semicircular duct

The lateral semicircular duct is about 30-degree angle from the horizontal plane.

The semicircular ducts provide sensory input for experiences of rotary movements.

This continues until the head stops rotating which simultaneously halts semicircular duct rotation.

The semicircular ducts are filled with endolymph, and contain the crista ampullaris.

The cavity of the utricle communicates behind with the semicircular ducts by five orifices.

The anterior and posterior semicircular ducts are oriented vertically at right angles to each other.

When the head rotates, the endolymph filling the semicircular ducts initially lags behind due to inertia.

The Semicircular canals are filled with endolymph, and also contain an inner membranous sleeve that form semicircular ducts.

The saccule opens into the cochlear duct, through the canalis reuniens, and the semicircular ducts communicate with the utricle.

Upon angular acceleration (rotation), the endolymph within the semicircular duct deflects the cupula against the hair cells of the crista ampullaris.

After a short time of continual rotation however, the endolymph's acceleration normalizes with the rate of rotation of the semicircular ducts.

Kinocilia are present in the crista ampullaris of the semicircular ducts and the sensory maculae of the utricle and saccule.

The receptor cells located in the semicircular ducts are innervated by the eighth cranial nerve, aka vestibulocochlear nerve (more specifically the vestibular portion).

The apertures in the pyramid transmit the nerves to the utricle; those in the recessus ellipticus are the nerves to the ampullæ of the superior and lateral semicircular ducts.

I . . .' "The parts of the ear are the auricle, auditory meatus, tympanic membrane, the chain of ossicles hammer, anvil and stirrup ympanic cavity, the semicircular duct, oval window, the eustachan tube, auditory nerve, and the cochlear duct.'

Three others appear as disk-like evaginations on the surface of the vesicle; the central parts of the walls of the disks coalesce and disappear, while the peripheral portions persist to form the semicircular ducts; of these the superior is the first and the lateral the last to be completed.