You are the best channel for GCSE and IGCSE Sciences and Math. I cannot type out enough words to describe how useful your content has been. God bless your soul. You are an angel
Hey, this is awesome! I found this really helpful for my biology revision for my test next week. My teacher reccommended you to my class. Short, sweet and quick
please become my teacher i am understanding my syllabus because of you you don't know how much i am grateful for this continue making this kind of amazing videos!!
If you’d like to practise what's covered in this video, check out the lesson on the Cognito platform - cognitoedu.org/coursesubtopic/b2-gcse-aqa-h-t_4.13. The platform’s totally free, and has been built to make learning and revision as easy as possible. The main features are: - Lessons organised by topic, only the lessons relevant to your specific exam board and tier are shown. - Automatic progress tracking. Progress bars tell you what you’re doing well at, and what you need to spend some time on. - Practise quizzes so you can test your knowledge. You can quiz yourself on any combination of topics you like. - A huge number of fully-hinted questions that take you step-by-step through some of the trickiest calculations & concepts. - A comprehensive bank of past exam papers, organised both by year, and also by topic. Amadeus & Tom
As light hits the eye, the first structure that it meets is the cornea. To allow light to pass through, the cornea is completely transparent, and so has no blood vessels. This means that all of the oxygen that it needs has to diffuse into it from the outside air rather than being supplied by the blood, unlike all other parts of the body. The reason we need the cornea is because it causes all the light that passes through it to refract (bend by a certain amount). The next important structue is the iris which is the coloured bit of the eye. It controls how big or small the pupil is. The pupil itself is not actually a structure, rather a gap in the middle of the iris which allows the light to pass through to the lense. Just like the cornea, the job of the lense is to refract or bend light, but importantly the lense can change its shape - this allows it to control how strongly it refracts the light. This helps it always focus the light perfectly onto the retina at the back of the eye. The retina itself is made up of two different types of receptor cells - cone cells which are sensitive to the colour of light (allowing us to see colour but don't work very well in low light conditions) and rod cells which are more sensitive to light but only allow you to see black and white. This is why you can't see colours in the dark as it is only your rod cells that are working. The next structure to know is the fovea which is a special spot on the retina which is filled with only cone cells and it is this region which we try to focus light on so that we can see things most clearly. Lastly, we have the optic nerve. This takes all the impulses generated by the receptor cells and transmits them to the brain. When in an extremely bright environment, the intensity of the light can cause damage to the retina, so to prevent this, you have a reflex that controls the size of your pupil, making it smaller in bright light environments so that less light can enter and damage your retina. The pupil is referred to as constricted. This becomes larger in lower light conditions as it lets more light in. helping you see in the dark. The pupil is referred to as dilated. To control this, the iris is made up of two different types of muscles. On the inside are circular muscles which stretch around the pupil in circles. Around the outside are radial muscles which stretch from the inside to the outside like the radius of a circle. In order to make the pupil smaller in bright light, the circular muscles contract, squeezing the pupil smaller and the radial muscles are relaxed so that they can be stretched longer. If it is dark, the circular muscles relax and the radial muscles contract to mark it shorter and to pull the pupil open, letting in more light.
This video was really helpful! It got me thinking about treating colour-blindness: could scientists treat it by inserting cone cells into the (colour-blind) patient’s eye?
Thank you so much for your videos. Sadly, a lot of my teachers skip and rush content, but thanks to this channel I am able to easily learn it :) I hope you know that you help many students with their GCSEs
when in bright light, the pupil constricts to reduce light entering the eye this can be done when the radial muscles relax and the circular muscles contract when in dim light, the pupil dilates to allow more light to enter the eye, this can be done when the circular muscles relax and the radial muscles contract
Since they cornea absorbs oxygen only by diffusion directly from the air, then if a person sleeps and closes his/her eyelid, the cells in the cornea wouldn't respire any way right? And consider if a person sleeps for a long time, say 10 hours. Does that have an effect on the cells of the cornea and its job in the eye?
