Here's how they work:

* Structure: The maculae are sensory patches within the utricle and saccule, both of which are chambers within the inner ear. Each macula contains hair cells, which are specialized sensory cells, embedded in a gelatinous layer called the otolithic membrane. On top of the membrane are tiny calcium carbonate crystals called otoliths.

* Function: When the head moves linearly, the otoliths, being heavier than the surrounding fluid, lag behind due to inertia. This shifts the otolithic membrane, bending the hair cells within the macula. The bending of the hair cells sends signals to the brain via the vestibular nerve, informing the brain about the direction and intensity of the linear acceleration.

* Specifics:

* Utricle: The utricle is more sensitive to horizontal acceleration, such as when you walk or run.

* Saccule: The saccule is more sensitive to vertical acceleration, like when you jump or ride an elevator.

In addition to linear acceleration, the maculae also provide information about the head's position relative to gravity. This is because the otoliths always pull on the otolithic membrane in the direction of gravity. So, even when the head is stationary, the maculae are constantly sending signals to the brain about the head's orientation.

This information from the maculae is crucial for maintaining balance, coordinating eye movements, and keeping a stable sense of spatial awareness.