File:Gray0928.jpg - Revision history

S8600021: /* Cross-section of Cochlea */

2011-10-27T23:39:10Z

Cross-section of Cochlea

← Older revision		Revision as of 10:39, 28 October 2011
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	==Cross-section of Cochlea==		==Cross-section of Cochlea==

			Ductus Cochlearis (membranous cochlea; scala media)

	~~Ductus Cochlearis (membranous cochlea; scala media).—The~~ ductus cochlearis consists of a spirally arranged tube enclosed in the bony canal of the cochlea and lying along its outer wall. 21 ~~As already stated, the~~ osseous spiral lamina extends only part of the distance between the modiolus and the outer wall of the cochlea~~, while the~~ basilar membrane stretches from its free edge to the outer wall of the cochlea, and completes the roof of the scala tympani. A second and more delicate membrane, ~~the vestibular membrane (Reissneri)~~ extends from the thickened periosteum covering the osseous spiral lamina to the outer wall of the cochlea~~, where~~ it is attached at some little distance above the outer edge of the basilar membrane. A canal is thus shut off between the scala tympani below and the scala ~~vestibuli~~ above~~; this is the ductus cochlearis or scala media (Fig. 928). It is~~ triangular on transverse section, its roof being formed by the vestibular membrane~~, its~~ outer wall by the periosteum lining the bony canal~~, and its~~ floor by the membrana basilaris and the outer part of the lamina spiralis ossea. ~~Its~~ extremities are closed; the upper is termed the lagena and is attached to the cupula at the upper part of the helicotrema; the lower is lodged in the recessus cochlearis of the vestibule. ~~Near~~ the lower end the ductus cochlearis is brought into continuity with the saccule ~~by a narrow, short canal, the canalis reuniens of Hensen (Fig. 924)~~. On the membrana basilaris is situated the spiral organ of Corti. The vestibular membrane is thin and homogeneous, and is covered on its upper and under surfaces by a layer of epithelium. The periosteum, forming the outer wall of the ductus cochlearis, is greatly thickened and altered in character, and is called the spiral ligament. It projects inward below as a triangular prominence, the basilar crest, which gives attachment to the outer edge of the basilar membrane; immediately above the crest is a concavity, the sulcus spiralis externus. ~~The~~ upper portion of the spiral ligament contains numerous capillary loops and small bloodvessels~~, and is termed the stria vascularis~~.		* ductus cochlearis consists of a spirally arranged tube enclosed in the bony canal of the cochlea and lying along its outer wall.
			* osseous spiral lamina extends only part of the distance between the modiolus and the outer wall of the cochlea
			* basilar membrane stretches from its free edge to the outer wall of the cochlea, and completes the roof of the scala tympani.
			* vestibular membrane (Reissneri), a second and more delicate membrane, extends from the thickened periosteum covering the osseous spiral lamina to the outer wall of the cochlea
			** it is attached at some little distance above the outer edge of the basilar membrane.
			* ductus cochlearis or scala media (Fig. 928) is the canal thus shut off between the scala tympani below and the scala vestibule above
			** triangular on transverse section, its roof being formed by the vestibular membrane
			** outer wall by the periosteum lining the bony canal
			** floor by the membrana basilaris and the outer part of the lamina spiralis ossea.
			** extremities are closed; the upper is termed the lagena and is attached to the cupula at the upper part of the helicotrema; the lower is lodged in the recessus cochlearis of the vestibule.
			* canalis reuniens of Hensen (Fig. 924) a narrow, short canal, located at the lower end the ductus cochlearis brought into continuity with the saccule.
			* On the membrana basilaris is situated the spiral organ of Corti.
			* The vestibular membrane is thin and homogeneous, and is covered on its upper and under surfaces by a layer of epithelium.
			* The periosteum, forming the outer wall of the ductus cochlearis, is greatly thickened and altered in character, and is called the spiral ligament.
			** projects inward below as a triangular prominence, the basilar crest, which gives attachment to the outer edge of the basilar membrane
			** immediately above the crest is a concavity, the sulcus spiralis externus.
			** stria vascularis forms the upper portion of the spiral ligament contains numerous capillary loops and small bloodvessels.