@@ss-hc7tb Look it up. I believe that the cornea is the only tissue that gets oxygen directly from air. If blood were to flow through it, the cornea would be red since blood itself isn't transparent, and the red veins in the eye when having tiresome eyes seems very obvious and clear the eye is redish that time.
your videos have been very useful to me thank you very much and plus they are free,first time i heard about them it seemed like i had to pay to view them but nope🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥
Thank you so much for this wonderful video, it was very helpful! Why I cannot even believe how much I just learned from you in just under 5 minutes 😃😂😁
Hey, we’re now releasing alternating videos for each subject as we’ve done the bulk of each one. The videos coming out now are mostly the triple science material for each subject 🙌
Very useful page i am impressed very very very Nice Best Of Luck and Thank You for these intense and useful information not less than a Good and inspiring lecture.
It’s the light-sensitive lining of the eye: it’s part of the nervous system. Pain nerves sense pain, temperature nerves sense hot and cold, and retinal photoreceptors sense light and send it to the visual part of the brain to produce the experience we call sight
@@Cognitoedu Often questions are asked about the structure and function of the three layers of eye - sclera, choroid and retina. This part was not explained properly. May be a separate video explaining the different layers and parts of the eye is required.
❤high majesty ,accept my poor opinion to the eye,the is united to the brain and heart. Sense of feeling and taste and touch or etc.the is a magic sense,many hide on this? Even they pick up to the camera or to the cctv camera or etc. To erase it and gone! the@ EYE@
You are the best channel for GCSE and IGCSE Sciences and Math.
I cannot type out enough words to describe how useful your content has been. God bless your soul. You are an angel
Thank you so much 😊
Hey, this is awesome! I found this really helpful for my biology revision for my test next week. My teacher reccommended you to my class. Short, sweet and quick
Thanks Gaia, glad it was helpful 😊
Yea Short,Sweet,Quick
please become my teacher i am understanding my syllabus because of you
you don't know how much i am grateful for this continue making this kind of amazing videos!!
Thanks Khushi, we're glad you're finding them helpful 😊
If you’d like to practise what's covered in this video, check out the lesson on the Cognito platform - cognitoedu.org/coursesubtopic/b2-gcse-aqa-h-t_4.13. The platform’s totally free, and has been built to make learning and revision as easy as possible. The main features are:
- Lessons organised by topic, only the lessons relevant to your specific exam board and tier are shown.
- Automatic progress tracking. Progress bars tell you what you’re doing well at, and what you need to spend some time on.
- Practise quizzes so you can test your knowledge. You can quiz yourself on any combination of topics you like.
- A huge number of fully-hinted questions that take you step-by-step through some of the trickiest calculations & concepts.
- A comprehensive bank of past exam papers, organised both by year, and also by topic.
Amadeus & Tom
Tysm this rlly helped for revision
WOW!! I can't wait for part 2 because this is really useful!
Thanks Kuba! Not long now 🙌
I'm two years late but this really does sound like you were held at gunpoint
@@avymar7167 PLS-
shush
@@umarrana4857 u having a test
You explain it so much easier omg I wish I wrote notes from you
As light hits the eye, the first structure that it meets is the cornea. To allow light to pass through, the cornea is completely transparent, and so has no blood vessels. This means that all of the oxygen that it needs has to diffuse into it from the outside air rather than being supplied by the blood, unlike all other parts of the body. The reason we need the cornea is because it causes all the light that passes through it to refract (bend by a certain amount).
The next important structue is the iris which is the coloured bit of the eye. It controls how big or small the pupil is. The pupil itself is not actually a structure, rather a gap in the middle of the iris which allows the light to pass through to the lense. Just like the cornea, the job of the lense is to refract or bend light, but importantly the lense can change its shape - this allows it to control how strongly it refracts the light. This helps it always focus the light perfectly onto the retina at the back of the eye.
The retina itself is made up of two different types of receptor cells - cone cells which are sensitive to the colour of light (allowing us to see colour but don't work very well in low light conditions) and rod cells which are more sensitive to light but only allow you to see black and white. This is why you can't see colours in the dark as it is only your rod cells that are working.
The next structure to know is the fovea which is a special spot on the retina which is filled with only cone cells and it is this region which we try to focus light on so that we can see things most clearly.
Lastly, we have the optic nerve. This takes all the impulses generated by the receptor cells and transmits them to the brain.
