3. Compare the relative diameters of the afferent and efferent arterioles and explain the significance in this size differential. The afferent arteriole is wider than the efferent arteriole which means that blood enters the glomerulus through a wider opening than the blood exiting the glomerulus, thus creating an increased “back pressure” (=hydrostatic filtration pressure). They hydrostatic pressure is higher in the glomerulus than in other capillaries. By varying the size of the afferent and/or arterioles, the glomerular filtration rate (GFR) may be increased or decreased.

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Human Anatomy and Physiology I

Kolb’s experiential learning cycle is perhaps the most scholarly influential and cited model regarding experiential learning theory. However, a key issue in interpreting Kolb’s model concerns a lac...

/pdf/experiential-learning-a-systematic-review-and-revision-of-3vuy81bkkr.pdf

Experiential learning – a systematic review and revision of Kolb’s model

What is Analytic Induction

Various internal and external factors negatively affect the homeostatic equilibrium of organisms at the molecular to the whole-body level, inducing the so-called state of stress. Stress affects an organism's welfare status and induces energy-consuming mechanisms to combat the subsequent ill effects; thus, the individual may be immunocompromised, making them vulnerable to pathogens. The information presented here has been extensively reviewed, compiled, and analyzed from authenticated published resources available on Medline, PubMed, PubMed Central, Science Direct, and other scientific databases. Stress levels can be monitored by the quantitative and qualitative measurement of biomarkers. Potential markers of stress include thermal stress markers, such as heat shock proteins (HSPs), innate immune markers, such as Acute Phase Proteins (APPs), oxidative stress markers, and chemical secretions in the saliva and urine. In addition, stress biomarkers also play critical roles in the prognosis of stress-related diseases and disorders, and therapy guidance. Moreover, different components have been identified as potent mediators of cardiovascular, central nervous system, hepatic, and nephrological disorders, which can also be employed to evaluate these conditions precisely, but with stringent validation and specificity. Considerable scientific advances have been made in the detection, quantitation, and application of these biomarkers. The present review describes the current progress of identifying biomarkers, their prognostic, and therapeutic values.

/pdf/biomarkers-in-stress-related-diseases-disorders-diagnostic-50ihcgyuts.pdf

Biomarkers in Stress Related Diseases/Disorders: Diagnostic, Prognostic, and Therapeutic Values.

This Special Issue addresses the intersections of outdoor recreation, nature-based tourism, and sustainability. Outdoor recreation and nature-based tourism provide essential benefits to individuals, communities, and society and thereby contribute to sustainability. Equitable provision of opportunities, cultural variations in desired experiences, barriers to outdoor recreation, and diverse perceptions of both nature and recreation add to the complexity in outdoor recreation and nature-based tourism service delivery. Outdoor recreation and nature-based tourism occur within a socioecological system with feedback loops to changing social, economic, technological, and ecological conditions. On a global scale, climate change and other disturbance factors are impacting ecosystems and opportunities, increasing the importance of adaptation strategies for longer-term planning. Population growth and regional shifts in demographics and distribution (e.g., urbanization), as well as socioeconomic trends, affect who engages in outdoor recreation and nature-based tourism, opportunities sought, nature access, and governance of outdoor services. Overall the complexity of sustainable outdoor recreation and tourism may suggest a need for different approaches to service delivery, culture change among service providers and managers of natural spaces, and novel approaches to inclusive governance and shared stewardship. Given the clear importance of outdoor recreation and nature-based tourism to society, we invite you to consider this initial introduction to our assembled collection, which is meant to advance our understanding of the intersections of outdoor recreation, nature-based tourism, and sustainability.

https://www.fs.fed.us/psw/publications/winter/psw_2020_winter002.pdf

Outdoor recreation, nature-based tourism, and sustainability

A growing number of studies have shown that visiting green spaces and being exposed to natural environments can reduce psychological stress. A number of questions concerning the effects of natural environments on levels of stress remain including, “Are activities engaged in natural environments more or less beneficial at reducing stress when compared to those done in more urban settings?” This study examined this question from the perspective of “levels of nature”. That is, data on levels of stress were collected from three sites, one site having wilderness-like characteristics, a second site representing a municipal-type park, and a third site representing a built environment (indoor exercise facility) within a city. Data were generated using biophysical markers (cortisol and amylase) and a psychological measure within a pre- and post-visit format. Findings suggest that visiting natural environments can be beneficial in reducing both physical and psychological stress levels, with visitors to a natural environment reporting significantly lower levels of stress than their counterparts visiting a more urbanized outdoor setting or indoor exercise facility.

https://www.mdpi.com/2076-328X/8/5/49/pdf

Levels of Nature and Stress Response.

