**Correction*** Hey Ninja Nerds!! The laryngeal cartilages are actually derived from the 4th and 6th pharyngeal arches NOT the 1st!!! Sorry about that ninja Nerds!!! Hope this video is helpful! Love you ninja Nerds!!!

I love it when Zach says things like, "isn't that cool?!" I swear having an excited, passionate teacher makes SUCH a difference. Thanks, Zach!

A Pakistani med student here, trying to study embryology from scratch 2 days prior to the exam. Thank you for your energy and explanation!

Development of limbs 1.HOX, TBX4 & TBX5 genes determine the position of formation of limb buds. Once activated, they stimulate release of FGF-10 (fibroblast growth factor). Ectoderm grows off as 4 limb buds. Somatic layer of lateral plate mesoderm moves into limb buds. FBG-10 stimulates a thickening at the tip of the limb buds called apical ectodermal ridge (AER). AER secretes FGF-4 & FGF-8 which causes proliferation of somatic mesoderm. the most distal part keeps proliferating (progress zone) while the proximal part of limb bud starts to differentiate. From cartilage to bone (endochonrdal). Some tissue in AER undergoes apoptosis due to bone morphogenic protein (BMP) & retinoic acid increase. Starts to form fingers. Mesoderm starts to proliferate to make finger bones. AER dies off to stop growth. Tissue called zone of polarizing activity (ZPA) develops on posterior disal limb which causes the asymmetrical growth of the hand. Thumb to pinky.

A Pakistani Med student here, learning a lot from your videos. Keep up the good work

Hello Zack, I’m a medical student from Iraq, and I just want to thank you for all the work and time you’ve given for everyone who watches your videos. You explain in a such way that is comprehensive yet still fun and enjoyable. Keep going man, wish you the best of luck!

Zach you are my mentor and hero. You don't even take Sundays Off! Thank you so much. God Bless you and everyone

when my med school prof lectures about this subject she just throws it all up on one powerpoint slides and talks through the whole thing at once, which i find very hard to follow and understand. drawing it out step by step like this is immensely helpful, thanks!

I just wanted to say a most sincere THANK YOU! I really appreciate your work and you must know how much it helps everyone who wants to learn. Thank you again ♡

i'm an Italian med student and I actually prefer this to may Professors. Thank you for everything you make Zack and crew

Am a proud Ninjanerdian 🎉. Thanks buddy 👍

Thank you so much for providing all these lectures!!! 💕 looking forward to more embryology lectures from you!

I can't stress enough how you actually saved my medschool life 😭

Those with ADHD but still fighting, i feel u and im proud of u guys we can be even better …

I am very grateful for the support you are giving us ninja nerds you are the most influential man in my medicine career

You are SIMPLY THE BEST ZACH!!! thank you thank you for all your hard work and dedication!

Ayyyyy, let's go! Missed embryo lectures

I've been waiting for a long time for this! Thanks a lot!

It is amazing how you are able to make these wonderful educational lectures! I am Rachel from NL and I really love them!

Never have I ever wanted to hit the like button so many times. Thank you so much!

Nerdology : Development of Ninja Nerds

Hi Zach. I am Alice, a Nursing Student from Nigeria. I love your energy and enthusiasm while teaching. You also made this topic easier for me. Thank you.

omg! finally it all comes together making sense! I am so thankfull for your job and for the fact i had the luck finding you

In love with his way of teaching 😭❤

Thank you for breaking down such difficult topics!!!

Zach is a treasure that must be preserved!

Embryology😻 The greatest gift ever for my upcoming semester. Thank You Mr👍🏻👍🏻👍🏻👍🏻

Wow! Excellent explanation! Thank you so so much for putting the time and the effort to make these topics very enjoyable to learn.

Brilliant as usual. But what i really want to thank you for is your positive energy. I woke up not in the mood for learning anything about embryology 😂. But the way you explain and the way you seemed so excited is so refreshing! And contagious. So again, thankyouu for making our lives easier

Having histo+ embryo in two days and this just came perfectly in time!! THanks!

I'm in love with this channel, thank you so much

I'm not even learning this yet but I just wanted to comment to voice my support for this channel. Just incredible

Lucky to have you as my teacher thanks sir for all the beautiful informative videos

Your passion really gives it more color and makes it interesting.. very inspiring thank you

Your videos are as good as it can get.thankyou so much and please keep them free on youtube

Love this. Ur passion really gives me the motivation to learn!

I always hated embryology!! until I found your videos :)) it can be sooo interesting! THANK YOU 😀

Finally, embrio vids, really needed these to jog the memory

Hi ZACH . I am an Electrical Engineering Student But I'm here to Subscribe you channel because My Brother loves Your Lectures. Keep up the great work! LOVE From PAKISTAN..............

