Term
| where does the skeletal system develop from |
|
Definition
| the paraxial and lateral plate mesoderm and neural crest |
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|
Term
| how does the paraxial mesoderm form the skeletal system |
|
Definition
| it forms a series of somitomeres and somites on each side of the neural tube |
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|
Term
| where do somatomeres come from, where are they located, what do they make |
|
Definition
| they come from the paraxial mesoderm and are located in the head, they make the skeleton |
|
|
Term
| where do somites come from, where are they located, what do they make |
|
Definition
| they come from the paraxial mesoderm and are located in the occipital region caudally, they make the skeleton |
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|
Term
| what does the ventromedial part of the somite differentiate into |
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Definition
|
|
Term
| where does the sclerotome come from, what does it make and do |
|
Definition
| it comes from somite differentation, becomes mesenchyme which differentiates into cartilage and bone forming cells and vertebra |
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|
Term
| what skeletal structures does the lateral plate mesoderm form |
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Definition
| pelvic and sholder girdles, bones of the limbs |
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|
Term
| what skeletal structures does the neural crest cells form |
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Definition
|
|
Term
| what skeletal structures does the occipital somites and somitomeres form |
|
Definition
| cranial vault and base of scull |
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|
Term
| what skeletal structures does the mesenchyme differentiate into |
|
Definition
| flat bones of the scull, hayline cartilage modles for later bones |
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|
Term
| what is different about mesenchyme from the other bone forming components of embryology |
|
Definition
| it can differentiate directly into bone or make cartilage models of bone |
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|
Term
| what are the parts of the scull |
|
Definition
| neurocranium and viscerocranium |
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|
Term
| what is the purpose of the neurocranium |
|
Definition
| form protective part around the brain |
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|
Term
| what is the purpose of the viscerocranium |
|
Definition
| forms skeleton of the face |
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|
Term
| what are the parts of the neurocranium |
|
Definition
| membranous and cartilagnious (chondocranium) |
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|
Term
| what is the membranous part of the neurocranium |
|
Definition
| flat bones that surround the brain as the cranial vault |
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|
Term
| what is the chondrocranium |
|
Definition
| forms bones of the base of the scull |
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|
Term
|
Definition
| seams of fibrous tissue that seperates flat bones |
|
|
Term
| where is the saggital suture derived from |
|
Definition
|
|
Term
| what is the coronal suture derived from |
|
Definition
|
|
Term
|
Definition
| wide sutures where more than two bones meet |
|
|
Term
|
Definition
| 5-7 yrs old, but some stay until adulthood |
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|
Term
| where are the cartilages in the front of the rostal limit of the notochord in the neurocranium derived from |
|
Definition
| neural crest prechordal chondrocranium |
|
|
Term
| what is the rostral limit of the notochord, what does it mark |
|
Definition
| the middle of the sella turcia or where the notochoed travels around where the pituitary is, marks where the mesenchyme derived the structures behind this point and the neural crest the structures in front |
|
|
Term
| how is the base of the scull formed |
|
Definition
| ehn the cartilages of the neurocranium fuse and ossify with endocrinal ossification |
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|
Term
| where are the cells posterior to the limit of the notochord in the neurocranium derived from |
|
Definition
| sclerotomes chordal chondrocranium |
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|
Term
| iin the viscerocranium, what are the bones of the face formed by |
|
Definition
| the first two pharyngeal arches |
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|
Term
| what does the first pharyngeal arch dorsal portion form |
|
Definition
| maxillary process, zygomatic and temporal bones |
|
|
Term
| what does the first pharyngeal arch ventral position |
|
Definition
| mandibular process from the mesenchyme next to the meckel cartilage |
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|
Term
| what does the maxillary process form |
|
Definition
| maxilla, zygomatic bone, part of the temporal bone |
|
|
Term
| what does the dorsal tip of the mandibular process along with the second pharyngeal arch form |
|
Definition
|
|
Term
| in the mandibular process, what does the meckel cartilage mesenchyme form, how |
|
Definition
| mandible with membranous ossification |
|
|
Term
| where are the nasal and lacrimal bones derived from |
|
Definition
|
|
Term
| when are limb buds visible |
|
Definition
|
|
Term
| what do limb buds look like when they can first be seen |
|
Definition
| outpocketings of the ventrolateral body wall with a mesoderm core and ectoderm shell |
|
|
Term
| what happens to the limb buds at 6 weeks |
|
Definition