When in an extremely bright environment, the intensity of the light can cause damage to the retina, so to prevent this, you have a reflex that controls the size of your pupil, making it smaller in bright light environments so that less light can enter and damage your retina. The pupil is referred to as constricted. This becomes larger in lower light conditions as it lets more light in. helping you see in the dark. The pupil is referred to as dilated. To control this, the iris is made up of two different types of muscles. On the inside are circular muscles which stretch around the pupil in circles. Around the outside are radial muscles which stretch from the inside to the outside like the radius of a circle.
In order to make the pupil smaller in bright light, the circular muscles contract, squeezing the pupil smaller and the radial muscles are relaxed so that they can be stretched longer. If it is dark, the circular muscles relax and the radial muscles contract to mark it shorter and to pull the pupil open, letting in more light.
This video was really helpful! It got me thinking about treating colour-blindness:
could scientists treat it by inserting cone cells into the (colour-blind) patient’s eye?
I don't think so. I have a friend who is colour blind, they can see certain colours, but not all.
it’s probably more of an inability to see certain wavelengths (?) -> since colours are made up of wavelengths on the electromagnetic spectrum
This was so helpful, I have a bio exam tmr and this helped me revise so much, thank u daddy
Thank you so much for your videos. Sadly, a lot of my teachers skip and rush content, but thanks to this channel I am able to easily learn it :) I hope you know that you help many students with their GCSEs
i don't understand what my teachers explain in school so i rely on u but u never let em down thx
really helping have got my biology exam this morning!
you give hand in revising my portions for my exams in a sweet,short and in a crisp way. love all ur videos. love from India❤❤❤
Perfect, glad we could help you out Abirami 👍
Yo, whos here for there biology lesson
Aren't we supposed to?
I don't know if anyone fell for that 😂😂 but @Oscar Moises and @Augustine Pablo are duo scammer. I've seen them in other places too XD
im 1 yyea r late but i have a presentation about this tomorrow 😢
@@dania-c1y good work
when in bright light, the pupil constricts to reduce light entering the eye this can be done when the radial muscles relax and the circular muscles contract
when in dim light, the pupil dilates to allow more light to enter the eye, this can be done when the circular muscles relax and the radial muscles contract
Got my bio exam tomorrow and i am so cooked, what a fod subject!
Bro same 💀
gl for tomorrow asw if u take triple, lucky the eye wasn't in paper 1 (for igcse)
My friend u are the GOAT of IGCSE science
Bro u are sigma because u help me with ma homework, you are a true ohian rizzler, Keep it up!
whos revising for paper 2 tomorrow? 😒
me amigo
@@velocityyy1244 get me out of here
Meee 😢😢😢
Me but its a mock lol
P4 bro:')
Thanks for you teaching, you've made it simpler for me than my teacher👏👏
thankyou so much for this video! really well explained! it makes so much more sense now !
Great to hear - thanks Gary!
when you are going to put more videos
!!!!!!!!!!!! i need videos for 11 grade please without you i whould not pass
i really love you
I ABSOLUTELY LOVE YOUR VIDEOS AND YOUR WEBSITE
Great video! Really helpful for my biology test! Thanks!
Hi triple science class 👀
dim light - pupil dilate- radial muscles contract- circular muscles relax
bright light - pupil constrict - circular muscles contract- radial muscles relax
In this playlist for GSCE biology what content do you miss out on? Because it mentions that you covered the majority of content. Thank you so much.
Since they cornea absorbs oxygen only by diffusion directly from the air, then if a person sleeps and closes his/her eyelid, the cells in the cornea wouldn't respire any way right? And consider if a person sleeps for a long time, say 10 hours. Does that have an effect on the cells of the cornea and its job in the eye?
i dont think thats how it works. humans dont absorb oxygen from diffusion lmao, its from breathing
@@ss-hc7tb Look it up. I believe that the cornea is the only tissue that gets oxygen directly from air. If blood were to flow through it, the cornea would be red since blood itself isn't transparent, and the red veins in the eye when having tiresome eyes seems very obvious and clear the eye is redish that time.
your videos have been very useful to me thank you very much and plus they are free,first time i heard about them it seemed like i had to pay to view them but nope🔥🔥🔥🔥🔥🔥🔥🔥🔥🔥
this was insanely helpful, thanks!!
Thank you so much for this wonderful video, it was very helpful! Why I cannot even believe how much I just learned from you in just under 5 minutes 😃😂😁
Does damaging the cornea damages my eye sight?
