Subject(s)
Adenocarcinoma/surgery , Palliative Care/methods , Pancreatectomy/methods , Pancreatic Neoplasms/surgery , Stomach Neoplasms/surgery , Adenocarcinoma/drug therapy , Adult , Antineoplastic Combined Chemotherapy Protocols/therapeutic use , Combined Modality Therapy , Female , Humans , Neoplasm Invasiveness , Neoplasm Staging , Neoplasms, Second Primary , Pancreatic Neoplasms/drug therapy , Stomach Neoplasms/drug therapyABSTRACT
Chemical stimulation of the central nucleus of the amygdalar complex was carried out in rats during performance of tests of avoidance of "lighted square" and "threatening situation". Microinjections of monoamines, GABA, glutamate, some of their receptor agonists and antagonists revealed neurochemical heterogeneity of the structure and functional ambiguity of neurotransmitter systems in genesis of anxiety of different aversive modes. Chlordiazepoxid, phenibut, indoter, campiron, campironin decrease anxiety in the tests of avoidance of "lighted square" and "threatening situation", their effects being similar to those of dopamine, GABA, or serotonin. A conclusion is made that distinctions in spectra of anxiosedative and anxioselective drugs under study may be caused by unequal contribution of monoamine and amino acid transmitter mechanisms of the central region of the amygdalar complex in genesis of heteromodal aversive anxiety.
Subject(s)
Amygdala/drug effects , Anti-Anxiety Agents/pharmacology , Anxiety/physiopathology , Disease Models, Animal , Amygdala/metabolism , Animals , Anti-Anxiety Agents/administration & dosage , Anxiety/etiology , Avoidance Learning/drug effects , Avoidance Learning/physiology , Male , Microinjections , RatsABSTRACT
Horizontal "extension-flexion" movement of human arm at the elbow joint was studied. Humans performed movements in accordance with the instruction to ignore sudden trajectory changes that arose by the arm during lengthening of different elastic rods with friction. It was shown by multi-dimension regression analysis that the electric activity of biceps and triceps muscles of the shoulder was correlated first of all with the work of load and then with loading force, muscle work and other mechanic and myographic characteristics. One could suppose that information on energy quantities was contained in afferentation signals of the nervous system to correct the program commands on the spinal level. The purpose of correction was to preserve constant quantity of energy expenditure, as well as accuracy and duration of movement.
Subject(s)
Elbow Joint/physiology , Muscles/physiology , Biomechanical Phenomena , Electromyography , Humans , WorkABSTRACT
The muscle force action at the human elbow joint was studied during disturbed and non-disturbed horizontal rhythmic movement of forearm. It was shown that at the initial phase of unshocked perturbation++ the muscles efficiently resist the loading because its viscoelastic properties are quickly changed. Then the influence of the changes is almost vanished, apparently, with participation of nervous regulation.
Subject(s)
Elbow Joint/physiology , Movement , Muscles/physiology , Humans , MathematicsABSTRACT
It was shown by experiments with human forearm rhythmic movements that summary force, stiffness and viscosity of musculature quickly increased during the action of external unshocked disturbance. These effects limited the movement trajectory changes during latent interval preceding nervous reactions.
Subject(s)
Movement , Muscle Contraction , Muscles/physiology , Adult , Biomechanical Phenomena , Forearm/physiology , Humans , Male , Middle AgedABSTRACT
It has been found that there were almost piece linear functions "moment of control forces-joint angle" during non-rhythmic human habitual movements whose basis was flexion or extension of elbow. It means that non-linear effects due to direct effects of time, muscle length and contraction velocity in net muscle force were eliminated by neural regulation. One of the main regulation tasks seems to achieve invariability of energy expenditure in regard to motion trajectories. So, the linearizing of control forces indicates uniparametric nature of control process. It was shown that in addition to linear dependences there were also non-linear functions "moment of control force-joint angle". This suggests that on the whole the control process is characterized by more than one parameter.
Subject(s)
Elbow Joint/physiology , Movement , Muscles/physiology , Biomechanical Phenomena , Humans , Muscles/anatomy & histologyABSTRACT
It was shown by studying control forces and phasic trajectories during oscillation of human forearm, locomotion and rocking of the body on the support that there was an image of accomplished movement in the central nervous system. This image seems to be realized by linear connected displacements of the muscle tension level and threshold of tonic stretch reflex. During the control process, velocity of the threshold and tension level is similarly transformed to that of the body part. The piece constant similarity coefficient is regulated centrally. The main result of such control is moving of the body along energy optimal trajectories.
Subject(s)
Movement , Ankle Joint/physiology , Biomechanical Phenomena , Elbow Joint/physiology , Electromyography , Humans , Mathematics , Models, TheoreticalABSTRACT
It was shown theoretically that trajectories of movements might be invariant to energy expenditure of the organism. In this instance control parameters are changed discontinuously, and force actions of muscles are characterized by potentials. The analysis of well-known experimental data, as well as special investigations of human walking and forearm rhythmic movements confirmed that the activity of the muscle and nervous systems was adapted to the isoenergetic control.
Subject(s)
Energy Metabolism , Movement , Muscles/physiology , Biomechanical Phenomena , Humans , Mathematics , Models, BiologicalABSTRACT
It has been found by transforming experimental kinematic data to normal coordinates with calculating of muscle force moments during walking that the locomotor movements are regulated almost discontinuously at each degree of freedom of leg, so two piece constant parameters of control are switched few times during gait cycle. Therefore musculature acts like switched elastic constraints, and energy expenditure depends on the trajectories of movements essentially less than on the kinematic conditions displayed during fixed switchings.
Subject(s)
Locomotion , Movement , Biomechanical Phenomena , Humans , Models, BiologicalABSTRACT
A linear rheology model with memory was constructed theoretically for an activated muscle moving joint of animal body. It was shown that during unidirectional moving the muscle acts like a controlled viscoelastic body with drifting of length.
Subject(s)
Movement , Muscle Contraction , Muscle Relaxation , Muscles/physiology , Animals , Energy Metabolism , In Vitro Techniques , Time FactorsABSTRACT
It has been found that phasic trajectories were composed of some few elliptical segments during rhythmic movements of human forearm at the elbow. The control program of the movement was shown to be realised as piece constant functions of two control parameters depending on boundary conditions in junctions of the elliptical segments. The control process at the interval between junctions is characterized by an energetic functional being invariant in respect to the trajectories of movements.
Subject(s)
Movement , Muscles/physiology , Elbow Joint/physiology , Humans , Models, Biological , PeriodicityABSTRACT
For human locomotion along the hard ground it was shown that the power of bearing reaction was approximately ten times less than that of the mulscles. Therefore the control of locomotion on the hard surface may be accomplished practically without any information on forces acting between body and support.