Asunto(s)
Inmersión/fisiopatología , Pulmón/fisiología , Oxígeno/fisiología , Respiración/fisiología , Adulto , Pruebas Respiratorias , Cardiografía de Impedancia , Histamina/análisis , Histamina/metabolismo , Humanos , Pulmón/metabolismo , Masculino , Persona de Mediana Edad , Oxígeno/administración & dosificación , Pruebas de Función Respiratoria , Serotonina/análisis , Serotonina/metabolismo , Temperatura , Factores de TiempoRESUMEN
Cardiovascular responses of sports-pilots to aerobatic maneuvers have been inadequately studied. However many Soviet and foreign authors believe that acceleration effects may seriously deteriorate pilot performance. Our study has shown that cardiovascular changes are to maintain the necessary level of blood pressure in brain and eye arteries. During exposure to +Gz heart rate may be as high as 160 beats/min while during exposure to -Gz it may be as low as 60 beats/min. Pulse photoplethysmography recorded inflight has shown that during exposure to +Gz its amplitude decreases until pulse oscillations disappear, suggesting the development of visual disorders. Pulse photoplethysmography has revealed cardiac arrhythmias in the form of extrasystoles in some pilots. It has also been demonstrated that during flight cardiac arrhythmias can be best detected with the aid of correlation rhythmography.
Asunto(s)
Aceleración/efectos adversos , Medicina Aeroespacial , Arritmias Cardíacas/etiología , Frecuencia Cardíaca , Deportes , Humanos , Masculino , Pulso ArterialRESUMEN
Thirty well-qualified flying sportsmen, aged 22-42, who performer 210 aerobatic flights onboard a sporting airplane Yak-50, were examined, using an automatic monitoring system. The flyers were exposed to +9 Gz and -6 Gz as a maximum the duration of which was 10 s and 5 s, respectively. The onset rate varied from 0.5 to 2.5 G/s (with the mean rate 1 G/s), reaching 4.2 G/s as a maximum. On the average, the training flight lasts 25 min, 45-50% of which the pilot experiences acceleration of various values and different sign. The most common acceleration values are: +6 and +7 Gz or -4 and -5 Gz.
Asunto(s)
Medicina Aeroespacial , Gravitación , Deportes , Aceleración , Adulto , Humanos , Masculino , Factores de TiempoRESUMEN
Circulation variations during LBNP immediate aftereffects were investigated. The test subjects with different test tolerance showed dissimilar cardiovascular responses. The lack of reflex bradycardia in the test subjects with reduced LBNP tolerance gives evidence that their regulatory mechanisms are insufficiently reactive; this is manifested during aftereffects of low LBNP (up to -40 mm Hg).
Asunto(s)
Fenómenos Fisiológicos Cardiovasculares , Descompresión , Presión Negativa de la Región Corporal Inferior , Adolescente , Pruebas de Función Cardíaca , Hemodinámica , Humanos , Masculino , Resistencia Física , Factores de TiempoAsunto(s)
Enfermedades Cardiovasculares/prevención & control , Respiración con Presión Positiva , Ingravidez/efectos adversos , Adaptación Fisiológica , Adulto , Gasto Cardíaco , Enfermedades Cardiovasculares/etiología , Circulación Cerebrovascular , Hemodinámica , Humanos , Masculino , Oxígeno , Postura , Volumen SistólicoAsunto(s)
Hemodinámica , Modelos Estructurales , Ropa de Protección , Ingravidez , Adaptación Fisiológica , Humanos , VacioRESUMEN
It has been shown that during head-down tilting at an angle of -30 degrees occlusion of the four limbs by 70 mm Hg relieved unpleasant symptoms. According to rheoencephalography, cerebral blood flow decreased to the level normally seen in the supine position. During a prolonged head-down tilting at an angle of -15 degrees intermittent occlusion of only lower limbs by 60--30 mm Hg proved more effective.
Asunto(s)
Adaptación Fisiológica , Modelos Biológicos , Ingravidez/efectos adversos , Adulto , Brazo/irrigación sanguínea , Encéfalo/irrigación sanguínea , Humanos , Pierna/irrigación sanguínea , Masculino , Postura , Pulso Arterial , Flujo Sanguíneo Regional , Vuelo Espacial , Factores de TiempoRESUMEN
Thirty male athletes kept in recumbency served as test subjects in 90 LBNP experiments. In the experiments the negative pressure level varied from 40 to 80 mm Hg. During LBNP application the heart rate, arterial pressure, cardiac output, vascular tone and other parameters of circulation were measured. Cardiac output stabilized whereas other cardiovascular parameters changed significantly. Mechanisms of compensatory reaction during LBNP application and indications of its tolerance are discussed.
Asunto(s)
Presión del Aire , Presión Atmosférica , Hemodinámica , Adulto , Circulación Sanguínea , Presión Sanguínea , Fenómenos Fisiológicos Cardiovasculares , Humanos , Masculino , Postura , Pulso Arterial , Descanso , Factores de TiempoRESUMEN
With the aid of the caloric test the functional state of the vestibular analyzer of nine male athletes was investigated during their exposure to lower body negative pressure tests. The prolongation of the latent period of the caloric nystagmus and vertigo, shortening of the time of the nystagmus and vertigo were observed. It is concluded that the cerebral blood supply plays a major role in the development of vestibular reflexes.