File:Gray0653.jpg - Revision history

Z8600021 at 06:40, 26 Mayıs 2014

2014-05-26T06:40:55Z

← Older revision		Revision as of 17:40, 26 Mayıs 2014
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	==Interior of ~~brain~~ of ~~human embryo~~ of ~~five weeks~~==		==Interior of Brain of Human Embryo of Five Weeks==

	From model by {{His}}.		From model by {{His}}.

Z8600021: /* Interior of brain of human embryo of five weeks */

2014-05-26T04:15:07Z

Interior of brain of human embryo of five weeks

← Older revision		Revision as of 15:15, 26 Mayıs 2014
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	==Interior of brain of human embryo of five weeks==		==Interior of brain of human embryo of five weeks==

	From model by His.		From model by {{His}}.

			The Diencephalon.—From the alar lamina of the diencephalon, the thalamus, metathalamus, and epithalamus are developed. The thalamus (Figs. 650 to 654) arises as a thickening which involves the anterior two-thirds of the alar lamina. The two thalami are visible, for a time, on the surface of the brain, but are subsequently hidden by the cerebral hemispheres which grow backward over them. The thalami extend medialward and gradually narrow the cavity between them into a slit-like aperture which forms the greater part of the third ventricle; their medial surfaces ultimately adhere, in part, to each other, and the intermediate mass of the ventricle is developed across the area of contact. The metathalamus comprises the geniculate bodies which originate as slight outward bulgings of the alar lamina. In the adult the lateral geniculate body appears as an eminence on the lateral part of the posterior end of the thalamus, while the medial is situated on the lateral aspect of the mid-brain. The epithalamus includes the pineal body, the posterior commissure, and the trigonum habenulæ. The pineal body arises as an upward the evagination of roof-plate immediately in front of the midbrian; this evagination becomes solid with the exception of its proximal part, which persists as the recessus pinealis. In lizards the pineal evagination is elongated into a stalk, and its peripheral extremity is expanded into a vesicle, in which a rudimentary lens and retina are formed; the stalk becomes solid and nerve fibers make their appearance in it, so that in these animals the pineal body forms a rudimentary eye. The posterior commissure is formed by the ingrowth of fibers into the depression behind and below the pineal evagination, and the trigonum habenulæ is developed in front of the pineal recess.

	The corpus striatum (Figs. 651 and 653) appears in the fourth week as a triangular thickening of the floor of the telencephalon between the optic recess and the interventricular foramen, and continuous behind with the thalamic part of the diencephalon. It increases in size, and by the second month is seen as a swelling in the floor of the future lateral ventricle; this swelling reaches as far as the posterior end of the primitive hemisphere, and when this part of the hemisphere grows backward and downward to form the temporal lobe, the posterior part of the corpus striatum is carried into the roof of the inferior horn of the ventricle, where it is seen as the tail of the caudate nucleus in the adult brain. During the fourth and fifth months the corpus striatum becomes incompletely subdivided by the fibers of the internal capsule into two masses, an inner, the caudate nucleus, and an outer, the lentiform nucleus. In front, the corpus striatum is continuous with the anterior perforated substance; laterally it is confluent for a time with that portion of the wall of the vesicle which is developed into the insula, but this continuity is subsequently interrupted by the fibers of the external capsule.		The corpus striatum (Figs. 651 and 653) appears in the fourth week as a triangular thickening of the floor of the telencephalon between the optic recess and the interventricular foramen, and continuous behind with the thalamic part of the diencephalon. It increases in size, and by the second month is seen as a swelling in the floor of the future lateral ventricle; this swelling reaches as far as the posterior end of the primitive hemisphere, and when this part of the hemisphere grows backward and downward to form the temporal lobe, the posterior part of the corpus striatum is carried into the roof of the inferior horn of the ventricle, where it is seen as the tail of the caudate nucleus in the adult brain. During the fourth and fifth months the corpus striatum becomes incompletely subdivided by the fibers of the internal capsule into two masses, an inner, the caudate nucleus, and an outer, the lentiform nucleus. In front, the corpus striatum is continuous with the anterior perforated substance; laterally it is confluent for a time with that portion of the wall of the vesicle which is developed into the insula, but this continuity is subsequently interrupted by the fibers of the external capsule.

Z8600021: /* Interior of brain of human embryo of five weeks */

2013-02-15T00:44:33Z

Interior of brain of human embryo of five weeks

← Older revision		Revision as of 11:44, 15 February 2013
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	From model by His.		From model by His.

			The corpus striatum (Figs. 651 and 653) appears in the fourth week as a triangular thickening of the floor of the telencephalon between the optic recess and the interventricular foramen, and continuous behind with the thalamic part of the diencephalon. It increases in size, and by the second month is seen as a swelling in the floor of the future lateral ventricle; this swelling reaches as far as the posterior end of the primitive hemisphere, and when this part of the hemisphere grows backward and downward to form the temporal lobe, the posterior part of the corpus striatum is carried into the roof of the inferior horn of the ventricle, where it is seen as the tail of the caudate nucleus in the adult brain. During the fourth and fifth months the corpus striatum becomes incompletely subdivided by the fibers of the internal capsule into two masses, an inner, the caudate nucleus, and an outer, the lentiform nucleus. In front, the corpus striatum is continuous with the anterior perforated substance; laterally it is confluent for a time with that portion of the wall of the vesicle which is developed into the insula, but this continuity is subsequently interrupted by the fibers of the external capsule.

Z8600021 at 22:37, 19 Mayıs 2012

2012-05-19T22:37:39Z

← Older revision		Revision as of 09:37, 20 Mayıs 2012
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	~~:'''Week 5~~ Brain ~~Links:''' [[:File:Gray0652.jpg\|Exterior view]] \| [[:File:Gray0653.jpg\|Interior view]] \| [[Week 5]] \| [[Neural System Development]]~~		{{Gray-Brain}}

Z8600021 at 22:25, 19 Mayıs 2012

2012-05-19T22:25:31Z

← Older revision		Revision as of 09:25, 20 Mayıs 2012
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	:Week 5 Brain: [[:File:Gray0652.jpg\|Exterior view]] \| [[:File:Gray0653.jpg\|Interior view]]		:'''Week 5 Brain Links:''' [[:File:Gray0652.jpg\|Exterior view]] \| [[:File:Gray0653.jpg\|Interior view]] \| [[Week 5]] \| [[Neural System Development]]

Z8600021 at 22:22, 19 Mayıs 2012

2012-05-19T22:22:57Z

← Older revision		Revision as of 09:22, 20 Mayıs 2012
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	From model by His.		From model by His.


			:Week 5 Brain: [[:File:Gray0652.jpg\|Exterior view]] \| [[:File:Gray0653.jpg\|Interior view]]

Z8600021: ==Interior of brain of human embryo of five weeks== From model by His. {{Gray Anatomy}} Category:Human Category:Historic Embryology Category:Week 5 Category:Gray's 1918 Anatomy Category:Neural

2012-05-19T22:00:12Z

==Interior of brain of human embryo of five weeks== From model by His. {{Gray Anatomy}} Category:Human Category:Historic Embryology Category:Week 5 Category:Gray's 1918 Anatomy Category:Neural

New page

==Interior of brain of human embryo of five weeks==

From model by His.

{{Gray Anatomy}}

[[Category:Human]] [[Category:Historic Embryology]] [[Category:Week 5]] [[Category:Gray's 1918 Anatomy]] [[Category:Neural]]