The physiologic responses to exercise are mediated by a complex interaction of central, peripheral, and neurohumoral stimuli designed to increase cardiopulmonary function. With repetitive exercise, significant cardiovascular and muscular adaptations occur that facilitate and enhance the response to exercise. Exercise is beneficial not only to younger healthy individuals, but to ...

Ageing of the cardiovascular system presents several costly public health problems, loss of quality of life, dependency, and other various health hazards. Large declines of 0-24% per decade in cardiovascular function have been cited in the literature but no long-term longitudinal studies have been reported. Serially measured cardiovascular function was ...

In recent studies in humans the role of cardiopulmonary baroreflexes in modulating the cardiovascular responses to isometric exercise (somatic pressor reflex) has been investigated by performing static handgrip exercise during deactivation of cardiopulmonary receptors produced by low levels of lower body negative pressure; however, findings from these studies have not ...

The effect of imagery perspectives, i.e. internal imagery vs. external imagery, on the psychophysiological responses to imagined exercise was investigated in the present study. Thirty male and female college students were randomly assigned to perform either internal imagery, external imagery or simple rest in addition to actual exercise. Metabolic, cardiovascular ...

The relationship between the forces applied during laryngoscopy and cardiovascular changes were studied in patients undergoing laryngoscopy with or without intubation. This enabled us to differentiate between the cardiovascular effects of laryngoscopy and the effects of tracheal intubation. The forces applied during laryngoscopy were only weakly related to the cardiovascular ...

Peripheral vasopressin (AVP) can act centrally to sensitize the arterial baroreflex and/or peripherally to attenuate regional blood flow by a direct vascular effect. Because plasma concentrations of AVP increase during exercise, this study examined the possibility that AVP is capable of modulating the reflex cardiovascular response to static muscle contraction. ...

At the onset of exercise, signals from the central nervous system result in immediate vagal withdrawal and resulting increases in heart rate and arterial blood pressure. From the second heart beat peripheral nerve (reflex) influence from exercising muscle can be detected. With continued exertion, especially with large muscle groups, this ...

Cardiovascular hyperreactivity (i.e., response in excess of metabolic requirements) to psychological stress has been implicated in the development of coronary heart disease. The purpose of this study was to evaluate cardiovascular hyperreactivity to psychological stress in Type A and B subjects. Fifteen Type A and 15 Type B young men ...

More work needs to be done on the extent to which the pericardium can modulate the cardiovascular response to exercise and the mechanisms whereby this modulation is brought about. Studies are needed to differentiate the effects of the pericardium on the cardiovascular exercise response, comparing trained with untrained subjects. Evidence ...

The importance of +Gz-induced loss of consciousness as a major cause of inflight incapacitation emphasizes the need for predicting +Gz-tolerance and investigating its possible determinants. The cardiovascular changes from +Gz-stress are initially counteracted reflexly by the cardiovascular autonomic system. The integrity of neural cardiovascular reflex control can be assessed by ...

1. The species-specific experimental response to stressors (SSERTS) analysis has been applied to a number of species under varied short and long term conditions. 2. The measure provides quantitative data relating to the physiological responses of animals when exposed to stressors and results are presented comparing these for different methods ...

Exercise can impose an immense stress upon many physiological systems throughout the body. In order that exercise performance may be optimally maintained, it is essential that a profound and complex series of responses is coordinated and controlled. The primary site for coordination is the central nervous system, whereas control mechanisms ...

Exercise presents a major stress to the circulatory system. This article reviews the physiologic effects of acute exercise on the healthy cardiovascular system and contrasts them with the altered effects seen in selected cardiac conditions. The following topics are covered: oxygen production and utilization, isometric versus dynamic exercise, responses to ...

The value of physiological measurement in sport lies in the opportunity it provides to learn more about the responses of individuals to the demands of exercise, the particular physiological characteristics which allow some individuals to become successful at some sports, but not others, and the physiological adaptations to training which ...

Inactivity has a number of consequences for the cardiovascular system. In particular, inactivity can lead to obesity, which can aggravate arthritis. An examination of the effect of exercise on the cardiovascular system requires the review of epidemiologic or population-based studies, because there are no large randomized trials with an exercise ...

To evaluate the cardiovascular and plasma catecholamine responses to dynamic exercise in patients with cardiac neurosis (CN), treadmill testing was performed. Thirty-four patients with CN were chosen for this study based on exercise tolerance and the results were compared with those in 31 patients with organic heart disease and 12 ...

This study compared the physiological responses during roller skiing with the V1 skate, kick double pole, and double pole techniques. Eight male nordic ski racers roller skied over a flat one-mile track at 14 and 18 km.h-1 using each of the three techniques under study. Heart rates and oxygen uptakes ...

