development of forebrain by dr.arshad
TRANSCRIPT
![Page 1: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/1.jpg)
Development of forebrain
![Page 2: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/2.jpg)
![Page 3: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/3.jpg)
![Page 4: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/4.jpg)
![Page 5: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/5.jpg)
![Page 6: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/6.jpg)
![Page 7: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/7.jpg)
![Page 8: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/8.jpg)
![Page 9: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/9.jpg)
![Page 10: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/10.jpg)
![Page 11: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/11.jpg)
![Page 12: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/12.jpg)
Meroencephaly
![Page 13: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/13.jpg)
Meroencephaly
•failure of the rostral neuropore to close during the fourth week
•forebrain primordium is abnormal and development of the Most of the embryo's brain is exposed or extruding from the cranium-exencephaly.
• .
![Page 14: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/14.jpg)
•abnormal structure and vascularization of the embryonic exencephalic brain-nervous tissue degenerates.
•Remaining brain appear as a spongy, vascular mass; mostly hindbrain structures
![Page 15: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/15.jpg)
•often called anencephaly(Gr. an, without, + enkephalos, brain);a rudimentary brainstem and functioning neural tissue are always present in living infants.
•meroencephaly (Gr.meros, part) is the better term
![Page 16: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/16.jpg)
•common lethal anomaly, occurring at least once in every 1000 births.
•most common serious anomaly seen in stillborn fetuses
•Female preponderance- 2-4 times>males •always associated with acrania (absence
of the calvaria) and may be associated
![Page 17: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/17.jpg)
•suspected in utero when there is an elevated level of AFP in the amniotic fluid
•easily diagnosed by ultrasonography and MRI fetoscopy, and radiography because extensive parts of the brain and calvaria are absent.
•Associated polyhydramniosis- common
![Page 18: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/18.jpg)
Microcephaly
![Page 19: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/19.jpg)
Holoprosencephaly
![Page 20: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/20.jpg)
Holoprosencephaly
• severe and relatively common •Maternal diabetes and teratogens, such
as high doses of alcohol, can destroy embryonic cells in the median plane of the embryonic disc during the third week→ defective formation of the forebrain.
• infants have a small forebrain, merged lateral ventricles
![Page 21: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/21.jpg)
![Page 22: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/22.jpg)
![Page 23: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/23.jpg)
![Page 24: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/24.jpg)
![Page 25: Development of forebrain by DR.ARSHAD](https://reader033.vdocument.in/reader033/viewer/2022052315/556b04c6d8b42ae47d8b45ac/html5/thumbnails/25.jpg)