Notes in Limb MSK Development

To Subscribe, use this Key

Status	Last Update	Fields
Published	11/30/2024	Limb development begins in week {{c1::4}}
Published	11/30/2024	Limb development begins with appearance of small projections from the {{c1::ventrolateral}} trunk called the {{c1::upper limb bud and lower …
Published	11/30/2024	Initiation of limb development begins with proliferation of {{c1::mesenchymal::cell type}} cells in the {{c2::parietal (somatic) layer of la…
Published	11/30/2024	Cells forming the limb buds are composed of a {{c1::mesenchymal}} cell core and a layer of {{c1::ectoderm}} cells
Published	11/30/2024	Upper limb development starts {{c1::before::relative timing}} lower limbs
Published	11/30/2024	Upper limbs finish developing {{c1::at the same time as::relative timing}} lower limbs
Published	11/30/2024	Limbs developmental origins- Limb muscles: {{c1::Dermamyotome}}- Bones and dermis: {{c1::Parietal (somatic) layer of lateral plate mesoderm}…
Published	11/30/2024	the ectoderm at the distal end of the limb buds thicken and form {{c1::apical ectodermal ridge}}
Published	11/30/2024	apical ectodermal ridge's effect on adjcadent mesenchyme: {{c1::inductive influence causes adjacent mesenchyme to remain undifferentiated and rap…
Published	11/30/2024	Development of each limb proceeds in a {{c1::proximal}} to {{c1::distal}} direction
Published	11/30/2024	In late week {{c2::5}} - week {{c2::6}}, the distal portion (apex) of the limb bud becomes flattened to form a {{c1::hand plate or foot plate}}
Published	11/30/2024	After formation of the hand plate and foot plate, Mesenchyme within it condenses into {{c1::digital rays}}
Published	11/30/2024	Fingers and toes are formed in the apical ectodermal ridge when {{c1::cells die separating the AER into 5 parts}}
Published	11/30/2024	Fingers are formed in the apical ectodermal ridge (AER) during {{c1::late week 6::timeframe}}.What about toes?: {{c1::week 7::timeframe}}
Published	11/30/2024	Separated but still short fingers appear in week {{c1::8}}What about toes?: {{c1::week 8 (same)::timeframe}}
Published	11/30/2024	Process by which bones of the upper limb form: {{c1::endochondral ossification}} except for the {{c2::clavicle}}
Published	11/30/2024	Process by which clavicle forms: {{c1::intramembranous ossification}}
Published	11/30/2024	Endochondral ossification of the upper limb bones begins by {{c1::end of week 8::timeframe}}
Published	11/30/2024	Endochondral ossification process involves the formation of a {{c1::cartilaginous model}} which is invaded by a blood vessel called the {{c2…
Published	11/30/2024	Primary ossification centers are found in the limb bones (humerus/radius/ulna/femur/tibia/fibula) by week {{c1::12}}
Published	11/30/2024	the shaft of a bone is also called the {{c1::diaphysis}}
Published	11/30/2024	the proximal and distal ends of a bone are also called {{c1::epiphyses}}
Published	11/30/2024	At birth the diaphysis of the bone is {{c1::complete ossified::state}}
Published	11/30/2024	At birth, the epiphyses of the bone are {{c1::still cartilaginous::state}}
Published	11/30/2024	The plate between the primary and secondary ossification center is also called {{c1::epiphyseal}} or {{c1::growth plate}}
Published	11/30/2024	Upon formation of the growth plate, endochondral ossification proceeds on {{c1::both sides of the growth plate}}
Published	11/30/2024	In long bones, growth plates are found {{c1::on each end::location}}. Short bones are found {{c1::at one end::location}}
Published	11/30/2024	Limb muscles arise from dermamyotome and move {{c1::ventrally::direction}}
Published	11/30/2024	Upper limb bud arises adjacent to the {{c1::C4-T2}} somites
Published	11/30/2024	Migration of myogenic precursors (myoblasts) starts during week {{c1::5}}
