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Design of the morning sun simulator
Suský, Stanislav ; Krbal, Michal (referee) ; Štěpánek, Jaroslav (advisor)
This work deals with the introduction of the influence of electromagnetic radiation on circadian rhythms and their influence on the organism. The work describes circadian rhythms and their influence on the organism, the location and description of functions of important organs and the influence of electromagnetic radiation on these organs. There are described light sources and their influence on circadian rhythms.
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Circadian system and reproduction
Hrubá, Anežka ; Lužná, Vendula (advisor) ; Ladislavová, Lucie (referee)
Due to the alternation of day and night, mammals have developed internal circadian clocks, helping to synchronize physiological processes with the external environment. The circadian system is hierarchically organized, with central clocks located within suprachiasmatic nuclei of the hypothalamus (SCN). The main signal for setting the clocks to the external time is light, which enters the SCN through retina. The SCN communicate with peripheral oscillators in other organs, including reproductive ones, via hormonal signals, thereby synchronizing a variety of physiological processes. At the molecular level, clocks are controlled by clock genes. Cicradian system has a significant impact on reproduction. It is manifested by rythmical expression of clock genes and production of hormones in reproductive organs, as well as a success in reproduction if the clock's function is proper, and problems with reproduction if it is not. From a gender perspective, a several differences between women and men has been found throughout the SCN. Likewise, there are differences in chronotypes between both sexes over the course of their lives. Biological rhythms also include circannual rhythms, contributing to the timing of reproduction at the proper season of the year. Animals mate at different time depending on the length...
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Synchronization of circadian system during prenatal and early postnatal development
Houdek, Pavel ; Sumová, Alena (advisor) ; Novotná, Růžena (referee)
One of the few attributes common to almost all living organisms is an ability to generate and maintain endogenous rhythms, which are controlled by a biological clock. The processes, which recur with a period of about 24 hours, are known as the circadian rhythms. The circadian clock controls rhythms of molecular, physiological as well as behavioral processes and adapts their activity to regularly appearing changes in day and night or season. In case of mammals, central oscillator is located in the hypothalamic suprachiasmatic nuclei (SCN). The SCN clock entrains rhythms of peripheral oscillators located in cells of other tissues. The central oscillator itself is synchronized with external environment mainly by a light-dark cycle, however, other cues can entrain the SCN clock as well. For example, during prenatal development, entrainment of a fetal clock is entirely dependent on non-photic cues derived from maternal organism. This study aimed to investigate a mechanism of the communication between the maternal and fetal central oscillators. A hypothesis was tested whether maternal melatonin may play a role in entrainment of the circadian clock in the fetal SCN. Furthermore, a mechanism, how melatonin may entrain the fetal clock was investigated at molecular level. The results provided evidence, that...
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Design of the morning sun simulator
Suský, Stanislav ; Krbal, Michal (referee) ; Štěpánek, Jaroslav (advisor)
This work deals with the introduction of the influence of electromagnetic radiation on circadian rhythms and their influence on the organism. The work describes circadian rhythms and their influence on the organism, the location and description of functions of important organs and the influence of electromagnetic radiation on these organs. There are described light sources and their influence on circadian rhythms.
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Synchronization of circadian system during prenatal and early postnatal development
Houdek, Pavel ; Sumová, Alena (advisor) ; Novotná, Růžena (referee)
One of the few attributes common to almost all living organisms is an ability to generate and maintain endogenous rhythms, which are controlled by a biological clock. The processes, which recur with a period of about 24 hours, are known as the circadian rhythms. The circadian clock controls rhythms of molecular, physiological as well as behavioral processes and adapts their activity to regularly appearing changes in day and night or season. In case of mammals, central oscillator is located in the hypothalamic suprachiasmatic nuclei (SCN). The SCN clock entrains rhythms of peripheral oscillators located in cells of other tissues. The central oscillator itself is synchronized with external environment mainly by a light-dark cycle, however, other cues can entrain the SCN clock as well. For example, during prenatal development, entrainment of a fetal clock is entirely dependent on non-photic cues derived from maternal organism. This study aimed to investigate a mechanism of the communication between the maternal and fetal central oscillators. A hypothesis was tested whether maternal melatonin may play a role in entrainment of the circadian clock in the fetal SCN. Furthermore, a mechanism, how melatonin may entrain the fetal clock was investigated at molecular level. The results provided evidence, that...
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Comparation of circadian rhytms in teenagers at a comprehensive school and a specialized vocational school
KRATOCHVÍLOVÁ, Lenka
BACKGROUND:The aim of this thesis is to monitor from a professional point of view the area of health, healthy lifestyle, circadian rhythms, eating habits and free time activities in teenagers of today. Main focus is put on the sleeping regime which has enormous effect on behaviour and health of individuals and is closely connected to other biological rhythms. OBJECTIVE: The thesis aims to compare students at two different types of school, to give guidance in the area of health education during the process of form-filling as well as contribute to the formation of the students with regard to health, mental, physical and social sphere. Another purpose of this thesis is also to monitor health habits of this age group and possibly those of their families. METHOD: The method applied for the research was a set of questionnaires. Total number of respondents was 40 students of a comprehensive school and 40 students of a specialized vocational school in the age span between 15 to 17 years of age. Presentation of the study field "Health education" was given due to the students´ interest and space was given to their questions. Health education exists and is practically implemented in both types of schools. RESULT: Comparation between the two schools proved there are significant differences in sleeping regimes, eating or spending free time. Also it has been proven that most respondents suffer from lack of sleep and tend to shift sleep to later hours. CONCLUSION: Students were found to have serious violations of healthy habits including sleeping and eating. More emphasis should be put on teaching young people about the importance of adjustment to circadian rhytms and explanation how they would benefit from adhering to the natural rhytms.
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Animal Biorhythms {--} Additional Biology Curriculum at Grammar Schools
SCHLEICHEROVÁ, Monika
The main objective of the diploma thesis was to create a project of a tutorial on the subject of animal and human biorhythms. The tutorial is intentioned as an additional biology curriculum at grammar schools. Analysis of teaching biorhythms in secondary Biology schoolbooks used in the Czech Republic preceded a composition of this tutorial. Processing literary research based on reading Czech and foreign-language literature was another theoretical resource. The tutorial is divided into three parts {--} {\clqq}Animal Biorhythms``, {\clqq}Human Biorhythms`` and {\clqq}Seasonal Animal Biorhythms``. Some parts of the tutorial were verified in practice.
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