The Medulla Oblongata's General Functions. Whereas the pons is located in the upper part of the brainstem, the medulla oblongata is a structure located in the lower half of the brainstem. Just because the medulla oblongata is beneath the pons, doesn't mean it's any less significant. In fact, they often work in tandem on issues such as breathing.
Cirrus are detached clouds in the form of white, delicate filaments or white or mostly white patches or narrow bands. These clouds have a fibrous (hair-like) appearance, or a silky sheen, or both. Cirrus clouds are composed almost exclusively of ice crystals. These crystals are in general very small, a fact, which together with their sparseness, accounts for the semi-transparency of most cirrus clouds.
Water clouds tend to have sharp edges, and ice clouds are more wispy. Middle clouds include altocumulus and altostratus clouds. These are usually water clouds, except when it is cold enough at that altitude in the atmosphere for ice crystals to form. Low clouds include stratocumulus, cumulus, stratus, cumulonimbus, and nimbostratus clouds. These clouds are generally made of water droplets. Cumulus and cumulonimbus clouds can be very tall, with their tops as high as middle or high level clouds, but their bases are as low as the other low clouds. For tips on how to tell how high a cloud is in the sky, look for clues on each cloud type page.