- See:
-
Anatomy of the Physis
-
Deformities
-
Enchondral Ossification
-
Longitudinal Growth:
-
Pediatric Bone Circulation
-
Salter Harris
- Discussion:
- at about the 4th week of development, paired upper and lower limb buds appear;
- the upper limb bud appears at day 25-27;
- at approx 47 days when the joints of the hand develop;
- the lower limb bud appears at day 27-29;
- each limb bud onsists of mesenchyme covered by ectoderm of lateral body wall;
- mesenchyme of the limb bud derives from lateral body wall, & some if it migrated into limb bud from adjacent
somites;
- development of lower limb lags behind the upper limb;
- limb buds bend ventrally at sites of future elbows and knees, leaving these structures pointing laterally
while the palms and soles facing medially;
- upper limbs then undergo external rotation while lower limb undergo internal rotation;
The Ectodermal Thickening and Ridge in the Limbs of Staged Human Embryos.
R. O'Rahilly et al.
J. Embrylolgy Experimental Morphology. Vol 4, Part 3, p 254-264.
Development of the upper limb. Zaleske DJ. Development of the upper limb. Hand Clin 1985;1:383-390.
Reconstructing the history of human limb development: lessons from birth defects
The molecular control of upper extremity development: implications for congenital hand anomalies.
