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.
Estrogen is the hormone that helps control breast cell proliferation and division. According to OSUMC, breast development during puberty begins after the ovaries start to secrete estrogen. This accumulates fat within the connective tissue of the breasts, causing the breasts to enlarge.