Obgyn Key

GENERAL CONSIDERATIONS Print Section Listen The central nervous system (CNS) is the site of origin for approximately 20% of pediatric cancers. CNS neoplasms are the second most common type of…

BENIGN FOCAL BONE LESIONS Print Section Listen Benign Fibrous Bone Lesions Avulsive Cortical Irregularity Avulsive cortical irregularity (cortical desmoid) refers to the common radiographic irregularity over a short segment of…

DEVELOPMENT Print Section Listen The hepatobiliary system originates as a cluster of endodermal cells that forms a diverticulum from the duodenal region of the primitive embryonic gut. The diverticulum divides…

CLASSIFICATIONS AND NOMENCLATURE Print Section Listen Constitutional errors of bone development include dysostoses, disruptions, and skeletal dysplasias. The dysostoses are malformations of single bones, although multiple sites can be involved….

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…