This is an amazing resource and lovely hand drawn diagrams. Clear explanation too. I remember doing this in my first year of med school and it still sticks with me today!
He's absolutely right, it's all a matter of confusion on your part, and suboptimal explanation on his. Just know the Main Fact and the Main Confusion Point and that will clear up any mist (But before i say them, keep in mind that by saying right or left visual fields i mean the right or the left parts of the SINGLE picture you perceive eventually): 1- The Main Fact: The Right visual field is perceived by the left cortex and vice versa, That's the GOLDEN rule, so keep that in mind as a precondition that has to be fulfilled; so if we want the RT field to be perceived by the left cortex we need A) left temporal fibers and B) Right nasal fibres; and that's simply because the temporal ones don't cross while the nasal ones do. If we were to use the Right temporal fibres (temporal fibres of the Right eye) to perceive the right visual field, that would mean that it would have been perceived by the right cortex, and that would have violated our precondition. Remember that we're talking about the visual field as a whole; as a SINGLE picture. Now let's take the visual field of the right eye setting aside the left one for a second. You need to know that the right eye sees both right and left visual fields (right and left parts of the visual field), so cover the left eye for me for a second and see only with the right one: You'll see the right part of your one-eye visual field using the nasal fibres which will cross and go to your LEFT cortex. the left part of your one-eye (the right one remember) visual field on the contrary, is perceived using the temporal fibres, which will stay on the same side, till it reaches the RIGHT cortex; that means that a man with only one functional eye uses both his right and left cortices!! 2- The Main Confusion Point: Students most often confuse between temporal fibres and temporal part of visual field. and to clear that confusion, just know that the RIGHT part of your visual field has a temporal and a nasal portion (you can think of it as peripheral and central it's only a matter of terminology), so as the left part of that visual field (it has temporal and nasal portions too). The temporal portion of the right visual field is perceived by nasal fibres of the right eye, while the nasal portion of the right visual field is perceived by temporal fibres of the left eye. Read those last couple of sentences again and case closed.
Wow now it's perfectly alright. I had doubt in lesions and now it's cleared. This is correct guys. You have to understand the visual field and fibres that catch it concept and you'll get it
Good video! You explanations on the deficits after the LGN could definitely benefit from further research. The calcarine sulcus separates the parietal and the occipital lobes, and different branches of the visual pathway go to each.. you will have a homonymous quadrantanopia that's either superior or inferior, depending on affected area -- they're not all superior. In factt, what you have actually drawn at "D" would ,more than likely produce a "inferior" quadrantanopia, not a superior one. As it's projecting more towards the parietal.
This video is perfectly correct in the crossover concept. The axons at the "nasal" retina are responsible for "temporal" vision. That's what is labelled in the video.These cross over at the chiasma. Similarly, the axons at the "temporal" retina are responsible for" nasal" vision.
Fantastic job plus nice schema! But i think you should've labelled the nasal and temporal retina somewhere around the eyeballs. Hence clarifying the cross over concept.
i read in my textbook that the fiber from the nasal half of the retina of each side cross to the contralateral while the fibers representing the temporal half REMAINS UNCROSSED
You're right! I was thinking the same thing then I thought someone in the comment must have pointed it out and I found your comment. Thanks for pointing this mistake out
This is just my perspective, so take it for what it's worth. If you ever redo this video, if you draw the two temporal retinal pathways first at the very outset and indicate the nasal fields they cover and then draw the nasal retinal pathways and the temporal fields they cover, it would be a lot easier for students to grasp what's going on IMHO. However, great job as always. Love your videos.