Yes pritty much
U teached better than teacher.
Would u mind doing a video on Aerobic Respiration?
I thought you were doing physics so are you going back to biology or is this higher than gcse
Hey, we’re now releasing alternating videos for each subject as we’ve done the bulk of each one. The videos coming out now are mostly the triple science material for each subject 🙌
It says about the pupil reflex in the syllabus.... Is the iris relfex and the pupil reflex the same thing?
Very useful page i am impressed very very very Nice Best Of Luck and Thank You for these intense and useful information not less than a Good and inspiring lecture.
Could you please make a video on coordination?
Have a great day everyone!
ok nice comment but what does this have to do with the vedio its self
Same to you🥺😌
You are a life saver
Fact to impress your examiner: the point on the retina that the light focuses on is called the fovea (centralis)
Thanks my image i had to study overwhelmed me
anyone playing this just so your teacher doesn't think you're listening to music
not rlly , but i think imma snitch about u to the teacher for doing that : )
Only u😊
Doing it rn💀
Lol me 2
No
Thank you! :D
Is this gcse triple science biology??
I have a question- when you need to see objects at a distance, what happens to the lens??
GCSE today thanks cognitio
how much u got?
i love yall so much, thank you
Video was helpful... please create more videos🤩
What exam board do you teach
Y’all who’s here preparing for their igs
What exam board is this for?
Really good explanation!!! Just subbed to your channel!
U are an absolute life saver thank u so much!
Got biology tomorrow wish me luvk
Can this be downloaded and used for other students
what is the function of the retina
I think it helps you focus when the light retracts and hits it.
It’s the light-sensitive lining of the eye: it’s part of the nervous system. Pain nerves sense pain, temperature nerves sense hot and cold, and retinal photoreceptors sense light and send it to the visual part of the brain to produce the experience we call sight
The structure of the eye was not explained properly. The part explaining iris reflex was clear and well explained.
Hi there, would you mind elaborating on which part of the structure wasn't explained properly (so that we can fix it)?
@@Cognitoedu Often questions are asked about the structure and function of the three layers of eye - sclera, choroid and retina. This part was not explained properly. May be a separate video explaining the different layers and parts of the eye is required.
Thank you @@rangineechoudhury3755 Can I ask which exam board it is you do?
@@Cognitoedu IGCSE
IGCSE Edexcel or IGCSE Cambridge (CIE) is that sorry?
Please make a video on support movement and locomotion
4:00 very well explained sir
thank u
Thanks
You didn't talk about circally muscle and sercally legament
I see. How very intereyesting
thank you
Trying to remember which muscles contract and which muscles relax is so confusing
it's always the opposite when u think it contracts it relaxes and when u think it relaxes it contracts just like biceps and triceps. :)
@@suvarnikaradhakrishnan1247 that’s what I was thinking
It really helped me thanks ❤️❤️
How interesting…..
❤my eye seen something too seen even to the dark sign up the heaven above,why?stoney is a one eye,one heart.
❤❤❤❤
im the 135th comment!!!
I will let you know how I did on my test
I think I did pretty good but I don't think I'm getting my results cause schools are closed for the 3rd time due to covid
❤high majesty ,accept my poor opinion to the eye,the is united to the brain and heart. Sense of feeling and taste and touch or etc.the is a magic sense,many hide on this? Even they pick up to the camera or to the cctv camera or etc. To erase it and gone! the@ EYE@
did anyone else's eyes feel weird watching this? XD
Commented
ok but how do we use goggles if the eyes gets oxygen by it’s self and how do we sleep with out breathing from are eyed
algorithm
Pls sum things up at the end of your videos.
Thank you.
This is Indian and you
🤣 I think they mean "I am Indian, what about you?"
Hold up what did he sayyyyyyyyyyyyyyyyyyyyyy?????//
i have a phobia of too mny eyes! The pictue at the start is too much!!
Womp womp
Um? We dont gaf
hi guys
u might know me
lolz
We dont😊
my teacher gave me this 0-0
Education is not eazzzzzzy
teacher: tells me to watch the vedio
me: dislikes the vedio
me:😈
vedio ----> video
no beef just tryna help lmao :p
👎🏻