The graded treadmill (TM) exercise test is considered the optimal mode of exercise for evaluating the cardiovascular fitness of mentally retarded (MR) individuals. A new mode of exercise, the Schwinn Air-Dyne ergometer (SAE), was evaluated and compared to the TM for determining the cardiovascular fitness of adults. Twelve MR adults ...

The cardinal feature of multiple personality disorder (MPD) is the existence of two or more alter personality states that exchange control over the behaviour of an individual. Numerous clinical reports suggest that these alter personality states exhibit distinct physiological differences. We investigated differential autonomic nervous system (ANS) activity across nine ...

Serotonin is found in large quantities in the gastrointestinal tract, where it can increase gastrointestinal motility. Whether this response represents a physiologic event has not previously been shown. In our investigation eight conscious dogs were fitted with strain gauges to monitor motility responses to serotonin. When infused intravenously, serotonin significantly ...

We studied nine young adult beagles at rest and during four levels of dynamic exercise before and after electrolytic lesions were made in the hypothalamus in the region of the fields of Forel. The beagles were habituated to run freely on a motor-driven treadmill and were instrumented chronically to allow ...

It is known that muscle afferents and the hypothalamic locomotor region (HLR) both project to the nucleus reticularis gigantocellularis (NGC) and that the NGC is capable of influencing cardiovascular and respiratory variables. Therefore, the role of NGC in the cardiovascular and respiratory response to exercise-related signals was investigated in anesthetized ...

The identity of the residual taste response to NaCl after lingual application of the sodium transport blocker, amiloride, was studied by electrophysiological recordings from the rat chorda tympani nerve. Stimulation of the anterior tongue with salt solutions resulted in responses to halogenated sodium salts that were not eliminated by amiloride; ...

Bradykinin (BK, 0.03-1 microgram), capsaicin (1 microgram) or potassium chloride (KCl, 13 mumol) applied to the epicardium of the left ventricle of anaesthetized, open-chest dogs, caused reflex tachycardia and pressor effects, whereas des-Arg9-BK (1-100 micrograms), a selective bradykinin B1-receptor agonist, failed to produce any cardiovascular response. Superfusion of the epicardium ...

The cardiovascular response to static exercise has often been quantified on the basis of a comparison between static handgrip and dynamic cycling exercise. It is then difficult to make precise comparisons because the physical units of work are not compatible. If the data from dynamic exercise can be used to ...

The anatomy and physiology of the middle ear transformer mechanism in man and a species of rodent, desmodillus auricularis, are compared. This rodent's middle ear mechanism has a transformer ratio of 147:1 as compared to 18,3:1 in man--some 8 times greater. The reasons for this difference are given and possible ...

The purpose of this article is to provide background information concerning the cardiopulmonary responses to physical exercise. The focus is on acute and chronic responses to both strengthening and endurance exercise. Knowledge of normal exercise physiology provides the frame of reference for comparison with abnormal responses, especially as exercise relates ...

The sedative and cardiovascular effects of rectally administered diazepam (0.6 mg/kg) were compared to placebo in uncooperative children who required sedation during dental treatment. Twelve healthy preschool children, who required amalgam restorations, were treated during two standardized restorative appointments in a double-blind, crossover study. Blood pressure and pulse were obtained ...

The pressor reflex evoked by muscular contraction (exercise pressor reflex) is one important model of cardiovascular adjustments during static exercise. The central nervous system (CNS) structures mediating this reflex have remained largely obscure. Therefore, we examined the contribution of selected levels of the neuraxis in mediating the pressor reflex evoked ...

This review focuses on 3 aspects of experimental designs for prestress, physiological adaptation periods: (1) effects of duration on stabilization of various physiological parameters:(2) effect of type of activity and instruction on prestress physiological adaptation: and (3) definitions of physiological baselines. Analyses of the literature revealed that for many physiological ...

Neural components important in control of the cardiovascular system during exercise can be divided into central nervous system (CNS) components and peripheral components. CNS components would include the cerebral cortex, cerebellum, medullary region of the brain stem, and the spinal cord. Peripheral components would include the efferent limbs of the ...

In human subjects sustained static contractions of the quadriceps femoris in one leg were performed with the same absolute and the same relative intensity before and after partial neuromuscular blockade with either decamethonium or tubocurarine which reduced strength to about 50% of the control value. During the contractions performed with ...

Nafazatrom is an antithrombic drug that has been shown to have beneficial effects in traumatic shock and organ ischemia. This study evaluated the effect of nafazatrom on cardiovascular, sympathetic, and endocrine consequences to moderate or severe hemorrhagic shock in the conscious rat. Nafazatrom (2 mg/kg, i.v.) had no effect on ...

Corticotropin-releasing factor (CRF) acts within the central nervous system to modify the activity of the sympathetic and parasympathetic nervous systems, cardiovascular function, endocrine-pancreatic function, and carbohydrate metabolism. These changes in animal physiology induced by CRF provide a tenable basis for hypothesizing that this peptide may be physiologically involved in integrating ...