This study examines the effect of short-term adventure-based outdoor programs (AOP) on reducing college students’ stress levels. The effects of sex and different outdoor adventure activitie...

The impact of short-term adventure-based outdoor programs on college students’ stress reduction

The purpose of this study was to provide insight into what occurs in moments of high challenge within participants during an outdoor adventure education (OAE) program. Given the inherent risk and r...

Multiple Methods for Identifying Outcomes of a High Challenge Adventure Activity.

IntroductionRecreational and leisure experiences that present physical and emotional challenges often involve natural settings with participants engaged in Adventure Recreation (AR) activities such as mountaineering, white-water boating, caving, rock climbing, sea kayaking, and rappelling. AR can be defined as "recreational activities and experiences usually involving a close interaction with an outdoor natural setting and containing elements of real or perceived danger and risk in which the outcome, although uncertain, can be influenced by the actions of the participants and circumstances" (Ewert & Sibthorp, 2014, p. 5). While a substantial corpus of research-generated information exists concerning AR, much of this material comes from instruments using a selfreport format. Many, if not most of these efforts, generally report positive outcomes on a broad spectrum of variables such as self-efficacy, self-confidence, and locus of control, although less is known regarding the effect of AR activities on levels of stress from a biochemical perspective. From this perspective, how these levels of stress change over the course of the activity, and how these levels of stress are associated with variables such as gender and type of activity remains relatively under-researched.Within the recreation and leisure fields, the research that has been conducted involving changes in levels of specific hormones and other biomarkers, such as cortisol, epinephrine, and changes in heart rate, has often involved examining the relationship between stress and outdoor recreation (Godbey, 2009; Groff et al. 2010; Orsega-Smith, Mowen, Payne, & Godbey, 2004). Within the AR field, a small but growing interest in using biomarkers in the measurement of variables such as stress has developed. For example, Coetzee (2011) reported increased stress responses as measured by heart rate variability and levels of cortisol on beginning divers and attributed this effect to the novelty of SCUBA diving. In addition, Bunting and her colleagues' work (1986, 1995,) identified and quantified changes in selected biomarkers involving the neuroendocrine system (e.g., cortisol, epinephrine, norepinephrine) as a result of participation in selected AR activities. In a later work, Bunting, Tolson, Kuhn, Suarez, and Williams (2000) used biomarkers to identify the relationship between levels of fitness and participation in AR. More recently, Ewert, Klaunig, Wang, and Chang (2016) measured changes in cortisol for people hiking within a forested park area.Adventure recreation (AR) activities often present a different venue for studying stress that is typically not seen via controlled laboratory or classroom settings. Unlike laboratory-based studies, research involving a naturalistic setting, such as AR, typically involves a more holistic and "real-world" settings by exposing the participant to multiple forms of stress-related variables simultaneously often seen in active leisure experiences (Ulrich, Dimberg, & Driver, 1991). In the case of AR, while it would seem intuitive that rappelling would be a stress-producing activity, most of the evidence for this belief is primarily through self-reports or anecdotal records with few studies investigating any actual changes in the biochemical responses of the body.Because of the ubiquitous nature of AR activities in recreational programs and the challenging nature of these experiences, the study of stress is both important and timely. To accomplish this, levels of cortisol were measured several times during a rappelling experience. The goals of this research effort were guided by the following research questions.RQ1:Would rappelling serve as an effective stress-producing activity as measured by changing levels of cortisol?RQ2:Would levels of cortisol change as a function of where the individual was in the rappelling sequence (i.e., the day before, cliff edge, end of the rappel)?RQ3:Would gender have an effect on levels of cortisol throughout the rappel experience? …

Yun Chang

Papers

Levels of Nature and Stress Response.

The impact of short-term adventure-based outdoor programs on college students’ stress reduction

Multiple Methods for Identifying Outcomes of a High Challenge Adventure Activity.

The Body Doesn't Lie

Reducing Levels of Stress through Natural Environments (2016): Take a Park, Not a Pill