4:07 : If in the temporal part it results in Right Superior Homonimous Quadranopsia but if in the parietal side it results in Right Inferior Homonimous Quadranopsia
Actually this video is perfectly alright. Let me explain because the uploader thought we are genius and some of us know and some of us dont know few fundamentals. Basically for example lets take left eye We know there are two type of fibres nasal and temporal. Nasal fibres carry temporal field of vision of same eye and temporal fibres carry nasal visual field of same eye. I hope now u understand the video 😊
If temporal fibers are carrying nasal vision then lesions at level of optic chiasma should cause binasal hemianopia because these temporal fibers are actually carrying nasal vision. Isn’t it so ??😑 Someone plz explain this
Thank you so much for your help and explanation you are a life saver, all love and support from Algeria medical world 🇩🇿 I have remarked a little confusion, so the optic tract is the structure which origantes from the optic chiasma to the lateral genuclate body, meanwhile the structure you are reffering to as the optic tract (from the LGB to the calcariane cortex) is not the optic tract but it's the optic radiations
What he labelled in the video is correct. Notice the difference; he drew fields AND eyes (the small balls/circles): Fibers coming from temporal field of vision, go to nasal part of the eye and cross (because they ARE NASAL FIBERS but they give info about temporal(lateral) field/vision), and temporal fibers of temporal part of the eye that don’t cross give info about the nasal field (medial field) and do not cross. There's a difference between vision and fibers. It's always the opposite.
supper .... I Had a big confusion of how the fisual fields of each eye reach the nasal and temporal parts of the retina..... thanks cleared all the douts..... fantastic
hi armando you earn the respect with such a artistic way of presentation and make every thing so easy but there is a mistake i would like to mention that optic track is before the LGB and not after that.i hope you will make it clear in coming lecture.
the order is optic nerve, optic chiasma, optic tract, lateral geniculate body, optic radiations then visual cortex basically
Thanks! I've been looking for a written out version of this for a really long time and I finally found it
@@Wiimaster20091 😂😂😂😂
بسم الله ما شاء الله لا قوة إلا بالله
@@fatihabdjn9877 assingment برضو ههههه ؟
Yes it has been incorrectly labelled as optic tract instead of radiation!
I was really confused about this concept until I watched your helpful video. Thank you for this!
This is an amazing resource and lovely hand drawn diagrams. Clear explanation too. I remember doing this in my first year of med school and it still sticks with me today!
This man just need one page to clear every concepts of the topic😎 you’re incredible 🤩 Thanks a lot sir!❤
Thank you, you’ve made it much easier 🤍
Optic nerve -> optic chiasm -> optic tract -> (thalamus) lateral geniculate body -> visual cortex (occipital ) as optic radiation
armando you are the best artist in explanation videos never listen to foolish critics we respect and appreciate you
He's absolutely right, it's all a matter of confusion on your part, and suboptimal explanation on his. Just know the Main Fact and the Main Confusion Point and that will clear up any mist (But before i say them, keep in mind that by saying right or left visual fields i mean the right or the left parts of the SINGLE picture you perceive eventually):
1- The Main Fact: The Right visual field is perceived by the left cortex and vice versa,
That's the GOLDEN rule, so keep that in mind as a precondition that has to be fulfilled; so if we want the RT field to be perceived by the left cortex we need A) left temporal fibers and B) Right nasal fibres; and that's simply because the temporal ones don't cross while the nasal ones do. If we were to use the Right temporal fibres (temporal fibres of the Right eye) to perceive the right visual field, that would mean that it would have been perceived by the right cortex, and that would have violated our precondition.
Remember that we're talking about the visual field as a whole; as a SINGLE picture. Now let's take the visual field of the right eye setting aside the left one for a second. You need to know that the right eye sees both right and left visual fields (right and left parts of the visual field), so cover the left eye for me for a second and see only with the right one: You'll see the right part of your one-eye visual field using the nasal fibres which will cross and go to your LEFT cortex. the left part of your one-eye (the right one remember) visual field on the contrary, is perceived using the temporal fibres, which will stay on the same side, till it reaches the RIGHT cortex; that means that a man with only one functional eye uses both his right and left cortices!!
2- The Main Confusion Point: Students most often confuse between temporal fibres and temporal part of visual field. and to clear that confusion, just know that the RIGHT part of your visual field has a temporal and a nasal portion (you can think of it as peripheral and central it's only a matter of terminology), so as the left part of that visual field (it has temporal and nasal portions too).
The temporal portion of the right visual field is perceived by nasal fibres of the right eye, while the nasal portion of the right visual field is perceived by temporal fibres of the left eye. Read those last couple of sentences again and case closed.
