lec 4 prenatal lower limb development Flashcards
when do lower limb buds appear
week 4
when do lower buds become flattened and project at 90degree angle
week 5
when do knees point laterally
legs and feet rotated internally
week 6
when does free end of each lower limb turn 90 degrees medially
week 7
knees now point cranially/superiorly
soles of feet face each other
what happens in week 8
foot inhabits an equinus-supinates poition
rotation 1
coronal to parasagittal
rotation 2
medially along long axis of lower limb
lateral plate mesoderm destined to become
ligaments, bones, tendons, dermis
when is clearly defined footplate formed
week 5
when do toe rays become visible in foot plate
week 6
when do digits become webbed
week 7
ossification order
femur and tibia ilium metatarsals and phalanges ischium pubis tarsals
when do chrondrocytes form the 1st hyaline cartilage models and joints
week 6
posterior division of ventral rami supplies
developmentally dorsal muscles
anterior division of ventral rami supplies
developmentally ventral muscles
causes of limb abnormalities
genetic factors mutant genes environmental factors-alc or drug during pregnancy multifactoral inheritance stymied tissue interactions mechanical effects
polydactyly
duplication of digits
congenital hip dysplasia
abnormal development of hip joint most likely from breech posture
cutaneous syndactyly
webbing of digits
mesenchyme between prospective digits doesn’t undergo apoptosis
