Limb Developement (Movement / Embryology / Anatomy) Flashcards
When does limb developement occur?
5-8weeks
In what weeks are the limb buds visible as outpouchings from the ventrolateral body wall?
end of week 4
The mesoderm core of the limb bud differentiates into mesenchyme. What does this form in the limb/
Bones and connective tissue
What does the paraxial mesoderm form?
Paraxial mesoderm forms somites. The somites differentiate into structures - including skeletal muscle of limb.
The somites divide into the sclerotome and dermomyotome what do these give rise to?
Sclerotome = vertebral bodies
Dermomytome = skin and skeletal muscle
The epimere makes up the back muscles. What are they innervated by?
Dorsal rami of the spinal nerves
The hypomere makes up the muscles of the thoracic / abdo walls also muscles of the limbs. what are they innervated by?
ventral rami of the spinal nerves
Where does the limb musculature derive from?
Myotomt divides into epimere and hypomere. Limb muscles are from hypomere.
*Paraxial mesoderm»_space;>Somites»>dermomyotome»>myotome»>Hypomere
What is the upper limb inneravatd by?
brachial plexus (C5 - T1)
What is the lower limb innervated by?
lumbosacral plexus (L4-S3)
During limb rotation in which direction do the limbs rotate?
Upper limb = 90’ laterally so the flexors lie anteriorly
Lower Limb = 90’ medially so flexors lie posteriorly
When does limb rotation occur?
between weeks 6-8
What dermatome supplies the thumb?
C6
What dermatome supplies the 3 digit?
C7
What dermatome supplies the 5th digit?
C8
