Heterogeneous and lateralized cervical vascular responses to a 7-day head-down tilt bed rest

Figures

• 

  Fig. 1. BFVs of different vessels and total intracranial BFV at different time points. L left, R right, ICA internal carotid artery, VA vertebral artery, BFV blood flow volume, Pre-HDT pre-adaptation period prior to head-down tilt, HDT head-down tilt, R+ recovery time, d day.

• 

  Fig. 2. Significant differences in Vs and Vm-max of bilateral ICAs at different time points. L left, R right, ICA internal carotid artery, VA vertebral artery, Vs peak systolic flow velocity, Vm-max mean peak blood flow velocity, Pre-HDT pre-adaptation period prior to head-down tilt, HDT head-down tilt, R+ recovery time, d day.

• 

  Fig. 3. Significant differences in Vs, Vd, and Vm-max of bilateral VAs at different time points. L left, R right, VA vertebral artery, Vs peak systolic flow velocity, Vd end diastolic flow velocity, Vm-max mean peak blood flow velocity, Pre-HDT pre-adaptation period prior to head-down tilt, HDT head-down tilt, R+ recovery time, d day.

• 

  Fig. 4. Flowchart of the experimental protocol. Pre-HDT pre-adaptation period prior to head-down tilt bed rest, HDT BR head-down tilt bed rest, R+ recovery time, d day.

• 

  Fig. 5. Two-dimensional ultrasound image of a 31-year-old male participant with left VA dominance. The scan shows the bilateral VA diameters in the participant with left VA dominance. VA vertebral artery, L left, R right, D diameter.

• 

  Fig. 6. Hemodynamic features of the ICA in a 21-year-old male participant. Hemodynamic features of the ICA from a left ICA ultrasound Doppler image of the participant. ICA internal carotid artery.