Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
39 Cards in this Set
- Front
- Back
|
where and when do the limb buds on an embryo occur |
week 4 on ventrolateral body wall |
|
|
what develops from the mesenchymal mesoderm |
bones and connective tissue |
|
|
what develops form the epithelial ectoderm |
the digitis (fingers and toes) |
|
|
the apical ectodermal ridge (AER) is formed through the thickening of the distal border of what kind of ectoderm |
epithelial ectoderm |
|
|
the epithelial ectoderm thickens at its distal border to form the AER, which then surrounds the mesenchyme to form what? |
the 'progress zone' (PZ) of undifferentiated rapidly proliferating cells |
|
|
what is a congenital anomaly |
a defect present from birth |
|
|
out of 10,000 births, how many congenital defects will be in the upper limb |
3.4/10,000 |
|
|
out of 10,000 births, how many congenital defects will be in the lower limb |
1.1/10,000 |
|
|
what are congenital anomalies often associated with |
Often associated with craniofacial, cardiac and/or genitourinary defects. |
|
|
list the IFSSH classification problems |
type I • Failure of formation |
|
|
what are teratogens |
an agent or factor which causes malformation of an embryo. |
|
|
give examples of common teratogens |
Thalidomide Warfarin Alcohol Cocaine |
|
|
when in embryonic development is the most sensitive period for teratogen induced limb defects |
weeks 4-5 |
|
|
Cells further from AER differentiate into cartilage and muscle. Proceeds proximodistally. Morphogenesis of lower limbs is 1-2 days behind that of upper limbs. |
Cells further from AER differentiate into cartilage and muscle. Proceeds proximodistally. Morphogenesis of lower limbs is 1-2 days behind that of upper limbs. |
|
|
in what week of embryonic development does rotation of limbs occur |
week 7 |
|
|
list congenital anomalies |
|
|
|
what is amelia |
complete absence of one or more limbs |
|
|
what is meromelia |
partial absence of one or more limbs |
|
|
what is sirenomelia |
•Fusion of limbs. •Siren = mermaid (Greek) |
|
|
what is hemihypertrophy |
overgrowth of limb |
|
|
what is micromelia |
undergrowth of limb |
|
|
what is constriction band syndrome |
|
|
|
what is the pathogenesis of achondroplasia |
•Autosomal dominant. •Mutations in the fibroblast growth factor receptor-3 (FGF- R3) gene on chromosome 4p16.3. •Defect in cartilage-derived bone. |
|
|
what is the presentation of achondroplasia |
•Macrocephaly, frontal bossing, midface hypoplasia, small chest, rhizomelic limb shortening, redundant skin folds, joint laxity |
|
|
what is the pathogenesis of marina's syndrome |
•Autosomal dominant. •Disorder of connective tissue. •Mutations in the fibrillin 1 (FBN 1) gene on chromosome 15 |
|
|
what is the presentation of Marfan's syndrome |
•Tall stature, long thin digits (arachnodactyly), long thin limbs, hyperextensible joints, a high arched palate, dislocation (usually upwards) of the lenses of the eyes and severe myopia |
|
|
what are the complications in Developmental Displasia of the Hop (DDH) |
-Poorly developed acetabulum and head of femur -Dislocation commonly occurs after birth -Avascular necrosis of femoral head. |
|
|
when do the hands and feet plates occur in embryos |
week 6 |
|
|
how are the digits formed |
Cell death (apoptosis) in AER divides the ridge into 5 parts. Growth of the 5 parts of ectoderm continue. Mesenchymal condensation cartilaginous digital rays. Apoptosis between digital rays. |
|
|
what does dactyly mean in greek |
digit |
|
|
what is ectrodactyly |
failure of formation of digit(s) |
|
|
what is syndactyly |
failure of differentiation of digits |
|
|
what is polydactyly |
too many digits |
|
|
what is macrodactyly |
overgrowth of digits |
|
|
what is brachdactyly |
undergrowth of digits |
|
|
what is cleft hand and foot |
•3rd meta- carpal and phalangeal bones usually absent. •Fusion of thumb + index fingers & 4th + 5th fingers
what alex brooker has |
|
|
what is club foot |
hypoplasia of limb muscles |
|
|
what is the presentation of cleft foot |
•Hindfoot equinus and varus. •Forefoot adduction. •Shortened foot
varus - a deformity involving oblique displacement of part of a limb towards the midline |
|
|
what is the treatment for cleft foot |
Ponseti method (serial casting and percutaneous tenotomy of Achilles tendon). |
