scholarly journals CHEMICAL CHANGES IN THE ADDUCTOR MUSCLE OF THE CHELIPED OF THE CRAYFISH IN RELATION TO THE DOUBLE MOTOR INNERVATION

1938 ◽  
Vol 22 (2) ◽  
pp. 193-206 ◽  
Author(s):  
W. R. Bergren ◽  
C. A. G. Wiersma
Keyword(s):  
Lactic Acid ◽  
Adductor Muscle ◽  
Mechanical Action ◽  
Phosphate Content ◽  
Motor Innervation ◽  
Chemical Changes ◽  
Maximum Extent ◽  
Mechanical Effects ◽  
Slow Contraction ◽  
Stimulation Of

An investigation has been made of the phosphate and lactic acid changes in the adductor muscle of the cheliped of the crayfish Cambarus clarkii upon stimulation of the isolated axons for the fast and slow contractions at determined frequencies. The data obtained point to the following conclusions: 1. When the mechanical effects of the two types of contraction are the same, the chemical changes are of the same order. If the mechanical effects are different, the chemical changes likewise are not equivalent. This is especially to be seen in the case of stimulation at 50 shocks per second: a slowly rising, long continued, strong slow contraction takes place with no apparent change in the phosphate content; a quickly rising fast contraction occurs with a large increase in the phosphate. 2. Since equivalent chemical changes accompany equivalent mechanical action, the two types of contraction do not differ in the essential mechanism of the chemical changes involved, and only one type of contractile substance is present. 3. Even when a contraction has taken place to the maximum extent obtainable, only enough phosphate is found to correspond to one-fifth to one-third of the available phosphagen.

scholarly journals The Motor Innervation of a Triply Innervated Crustacean Muscle

1939 ◽  
Vol 16 (4) ◽  
pp. 398-402
Author(s):  
A. VAN HARREVELD
Keyword(s):  
Mechanical Injury ◽  
Muscle Fibres ◽  
Motor Innervation ◽  
Nerve Fibres ◽  
Crustacean Muscle ◽  
Conduction Process ◽  
Slow Contraction ◽  
Stimulation Of

The crustacean muscle is extremely sensitive to mechanical injury. This is due to the fact that the muscle fibres are innervated by a feltwork of nerve fibres which surrounds them. Apparéntly, there is a lack of a muscular conduction process in these muscles. Contractions have been observed in the same muscle fibres during stimulation of the axon for the fast contraction as well as during stimulation of the fibre for the slow contraction.

scholarly journals A Comparative Study Of The Double Motor Innervation In Marine Crustaceans

1938 ◽  
Vol 15 (1) ◽  
pp. 18-31
Author(s):  
C. A. G. WIERSMA ◽  
A. VAN HARREVELD
Keyword(s):  
Mechanical Response ◽  
Time Interval ◽  
Muscle Action ◽  
Motor Innervation ◽  
Action Current ◽  
Marine Crustaceans ◽  
First Case ◽  
Slow Contraction ◽  
Thick Fibre ◽  
Stimulation Of

A double motor innervation has been shown for several muscles of marine crustaceans. The adductors of the claws of Randallia and Blepharipoda and the adductor of the dactylopodite of the walking leg of Cancer were studied physiologically. The two motor axons which innervate these muscles have a different diameter (ratio 1.4: 1). Stimulation of the thick fibre causes a response, which, though it is not always faster than the response of the thin fibre, must be considered as a "fast" contraction. In Randallia and in Blepharipoda the slow contraction is higher than the fast with frequencies of less than ± 50 per sec., in Cancer with frequencies less than 100 per sec. The action currents of the two kinds of contraction are different. Both show facilitation, but under the same conditions of stimulation the fast-action currents are higher. The first stimulus of the thick fibre causes an action current top which is clearly distinguishable, the action currents of the slow contraction show up only after a number of stimuli. Even when the mechanical reaction on stimulation of the thick fibre is smaller than on similar stimulation of the thin fibre, the action currents are higher in the first case. A single impulse in the thick fibre does not cause a contraction, but sets up a muscle-action current. The chronaxie of this action current in Blepharipoda and Randallia is 0.8σ and is about the same as that found for the action current of the nerve. Two impulses in the thick fibre may cause a mechanical response, as is shown by summation experiments. The pseudo-chronaxie of this contraction was measured as 3.5 σ. The second action current shows facilitation, when it follows the first within 1 sec.; a mechanical reaction results with summation intervals of two stimuli of less than 10σ. The facilitation of the action current increases with decrease of the time interval between the two impulses; with the shortest intervals that give summation the resulting action current is a smooth high spike.

