The document discusses the ongoing professional development of teachers and the importance of pedagogical content knowledge. It notes that medical education has expanded significantly and there are now professional bodies focused on medical education. Effective teaching requires deep understanding of subject matter as well as knowledge of how students learn. Teachers must understand how ideas connect across fields and to everyday life in order to make concepts accessible to students. Pedagogical content knowledge is important for teaching specific concepts and topics, and teachers must consider student learning, curriculum resources, and collaboration. Investigating the effects of teaching on learning helps teachers improve. At the heart of effective teaching is a teacher's pedagogical content knowledge.