For each of the following descriptions, indicate whether it applies to a macula or a crista ampullaris: inside a semicircular canal; contains otoliths; responds to linear acceleration and deceleration; has a cupula; responds to rotational acceleration and deceleration; inside the vestibule.

Verified step by step guidance

1. Step 1: Understand the anatomical locations and functions of the macula and crista ampullaris. The macula is located in the vestibule of the inner ear (specifically in the utricle and saccule) and is responsible for detecting linear acceleration and deceleration. The crista ampullaris is located inside the semicircular canals and detects rotational acceleration and deceleration.
2. Step 2: Analyze the description 'inside a semicircular canal.' This applies to the crista ampullaris because it is specifically found within the ampulla of the semicircular canals.
3. Step 3: Analyze the description 'contains otoliths.' This applies to the macula because it contains otoliths (calcium carbonate crystals) embedded in a gelatinous layer, which help detect linear movements.
4. Step 4: Analyze the description 'responds to linear acceleration and deceleration.' This applies to the macula because its structure is designed to detect changes in linear motion using the otoliths and hair cells.
5. Step 5: Analyze the descriptions 'has a cupula' and 'responds to rotational acceleration and deceleration.' These apply to the crista ampullaris because it has a gelatinous structure called the cupula that bends in response to rotational movements, stimulating the hair cells within the ampulla.

Key Concepts

Macula

The macula is a sensory structure located within the vestibule of the inner ear, specifically in the utricle and saccule. It contains otoliths, which are small calcium carbonate crystals that help detect linear acceleration and deceleration. The macula is crucial for maintaining balance and spatial orientation by responding to changes in head position relative to gravity.

Crista Ampullaris

The crista ampullaris is a sensory structure found within the ampullae of the semicircular canals in the inner ear. It contains a gelatinous structure called the cupula, which moves in response to rotational acceleration and deceleration of the head. This movement stimulates hair cells in the crista, allowing the body to perceive changes in angular motion, which is essential for balance.

Semicircular Canals vs. Vestibule

The semicircular canals and vestibule are both parts of the inner ear involved in balance. The semicircular canals are oriented in three planes and are responsible for detecting rotational movements, while the vestibule contains the macula and is responsible for sensing linear movements. Understanding the distinct functions and locations of these structures is key to answering questions about their roles in the vestibular system.