Proposed mechanism for reduced jugular vein flow in microgravity
Internal jugular flow is reduced in space, which can be associated with internal jugular vein (IJV) thrombosis. We used a novel, microgravity ‐focused numerical model of the cranial vascular circulation to develop hypotheses for the reduced flow. Weightlessness reduces venous pressures throughout the body which reduces internal jugular vein diameter and thus internal jugular venous flow. AbstractInternal jugular flow is reduced in space compared with supine values, which can be associated with internal jugular vein (IJV) thrombosis. The mechanism is unknown but important to understand to prevent potentially serious vein thromboses on long duration flights. We used a novel, microgravity ‐focused numerical model of the cranial vascular circulation to develop hypotheses for the reduced flow. This model includes the effects of removing hydrostatic gradients and tissue compressive forces – unique effects of weightlessness. The IJV in the model incorporates sensitivity to transmural pressure across the vein, which can dramatically affect resistance and flow in the vein. The model predicts reduced IJV flow in space. Although tissue weight in the neck is reduced in weightlessness, increasing transmural pressure, this is more than offset by the reduction in venous pressure produc ed by the loss of hydrostatic gradients and tissue pressures throughout the body. This results in a negative transmural pressure and increased IJV resistance. Unlike the IJV, the walls of the vertebral ...
Source: Physiological Reports - Category: Physiology Authors: Mimi Lan,
Scott D. Phillips,
Veronique Archambault ‐Leger,
Ariane B. Chepko,
Rongfei Lu,
Allison P. Anderson,
Kseniya S. Masterova,
Abigail M. Fellows,
Ryan J. Halter,
Jay C. Buckey Tags: ORIGINAL ARTICLE Source Type: research
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