RECEPTOR ORGANS IN THORACIC AND ABDOMINAL MUSCLES OF CRUSTACEA

1967 ◽  
Vol 42 (2) ◽  
pp. 288-325 ◽  
Author(s):  
J. S. ALEXANDROWICZ
Keyword(s):  
Abdominal Muscles ◽  
Thoracic And Abdominal

Respiratory muscle control during vomiting

1990 ◽  
Vol 68 (2) ◽  
pp. 237-241 ◽  
Author(s):  
Alan D. Miller
Keyword(s):  
Response Pattern ◽  
Respiratory Muscles ◽  
Respiratory Neurons ◽  
Abdominal Muscles ◽  
Inspiratory Muscles ◽  
Medullary Respiratory Neurons ◽  
Gastric Contents ◽  
Expiratory Neurons ◽  
Expiratory Muscles ◽  
Thoracic And Abdominal

The changes in thoracic and abdominal pressures that generate vomiting are produced by coordinated action of the major respiratory muscles. During vomiting, the diaphragm and external intercostal (inspiratory) muscles co-contract with abdominal (expiratory) muscles in a series of bursts of activity that culminates in expulsion. Internal intercostal (expiratory) muscles contract out of phase with these muscles during retching and are inactive during expulsion. The periesophageal portion of the diaphragm relaxes during expulsion, presumably facilitating rostral movement of gastric contents. Recent studies have begun to examine to what extent medullary respiratory neurons are involved in the control of these muscles during vomiting. Bulbospinal expiratory neurons in the ventral respiratory group caudal to the obex discharge at the appropriate time during (fictive) vomiting to activate either abdominal or internal intercostal motoneurons. The pathways that drive phrenic and external intercostal motoneurons during vomiting have yet to be identified. Most bulbospinal inspiratory neurons in the dorsal and ventral respiratory groups do not have the appropriate response pattern to initiate activation of these motoneurons during (fictive) vomiting. Relaxation of the periesophageal diaphragm during vomiting could be brought about, at least in part, by reduced firing of bulbospinal inspiratory neurons.Key words: brain stem, bulbospinal respiratory neurons, vomiting center critique, diaphragm, abdominal muscles.

scholarly journals Temporal and Spatial Spread of an Intersegmental Reflex in Crayfish

1984 ◽  
Vol 113 (1) ◽  
pp. 109-122
Author(s):  
CHARLES H. PAGE ◽  
DOMINICK GADALETA ◽  
ANTHONY IACOPINO
Keyword(s):  
Nerve Cord ◽  
Ventral Nerve Cord ◽  
Correlation Coefficients ◽  
Extensor Muscle ◽  
Reflex Response ◽  
Abdominal Muscles ◽  
Response Latencies ◽  
Reflex Pathways ◽  
Low Correlation ◽  
Thoracic And Abdominal

An intersegmental reflex initiated by flexing a crayfish leg at the merocarpal joint was examined by recording reflex response latencies of cephalic, thoracic and abdominal muscles. The first response was an intrasegmental resistance reflex in the extensor muscle of the stimulated leg. Spread of the intersegmental reflex occurred in both cephalic and caudal directions. Activation of the cephalic appendages occurred first (antennal levators, with latencies of 14–18 ms) while the abdominal musculature was activated last (superficial extensors, with latencies of 51–62ms). Shift of the stimulus site from the second to the fifth leg resulted in shorter latencies of the fifth leg and abdominal muscle responses while the latency for second leg extensor muscle discharge increased. Low correlation coefficients between the response latencies of pairs of cephalic and abdominal muscles, and thoracic and abdominal muscles, indicate that reflex pathways which initiate the abdominal responses are different from those that evoke the cephalic and thoracic responses. High correlation coefficients indicate common reflex pathways for activating either ipsilateral or contralateral pairs of extensors or flexors in the second and fifth legs. High correlations suggesting common reflex pathways or cross-coupling were also obtained for bilateral pairs of abdominal extensors. Low correlation coefficients for the response latencies of paired muscles indicate separate reflex pathways for (1) bilaterally homologous leg muscles and (2) first-fifth segment abdominal extensors. Surgical isolation of the supraoesophageal ganglion from the ventral nerve cord eliminated the responses of the antennal levators while producing a substantial increase in the response latencies of both maxilliped extensors and the contralateral second leg extensor and flexor, as well as a small but significant decrease in the contralateral first abdominal extensor. The synaptic input zones of the interneurones that mediate the thoracic and abdominal responses are located in the ventral nerve cord and not in the supraoesophageal ganglion.

The effects of age of calves at castration on growth rate, carcass composition and feed efficiency

1963 ◽  
Vol 61 (1) ◽  
pp. 19-25 ◽  
Author(s):  
M. A. Carroll ◽  
J. Pearce ◽  
J. M. Basset ◽  
P. B. Gillard ◽  
T. L. J. Lawrence
Keyword(s):  
Feed Efficiency ◽  
Subcutaneous Fat ◽  
Live Weight ◽  
Growth Efficiency ◽  
Carcass Composition ◽  
Abdominal Muscles ◽  
Food Utilization ◽  
Total Fat ◽  
Thoracic And Abdominal ◽  
Total Muscle

An experiment is described in which four pairs of individually fed identical twin calves were used to investigate the effects of castration at 1 and 7 months, on growth, efficiency of food utilization and carcass composition and conformation.The results indicate that up to 28 weeks of age the late-castrated animals wore superior in liveweight increase, width of head and efficiency with which they converted food to live weight. By slaughter time, at about 18 months, these differences, except width of head, had been eliminated.The carcasses from both treatments were very similar except that a slightly greater percentage of the total muscle occurred in the thoracic and abdominal muscles of the late-castrated animals than in the early-castrated ones. A statistically significant higher percentage of the total fat occurred as subcutaneous fat in the late-castrated animals than in the early-castrated ones.

