. Le bulletin biologique. Biologie ; zoologie ; biologie ; biologie marine. CO-ACTIVATION DES MOTONEURONES ANTAGONISTES 245. La figure 5. (A, B) de la morphologie des neurones cabine révélé par carboxyfluorescéine injections. Une seule flèche indique la position de la cellule neurone de dbo RCAB. Les flèches montrent le paracerebral Double Tissu conjonctif : cer- ganglion cérébroïde, ped-ganglionnaires de la pédale, int-intestinale dorsale. leur réaction dépend uniquement de la vitesse de traction- musculaire. Cela pose la question intéressante de la façon dont la Clione cônes buccale, qui sont des structures d'hydrostatique, ex- pand à un taux qui est à l'intérieur de la plage o

• Contributeur: Library Book Collection / Alamy Banque D'Images
• ID de l’image: RHMDNA
• Taille du fichier: 7,2 MB (369,4 KB Téléchargement compressé)
• Autorisations: Modèle - non | Propriété - non
• Dimensions: 1895 x 1319 px | 32,1 x 22,3 cm | 12,6 x 8,8 inches | 150dpi

Informations supplémentaires

Cette image appartient au domaine public, ce qui signifie que le droit d’auteur a expiré ou que le titulaire du droit d’auteur a renoncé à ses droits. Les frais facturés par Alamy couvrent l’accès à la copie haute résolution de l’image.

Cette image peut avoir des imperfections car il s’agit d’une image historique ou de reportage.

. The Biological bulletin. Biology; Zoology; Biology; Marine Biology. CO-ACTIVATION OF ANTAGONISTIC MOTONEURONS 245. Figure 5. (A, B) Morphology of CAB neurons revealed by carboxyfluorescein injections. A single arrow shows the position of the cell bod of neuron RCAB. Double arrows show the paracerebral connective: cer— cerebral ganglion, ped—pedal ganglion, int—intestinal ganglia. their reaction depends only on the speed of muscle con- traction. This raises the interesting question of how the Clione buccal cones, which are hydrostatic structures, ex- pand at a rate that is within the range of muscular elon- gation. We propose here that co-activation of functionally reciprocal A and B motoneuron groups, which evoke pro- traction and retraction of buccal cones respectively, is critical for their rapid and powerful extrusion. The time of Clione buccal cone expansion depends on the time required for synchronizing the activities of all muscles involved in producing this reaction, and on the time required for moving hemocoelic fluid into the cone cavities. The first factor, synchronization, is a problem because buccal cone expansion requires the contraction of many muscle groups, including head wall muscles, neck muscles, circular muscles of buccal cones, and muscles opening the skin folds. Twenty-six A motoneurons whose activity evokes contraction of these muscles have been identified in the cerebral ganglia of C//om?(Norekian and Satterlie. 1993). Synchronized activity of all A neurons is required for initiating buccal cone extrusion. One second of co-activation observed in A and B motoneurons prior to buccal cone inflation would give time for synchroni- zation of activities of all A neurons and all muscle groups participating in this reaction. The second problem is the necessity to eject hemocoelic fluid into cone cavities as rapidly and forcefully as possible. Two factors appear to contribute to resolving this problem. First, Hermans and Satterlie (1992) demon

Recherche dans la banque de photos par tags

• bookauthorlilliefrankrat
• booksubjectbiology
• booksubjectzoology