Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Cerebral blood flow velocity and cranial fluid volume decrease during +Gz acceleration.

Y Kawai1, S C Puma, A R Hargens

  • 1NASA Ames Research Center, Gravitational Research Branch, Moffett Field, CA 94035-1000, USA.

Journal of Gravitational Physiology : a Journal of the International Society for Gravitational Physiology
|September 7, 2001
PubMed
Summary
This summary is machine-generated.

Related Concept Videos

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Lower body negative pressure reduces jugular and portal vein volumes and counteracts the elevation of middle cerebral vein velocity during long-duration spaceflight.

Journal of applied physiology (Bethesda, Md. : 1985)·2021
Same author

TRIPLETS - A Rare Case Report.

Medical journal, Armed Forces India·2016
Same author

Novel magnetism of Ir5+(5d4) Ions in the double perovskite Sr2YIrO6.

Physical review letters·2014
Same author

The focometer: use in aphakic correction.

Community eye health·2007
Same author

Cerebral calculi in the temporal horn of the lateral ventricle: report of an unusual case.

Histopathology·2007
Same author

Effects of respiratory muscle training on respiratory CO2 sensitivity in SCUBA divers.

Undersea & hyperbaric medicine : journal of the Undersea and Hyperbaric Medical Society, Inc·2007
Same journal

Hypergravity effects on pregnancy and parturition.

Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology·2013
Same journal

Characteristics of the parallel-plate flow chamber for mechanical stimulation of bone cells under microgravity.

Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology·2009
Same journal

From the first dog to the last monkey in space.

Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology·2008
Same journal

Columbus, the European Physiology Modules Facility and CADMOS.

Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology·2008
Same journal

Abdominal and fetal echography tele-operated in several medical centres sites, from an expert center, using a robotic arm & telephone or satellite link.

Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology·2008
Same journal

WISE-2005: developing a non-invasive method to monitor cardiovascular deconditioning.

Journal of gravitational physiology : a journal of the International Society for Gravitational Physiology·2008
See all related articles

High +Gz acceleration significantly reduces cerebral blood flow (CBF) velocity and cranial fluid volume. This study monitored CBF velocity and fluid shifts during simulated high-G exposure.

Area of Science:

  • Aerospace Medicine
  • Human Physiology
  • Cardiovascular Research

Background:

  • Understanding the physiological effects of +Gz acceleration is crucial for aviation safety.
  • Cerebral blood flow (CBF) and cranial fluid dynamics are key factors during high-G exposure.

Purpose of the Study:

  • To investigate the impact of graded +Gz acceleration on cerebral blood flow velocity and cranial fluid volume in humans.
  • To determine the relationship between +Gz exposure and physiological changes in the brain.

Main Methods:

  • Transcranial Doppler ultrasonography was used to measure CBF velocity.
  • Rheoencephalography was employed to assess cranial fluid volume changes.
  • Subjects were exposed to graded +Gz acceleration until vision loss (physiological end point).
Keywords:
NASA Center ARCNASA Discipline Cardiopulmonary

Related Experiment Videos

Main Results:

  • Mean CBF velocity decreased by 48% at the point of peripheral vision loss (5.7 Gz).
  • Cranial impedance, indicating fluid loss, increased significantly (p<0.05).
  • Both CBF velocity reduction and cranial impedance increase correlated with Gz levels.

Conclusions:

  • +Gz acceleration without straining maneuvers significantly reduces mean CBF velocity.
  • A caudal fluid shift from intra- and extracranial tissues likely occurs during +Gz exposure.
  • These findings highlight the cerebrovascular challenges associated with high-G environments.