MRI of a knee. MRIs employ powerful magnets which produce a strong magnetic field that forces protons in the body to align with that field. When a radiofrequency current is then pulsed through the patient, the protons are stimulated, and spin out of equilibrium, straining against the pull of the magnetic field.
Noun. 1. aestivation - (zoology) cessation or slowing of activity during the summer; especially slowing of metabolism in some animals during a hot or dry period. estivation. zoological science, zoology-the branch of biology that studies animals.
View Full Document. 03/28/13 page 10 Review Sheet Results 1. Define inactivation as it applies to a voltage-gated sodium channel. Your answer: Voltage-gated sodium channels have three types of states: deactivated (closed), activated (open), and inactivated (closed). Channels in the deactivated state are thought to be blocked on their intracellular side by an activation gate, which is removed in response to stimulation that opens the channel.