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 is a bridge connecting the Spinal Cord with the brain and parts of the brain with each other. Functions: 1. Nuclei of origin for several pairs of cranial nerves. a. Trigerminal (V) Nerves-relay nerve impulses for chewing and for sensation of the head and face.