On a Snellen chart we determine the line that the person can just recognize. If that line is twice as large as the reference standard (20/20), we state that that personâs MAgnification Requirement (MAR) is 2x. If the MAgnification Requirement is 2x, the visual acuity is 1/2 (20/40).
Posterior cranial fossa: It is the deepest and most capacious of the 3 cranial fossae. It contains the cerebellum, pons, and medulla oblongata. The foramen magnum is located centrally and inferiorly in the posterior fossa.
Pons. region of the brain stem that is a bulge wedged between the midbrain and the medulla oblongata; forms a bridge connecting not only the brain with the spinal cord, but also parts of the brain with each other, contains two nuclei: pneumotaxic and apneustic, also it contains the nuclei of cranial nerves V-VII.egion of the brain stem that is a bulge wedged between the midbrain and the medulla oblongata; forms a bridge connecting not only the brain with the spinal cord, but also parts of the brain with each other, contains two nuclei: pneumotaxic and apneustic, also it contains the nuclei of cranial nerves V-VII.