Search for dissertations about: "weightlessness"

Showing result 1 - 5 of 6 swedish dissertations containing the word weightlessness.

  2. 1. Lung function in micro- and in hypergravity

    Author : Stéphanie Montmerle; Karolinska Institutet; Karolinska Institutet; []
    Keywords : Lung physiology; human; spirometry; rebreathing; cardiogenic oscillations; phase IV; anti-G suit; stroke volume; weightlessness; closing volume; DLCO;

    Abstract : The lung is extremely susceptible to gravity, even during short-term changes of the gravity vector, because it is a mixture of air and elastic tissue components. Yet, there is limited knowledge of the effects of gravity on the respiratory system. READ MORE

  4. 2. Cardiovascular function after long-term bed rest

    Author : Jonas Spaak; Karolinska Institutet; Karolinska Institutet; []
    Keywords : Microgravity; simulated weightlessness; carotid baroreflex; static exercise; muscle chemoreflex; orthostasis; tilting; leg exercise; blood pressure; heart rate; stroke volume;

    Abstract : On earth, daily activities involve standing, changes of posture and various types of muscle action, all of which challenge the cardiovascular regulation. Removal of the orthostatic stress for a longer period, as during spaceflight or head-down tilt bed rest, consistently results in cardiovascular deconditioning. READ MORE

  5. 3. Effects of physical activity and gravitational stress on cardiovascular control

    Author : Patrik Sundblad; Karolinska Institutet; Karolinska Institutet; []
    Keywords : leg exercise; posture; blood pressure; heart rate; cardiovascular model; heart function; stroke volume; tilting; orthostasis; simulated weightlessness; long-term hypokinesia;

    Abstract : The long-term goal of the present work was to characterize the responses to gravitational challenges in exercising humans after long-term head-down-tilt bedrest (HDT). HDT is a simulation of weightlessness with respect to effects on the systemic circulation, and previous studies in resting men have suggested that impairments of arterial baroreflexes contribute to the orthostatic intolerance seen after HDT and spaceflight. READ MORE

  6. 4. Nitric oxide and the lung : effects of spaceflight and hypergravity

    Author : Lars Karlsson; Karolinska Institutet; Karolinska Institutet; []
    Keywords : ;

    Abstract : Nitric oxide (NO) is an important signal molecule in the body, in particular in the cardiovascular system. This highly reactive molecule is difficult to detect in tissues, but in gas-filled cavities such as the airways it can be detected in part per billion amounts. READ MORE

  7. 5. Biomechanical analyses of flywheel resistance exercise : From a space- and ground-based perspective

    Author : Maria Sjöberg; Ola Eiken; Elena Gutierrez-Farewik; Hans E Berg; Patrik Sundblad; Loren FZ Chiu; KTH; []
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; AnyBody Modeling System; concentric; eccentric; eccentric overload; inverse dynamics; knee extensors; microgravity; musculoskeletal deconditioning; net-joint moment; AnyBody Modeling System; excentrisk; excentrisk överbelastning; invers dynamik; knäextensorer; koncentrisk; ledmoment; mikrogravitation; muskuloskeletal nedbrytning; Teknik och hälsa; Technology and Health;

    Abstract : Astronauts suffer degradation of postural muscles and weight-bearing bones during long-duration spaceflight. Resistance exercise is used as a primary countermeasure against these degradations. READ MORE