敬請指教

本人才疏學淺,懇請諸位先進前輩不吝指正。歡迎光臨:空中視力保健室

2009年8月5日 星期三

胚胎

網膜虹睫表神經; 外肌外鞏血內皮。
水晶表角結膜淚; 其它都在神經脊。


七言絕句: 好詩!




外胚層 (Ectoderm)

表面外胚層 (Surface ectoderm)
Lens
Corneal epithelium
Cojunctiva
lacrimal glands cells


視經外胚層 (Neuroectoderm )

optic nerve
Retina (RPE and neurosensory retina)
ciliary epithelium (pigmented and nonpigmented)
Iris muscle : sphincter and dilator
Iris epithelium

神經外胚層–由後往前:
optic nerve→retina→ciliary epithelium→iris muscle+epithelium


神經脊( Neural crest)

sclera(teporal之外的大部份)
choroid
stroma of iris
corneal stroma+endothelium
trabecular meshwork
Ciliary muscle

=> cornea,iris,choroid,stroma都在neural crest!


* 中胚層 (Mesoderm)
構成:
眼外肌的muscle fiber (sheath與tendon屬於neural crest)
sclera的temporal portion (sclera的其它部份由neural crest構成)
眼部血管的endothelial lining


器官整理:
* cornea
epithelium – surface ectoderm
stroma and endothelium – neurocrest

* sclera
temporal portion–mesoderm
其它部份–neural crest

* optic nerve:neuroectoderm

* extraocular muscle
belly – mesoderm
tendon and sheath – neural crest


Uvea

* Iris
 Iris muscle (dilator/sphincter)/epithelium – neuroectoderm
 Iris stroma–neural crest

* Choroid – neural crest

* Ciliary muscle – neural crest
 Melanocyte – neural crest
 Trabecular meshwork – Neural crest

* Lens – surface ectoderm


* vitreous–mesoderm + surface ectoderm + neuroectoderm (只差沒有neural crest→因為vitreous沒有 stroma)
* Retina–neuroectoderm
* RPE–neuroectoderm


Anterior chambers 的形成是經由Neural crest cells migrate分化而來
第1波:形成corneal endothelium(1內)
第2波:形成iris, 部份papillary membrane(2彩)
第3波:形成Keratocytes(3角)

口訣: 跳土風舞:「前一二三…向內踩腳」… 1內,2彩,3角


lens embryology:

22天–optic primordium
25天–optic vesicle
27天–lens plate
29天–lens pit
33天–lens vesicle且同時optic vesicle →2 layered optic cup
40天–來至後方的cells elongated→primary lens fiber(embryonic nucleus)→7週至8個月→來至equator的epithelium分化成secondary lens fiber→fetus nucleus

suture–由於lens由外向內分泌fiber,當前後cells相會時,則形成suture,在8週時可見到前有正立Y,後有倒Y結構(前正後倒)

Tunical vasculosa lentis – 分成:
Ant. vascular capsule
 來自long ciliary a.
 形成pupillary strand
 Capsulopupillary portion
Post. vascular capsule
 來自hyaloid a.
 形成Mittendorf dot

zonular fiber在3個月大時由ciliary epithelium來
congenital aphakia – 分primary (根本沒發育)及secondary(發育後又absorb掉)


* Mesenchymal structures of the head, including the eye, are all derived from "a combination of neural crest cells and mesoderm"

* The mesoderm gives rise to all vascular endothelia, all extraocular muscles, and temporal sclera