Thank you prof Zach..You jus the best ...You make our med school life easy

this guy hits it everytime! thank you brother

You have no idea how easy you’ve made me revision process for exams

thank u soo much for this video, it's helping me to understand more during my uni class

During the first half of the video I was trying to figure out what kind of drug Zach is on. Then I realised it's just embryology. Because damn, embryology is so so cool!!

I can see how much effort you made when I see your videos

brilliant teaching from you Zach...you're a blessing to us!

This video published less than 48 hours before embryology exam. Nothing less of amazing. Thank you guys!

Thank you, thank you, thank you! Keep it up with embriology!

great video~ currently an MD1 and this has helped alot!

I just wanna say thank you very much and keep going in making wonderful videos

Thank you Zach so understandable and simplified

Omg... Perfect timing! ❤️❤️❤️

I swear I have NEVER even considered signing up for Patreon for any other channel except this one. I hope I will in the future.

Lots of love from Medical School of the University of The Gambia🇬🇲🇬🇲🇬🇲🇬🇲🇬🇲🇬🇲Thank you so much for your videos.. you're just Amazing!

Thanks ninja nerd, i am a second year medical studen from venezuela, your videos are super easy to understand and it have being keeping me motivated trhough quarantine. I am even thinking about opening my own youtube channel now. thanks

Thanks you sir. Really helpful.. forever a proud ninjanerd

youre the best thanking you for helping me through medical school

Nice to see, how much fun you have with this stuff

Its 3:00 am, i have an end of sem 1 exam and things just escalated quickly from neuroanatomy to embryology to bchem...am glad this made my work 1000 times easier

Dear Zach Thank you for this! Explanation for the 44:40 is missing about Retinoic Acid and SHH about how Gremlin-1 is released

Man you are literally my career saviour ❤️

I just got my psychotic preworkout in the mail! Omg!!! I feel the electrons coming out of my membranous neurocranium!!! Thank you Zach!!!! Biochemistry major let’s do this then MCAT!!

really appreciate your work , thank you .

Watching your videos from somalia 🇸🇴 and thank you for sharing these wonderful videos with us (med students)

Greatest teacher ever ❤

Thank you very much 💚. We are waiting for the embryonic formation of the cardiovascular system

Zach, After watching many Ninja Nerd Lectures on KZfaq, I've become very impressed with your knowledge. Are you accepting patient? If so, how would someone become a patient of yours?

The way you talk to the audience looks so enjoyable that really attracts us by your lectures. Love your spirit ❤️ Keep it up 👍

Hello guys !!!! Omgggg thanks for amazing videos really !!! I swear when ever Zach says " oh man it's so cool " or " isn't that cool ?" I keep rewatching that part 😍😍😍and I swear I learn a lot better he knows how to drag good attention to super important parts !!! And yet keep it so intresting ! Like only by his joy in his face he converts all boaring materials into such a cool one to learn ! Thank you guys ! May God always bless you and get your backs !!! I love youuuuu guys

Thank you very much zach. This is really top notch

One interesting (important) fact: The nucleus pulposus is the only remnant of the notochord, not sclerotome! Sclerotome gives rise to vertebral bodies, annulus fibrosus of the intervertebral discs and ribs!

Love ur dedication zack🖤🖤

Wow ...thank you ...your all videos are interesting...you make me love 😘 the medicine...

bro has rocked my world

Thanks for your efforts Ninja crew

Holy smokes! 1000 Likes and 0 dislike! Zach you are amazing!

Awesome lecture. This man is Good

from ninja to nerd and where I'm at? I'm dead in the water mate, and it ain't a pretty sight! But thank you for all the work you've done and are still doing.

The greatest ever Dude without you my medical journey is sh*ty♥️

I had to stop this video and appreciate this guy 👏

Bless y’all 💕

You make the madicine so easy 🔥🔥🔥love you

The lecture is so nice, understandable and interesting,,add more for us!!!!

Now this guy is just exceptional

Always wait for your videos

Thank youu soo muchh ninja nerd u make things soo much clear

thank you so much for such an effort and explanation

Really sir i have no words to explain how you are helping us by your great lectures......amazing sir

Life saving video .. zach❤

As always Amazing ❤👌

Thanks a lot from Iraq for providing these videos, keep going!!

Thank you Ninja Nerd.

I thought you went bold in first few seconds because of the hat lol 😂

Best instructor ever 🫀

Wonderful teaching

"baboom! babooshca!" he said😂😂...gets me every time!

Thank you so much for the embryology lecture!!! Just want to make sure that does hyoid bone and laryngeal cartilage comes from 2nd~6th pharyngeal arch. thanks a lot

Hi there. First of all, I love all your videos. Please do make a short video on the development of the joints. Thank you

Thanks dude this was great.

always helpful thank you mr