This was amazing thank you
Thank you for explaining this! 🤩
thank you suchhh a good explanation
Lovely explanatiom
Thanks for taking out the time to type out such a great explanation!
THE SIMPLEST VIDEO ON TH-cam! I've been confused over and over again. Thank you for teaching it with clarity
Yes !!! #Nainann
Wow now it's perfectly alright. I had doubt in lesions and now it's cleared. This is correct guys. You have to understand the visual field and fibres that catch it concept and you'll get it
i dont konw what to say, i just hope that such a talent not lost is .... this style of teaching is so high..
Incredible clarity, practicing on my friends this evening, thanks so much .
Wonderful video very easy to visualise it when you put it like that. Could have been very helpful for my exam on this subject 2 weeks ago.
Your drawing are so good!! Thank you! This video really helped me
Great video couldn't be that precise and that clear than this 👌
Thanks a lot
Good video! You explanations on the deficits after the LGN could definitely benefit from further research. The calcarine sulcus separates the parietal and the occipital lobes, and different branches of the visual pathway go to each.. you will have a homonymous quadrantanopia that's either superior or inferior, depending on affected area -- they're not all superior. In factt, what you have actually drawn at "D" would ,more than likely produce a "inferior" quadrantanopia, not a superior one. As it's projecting more towards the parietal.
Thanks a lot ....my neurologist teacher just explained this in class recently
Just won a bet with your video. Priceless! Nice work bro.
I was trying to figure this out last week and was so confused. You explained it so clearly, thank you!
Thank you for your awesome work
This video is perfectly correct in the crossover concept. The axons at the "nasal" retina are responsible for "temporal" vision. That's what is labelled in the video.These cross over at the chiasma. Similarly, the axons at the "temporal" retina are responsible for" nasal" vision.
Yup. He should do the same color for each nasal retina to prevent confusion bcs Im confused too at first haha
Andrea Joseph thanks for the information..
I got little bit confused
Thanks for posting the info. I was just introduced to this last week. You sound brilliant :)
thank you, your comment really helped
I'm not even studying this, i'm an arc student but these are so much better than those "educational" Vsauce/smarter everyday type videos.
Amazing way of explanation. Your drawing is superb.
Thank you so much sir 🙏
You've made this topic easier 💜
Fantastic job plus nice schema! But i think you should've labelled the nasal and temporal retina somewhere around the eyeballs. Hence clarifying the cross over concept.
This is amazing!
Thank you!
God bless you
i read in my textbook that the fiber from the nasal half of the retina of each side cross to the contralateral while the fibers representing the temporal half REMAINS UNCROSSED
Yes, and that's exactly what he has depicted here. You're confusing the retinal fibres with the side of the visual field that they detect.
Yes , same is the case with me and I have confirmed it in three books, nasal one goes to contralateral side and not temporal one
You're right! I was thinking the same thing then I thought someone in the comment must have pointed it out and I found your comment. Thanks for pointing this mistake out
Best explanation Ive seen! Thank you!
This is just my perspective, so take it for what it's worth. If you ever redo this video, if you draw the two temporal retinal pathways first at the very outset and indicate the nasal fields they cover and then draw the nasal retinal pathways and the temporal fields they cover, it would be a lot easier for students to grasp what's going on IMHO. However, great job as always. Love your videos.
Optic tract is before lateral geniculate body ,optic radiation is the one after Lgb
Waaa finally I found a clear, short and precise explanation! Thanks, you removed a big glich in my brain 👌
Super helpful, thank you for making this!
LEGEND!
Armando you one gifted individual. Thank you for the excellent videos.
thank you very much.... you actually beautifully explained the concept.
I have been difficulting in understanding it you explain it so awesomely and simply That I understand it so good thank you so much🌺🌺🌺🙏🙏🙏🙏
awesome video as usual ! thank you!
terrific vid.
thank you
Thanks man. AT last. !! I found a really helpful video !
God bless you. thanks man
Brilliant video! Thank you! 😊
Thank you so much sir🤩
Fantastic video ! Very helpful. Thank you!
