Musculoskeletal Development Flashcards
__________: bilateral paired blocks of paraxial mesoderm that form along the head to tail axis of the developing embryo
somites
name the 3 critical regions that somites differentiate into
- sclerotomes
- myotomes
- dermatomes
interactions between the _______, __________, and ________ are critical for normal development
- notochord
- somites
- neural tube
muscle development requires __________
innervation
proper joint/bone development requires __________
muscle activity
the dermatome will give rise to what?
the dermis of the skin
the myotome will give rise to what?
muscles of body wall, neck, and limbs
the sclerotome will give rise to what?
- cartilage
- bone
- ligaments/tendons
‘sonic hedgehog’ signaling from the notochord is vital to _________ development
sclerotome
Wnt from the neural tube is vital to _________ development
myotome
3 steps to vertebrae development
- ventral cells surround the notochord/neural tube
- distinct rostral-caudal growth from each somite
- adjacent somites fuse - spinal nerves exit/enter between vertebrae
dorsomedial myoblasts form the _________
epimere
____ signaling from the ________ promotes myotome differentiation
- Wnt
- dermatome
the ___________ develops into the epaxial muscles
epimere
dorsolateral myoblasts form the _________
hypomere
the ________ develops to form the hypaxial muscles
hypomere
What happens to the cervical hypomeres?
they fuse to form ventral neck musculature
What happens to hypomeres in the thoracic and abdominal regions?
they retain segmentation and give rise to 3 muscle layers
What 3 structures do the hypomeres in the lumbo-caudal region give rise to?
- pelvic diaphragm
- coccygeus
- levator ani
mitochondria organize ________ to sarcomeres
parallel
muscles are first innervated by _______ nerves and later by ________ nerves, which induce formation of _____________ and __________
- motor
- sensory
- muscle spindles
- intrafusal fibers
________ retain some muscular repair capacity which declines with age
satellite cells
satellite cells are no longer able to self renew when they lose _______
polarity
____________ are the main signal of the apical ectodermal ridge (AER)
FGFs
paralogous _________ specify the patterned identity of the limb
Hox genes
cranial/caudal axis of a limb is triggered by a small group of cells called _________
ZPA
orientation of the limb axis is maintaned by regional signaling/cross talk between the ___________ and ____________
- apical ectodermal ridge
- ZPA
dorsally positioned muscles become _______, ventrally positioned muscles become __________
- extensors
- flexors
a higher proportion of TBX5 expression will result in more pronounced ________ development
forelimb (bats)
a higher proportion of TBX4 expression will result in more pronounced ________ development
hindlimb (kiwi)