Respiratory thoraco-abdominal mechanics in man

1964 ◽  
Vol 19 (2) ◽  
pp. 217-223 ◽  
Author(s):  
Joseph Milic-Emili ◽  
Marcello M. Orzalesi ◽  
Charles D. Cook ◽  
James M. Turner
Keyword(s):  
Respiratory Muscles ◽  
Abdominal Muscles ◽  
General Description ◽  
Breathing Patterns ◽  
Lung Volumes ◽  
Trained Subjects ◽  
Thoracic And Abdominal ◽  
Maximal Voluntary Ventilation

The behavior of the diaphragm and the thoracic and abdominal muscles during various static and dynamic respiratory maneuvers was studied in six trained men by measuring intrathoracic (esophageal) and intra-abdominal (gastric) pressures together with lung volumes. The static maneuvers included voluntary relaxation of respiratory muscles, maximal inspiratory and expiratory efforts, and maximal abdominal expulsive efforts. The dynamic maneuvers were forced inspiratory and expiratory vital capacities and maximal voluntary ventilation. The patterns during the various respiratory maneuvers were relatively uniform. Although the number of subjects studied was small, our results would appear to give a general description of thoraco-abdominal mechanics, at least in trained subjects. breathing patterns; static respiratory maneuvers; maximal voluntary ventilation; forced inspiration and expiration; dynamic respiratory maneuvers; abdominal pressures and thoracic pressures at varying lung volumes Submitted on May 13, 1963

scholarly journals Connections between expiratory bulbospinal neurons and expiratory motoneurons in thoracic and upper lumbar segments of the spinal cord

2013 ◽  
Vol 109 (7) ◽  
pp. 1837-1851 ◽  
Author(s):  
J. D. Road ◽  
T. W. Ford ◽  
P. A. Kirkwood
Keyword(s):  
Cross Correlation ◽  
Intercostal Nerve ◽  
Oblique Muscle ◽  
Abdominal Muscles ◽  
Intercostal Muscle ◽  
Nerve Branch ◽  
Monosynaptic Connection ◽  
Distal Branch ◽  
Caudal Medulla ◽  
Thoracic And Abdominal

Cross-correlation of neural discharges was used to investigate the connections between expiratory bulbospinal neurons (EBSNs) in the caudal medulla and expiratory motoneurons innervating thoracic and abdominal muscles in anesthetized cats. Peaks were seen in the cross-correlation histograms for around half of the EBSN-nerve pairs for the following: at T8, the nerve branches innervating internal intercostal muscle and external abdominal oblique muscle and a more distal branch of the internal intercostal nerve; and at L1, a nerve branch innervating internal abdominal oblique muscle and a more distal branch of the ventral ramus. Fewer peaks were seen for the L1 nerve innervating external abdominal oblique, but a paucity of presumed α-motoneuron discharges could explain the rarity of the peaks in this instance. Taking into account individual EBSN conduction times to T8 and to L1, as well as peripheral conduction times, nearly all of the peaks were interpreted as representing monosynaptic connections. Individual EBSNs showed connections at both T8 and L1, but without any discernible pattern. The overall strength of the monosynaptic connection from EBSNs at L1 was found to be very similar to that at T8, which was previously argued to be substantial and responsible for the temporal patterns of expiratory motoneuron discharges. However, we argue that other inputs are required to create the stereotyped spatial patterns of discharges in the thoracic and abdominal musculature.

The ultrastructure of the abdominal musculature of an orchestid amphipod

1990 ◽  
Vol 48 (3) ◽  
pp. 464-465
Author(s):  
Martin A. Levin ◽  
Lisa L. Cale ◽  
Valerie Lynch-Holm
Keyword(s):  
Intertidal Zone ◽  
High Water ◽  
Abdominal Muscles ◽  
Abdominal Musculature ◽  
Dorsal Muscle ◽  
High Water Mark ◽  
Thoracic Legs ◽  
Orchestia Cavimana

Orchestia is a genus of amphipod in the crustacean class Malacostraca. The order Amphipoda contains over 6000 species commonly called side swimmers, scuds and beach fleas(1). Most are marine bottom-dwellers utilizing their thoracic legs and posterior abdominal uropods for walking, crawling and swimming. However, some, like those in the genera Orchestia and Hyale are semiterrestrial. These amphipods, commonly referred to as “beach fleas,' “beach hoppers” or “sand fleas” can hop vigorously for great distances (up to 50 times their length) by extending their abdomens and telsons against the sand(2).In our study, the ultrastructure of the dorsal muscle cord of Orchestia grillus was examined. Vogel(3) described the abdominal muscles of Orchestia cavimana as consisting of two groups of muscles: a strong, complex, dorsal muscle cord used mainly for hopping and a group of weaker, ventral, longitudinal and oblique muscles.The specimens were collected in clumps of decaying seaweed and other detritus from the intertidal zone near the high water mark at Avery Point Beach, Connecticut.

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