"Local control": another core concept of physiology.

The maintenance of a more or less constant internal environment by homeostatic (negative feedback) mechanisms is well understood, and "homeostasis" is regarded as an important core concept for students to understand. However, there are critically important control mechanisms that operate at the local level and are more or less independent of homeostasis. Here we define a core concept of "local control," present examples of it in many different organ systems, and propose a conceptual framework for it. Local control, like all of the other core concepts, can provide students with a learning tool that can facilitate understanding physiology.NEW & NOTEWORTHY Local control of many physiological phenomena occurs to meet the needs of certain systems and to enable these systems to meet the episodic challenges that occur. The mechanisms by which local control is exerted include locally released chemical messengers, physical stimuli acting on the structures, and local neural networks. Examples of important local controls are present throughout the body.

Use of core concepts of physiology can facilitate student transfer of learning.

Students often fail to utilize what they know about one topic (e.g., hemodynamics) when attempting to master another topic involving a similar phenomenon (e.g., airflow in airways). What accounts for this difficulty that students have? And how can students be assisted in doing a better job of applying what they already know to new topics? The phenomenon described above is an example of a failure of transfer of learning. However, much is known about the conditions that foster or promote transfer of learning. Applying this emerging knowledge and focusing on the core concepts of physiology can make learning physiology easier and provide students with tools to support lifelong learning.NEW & NOTEWORTHY Students often fail to utilize knowledge from prerequisite courses while learning physiology. They also fail to use what they know about one physiology topic when attempting to learn another topic. Much is known about the conditions that foster or promote transfer of learning. Applying this emerging knowledge and focusing on the core concepts of physiology can making learning physiology easier and provide students with tools to support lifelong learning.

What do we mean when we talk about "structure/function" relationships?

In multiple studies "structure/function" has been identified as an important core concept in biology and physiology. Teachers expect their students to be able to use this concept in making sense of physiology. However, it is unclear exactly what physiologists are referring to when they use the term "structure/function." Here I first offer examples of four different ways in which I have used the term in the classroom. Then, I propose a conceptual framework that is an explicit statement of the "structure/function" core concept that can be used by teachers and their students as they attempt to master physiology. Determining whether this conceptual framework is completely accurate and whether it will prove useful in the classroom will require feedback from physiology teachers who attempt to use it in their classroom with their students.

Validating The Core Concept Of "Mass Balance".

We have created a conceptual framework for the core concept of "mass balance." Unlike the previous conceptual frameworks that we have created and validated, the framework for "mass balance" is simply a description in words of the fundamental mass balance equation and the implications of the equation. We surveyed physiology faculty and asked them to rate the importance of "mass balance" as defined by the conceptual framework and also to rate the importance for their students of being able to apply the core concept to liquids, gases, solutes, and solids. Respondents indicated that "mass balance" is important and that our conceptual framework provides a useful tool for teaching and learning. We discuss several examples of how "mass balance" can be used in making sense about a variety of physiological phenomena.

Another look at the core concepts of physiology: revisions and resources.

In 2011, we published a description of 15 core concepts of physiology, and in 2017 we described how core concepts could be used to teach physiology. On the basis of publications and conference presentations, it is clear that the core concepts, conceptual frameworks, and the homeostasis concept inventory have been used by faculty in many ways to improve and assess student learning and align instruction and programs. A growing number of colleagues focus their teaching on physiology core concepts, and some core concepts have been used as explicit themes or organizing principles in physiology or anatomy and physiology textbooks. The core concepts published in 2011 were derived from inputs from a diverse group of physiology instructors and articulated what this group of instructors expressed a decade ago. On the basis of current feedback from the physiology teaching community as a consequence of the use of core concepts in teaching and learning, we have revisited these concepts and made revisions to address issues that have emerged. In this article, we offer revised definitions and explanations of the core concepts, propose an additional core concept ("physical properties of matter" which combines two previous concepts), and describe three broad categories for the revised core concepts. Finally, we catalog published resources for each of the core concepts that provide instructors tools to focus facilitation of student learning on goals (learning outcomes), activities and assessments to enable students to develop and apply their understanding of the core concepts of physiology.

Reflections on core concepts for undergraduate physiology programs.

Undergraduate education should help students build a deep, conceptual understanding of their discipline, not merely compel them to acquire factual knowledge. The core concepts for physiology (described in 2011), conceptual frameworks, and conceptual assessments are available to focus undergraduate physiology education on helping students understand and apply principles that govern and describe physiological processes. We review the context in which physiology core concepts were identified by a community of physiology educators. We explain the structure of conceptual frameworks and concept inventories and their benefit. We describe how core concepts have been used in physiology courses and departments, as communicated in publications, through presentations at physiology and biology education meetings, and within the Physiology Majors Interest Group (P-MIG). Finally, we share our recommendations and hopes for the next decade.

New Medical Device and Therapeutic Approvals in Otolaryngology: State of the Art Review of 2019.