| terminal portions flatten forming handplates and footplates |
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|
Term
| how do fingers and toes form |
|
Definition
| constrictions develop proximal to the hand and foot plates dividing the limb into two segments, cell death at the AER seperates the five parts along with continued outgrowth |
|
|
Term
| what is different in the timing of the development of the upper vs lower limbs |
|
Definition
| lower limbs are about 1-2 days behind |
|
|
Term
| what happens to the limbs at 7 weeks |
|
Definition
| they rotate in opposite directions |
|
|
Term
| how do the upper limbs rotate |
|
Definition
| laterally 90 deg, making the thumb lateral |
|
|
Term
| how do the lower limbs rotate |
|
Definition
| medial 90 deg, making the big toe medial |
|
|
Term
| when are the hayline cartilage models of bones formed |
|
Definition
|
|
Term
|
Definition
| mesenchyme condenses and cells differentate |
|
|
Term
| at what point can joints form, from what |
|
Definition
| after chondrogenesis is complete, forms from constrictions and the joint interzones that form |
|
|
Term
| when are the primary ossification centers established |
|
Definition
|
|
Term
| where does embryo ossification begin and what way does it extend |
|
Definition
| diaphysis, towards the ends of the model |
|
|
Term
| what what point in time is the diaphysis completely ossified |
|
Definition
|
|
Term
| what does the HOX gene control in bone development |
|
Definition
| positioning of limbs along the craniocaudal axis, regulates types ahd shapes of limb bones |
|
|
Term
| what controls growth along the proximodistal, anteriorposterior, and dorsoventral axes |
|
Definition
|
|
Term
| what does FGF-10 control in bone development |
|
Definition
|
|
Term
| what does BMPs control in bone development |
|
Definition
|
|
Term
| what maintains the progress zone in bone development |
|
Definition
|
|
Term
| what is anteroposterior patterning regulated by |
|
Definition
| zone of polarizing activity (ZPA) |
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| what does retinoic acid do in bone development |
|
Definition
| initiates expression of sonic hedgehog |
|
|
Term
| what does sonic hedgehod control in limb development |
|
Definition
| digits appearing in the proper order |
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|
Term
| describe the process of dorsalventral patterning |
|
Definition
| BMPs in verntal mesoderm repress WNT7a which induces LMX1 which specifies cells to be dorsal |
|
|
Term
| what part of the somite to vertebra form from |
|
Definition
|
|
Term
| in what week does vertebre development begin |
|
Definition
|
|
Term
| describe the process of vertebra development |
|
Definition
1. sclerotome cells migrate around spinal cord and notochord on each side and merge
2. each somit block divides into caudal and rostral position that divide and hook up with a different one putting the vertebra a 1/2 step out of sequence giving proper line up for the nerves and vessels
3. the area where sclera divided will not proliferate and will form intervetebral discs |
|
|
Term
| due to the organization of the scletotome durine vertebra development, what does each vertebra contain |
|
Definition
| two different parts of the sclerotome |
|
|
Term
| how are intervetebral discs formed |
|
Definition
| when cells of the sclerotome migrate to make the certebra, some do not proliferate, the notochord in the disc area does not regress but enlarges making the nucleus pulposus |
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|
Term
| due to resegmentation in vertebral development what happens to myotomes |
|
Definition
| they bridge the intervetebral discs giving them the capacity to move |
|
|
Term
| due to resegmentation in vertebral development what happens to the intersegmental arteries |
|
Definition
| they pass midway over the vertebral bodies |
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|
Term
| due to resegmentation in vertebral development what happens to the spinal nerves |
|
Definition
| lie next to intervetebral discs and leave vertebra column through intervetebral foramen |
|
|
Term
| where do the ribs form from |
|
Definition
| the costal process of the thorasic vertebra, sclerotome of paraxial mesoderm |
|
|
Term
| what does the sternum develop from |
|
Definition
| somatic mesoderm of the ventral body wall |
|
|
Term
| describe sternum development |
|
Definition
| two sternal bands form on each side of the midline, they later fuse to corm cartilagnious models of the manubrium, sternbrae, and zyphoid process |
|
|
Term
| what tissues form the structures of the neurocranium |
|
Definition
| neural crest and paraxial |
|
|
Term
| what is the frontal fontanell |
|
Definition
| soft spot on the front of the head where more than two flat bones meet that closes at ~2yrs old |
|
|
Term
| what does the 2nd pharyngeal arch form |
|
Definition
|
|
Term
| once the limb buds form, what happens next in limb development |
|
Definition
| ectoderm thickens on one spot onto apical ectodermal ridge to direct growth and releases growth factors. most proximal tissue will then differentate |
|
|
Term
| describe the process of proximal conditioning |
|
Definition
| FGF-10 begins limb bud outgrowth, BMPs induce AERidge, radical fringe keeps it from twisting, FGF-4 and FGF-8 keep limb tissue undifferentated out the outside and it moves outward so the inner layers can differentiate |
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|
Term
|
Definition
| allows for vertebra to move during development, involved in the splitting of the pre vetebral discs and the fusion of the top part of one with the bottom part of the one above |
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