so hello everyone welcome to my new video so today in this video i will discuss with you all about the embryology of the eye so let's start so there is three germinal layer present that you know there is ectoderm mesoderm and endoderm so for the development of the eye ectoderm and mesoderm take part and endoderm do not take any participation in it now this ectoderm having three part surface ectoderm neuro ectoderm and neural crest cell and this neural crest cell and mesoderm together they are making mesenchyme okay so uh this is surface ectoderm and this is neuro ectoderm now you will ask me the question where is neural crest cell so neural crest cell are around the neural ectoderm and this neuro ectoderm making the forebrain so this forebrain having two groove these are called optic groove now at about third week of gestation this optic groove will grow inward and it will make the optic vesicle so this is optic vesicle and this starting point is called optic stalk so this optic stalk is the future optic nerve as the optic vesicle is formed then at the same time this part of the surface ectoderm get thickened and it form the lens placard now let's see this portion only so as the optic vesicle start forming then This portion of the surface ectoderm start thickening and it form the lens placard. Now optic vesicle get depressed inside as well as the lens placard follow optic vesicle and invaginate and it form the lens pit. So this invagination of the lens placard is done by the help of microfilament that present in the early retinal cells.
Now the optic vesicle will form the optic cup and the lens bit will invaginate more and optic vesicle will enclose it completely and ultimately this will get separated and it will form the lens vesicle and surface ectoderm will get normal again so this lens vesicle is the future crystalline lens of the eye now this optic cup having two layers outer layer inner layer So outer layer is forming the retinal pigment epithelium and inner layer form the neurosensory retina right and this surface ectoderm form the lens vesicle that will transform to crystalline lens in future okay. So now these are the neural crest cell and mesenchyme these are taking very Vital role for the development of the ocular structure as it form sclera, desmat membrane, endothelium and bony structure of the orbit. And as the lens vesicle is made, so this lens vesicle get its nutrition by hyalide artery and hyalide vein.
And at about 23rd week of gestation, this hyalide artery get disappear and then lens get its nutrition from aqueous humor. Now you can see that the surface ectoderm is taking form to eyelid epithelium, that is the skin of eyelid, then cornea, epithelium, then again eyelid. It is also responsible for making the gland of crows and wolfring, right?
Now this neuroectoderm taking participation for making the ciliary body, iris, optic nerve, right? And so mainly this neuroectoderm will form the ciliary body epithelium and iris epithelium as well as optic nerve. And also I told you that outer layer, this outer layer will form the retinal pigment epithelium and inner will form the neurosensory retina.
Right? So this picture describe this thing very nicely. Okay.
And this green is the neural crest cell so neural crest cell actually responsible for making the corneal stroma and endothelium sclera trabecular meshwork ciliary body ciliary ganglion okay and this uh surface ectorum is making the lens and then uh eyelid skin vitreous epithelium of cornea and conjunctiva and lacrimal gland so This is the neuroectoderm is responsible for RP, neurosensory retina, ciliary body, iris, epithelium and optic nerve. Right. And optic nerve means. the optic stock is transforming to optic nerve right now this surface ectoderm is making length eyelid skin vitreous epithelium of the cornea and conjunctiva and lacrimal gland right and mesoderm take part in the development of extracolar muscle temporal sclera orbicular soculi lps muscle blood vessel endothelium is made by mesoderm cells and neural crest cell are responsible for corneal stoma and endothelium sclera, tebicular meshwork, ciliary body, ciliary ganglion.
So this presentation is not for that much detailed discussion on the embryology of the eye. It's a very vast thing. Just I made this video to give you a brief idea about the embryology of the eye so that you will get an idea that how I actually form and that will help you in your syllabus also, right?
So that's why this video is dedicated to all of you to revise. what is the embryology of the eye okay so thank you so much for your kind listening and kind watching