The hippocampus a seahorse shaped structure within the temporal lobe- the area of above your ears. It is part of the limbic system (involved in emotion, learning, and memory). Recently, a division of the hippocampus has been proposed that separates it into two functional areas: the dorsal (upper) hippocampus is believed to be a factor in spatial learning and memory; and the ventral (lower) hippocampus is believed to play a role in regulation of emotion (Sahay and Hen, 2007).
The olfactory bulb is a forebrain structure at the end of the olfactory nerve which receives smell input from the nose. Particles from the world bind to smell receptors in the nose. These receptors send signals, via the olfactory nerve, to the olfactory bulb.
Bear, Connors, and Paradiso: Neuroscience: Exploring the Brain (Third Edition)
Carlson: Physiology of Behavior (Tenth Edition)
By Matt McGranaghan and Mike Hadley