Time period: day 24 to birth
The glands of the endocrine system begin to form during the embryonic period and continue to mature during the foetal period. Functional development can be detected by the presence of the various hormones in the foetal blood, generally in the second trimester of pregnancy.
The development of the gonads, pancreas, kidneys and placenta are covered elsewhere in this book.
Also known as the hypophysis, the pituitary gland develops from two sources. An out pocketing of oral ectoderm appears in week 3 in front of the buccopharyngeal membrane (Figure 39.1). This forms the hypophysial diverticulum (or Rathke’s pouch), which will become the anterior lobe.