The physiology core concepts are designed to guide instructors in undergraduate physiology courses. However, although past work has characterized the alignment of physiology programs with the core concepts, it is unclear to what extent these core concepts have influenced instructors' pedagogical decisions or how represented these core concepts are across physiology courses. We surveyed undergraduate physiology instructors to determine their familiarity with the core concepts, the impact of the core concepts on their teaching, as well as the alignment of their courses with these core concepts. Instructors report predominantly relying on textbooks and past syllabi of their courses as resources that influence their instructional decisions on which topics to include in a course. However, many instructors report reorganizing their physiology courses in subsequent iterations or reducing the number of concepts covered to allow more time for critical thinking and active learning. In addition, we find that the majority of instructors indicate that they are not knowledgeable about the list of physiology core concepts and that the influence of these core concepts is limited even for those who report familiarity with the list of core concepts. Finally, we find that instructors report uneven coverage of physiology core concepts in their courses, with some core concepts ubiquitous while others are sparsely covered. We conclude by discussing implications of our work for the physiology education community and call for the continued development of resources to support new physiology instructors and the need to promote coverage of certain core concepts in physiology courses.