Use "outermost part" in a sentence

1. The Chromosphere is located between the photosphere and the corona, which is the outermost part of the sun’s atmosphere

2. Cortical atrophy is a medical diagnosis indicating a degeneration of brain cells, which is why it’s sometimes called “brain atrophy.” The word “Cortical” refers to the cortex, the outermost part of the brain, which consists of six folded layers of connected neurons.