This animation depicting the development of the endocrine glands begins with the development of the hypophysis.

The first diagram details the mediosagittal section of the head of a 4-week-old embryo. The cerebral hemisphere reveals diencephalon with the epithalamus and hypothalamus, including the infundibulum and optic chiasma, the stomodeum with the maxillary and mandibular arches as well as the Rathke's pouch. This diagram includes numerous legends.

A frame presents the infundibulum, optic chiasma, the primordium of the Rathke's pouch, intercalated mesenchyme, anterior portion of the notochord and pharyngeal gut. The framed structures are then magnified.

The gradual separation of the Rathke's pouch from the stomodeum and migration toward the infundibulum is animated. The hyaline cartilage develops from the mesenchyme while the notochord stepwise disappears. The next sequence shows the formation of the adenohypophysis, its contact with the neurohypophysis to form the hypophysis, and all of its components. The formation of the sphenoid bone is animated without endochodral ossification.

The next sequence is dedicated to the development of the pineal gland, or epiphysis.

A diagram details the mediosagittal section of a 7-week-old embryo. Among numerous other structures, the pineal thickening and the epithalamus are visible on the diagram. In the next sequence, these two structures are framed and shown under moderate magnification. The pineal thickening with the neuroepithelium and the roof plate of the diencephalon are visible. The next sequence shows the formation of the pineal diverticulum from the neuroepithelium in an 8-week-old fetus. The further evolution of the pineal diverticulum is animated for an 8- and 10-week-old fetus. The formation of future habenular and posterior commissures together with the lamina quadrigemina is shown. The pineal diverticulum increases in volume while its neuroepithelial wall thickens. A 10- and 14-week-old fetus illustrate the formation of folded neuropithelial cell cords and crooked plates. The closure of the pineal stalk and its transformation into the pienal recess is also animated.

The next sequences animate the development of the thyroid gland, parathyroid glands, ultimobranchial bodies and the thymus. The first diagram shows the head and neck of a 29-day-old embryo, indicating the pharyngeal arches and clefts. A frontal section of the neck of the embryo is shown in transparency. The section passes through pharyngeal arches and clefts to end in the region of the future pleural cavity, which penetrate the lung bud.

Then, the pharyngeal arches and clefts are framed and shown in 3D posterior view. Artery, nerve, and cartilage are visible within the sectioned pharyngeal arches. The five pharyngeal pouches are shown as well as the lateral lingual swellings, tuberculum impar, foramen cecum, copula, epiglottal swelling and laryngeal orifice. The same diagram describes all derivatives of the pharyngeal clefts, pharyngeal pouches and the foramen cecum.

The next sequence illustrates the data described in the quoted diagram. From a 29-day-old embryo to a 32-day-old embryo, the future paired cervical sinuses begin to form while the 3rd pharyngeal pouches divide into two parts: the cranial ones become the inferior parathyroid glands, while the inferior ones form the thymuses. The 4th pharyngeal pouch also divides into two portions: the cranial ones give rise to the superior parathyroid glands, while the caudal ones (i.e. the 5th pouches) transform into the ultimobranchial bodies. In the meantime the thyroglossal duct grows from the foramen cecum. In a 5-week-old embryo, the tympanic membranes form between the 1st pharyngeal clefts and the 1st pharyngeal pouches, while the cervical sinuses close. The same sequence shows the formation of the palatine tonsils from the 2nd pharyngeal pouches and the continual development and differentiation of the inferior and superior parathyroid glands, thymuses and ultimobranchial bodies. The bottom of the thyroglossal enlarges to form the future thyroid gland. The body of the tongue also grows.

A 6-week-old embryo shows the obliteration of the cervical sinuses. In addition, the palatine tonsils further develop, and the inferior parathyroid glands fuse with the neighbouring thymus lobes. The superior parathyroid glands and the ultimobranchial bodies remain in their positions. The thyroglossal duct, also visible in transparency, prepares to obliterate, followed by the newly formed pyramidal lobe and the two lateral lobes of the thyroid gland. The animation for a 6- and 7-week-old embryo shows the caudal migration of the thymus lobes, during which the inferior parathyroid glands become incorporated into the caudal portions of the lateral lobes of the thyroid gland. At the same time, the C-cells from the ultimobranchial bodies invade the thyroid lobes. The anterior view of the development and migration of the thyroid gland, parathyroid glands, ultimobranchial bodies and the thymus is also animated. (Further migration and development of the thymus lobes is shown in the "Development of the Lymphatic System" animation.)

The sequence detailing the suprarenal glands begins with an embryo at the beginning of the 5th week.

A diagram details the body of the embryo, including the pronephrotic ducts, mesonephroi, mesonephric ducts and metanephroi. A horizontal section of the embryo body at the level of the future urogenital ridges is magnified. The diagram illustrates the urogenital ridges lined by the celomic epithelium, which also lines the dorsal mesentery, gut, neural tube, neural crests, notochord and aorta. Then, the animation shows the proliferation of the celomic epithelium and the migration of the sympathoblasts from the neural crests in an embryo at the end of the 5th week. Next, in an approximately 6-week-old embryo, the fetal cortex of the adrenal gland form from the celomic epithelium, and clumps of sympathoblasts approach the fetal cortex. In addition, future dorsal root ganglia appear along with future sympathetic ganglia and future preaortic ganglia. The adrenal glands are animated for each fetal cortex from a 6- to a 9-week-old fetus. The development of the preaortic ganglion and the further evolution of sympathetic ganglia are also shown. In a 10-week-old fetus, a new wave of celomic cells forms the definitive cortex of each suprarenal gland, while the sympathoblast comprise the medulla. The advanced connection of the spinal nerves with the sympathetic ganglion is also demonstrated. Finally, in a 32-week-old fetus, the suprarenal glands form their normal structure. The sympathetic ganglia connect with the spinal nerves, and migrating sympathoblasts reach the organ plexus of the gut.

The following malformations of endocrine glands are animated: ectopic hypophyses (craniopharyngeoma, pharyngeal hypophysis), ectopic parathyroid glands, ectopic thymus tissue, malformations of the thyroid gland (lingual thyroid) and remnants of the thyroglossal duct (medial cervical cyst). The thymoparathyroid aplasia and the lateral cervical cysts are shown without animation.

(This animation is essential for students of medicine, veterinary medicine and biology as well as for departments of anatomy, histology, embryology, physiology and cell biology; it is also recommended for students of stomatology as well as for departments and clinics of maxillofacial surgery, medicine and endocrinology and research institutes of endocrinology.)