The effect of premedication with intramuscular atropine and glycopyrrolate on the cardiovascular changes resulting from the performance of laryngoscopy and tracheal intubation has been evaluated in two groups of 25 patients undergoing surgery. Neither atropine nor glycopyrrolate attenuated the hypertensive and tachycardic response to laryngoscopy and intubation; both significantly enhanced ...

The heart and lungs work in synchrony as a metabolic unit to transport the respiratory gases, O2 and CO2, between the atmosphere and the metabolizing tissues. This article reviews the physiologic behavior of the cardiopulmonary unit; in particular it focuses on the physiologic stress of exercise and the utility of ...

In six dogs trained to run at 2, 4, and 6 mph, we caused graded reductions in hindlimb perfusion by compressing the terminal aorta. Our goal was to examine the relationship between hindlimb perfusion [terminal aortic flow (TAQ) and femoral arterial pressure (FP)] and cardiovascular responses [aortic pressure (AP), heart ...

The author carried out investigations of the adaptation to exercise of the cardiovascular system in pilots breathing an oxygen-poor gas mixture analysing the polycardiographic parameters at rest and during postexercise restitution. It was found that hypoxia increased the degree of the adaptation response of the cardiovascular system to exercise. Polycardiographic ...

The child with a stiff neck can be a challenging diagnostic exercise. Four unusual examples of acute neck stiffness, not associated with meningitis, are presented to illustrate the various pathologic conditions which may produce this symptom. A differential diagnostic schema is suggested on the basis of pathologic and physiologic alterations ...

It has been suggested that the pancreatic polypeptide response to a meal is inhibited by truncal vagotomy but returns towards normal with time. We have examined this hypothesis by measuring the pancreatic polypeptide response to a meal in five dogs before and 1 and 6 months after truncal vagotomy. Pancreatic ...

The discovery of an iso-renin angiotensin (AII) system within the central nervous system (CNS) led investigators to theorize a physiological and/or pathological role for the central actions of AII. Activation of central AII receptors in specific brain regions elicits antidiuretic, dipsogenic and pressor responses subsequently producing net body fluid retention. ...

The adrenal medullary catecholamine response to graded hemorrhage has not been characterized in awake animals. Using high performance liquid chromatography with electrochemical detection, secretion rates of epinephrine and norepinephrine were measured in trained awake dogs with chronic adrenal venous cannulas. The results indicate that the adrenal medulla responds to small ...

The changes in circulatory system behavior occurring in response to exercise stress are integrated by the central neural circulatory control system working in cooperation with local regulatory mechanisms. The regulatory events occurring during exercise may be analyzed using a closed-loop regulatory system model of the circulation. In this model, the ...

This study examined the effects of individual differences in electrodermal lability on cardiovascular, respiratory, and electrodermal responses (EDRs) in the detection of deception. One Day 1 each of 74 subjects rested quietly for 3 min. while skin conductance was recorded. Electrodermal lability was scored for each subject, those giving frequent ...

Normal male subjects attempted to deceive an experimenter recording electrodermal, respiratory, an cardiovascular activity. Those who had ingested a placebo or nothing were detected with statistically significant frequency on the basis of their phasic electrodermal responses, which clearly distinguished them from truthful suspects. That was not the case with deceptive ...

The influence of spinal somatic afferent pathways upon cardiovascular parameters were studied in anesthetized and conscious dogs. Previous studies on anesthetized cats indicated that activation of somatic A afferent fibres results in a depressor response mediated by ascending spinal pathways in the dorsolateral funiculus (DLF). Additional activation of somatic C ...

A variety of physiological responses, classified as local or central factors, have been suggested as providing the primary input for perception of effort during exercise. The potency of these responses as perceptual cues, however, has seldom been addressed in terms of relevant modifying variables such as exercise intensity, exercise duration, ...

It has long been established that neural activity generated wholly within the central nervous system can affect cardiovascular control. Even during complete paralysis the central cycling of respiratory neurones can impose respiratory rhythmicity on heart rate and vasomotion, and alter the effectiveness of purely cardiovascular reflexes. During muscular exercise centrally-generated ...

A study was made of the physiological effects of smoking, psychological stressors, heat, exercise, and fat ingestion on 12 healthy men. Repeated measurements were made of cardiovascular, neuroendocrine, enzyme, lipid, and other variables in all stressor situations. The main findings were that psychological stressors and exercise were associated with more ...

The statistical features of absolute-based and percentage-based post-caloric EOG response measures were investigated on ten normal and twenty pathological cases. Criteria for the best EOG response measure are introduced. It is concluded that, using the method adopted in this study, the mean interbeat interval can be regarded as the measure ...