Final answer:
The vestibular apparatus consists of the utricle, saccule, and semicircular ducts, which detect linear and rotational movements to assist with balance.
Step-by-step explanation:
The components of the vestibular apparatus include the utricle, saccule, and semicircular ducts.
The utricle and saccule are responsible for detecting linear accelerations and head positions relative to gravity. These organs contain hair cells with stereocilia that project into a gelatinous layer. Embedded within this gelatin are calcium carbonate crystals that shift when the head is tilted, stimulating the hair cells, and sending signals to the brain about the head's orientation.
The semicircular ducts (canals) are involved in detecting rotational movements. They consist of three fluid-filled loops, each oriented in a different plane. When the head is rotated, the fluid inside an aligned semicircular canal moves and bends the hair cells' stereocilia, which in turn sends signals to the brain to assist with balance.
The cochlea and spiral organ are involved in hearing, not balance, and therefore are not part of the vestibular apparatus.
The components of the vestibular apparatus are the utricle, saccule, and semicircular ducts.
The utricle and saccule respond to acceleration in a straight line, such as gravity, and help measure head orientation. They contain hair cells that are activated when the head is tilted, bending the stereocilia and stimulating neurons that signal to the brain that the head is tilted, allowing for balance.
The semicircular ducts, which include the posterior, superior, and horizontal canals, respond to rotational movement. They also contain hair cells that bend with fluid movement, allowing the vestibular system to detect the direction of head movements.