1 This drug may have the effect of speeding up your heart rate. 2  I worry about the effect that violent movies may have on children. 3  Certain chemicals have been banned because of their damaging effect on the environment.  It's important to protect your skin from the harmful effects of the sun.
The CSF from all theses sources , as well as any formed in the central canal of the spinal cord, escapes from the fourth ventricle into the subarachnoid space through the median aperture (of Magendie) and lateral aperture (of Luschka).
Part of the pressure-flow theory is that the sucrose produced is moved by active transport into the companion cells of the phloem in leaf veins. This raises the concentration of sucrose molecules in the companion cells above that in the sieve tubes, so they can then move into the sieve tubes by diffusion.