OBJECTIVE: To review new devices and drugs relevant to otolaryngology-head and neck surgery that were approved by the US Food and Drug Administration (FDA) in 2019. DATA SOURCES: Approval notifications for 2019 were extracted from the ENT (ear, nose, and throat) and general and plastic surgery sections of the FDA's medical devices and therapeutics listings. REVIEW METHODS: New therapeutics and medical devices identified from the query were analyzed by members of the American Academy of Otolaryngology-Head and Neck Surgery's Medical Devices and Drugs Committee. Technologies were assessed by 2 independent reviewers to ascertain relevance to otolaryngology, prioritized, and classified to subspecialty field with critical review based on extant scientific literature. CONCLUSIONS: Query of the FDA drug and device database returned 105 ENT devices (50 cleared, 55 with premarket approval, and 0 de novo), 543 general and plastic surgery devices (372 cleared, 170 with premarket approval, and 1 de novo), and 46 new otolaryngology-relevant drug approvals that occurred in 2019. Advances spanned all subspecialty areas with otology predominating, primarily due to hearing-related technologies. While scientific evidence was available for all new devices, there was significant heterogeneity in rigor of supporting scientific data. IMPLICATIONS FOR PRACTICE: Technological and pharmaceutical innovation is an important catalyst for advances in the surgical specialties. Familiarity with new devices and therapeutics in otolaryngology-head and neck surgery ensures that clinicians keep abreast of developments with potential to improve prevailing standards of care.

A conceptual framework for the core concept of "cell membrane".

We have created and validated a conceptual framework for the core physiology concept of "cell membrane." The conceptual framework is composed of 27 items arranged in a hierarchy that is, in some instances, four levels deep. We have validated it with input from faculty who teach at a wide variety of institutional types. All items making up the framework were deemed essential to moderately important. However, some of the main ideas were clearly judged to be more important than others. Furthermore, the lower in the hierarchy an item is located, the less important it is thought to be. Finally, there was no significant difference in the ratings given by faculty at different types of institutions.

Development and Validation of the Homeostasis Concept Inventory.

We present the Homeostasis Concept Inventory (HCI), a 20-item multiple-choice instrument that assesses how well undergraduates understand this critical physiological concept. We used an iterative process to develop a set of questions based on elements in the Homeostasis Concept Framework. This process involved faculty experts and undergraduate students from associate's colleges, primarily undergraduate institutions, regional and research-intensive universities, and professional schools. Statistical results provided strong evidence for the validity and reliability of the HCI. We found that graduate students performed better than undergraduates, biology majors performed better than nonmajors, and students performed better after receiving instruction about homeostasis. We used differential item analysis to assess whether students from different genders, races/ethnicities, and English language status performed differently on individual items of the HCI. We found no evidence of differential item functioning, suggesting that the items do not incorporate cultural or gender biases that would impact students' performance on the test. Instructors can use the HCI to guide their teaching and student learning of homeostasis, a core concept of physiology.

Validating a conceptual framework for the core concept of "cell-cell communication".

We have created and validated a conceptual framework for the core physiology concept of "cell-cell communication." The conceptual framework is composed of 51 items arranged in a hierarchy that is, in some instances, four levels deep. We have validated it with input from faculty who teach at a wide variety of institutional types. All items making up the framework were deemed essential to moderately important. However, some of the main ideas were clearly judged to be more important than others. Furthermore, the lower in the hierarchy an item is, the less important it is thought to be. Finally, there was no significant difference in the ratings given by faculty at different types of institutions.

A conceptual framework for homeostasis: development and validation.

We have developed and validated a conceptual framework for understanding and teaching organismal homeostasis at the undergraduate level. The resulting homeostasis conceptual framework details critical components and constituent ideas underlying the concept of homeostasis. It has been validated by a broad range of physiology faculty members from community colleges, primarily undergraduate institutions, research universities, and medical schools. In online surveys, faculty members confirmed the relevance of each item in the framework for undergraduate physiology and rated the importance and difficulty of each. The homeostasis conceptual framework was constructed as a guide for teaching and learning of this critical core concept in physiology, and it also paves the way for the development of a concept inventory for homeostasis.

A physiologist's view of homeostasis.

Homeostasis is a core concept necessary for understanding the many regulatory mechanisms in physiology. Claude Bernard originally proposed the concept of the constancy of the "milieu interieur," but his discussion was rather abstract. Walter Cannon introduced the term "homeostasis" and expanded Bernard's notion of "constancy" of the internal environment in an explicit and concrete way. In the 1960s, homeostatic regulatory mechanisms in physiology began to be described as discrete processes following the application of engineering control system analysis to physiological systems. Unfortunately, many undergraduate texts continue to highlight abstract aspects of the concept rather than emphasizing a general model that can be specifically and comprehensively applied to all homeostatic mechanisms. As a result, students and instructors alike often fail to develop a clear, concise model with which to think about such systems. In this article, we present a standard model for homeostatic mechanisms to be used at the undergraduate level. We discuss common sources of confusion ("sticky points") that arise from inconsistencies in vocabulary and illustrations found in popular undergraduate texts. Finally, we propose a simplified model and vocabulary set for helping undergraduate students build effective mental models of homeostatic regulation in physiological systems.