Cross-Innervation of the Thyroarytenoid Muscle by a Branch from the External Division of the Superior Laryngeal Nerve

1997 ◽  
Vol 106 (7) ◽  
pp. 594-598 ◽  
Author(s):  
Sina Nasri ◽  
Joel A. Sercarz ◽  
Pouneh Beizai ◽  
Young-Mo Kim ◽  
Ming Ye ◽  
...  
Keyword(s):  
Vocal Fold ◽  
Superior Laryngeal Nerve ◽  
Laryngeal Nerve ◽  
Spasmodic Dysphonia ◽  
Clinical Implications ◽  
Motor Innervation ◽  
Vocal Fold Vibration ◽  
Adductor Spasmodic Dysphonia ◽  
Thyroarytenoid Muscle ◽  
Stimulation Of

The neuroanatomy of the larynx was explored in seven dogs to assess whether there is motor innervation to the thyroarytenoid (TA) muscle from the external division of the superior laryngeal nerve (ExSLN). In 3 animals, such innervation was identified. Electrical stimulation of microelectrodes applied to the ExSLN resulted in contraction of the TA muscle, indicating that this nerve is motor in function. This was confirmed by electromyographic recordings from the TA muscle. Videolaryngostroboscopy revealed improvement in vocal fold vibration following stimulation of the ExSLN compared to without it. Previously, the TA muscle was thought to be innervated solely by the recurrent laryngeal nerve. This additional pathway from the ExSLN to the TA muscle may have important clinical implications in the treatment of neurologic laryngeal disorders such as adductor spasmodic dysphonia.

Motor innervation within supernumerary legs of cockroaches

1975 ◽  
Vol 63 (2) ◽  
pp. 497-503
Author(s):  
J. Westin ◽  
J. M. Camhi
Keyword(s):  
Motor Innervation ◽  
Stimulation Of

1. Clusters of legs having prothoracic and metathoracic origins were grown from the metathoracic coxa of the cockroach. 2. Or occasionally two, of the three major nerves innervating the cockroach leg. 3. Stimulation of a particular leg nerve (no. 3, 5 or 6) evoked movement at the same joints and in the same directions in a leg having only one nerve as in a normal leg. 4. Stimulation of a particular metathoracic nerve generally produced the same movements in a prothoracic leg transplanted to the metathoracic site as it did in a regenerated or intact metathoracic leg.

scholarly journals Influence of fat-free, fat and sucrose diets on rat periodont condition

2021 ◽  
Vol 11 (5) ◽  
pp. 179-184
Author(s):  
T. I. Pupin
Keyword(s):  
Lactic Acid ◽  
Dental Caries ◽  
Sunflower Oil ◽  
Catalase Activity ◽  
The State ◽  
Tooth Decay ◽  
Elastase Activity ◽  
Sucrose Diet ◽  
Different Content ◽  
Stimulation Of

Aim. To investigate the effect of consumption of diets with different content of fat and sugar on the state of the periodontium of rats.Methods. The rats received a semi-synthetic fat-free diet (FFD), a fat diet (5 % sunflower oil), and a sucrose diet (50 % sucrose) for 30 days. Determined the degree of periodontal atrophy, tooth decay and in the gum homogenate - the activity of elastase, catalase, urease, lysozyme and the content of malondialdehyde (MDA).Results. Sugar diet increases the degree of periodontal atrophy and tooth decay, but decreases elastase activity in the gums and increases catalase activity.  Fat diet does not affect periodontal atrophy and tooth decay, but it reduces catalase activity.Conclusion. The increase in the intensity of caries and periodontal atrophy under the influence of a sucrose diet is probably due to the stimulation of the formation of lactic acid. Fat nutrition does not affect the intensity of dental caries and the degree of periodontal atrophy.

