Final answer:
The otolithic organs' receptor organ is the hair cells located within the macula, which detect changes in head position by responding to movements of the otolithic membrane influenced by gravity.
Step-by-step explanation:
The receptor organ of the otolithic organs is hair cells.
The macula is the specific region within the otolithic organs where the hair cells are located. These hair cells are surrounded by supporting cells and have their stereocilia extending into a viscous gel known as the otolithic membrane. Over this membrane, a layer of calcium carbonate crystals called otoliths resides.
Upon head movements, the otolithic membrane slides over the macula changing the tension on the stereocilia, leading to depolarization or hyperpolarization of the hair cells. The brain interprets this activity to determine the exact position of the head. In contrast, the organ of Corti is involved in the auditory system, where it performs sound transduction via a different set of hair cells.