Development of the endocrine system alpha cells. The insulin concentration within the fetal pancreas is 3.6 pmol/g at seven to ten weeks, which rises to 30 pmol/g at 16–25 weeks of gestation. Near term, the insulin concentration increases to 93 pmol/g. The endocrine cells have dispersed throughout the body within 10 weeks. At 31 weeks of development, the islets of Langerhans have differentiated. While the fetal pancreas has functional beta cells by 14 to 24 weeks of gestation, the amount of insulin that is released into the bloodstream is relatively low. In a study of pregnant women carrying fetuses in the mid-gestation and near term
The Description of the Human Body The Description of the Human Body The Description of the Human Body () is an unfinished treatise written in 1647 by René Descartes (1596-1650). Descartes felt knowing oneself was particularly useful. This for him included medical knowledge. He hoped to cure and prevent disease, even to slow down aging. René Descartes believed the soul caused conscious thought. The body caused automatic functions like the beating of the heart and digestion he felt. The body was necessary for voluntary movement as well as the will. However, he believed the power to move the body was wrongly imagined to come from the