One interesting and poorly understood phenomenon is the relationship with sex determination: in human hermaphrodites, ovaries develop on the left, testes on the right.
-
Show this thread
-
The heart's origins as a midline tube & sensitivity to errors in asymmetry explain why there is a whole field dedicated to congenital heart disease but no other organs.
#ACHDpic.twitter.com/r1NAxutkqZ
1 reply 11 retweets 45 likesShow this thread -
At around 3 weeks, the symmetry is broken as the heart twists. It then develops into a highly asymmetric organ.pic.twitter.com/5QtixM9NDk
1 reply 2 retweets 24 likesShow this thread -
A problem with cilia might explain diseases like Kartagener's, which is a ciliary dysmotility disorder characterised by multiple respiratory issues along with dextrocardia (heart on the wrong side)
3 replies 0 retweets 18 likesShow this thread -
The asymmetry is thought to come from *molecular* chirality of some component in the cilia. So we might owe our entire anatomy to the shape of an individual molecule.
1 reply 2 retweets 32 likesShow this thread -
However - mammals like pigs don't have those cilia and are still laid out in a similar manner to us, so some propose that all cells have a natural chirality. Again, this is thought to be due to the chiral nature of our most fundamental molecules - proteins, sugars & DNA.pic.twitter.com/52D6sz2DBr
2 replies 0 retweets 18 likesShow this thread -
BTW, the chirality of organic molecules was first noticed due to a curious property of light - linear plane-polarised light beams behave in a chiral manner, with L and R 'handed' components. Chiral molecules in the beam act differently with each part (snuck some physics in).
3 replies 0 retweets 27 likesShow this thread -
Personally I find the idea that we owe our macroscopic layout - where each organ goes - to the asymmetry present at the microscopic level, which has set off a chain reaction of asymmetry for millions of years of evolution, pretty bloody amazing.
1 reply 9 retweets 55 likesShow this thread -
So next time some beauty magazine raves about symmetry being more attractive, remember that in a symmetrical world, we'd all be dead. Then give them two chiral fingers.pic.twitter.com/VVG6KKDSkK
4 replies 11 retweets 88 likesShow this thread -
Medlife Crisis (Rohin) Retweeted Medlife Crisis (Rohin)
BONUS ADDITIONAL TWEETS TO MAKE IT MORE ASYMMETRICAL: Thanks to
@Plinz for asking a great question, I have added a few more tweets for a bit more depth
https://twitter.com/MedCrisis/status/1014412974063316993 …Medlife Crisis (Rohin) added,
Medlife Crisis (Rohin)Verified account @MedCrisisGood points. As I said, cilia is the leading theory. Mice & humans use cilia but some animals don't. When I talked about intrinsic asymmetry in cells, I meant the initiation must be earlier than the cilia phase. Some say asymmetries exist ~first cell cleavage after fertilisation. https://twitter.com/Plinz/status/1014382798805913600 …Show this thread3 replies 0 retweets 3 likesShow this thread
Our body is a cellular automaton on a selfgenerated lattice. There are several obvious ways to break the symmetry, but using the chirality of molecules within the cells seems hard, because you'd have to align these molecules in space *across* cells first.
Loading seems to be taking a while.
Twitter may be over capacity or experiencing a momentary hiccup. Try again or visit Twitter Status for more information.