What is the Difference Between Crista and Macula

The key difference between crista and macula is that crista is a sense organ present in the ampullae of the semicircular canals of the inner ear, while macula is a sensory spot present in the walls of the saccule within the vestibule of the inner ear.

Crista and macula are two important parts of the vestibular system present in the inner ear. The vestibular system in humans performs essential tasks. It engages a number of important reflex pathways that are responsible for making movements and adjustments in the body position. It also engages in reflex pathways that help the brain to provide perceptions of gravity and body movement.

CONTENTS

1. Overview and Key Difference
2. What is Crista 
3. What is Macula
4. Similarities – Crista and Macula
5. Crista vs Macula in Tabular Form
6. Summary – Crista vs Macula

What is Crista?

Crista is a sense organ present in the ampullae of the semicircular canals of the inner ear. It is also known as crista ampullaris, and it is a sensory organ of rotation. There are three pairs of crista in the inner ear. The normal function of the crista is to sense the angular acceleration and deceleration directed along the plane of the duct.

The inner ear has three specialized regions of the membranous labyrinth (fluid-filled tubes and chambers that are the receptors for the senses of equilibrium and hearing). They are the utricle, saccule, and semicircular canals, which are also known as vestibular organs. The inner ear also has a cochlear duct, which is involved in a special sense of hearing. Semicircular canals are filled with a fluid called endolymph due to its connection with the cochlear duct via saccule, which also normally contain endolymph. Moreover, semicircular canals also contain an inner membranous sleeve that lines the semicircular canals. Furthermore, semicircular canals contain crista ampullaris. The crista ampullaris is a cone-shaped structure covered in receptor cells called hair cells. Crista ampullaris is covered by a gelatinous mass known as the cupula. When there is angular acceleration or rotation, the endolymph in the semicircular canals deflects the cupula against the hair cells of the crista ampullaris. Thus, the hair cells respond by stimulating neurons (vestibulocochlear nerve) that innervate them.

What is Macula?

The macula is a sensory spot present in the walls of the saccule within the vestibule of the inner ear. In fact, the macula is basically hair cells. Its normal function is to detect linear acceleration in a vertical plane. Saccule and utricle are present in the vestibule region of the inner ear. Each saccule and utricle contain a macula to detect linear acceleration.

The macula of the saccule lies in a vertical position. A macula is a 2 mm by 3 mm patch of hair cells. Moreover, each hair cell of the macula contains 40 to 70 stereocilia and one true cilium. The true cilium is known as kinocilium. The tips of the stereocilia and one true cilium are covered by a gelatinous cover known as an otolithic membrane. Furthermore, the otolithic membrane has small, densely packed protein-calcium carbonate granules called statoconica.

What are the Similarities Between Crista and Macula?

• Crista and macula are two important parts of the vestibular system present in the inner ear.
• Both have hair cells.
• Both play key roles in maintaining balance and end equilibrium.
• They are involved in controlling acceleration.
• Both are covered by gelatinous mass or cover.

What is the Difference Between Crista and Macula?

Crista is a sense organ present in the ampullae of the semicircular canals of the inner ear, while macula is a sensory spot present in the walls of the saccule within the vestibule of the inner ear. Thus, this is the key difference between crista and macula. Furthermore, crista is responsible for controlling angular acceleration, while macula is responsible for controlling linear acceleration.

The below infographic presents the differences between crista and macula in tabular form for side-by-side comparison.

Summary – Crista vs Macula

Crista and macula are two important parts of the vestibular system of the inner ear. Crista is a sense organ present in the ampullae of the semicircular canals of the inner ear. It helps to sense the angular acceleration and deceleration directed along the plane of the duct. The macula is a sensory spot present in the walls of the saccule within the vestibule of the inner ear. It helps to detect linear acceleration in a vertical plane. So, this summarizes the difference between crista and macula.

Reference:

1. “Crista Ampullaris.” An Overview | ScienceDirect Topics.
2. “Macula.” Encyclopædia Britannica, Encyclopædia Britannica, Inc.

Image Courtesy:

1. “Blausen 0329 Ear Anatomy Internal Ear” By Blausen.com staff (2014). “Medical gallery of Blausen Medical 2014”. WikiJournal of Medicine 1 (2). DOI:10.15347/wjm/2014.010. ISSN 2002-4436. – Own work (CC BY 3.0) via Commons Wikimedia
2. “1409 Maculae and Equilibrium” By OpenStax College – Anatomy & Physiology, Connexions Web site, Jun 19, 2013. (CC BY 3.0) via Commons Wikimedia