Flashcards in Development--Sievert Deck (20)
Somites give rise to what 2 things?
dermatomyotome & sclerotome
What does sclerotome make?
How do you developmentally form a vertebral body?
the sclerotomal cells migrate around the notochord & neural tube & form the vertebral body.
If vertebral body formation doesn't work out well, what could you end up w/?
**& bad lamina & spinous process formation
What is spina bifida occulta?
this means that you can't immediately tell that the child has spina bifida...the spine is just bulging out of the back & susceptible to injury.
What is a meningocele?
some of the meninges of the spinal cord are bulging out
What is a myelomeningocele?
a little more severe, the spinal cord is kind of bulging out the back.
What is Rachischisis?
this is where the neural tube doesn't fully close
Sclerotomal segments must _____ to make up vertebrae. If this doesn't happen correctly you could get _______.
When do the limbs develop?
Day 24 for the upper limb
Day 28 for the lower limb
What is the sequence for limb development?
upper limb before the lower limb
T/F The developmental process in the formation of limbs is molecularly regulated by proteins. Give examples.
positioning of the limb, what migrates to the anterior & posterior compartments, where the thumb goes
T/F Congenital defects of the limb are quite common b/c it develops early on in gestation.
False. Even tho they develop early on, defects are NOT common.
T/F Limb development is susceptible to teratogens.
TRUE drugs etc can have a huge effect b/c the limbs are developing in the 4th & 5th week
When congenital defects do occur in the limbs, they are usu associated w/ severe defects. Give examples.
How can amniotic bands cause congenital defects?
strips of amnion go inside the amniotic sac & can wrap around the fetus...they can constrict so much that you can lose a limb or finger.
What is polydactyly?
Ex: six fingered man
What is syndactyly?
this is where some of the fingers are fused, so you technically have fewer fingers & you have a web hand sorta.
What is adactyly?
This is where you have no fingers.