Best explanation one can give
Amazing video, keep it up !
Really amazing
4:07 : If in the temporal part it results in Right Superior Homonimous Quadranopsia but if in the parietal side it results in Right Inferior Homonimous Quadranopsia
youre just amazing. so easy to understand
BRAVO!!! Amazing video!
Thank you Dr. armando
Superb video. Well done and thanks!
Fantastic work.
Thank you so much!
I'm so glad for that.
Thanks a lot 😊🖤
I realy appreciate your effort
c'était génial merci le sang
Actually this video is perfectly alright.
Let me explain because the uploader thought we are genius and some of us know and some of us dont know few fundamentals.
Basically for example lets take left eye
We know there are two type of fibres nasal and temporal.
Nasal fibres carry temporal field of vision of same eye and temporal fibres carry nasal visual field of same eye.
I hope now u understand the video 😊
suhail lone Thanks alot!
really thank you man!
but thats what he showed when drawing tho
Thank you man! 😊
If temporal fibers are carrying nasal vision then lesions at level of optic chiasma should cause binasal hemianopia because these temporal fibers are actually carrying nasal vision.
Isn’t it so ??😑
Someone plz explain this
Thanks so much!
Thank you so much for your help and explanation you are a life saver, all love and support from Algeria medical world 🇩🇿
I have remarked a little confusion, so the optic tract is the structure which origantes from the optic chiasma to the lateral genuclate body, meanwhile the structure you are reffering to as the optic tract (from the LGB to the calcariane cortex) is not the optic tract but it's the optic radiations
Sir thank very much all very good , how much your crystalic for the eye 👁️👁️👁️ please let me know please. Thanks for you sir and God be bless
Thank you, sir
Thank you so much sir
Thank you Armando! Still watching in 2020 :)
Such a helpful video.Thankyou so much!!!
Very clear illustrations!
Best video ever describing everything in detail.....👍👍👍👍
Good video i under stood lesions as it was difficult from the book
What he labelled in the video is correct.
Notice the difference; he drew fields AND eyes (the small balls/circles):
Fibers coming from temporal field of vision, go to nasal part of the eye and cross (because they ARE NASAL FIBERS but they give info about temporal(lateral) field/vision), and temporal fibers of temporal part of the eye that don’t cross give info about the nasal field (medial field) and do not cross. There's a difference between vision and fibers. It's always the opposite.
Tq for clearing my confusion!❤
Thank you very much for your videos, may I ask what pens you use for your illustrations as they seem really good.
supper .... I Had a big confusion of how the fisual fields of each eye reach the nasal and temporal parts of the retina..... thanks cleared all the douts..... fantastic
Finally understood it!! Thank you!!!
This is great! I understood this very well!
Perfect video sir
hi armando you earn the respect with such a artistic way of presentation and make every thing so easy but there is a mistake i would like to mention that optic track is before the LGB and not after that.i hope you will make it clear in coming lecture.
you hv mislabelled optic tract. its the optic radiations
Exactly
Geniculo-calcarine tract is also known as Optic Radiations!!
Yes.. He has mislabelled optic tract as geniculpcalcarine pathway.. But i think he's showing optic radiation by lines.
Yeah optic tract should be between Optic chiasm and LGN
not just that, even LGB comes after optic tract, the diagram itself is wrong
Simplified and the best❤
Thanks Dr , really amazing
well explained, Thank you
thankyou very much sir! you made my life easy
A great video! Thank you!
Superb lecture
The Brilliant video💡
Perfect video buddy❣️❣️
Thank you!!!
best video- thanku!
Thank you from iraqi optometrist
AMAZING STUFF
He took my prof's lecture but made 100x better
thank you
Outstanding! in one word.. Absolutely!
Thankyou ❤️
i just got saved from the wrath of physiology...thank you
You are phenomenal 🔥
Thankyou!
Thanku so much brother😇
Thank you its very helpful
Thank you.
great visual! thank you :)
So the order is optic nerve, optic chiasm, optic tract, lateral geniculate body, optic radiation, visual cortex
Excellent video
Great explanations