ANATOMIC SPACES OF THE NECK Print Section Listen There are various techniques for categorizing the complex anatomy of the neck. Based on anatomic boundaries, the neck is divided into anterior…

DEVELOPMENTAL ANOMALIES OF THE SMALL INTESTINE Print Section Listen Normal Development The duodenum derives from the distal portion of the foregut. During the fourth to eighth weeks of gestation, rapid…

NORMAL DEVELOPMENT OF THE VERTEBRAL COLUMN AND SPINAL CORD Print Section Listen Spinal Cord During gestation week 3, pluripotent ectodermal cells proliferate along the surface of the embryo to form…

DEVELOPMENTAL ANOMALIES OF THE COLON Print Section Listen Hirschsprung Disease Hirschsprung disease is a developmental disorder of colonic function, in which spasm and lack of normal peristalsis interfere with normal…

INTRODUCTION Print Section Listen The spectrum of congenital brain malformations is complex and classification schemes are imperfect. Neuroimaging evaluations provide extensive information concerning abnormal brain morphology and cellular organization. Correlation…

NORMAL DEVELOPMENT Print Section Listen The adrenal cortex is of mesodermal origin, whereas the medulla forms from ectodermal elements. The primitive adrenal cortex arises from coelomic mesoderm around the fifth…

NORMAL DEVELOPMENT Print Section Listen The Müllerian (paramesonephric) ducts develop at 5 to 6 weeks gestational age in conjunction with the Wolffian (mesonephric) ducts. In the absence of “testis-determining factor”…

THE NORMAL GROWTH PLATE Print Section Listen The growth plate is an important site of involvement with many of the metabolic bone diseases. The physis, or growth plate, is composed…

OVERVIEW OF RENAL CYSTIC DISEASE Print Section Listen Renal cystic disease is a spectrum of genetic, developmental, and acquired abnormalities (Table 45-1). The clinical spectrum ranges from severe bilateral cystic…

DEVELOPMENTAL ABNORMALITIES Print Section Listen Development of the Eye and Orbit The initial manifestation of eye development in the embryo occurs during the third week of gestation when grooves appear…