickness ◽  
Muscle Layer ◽  
Smooth Muscle Layer ◽  
Topographical Anatomy ◽  
Transition Level ◽  
The Mean ◽  
High Pressure Zone

Objectives The purpose of the present study was to describe histologically the gastro-oesophageal junction in the cat and interrelationships of this region. Our hypothesis was that cats are devoid of abdominal oesophagus. Methods Three centimetres of the terminal oesophagus, the phreno-oesophageal membrane with 1–2 cm margins of the diaphragmatic crural muscle and the proximal 3 cm of the gastric cardia were obtained from nine domestic shorthair cats and one domestic longhair cat that were euthanased for reasons other than digestive tract pathology. Longitudinal samples were examined histologically. Evaluated parameters included the location of the phreno-oesophageal membrane with reference to the transition between the oesophageal and gastric mucosa, the thickness of the circumferential smooth muscle of the muscular layer of the distal oesophagus at points 3 mm and 6 mm cranial to the mucosa transition, and the thickness of the circumferential smooth muscle layer at the mucosa transition level. Median differences in the thickness of the smooth muscle layer were compared by performing non-parametric statistical analysis using the Mann–Whitney U-test. Results The transition of the oesophageal to gastric mucosa was abrupt and corresponded to the point of insertion of the phreno-oesophageal membrane at the diaphragm level in all cats. The mean thickness of the circumferential smooth muscle layer at the point of oesophageal to gastric mucosa transition was significantly greater than the mean thickness of the oesophageal circumferential smooth muscle layer at 3 mm and 6 mm cranial to the mucosa transition ( P ⩽0.05). The increased muscle thickness at the gastro-oesophageal junction correlates with the accepted location of the high-pressure zone, reflecting the caudal oesophageal sphincter. It seems that the whole oesophagus was situated within the thoracic rather than the abdominal cavity. Conclusions and relevance No distinct abdominal oesophagus was observed in nine domestic shorthair cats and one domestic longhair cat. These findings might have implications for the pathophysiology of hiatal hernia in cats.

Regulation of postsynaptic alpha-1 adrenoceptors in smooth muscle of the cat nictitating membrane

1990 ◽  
Vol 21 (6) ◽  
pp. 514-518
Author(s):  
�. N. Telina ◽  
S. V. Kirshin ◽  
R. S. Nizamov ◽  
R. Kh. Akhmedzyanov ◽  
Kh. S. Khamitov
Keyword(s):  
Smooth Muscle ◽  
Nictitating Membrane ◽  
Cat Nictitating Membrane

Responses of smooth muscles to quick stretch; relation of stretch to conduction

1960 ◽  
Vol 198 (5) ◽  
pp. 921-925 ◽  
Author(s):  
Geoffrey Burnstock ◽  
C. L. Prosser
Keyword(s):  
Smooth Muscle ◽  
Membrane Potential ◽  
Critical Level ◽  
Smooth Muscles ◽  
Taenia Coli ◽  
Nictitating Membrane ◽  
Active Muscle ◽  
Gap Measurement ◽  
Sucrose Gap ◽  
Visceral Muscles

Quick stretches applied to isolated strips of visceral muscles elicit contractions and electrical responses, similar stretches elicit no responses from blood vessels and nictitating membrane. Highly excitable muscles gave repetitive responses. Spontaneously active taenia coli relaxed in response to stretch and electrical activity diminished correspondingly. The membrane potential (sucrose gap measurement) decreased during stretch; spikes appeared at a critical level of depolarization. A single initial spike sometimes occurred before membrane depolarization. The membrane potential of spontaneously active muscle increased during stretch. Strips of smooth muscle mechanically immobilized in the center showed conduction from one side to the other; signals for both activation and relaxation were conducted. It is concluded that conduction can occur in absence of stretch, that quick stretch can alter membrane potential and thus alter excitability of smooth muscle.

In Vitro Responses of Nictitating Membrane to Drugs and to Denervation

1956 ◽  
Vol 186 (1) ◽  
pp. 152-156 ◽  
Author(s):  
William C. Wescott ◽  
Herbert E. Christensen ◽  
Amedeo S. Marrazzi
Keyword(s):  
Smooth Muscle ◽  
Electrical Impedance ◽  
In Vivo Studies ◽  
Isometric Contractions ◽  
Nictitating Membrane ◽  
Smooth Musculature ◽  
Permeability Studies ◽  
Isotonic Contractions

The smooth musculature of the cat's nictitating membrane, whose characteristics make it interesting and suitable for permeability studies as measured by transverse electrical impedance, has been studied in vitro. The inferior smooth muscle was removed, divested of its connective tissue covering, and mounted in a controlled temperature muscle bath composed of oxygenated ringer buffered with phosphate and containing glucose. Isotonic contractions were recorded on a kymograph using a frontal writing lever. The responsiveness of the muscle to adrenergic and cholinergic drugs was qualitatively in agreement with the results reported in in vivo studies. The cholinesterase inhibitor DFP enhances responsiveness to ACh without otherwise affecting brane length. ACh responsiveness is counteracted by small amounts of atropine. Denervated membranes exhibited a lowered threshold for adrenaline and noradrenaline—the sensitization being greater for the latter—and a lack of response to ephedrine. A method for recording isometric contractions by a mechano-electronic transducer has been developed for use in the conductance studies that are to follow. It is believed that, in addition to its use in study of permeability, this preparation will be of value in further elucidating the mechanism of action of various agents acting at autonomic neuro-effector junctions.

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