S8600021 at 23:33, 27 October 2011

2011-10-27T23:33:25Z

← Older revision		Revision as of 10:33, 28 October 2011
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	==Cross-section of Cochlea==		==Cross-section of Cochlea==


			Ductus Cochlearis (membranous cochlea; scala media).—The ductus cochlearis consists of a spirally arranged tube enclosed in the bony canal of the cochlea and lying along its outer wall. 21 As already stated, the osseous spiral lamina extends only part of the distance between the modiolus and the outer wall of the cochlea, while the basilar membrane stretches from its free edge to the outer wall of the cochlea, and completes the roof of the scala tympani. A second and more delicate membrane, the vestibular membrane (Reissneri) extends from the thickened periosteum covering the osseous spiral lamina to the outer wall of the cochlea, where it is attached at some little distance above the outer edge of the basilar membrane. A canal is thus shut off between the scala tympani below and the scala vestibuli above; this is the ductus cochlearis or scala media (Fig. 928). It is triangular on transverse section, its roof being formed by the vestibular membrane, its outer wall by the periosteum lining the bony canal, and its floor by the membrana basilaris and the outer part of the lamina spiralis ossea. Its extremities are closed; the upper is termed the lagena and is attached to the cupula at the upper part of the helicotrema; the lower is lodged in the recessus cochlearis of the vestibule. Near the lower end the ductus cochlearis is brought into continuity with the saccule by a narrow, short canal, the canalis reuniens of Hensen (Fig. 924). On the membrana basilaris is situated the spiral organ of Corti. The vestibular membrane is thin and homogeneous, and is covered on its upper and under surfaces by a layer of epithelium. The periosteum, forming the outer wall of the ductus cochlearis, is greatly thickened and altered in character, and is called the spiral ligament. It projects inward below as a triangular prominence, the basilar crest, which gives attachment to the outer edge of the basilar membrane; immediately above the crest is a concavity, the sulcus spiralis externus. The upper portion of the spiral ligament contains numerous capillary loops and small bloodvessels, and is termed the stria vascularis.


	{{Template:Gray Anatomy}}		{{Template:Gray Anatomy}}

S8600021 at 13:42, 28 October 2010

2010-10-28T13:42:19Z

← Older revision		Revision as of 00:42, 29 October 2010
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	==Cross-section of Cochlea==		==Cross-section of Cochlea==

	{{Template:~~Grays~~ Anatomy}}		{{Template:Gray Anatomy}}

	[[Category:Historic Embryology]] [[Category:Gray's 1918 Anatomy]] [[Category:Cartoon]]		[[Category:Historic Embryology]] [[Category:Gray's 1918 Anatomy]] [[Category:Cartoon]]
	[[Category:Senses]] [[Category:Hearing]]		[[Category:Senses]] [[Category:Hearing]]

S8600021 at 13:42, 28 October 2010

2010-10-28T13:42:03Z

← Older revision		Revision as of 00:42, 29 October 2010
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	Cross-section of Cochlea		==Cross-section of Cochlea==

			{{Template:Grays Anatomy}}

	[[Category:Historic Embryology]] [[Category:Gray's 1918 Anatomy]] [[Category:Cartoon]]		[[Category:Historic Embryology]] [[Category:Gray's 1918 Anatomy]] [[Category:Cartoon]]
	[[Category:Senses]] [[Category:Hearing]]		[[Category:Senses]] [[Category:Hearing]]

S8600021 at 14:48, 27 September 2009

2009-09-27T14:48:37Z

← Older revision		Revision as of 01:48, 28 September 2009
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			Cross-section of Cochlea

	[[Category:Historic Embryology]] [[Category:Gray's 1918 Anatomy]] [[Category:Cartoon]]		[[Category:Historic Embryology]] [[Category:Gray's 1918 Anatomy]] [[Category:Cartoon]]
	[[Category:Senses]] [[Category:Hearing]]		[[Category:Senses]] [[Category:Hearing]]

S8600021 at 14:48, 27 September 2009

2009-09-27T14:48:17Z

← Older revision	Revision as of 01:48, 28 September 2009
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		[[Category:Historic Embryology]] [[Category:Gray's 1918 Anatomy]] [[Category:Cartoon]]
		[[Category:Senses]] [[Category:Hearing]]

S8600021 at 14:18, 27 September 2009

2009-09-27T14:18:19Z

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