Published	11/30/2024	As the long bones form during week 5, {{c1::myoblasts}} aggregate and form two large condensations in the {{c2::dorsal and ventral aspects}}…
Published	11/30/2024	The dorsal mass gives rise to {{c1::extensors and supinators}} of the upper limb
Published	11/30/2024	The ventral mass gives rise to {{c1::flexors and pronators}} of the upper limb
Published	11/30/2024	The innervation of each muscle correlates to the {{c1::hypomere (and thus the somite)}} from which the muscle cells developed
Published	11/30/2024	Up until the {{c2::7th}} week, limbs are positioned so the flexor compartment is placed {{c1::ventrally}} and the extensor compartments are place…
Published	11/30/2024	During week {{c2::7 & 8}}, the upper limbs rotate {{c1::laterally 90 degrees}}
Published	11/30/2024	By week {{c2::8}}, the hands can {{c1::meet and cross in front of the torso}}
Published	11/30/2024	Typical causes of upper limb defects: {{c1::Genetic factors and teratogens}}
Published	11/30/2024	Developmental abnormalities notably associated with limb abnormalities: {{c1::amniotic band syndrome and oligohydramnios}}
Published	11/30/2024	Amelia: {{c1::absence of one or more limbs due to suppression of limb bud development}}
Published	11/30/2024	Amelia occurs during {{c1::early part of the 4th week::timeframe}}
Published	11/30/2024	Meromelia: {{c1::partial absence of at least one limb}}
Published	11/30/2024	Meromelia occurs during {{c1::the 5th week::timeframe}}
Published	11/30/2024	Phocomelia: {{c1::presence of hands/feet attached to torso or very short limbs}}
Published	11/30/2024	Phocomelia caused by failure of limb buds to elongate due to {{c1::minimal mesenchyme availability}}
Published	11/30/2024	Cleft hand is also called {{c1::split hand}}
Published	11/30/2024	Cleft hand: {{c1::the hand appears as a bifurcate (forked) hand due to missing one or more central digits}}
Published	11/30/2024	Cause of split hand/foot: {{c1::failure of one or more digital rays to form}}
Published	11/30/2024	Polydactyly: {{c1::presence of extra digit (typically on one hand/foot only)}}
Published	11/30/2024	Cause of polydactyly: {{c1::additional complete or partial digital rays}}
Published	11/30/2024	Most polydactyly appears {{c1::most medial or most lateral::location}} on the hand
Published	11/30/2024	Syndactyly: {{c1::webbed or joined digits}}
Published	11/30/2024	Cause of syndactyly: {{c1::lack of cell death between digital rays}}
Published	11/30/2024	Most common upper limb difference: {{c1::syndactyly}}
Published	11/30/2024	Syndactyly most commonly affects the {{c1::3rd and fourth}} digits of the upper limb
Published	11/30/2024	Syndactyly types- {{c1::Simple (only soft tissue)}}- {{c1::Complex (bone, cartilage, and soft tissue)}}- {{c1::Complicated (abnormally …
Published	11/30/2024	Poland syndrome: {{c1::absence of at least a portion of the pectoralis major muscle. Sometimes other nearby muscles as well}}
Published	11/30/2024	In poland syndrome, nipple and areola are typically {{c1::absent or displaced}}
Published	11/30/2024	Poland syndrome may also be accommpanied with differences in development of {{c1::digits, shortened radius and ulna, or shortened ribs}}
Published	11/30/2024	Musculoskeletal system develops primarily from:- {{c1::Paraxial mesoderm}}- {{c1::Lateral plate mesodern}}- {{c1::Neural crest}}
Published	11/30/2024	Lower limb bud appears by day {{c1::26}}
Published	11/30/2024	Process by which bones of the lower limb form: {{c1::endochondral ossification}}
Published	11/30/2024	Bones reach their full length during {{c1::late adolescence (~ age 18)::life phase/year}}
Published	11/30/2024	Body growth is complete during {{c1::early adulthood (~ age 20)::life phase/year}}
