9/25 Development Of Musculature - Dennis Flashcards
What rises from paraxial mesoderm? 4
Somites
What gives rise to muscle of the trunk? 4
Myotomes
What gives rise to cartilage? 4
Sclerotomes
Where do sclerotomes begin and end? 5
Begin as a portion of the sclerotome and are then released and move inferior to the sclerotome
Once the somite opens and becomes linear what are the different layers from superficial to deep? 6
Dermatomes —> myotome —> Syndetome (tendons) —> sclerotome
What does the myotome differentiate into? 7
Epidermis
Hypomere
What does the epimere give rise to? 7
Deep epaxial muscle (dorsal rami):
—> erector spinae
—> transversospinalis
What does the hypomere give rise to? 7
Hypaxial muscle (ventral rami):
—> lateral body wall
—> ventral body wall
What are the four Hypaxial divisions? 9
Cervical myotomes
Thoracic myotomes
Lumbar myotomes (Quadratus lumborum)
Sacrococcygeal myotomes (pelvic floor musculature)
What occurs in Poland Syndrome? 10
Absence of pectoralis minor
Partial loss of pectoralis major
What occurs in Prune-Belly Syndrome? 11
Partial/complete absence of abdominal musculature
Cryptorchidism (failure for one or both testes to descend)
Malformation of urinary tract/bladder
Within a sclerotome, what do the ventral, dorsal, and lateral cells become? 12
Ventral cells —> vertebral body
Dorsal cells —> vertebral arch & spine
Lateral cells —> vertebral transverse processes and ribs
What occurs during sclerotomal break-up? 13, 14
Sclerotome is split by a spinal nerve into a rostral (superior) segment and a caudal (inferior) segment
A posterior, caudal segment joins with a superior, rostral segment to form a vertebrae
Where would you find a C4 nerve root? 14
Above the C4 vertebrae (true for all vertebrae)
What does the centrum develop from? 15
Immediately caudal sclerotomes?
What gives rise to intervertebral discs? 15
Add
As the vertebral column develops what does the notochord expand and turn into? 18
The nucleus purposes
What comes to surround the nucleus pulposus and is wedged between vertebrae? 18
Annulus fibrosus
What do the sternal bars give rise to? 19
Manubrium
sternebrae (segments of the sternal body)
Xiphoid process
What decides the shape of each vertebrae and determines where the transition point between vertebrae will be? 20
Hox genes
Hox10 - forms the thoracic/Lumbar boundary
What problem can cervical ribs cause? 22
Can impinge:
—> Brachial plexus
—> subclavian artery
What syndrome is associated with impingement of the subclavian artery? 22
Thoracic outlet syndrome
What malformation shows a depressed sternum that is sunken posteriorly?
Pectus excavatum
What malformation causes bilateral flattening of the chest with an anteriorly projecting sternum? 22
Pectus carinatum
Do concept map
Slide 24
