Development--Sievert Flashcards
Somites give rise to what 2 things?
dermatomyotome & sclerotome
What does sclerotome make?
bone
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/?
spina bifida
**& 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 _______.
fuse
scoliosis
When do the limbs develop?
Early!
Day 24 for the upper limb
Day 28 for the lower limb
What is the sequence for limb development?
rostral –>caudal
upper limb before the lower limb
T/F The developmental process in the formation of limbs is molecularly regulated by proteins. Give examples.
True
Ex:
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.
cardiovascular
genitourinary
craniofacial
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?
extra digits
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.
What is Prune Belly Syndrome?
congenital muscular disorder
anterior abdominal wall doesn’t completely form so you get kinda one giant hernia
belly has no muscular structure to the anterior wall