Published	11/30/2024	When body growth is complete, the {{c1::growth plates}} of the long bones completely ossify
Published	11/30/2024	The dorsal mass gives rise to {{c1::extensors}} of the lower limb
Published	11/30/2024	The ventral mass gives rise to {{c1::flexors}} of the lower limb
Published	11/30/2024	Dorsal mass gives rise to the extensors which includes {{c1::gluteal}} muscles of the gluteal region, {{c1::anterior}} compartment of the thigh, …
Published	11/30/2024	Ventral mass gives rise to the flexors which includes: {{c1::no}} muscles of the gluteal region, {{c1::medial and posterior}} compartment of the thigh…
Published	11/30/2024	During week {{c2::7}}, the lower limbs rotate {{c1::medially 90 degrees}}
Published	11/30/2024	By week {{c2::8}}- the extensors of the lower limb are positioned {{c1::anteriorly::direction}}- the flexors are positioned {{c1::posteriorly::directi…
Published	11/30/2024	The feet are appropriately pronated by {{c1::some time into the postanatal period}}
Published	11/30/2024	At days {{c1::25 - 26}}, amelia is more likely to effect the lower limb only
Published	11/30/2024	Split foot: {{c1::the foot appears as a bifurcate (forked) foot due to missing one or more central digits}}
Published	11/30/2024	Most polydactyly appears {{c1::most lateral::location}} on the foot
Published	11/30/2024	Hip development begins by week {{c1::7}}
Published	11/30/2024	Femoral head and acetabulum are formed by a {{c2::cleft through the same mass of mesenchyme}} during weeks {{c1::7-8}}
Published	11/30/2024	The acetabulum cavity is shaped in part by {{c1::the femoral head}}
Published	11/30/2024	If femoral head's position is incorrect or its movement is restricted during the pregnancy, it may result in {{c1::a shallow socket (developmental dys…
Published	11/30/2024	By week {{c1::11}}, The hip joint complex is formed
Published	11/30/2024	By week 11, the femoral head is {{c1::cartilaginous::cartilaginous/ossified}}
Published	11/30/2024	By week 11, the acetabulum is {{c1::cartilaginous::cartilaginous/ossified}}
Published	11/30/2024	{{c1::Abducted::action}} positiong during development is important for the development of the {{c2::acetabulum::structure}} by {{c1::maximizing t…
Published	11/30/2024	The acetabulum ossifies by {{c1::late adolescence (~18 years old)::infancy/childhood/adulthood}}
Published	11/30/2024	Developmental dysplasia of the hip refers to a difference in {{c1::size::feature}}, {{c1::shape::feature}}, {{c1::orientation::feature}…
Published	11/30/2024	Hip dysplasia results in {{c1::hip instability}}
Published	11/30/2024	Hip instability results in {{c1::hip subluxation or dislocation}}
Published	11/30/2024	Developmental Dysplasia of the Hip (DDH) is more common on the {{c1::left::left/right}} side because of {{c2::intra-uterine position}}
Published	11/30/2024	Physical examination of patient with Developmental Dysplasia of the Hip (DDH) could reveal:- {{c1::hip instability}}- {{c1::unequal leg leng…
Published	11/30/2024	Prenatal and perinatal risk factors for DDH- {{c1::Breech presentation (forces lower limbs into adducted position)}}- {{c1::Birth (birthing hormones -…
Published	11/30/2024	Postanatal development dysplasia of the hip (DDH) risk factors:- {{c1::Repetitive/sustained adducted positioning}}- {{c1::Repetitive/sustain…
Published	11/30/2024	Club foot is also called {{c1::Congenital Talipes Equinovarus (CTEV)}}
Published	11/30/2024	Congenital talipes equinovarus (CTEV) clinical presentation:- {{c1::Medially rotated foot}}- {{c1::shorter Leg}}- {{c1::shorter&nb…
Published	11/30/2024	Congenital Talipes Equinovarus (CTEV) most likely causes:- {{c1::Failure of lower limb to rotate fully}}- {{c1::Genetics}}
Status	Last Update	Fields