Flashcards in Embryology - Muscles, Somites, Limbs, Lung Deck (45)
A somite starts off as mesenchymal cells. they then differentiate into ___, ___, and ___
sclerotome, dermatome, and myotomes (sometimes the last two are combined : dermomyotome)
Sclerotome cells surround ___
the notochord and neural tube
__sclerotomes split and recombine to form __
segmental; intersegmental vertebral rudiments and ribs
What are somites made from? What do they establish?
paraxial mesoderm; segmental org. of the body
paraxial mesoderm is from what?
the intraembryonic mesoderm lateral to the notochord and neural tube
what embryonic tissue forms cartilage
what are the two embryonic types of connective tissue that form bone
mesenchyme and cartilage
embryonic intramembranous ossification ossifies_____.
embryonic intracartilaginous ossification ossifies ___.
synovial joints are made from what? What about the joint capsule and synovial membrane?
interzonal mesenchyme located between developing bones. the other parts are also interzonal mesenchyme
cartilagenous joints are made from what?
interzonal mesenchyme that differentiates into hyaline or fibrocartilage
fibrous joints are made from what?
interzonal mesenchyme that differentiates into fibrous connective tissue
during the 4th week, mesenchymal cells from somites are found in the ____, ____, and ___.
surrounding notochord, surrounding the neural tube, and in body wall.
limb buds appear from ____.
lateral plate mesoderm
each limb bud contains what two things?
apical ectodermal ridge and mesenchyme
what is the apical ectodermal ridge? what is a possible modulator?
it is a thickening of ectoderm at the apex of a limb bud. It is possibly modulated by retinoic acid
which muscle is NOT from mesoderm
developmental tissues leading to muscle
mesenchyme > myoblasts > muscle
each myotome splits into two structures?
dorsal epimere and ventral hypomere
visceral muscles (iris, sweat gland muscles etc) are from what?
Cardiac muscle is from what? Are purkinje fibers from that as well?
splanchnic mesoderm. NO. Purkinje fibers are from a different dvpmntal pathway
Name the 5 things that are derived from sclerotomes
vertebral bodies, vertebral arches, annulus fibrosis, costal processes, sternum/sternal bars
what 3 things are derived from costal processes?
Ribs, transverse processes, and sacral mass
Epimeres give rise to___
deep epaxial m of back
Hypomeres give rise to what muscles
lateral and ventral body wall: intercostals, abdominal girdle muscles and rectus abdominus
In the limb, what makes the bones, tendons, ligaments and vasculature?
Lateral plate mesoderm
appendicular skeleton is formed with what type of ossification?
Which bones appear in weeks 7-12
Clavicle> upper limb> lower limb> scapula and ilium> phalanges> ischium and pubis> tarsals and carpals
(basically starts with arm and alternates from arm to legs, going distally)
the upper limb rotates ___(direction) so that the extenors are on the __ and __ aspects
laterally; lateral; dorsal