Final answer:
The transient cells of the vestibular system are the hair cells located in the utricle, saccule, and semicircular canals, which are responsible for sensing head movements and maintaining balance through their interaction with calcium carbonate crystals called otoliths.
Step-by-step explanation:
The transient cells of the vestibular system are the hair cells located in the utricle and saccule, as well as in the three semicircular canals. These cells are essential for detecting head movements and gravitational forces. The utricle and saccule, which contain about 30,000 and 16,000 hair cells respectively, detect linear acceleration, such as gravity. The hair cells in these structures beneath a gelatinous layer called the otolithic membrane, where their stereocilia extend into. Embedded in the membrane are calcium carbonate crystals known as otoliths.
When the head is tilted, gravity causes the otoliths to shift, causing the gelatin to move and bend the stereocilia of the hair cells. This bending stimulates the adjacent neurons, sending signals through the vestibular nerve to the brain, indicating the direction of tilt and helping to maintain balance. Signals from these hair cells also project to various parts of the brain including the cerebellum and somatosensory cortex for coordination of movement and perception of balance and spatial orientation.