Memoirs: The Neuro-Muscular Mechanism of the Gill of Pecten

1930 ◽  
Vol s2-73 (291) ◽  
pp. 365-392
Author(s):  
S. B. SETNA
Keyword(s):  
Feeding Habits ◽  
Adductor Muscle ◽  
The Body ◽  
Muscle Fibres ◽  
Direct Stimulation ◽  
Gill Filaments ◽  
Lateral Extent ◽  
Branchial Nerve ◽  
The Individual ◽  
Stimulation Of

Experimental. 1. The contraction of the adductor-muscle which follows stimulation of the palial nerve is preceded by a marked contraction of the ctenidial axis, so that the gill contracts before the adductor-muscle becomes active. This movement of the ctenidium is abolished if the main branchial nerve is cut near its origin. 2. The gills of Pecten possess a neuromuscular mechanism which is to some extent independent of the rest of the body, so that excised gills when stimulated react in the same way as an attached gill. 3. The lamellae of the gill possess two distinct types of movement. (a) When the surface of the gill is stimulated by contact with a glass rod or by carmine particles, the frontal surfaces of the two lamellae approach each other; the movement very often being executed by the lamella which is not actually being stimulated. The lateral extent of these movements (concertina movements) is roughly proportional to the intensity of the stimulus. Such movements normally appear to transfer the bulk of the material on to the mantle. Separation of the main branchial nerve abolishes these movements. (b) Each principal filament is capable of moving the ordinary filaments to which it is attached. This movement (flapping movement) is due to the movements of the interfilamentar junctions which alternatively move up and down at right angles to their length. This motion is independent of the branchial nerve and can be produced by direct stimulation of very tiny pieces of the individual filaments. 4. The significance of gill movements to feeding habits is discussed. The course of food particles depends on the nature of the stimuli affecting the gill. Histological. 5. The ctenidial axis and the principal filaments have a stratum of anastomosing nerve-cells which appear to form a true nerve-net comparable to that of the mantle. 6. The gill receives nerve-fibres from two sources, the brain and the visceral ganglion. The subsidiary branchial nerve is a structure hitherto unknown in the molluscan gill; so far its function is unknown. Each gill has four main longitudinal nerve-trunks. 7. The osphradium of the gill has a much more extensive distribution than has hitherto been supposed. 8. Two sets of muscles exist at the base of the gill-filaments, and these are responsible for movements of the lamellae. The muscle-fibres are non-striated. 9. The principal filaments are connected to the ordinary filaments by processes containing true muscle-cells, and by these cells movements of the filaments are effected.

Expansion and Contraction of the Oral Disc in the Sea Anemone Tealia Felina

1972 ◽  
Vol 57 (3) ◽  
pp. 633-649
Author(s):  
I. D. MCFARLANE ◽  
I. D. LAWN
Keyword(s):  
Recovery Period ◽  
Stimulus Frequency ◽  
Sensory Response ◽  
Frequency Range ◽  
Oral Disc ◽  
Nerve Net ◽  
Slow Contraction ◽  
Slow Onset ◽  
Radial Muscle ◽  
Stimulation Of

1. Electrical stimulation of the SS 1 of Tealia felina causes inhibition of spontaneousactivity and increase in length of oral disc radial muscle preparations. This response is elicited over a wide stimulus frequency range (1 every 2 sec to 1 every 30 sec). The response shows a slow onset and a long recovery period. 2. Stimulation of the nerve net at frequencies between 1 shock every 5 sec and 1 shock every 20 sec produces slow contraction. The radials also show fast contractions to shocks less than 2 sec apart. 3. Dissolved food substances excite the SS 1 in the column. The sensory response to application of food extract to a small area of the column shows evidence of sensory adaptation. 4. These observations are related to the pre-feeding response of Tealia and a model for oral disc expansion is described.

Ascorbic Acid Stimulation of Diacetyl Production in Mixed-Strain Lactic Acid Cultures

1979 ◽  
Vol 42 (4) ◽  
pp. 294-296 ◽  
Author(s):  
R. L. RICHTER ◽  
W. S. BRANK ◽  
C. W. DILL ◽  
C. A. WATTS
Keyword(s):  
Ascorbic Acid ◽  
Lactic Acid ◽  
Acid Production ◽  
Sodium Citrate ◽  
Total Solids ◽  
Dry Milk ◽  
Nonfat Dry Milk ◽  
Stimulation Of

The effect of three levels of ascorbic acid on diacetyl and acid production by two mixed-strain cultures was investigated. Each culture was grown in nonfat dry milk reconstituted to 11% total solids with 0.1% added sodium citrate. Ascorbic acid concentrations in the milk were 0, 0.10, and 0.25%. Stimulation of diacetyl production was observed at both concentrations of ascorbic acid. The stimulatory effect of ascorbic acid at both concentrations was approximately the same for each culture. Diacetyl production was initiated earlier in samples containing ascorbic acid. Ascorbic acid did not stimulate acid production.

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