Cold stress and the cold pressor test.

Temperature and other environmental stressors are known to affect blood pressure and heart rate. In this activity, students perform the cold pressor test, demonstrating increased blood pressure during a 1- to 2-min immersion of one hand in ice water. The cold pressor test is used clinically to evaluate autonomic and left ventricular function. This activity is easily adapted to an inquiry format that asks students to go to the scientific literature to learn about the test and then design a protocol for carrying out the test in classmates. The data collected are ideal for teaching graphical presentation of data and statistical analysis.

The core principles ("big ideas") of physiology: results of faculty surveys.

Physiology faculty members at a wide range of institutions (2-yr colleges to medical schools) were surveyed to determine what core principles of physiology they want their students to understand. From the results of the first survey, 15 core principles were described. In a second survey, respondents were asked to rank order these 15 core principles and, independently, to identify the three most important for their students to understand. The five most important core principles were "cell membrane," "homeostasis," "cell-to-cell communications," "interdependence," and "flow down gradients." We then "unpacked" the flow down gradients core principle into the component ideas of which it is comprised. This unpacking was sent to respondents who were asked to identify the importance of each of the component ideas. Respondents strongly agreed with the importance of the component ideas we had identified. We will be using the responses to our surveys as we begin the development of a conceptual assessment of physiology instrument (i.e., a concept inventory).

The "core principles" of physiology: what should students understand?

The explosion of knowledge in all of the biological sciences, and specifically in physiology, has created a growing problem for educators. There is more to know than students can possibly learn. Thus, difficult choices have to be made about what we expect students to master. One approach to making the needed decisions is to consider those "core principles" that provide the thinking tools for understanding all biological phenomena. We identified a list of "core principles" that appear to apply to all aspects of physiology and unpacked them into their constituent component ideas. While such a list does not define the content for a physiology course, it does provide a guideline for selecting the topics on which to focus student attention. This list of "core principles" also offers a starting point for developing an assessment instrument to be used in determining if students have mastered the important unifying ideas of physiology.

The second Conceptual Assessment in the Biological Sciences workshop.

A second National Science Foundation-sponsored workshop on Conceptual Assessment in Biology was held in January 2008. Reports prepared for the workshop revealed that research groups working in a variety of biological sciences are continuing to develop conceptual assessment instruments for use in the classroom. Discussions at this meeting largely focused on two issues: 1) the utility of the backwards design approach of Wiggins and McTighe (11), in which identification of learning outcomes (determining what to assess) lies at the beginning of course design; and 2) the utility of defining expected learning outcomes as the building of runable mental models (and designing conceptual assessments that would test the correctness of these mental models). A third meeting is being planned that will focus on the processes involved in writing and validating conceptual assessment instruments.

Conceptual assessment in the biological sciences: a National Science Foundation-sponsored workshop.

Twenty-one biology teachers from a variety of disciplines (genetics, ecology, physiology, biochemistry, etc.) met at the University of Colorado to begin discussions about approaches to assessing students' conceptual understanding of biology. We considered what is meant by a "concept" in biology, what the important biological concepts might be, and how to go about developing assessment items about these concepts. We also began the task of creating a community of biologists interested in facilitating meaningful learning in biology. Input from the physiology education community is essential in the process of developing conceptual assessments for physiology.

What makes physiology hard for students to learn? Results of a faculty survey.

Teachers of physiology at all postsecondary levels were asked to participate in a survey about the possible sources of students' difficulty in learning physiology. Sixty-three physiology teachers responded to the 18-question survey; 35 of the respondents also responded to a request for written comments about this issue prior to taking the survey. Three categories of possible factors contributing to physiology being hard to learn were defined: 1) the nature of the discipline, 2) the way it is taught, and 3) what students bring to the task of learning physiology. Respondents thought that characteristics of the discipline (it requires causal reasoning, it uses graphs and mathematics, and it is highly integrative) and characteristics of students (they believe that learning and memorizing are the same thing, they cannot or will do attempt to integrate, and they compartmentalize) were significantly more important than any aspect of teaching in making physiology hard to learn. Recommendations are offered in this article to help students deal with the sources of difficulty that were identified.

Where's the evidence that active learning works?

Calls for reforms in the ways we teach science at all levels, and in all disciplines, are wide spread. The effectiveness of the changes being called for, employment of student-centered, active learning pedagogy, is now well supported by evidence. The relevant data have come from a number of different disciplines that include the learning sciences, cognitive psychology, and educational psychology. There is a growing body of research within specific scientific teaching communities that supports and validates the new approaches to teaching that have been adopted. These data are reviewed, and their applicability to physiology education is discussed. Some of the inherent limitations of research about teaching and learning are also discussed.