http://nova.newcastle.edu.au/vital/access/services/Feed ${session.getAttribute("locale")} 5 http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12744 Questions concerning the power of central nervous factors to significantly regulate coronary conductance receive new impetus each time a patient presents with unexplained chest pain. A familiar story is that of Mrs. V. C., who has bouts of crushing central chest pain at inappropriate times, as well as reproducible progressive and diagnostic ST segment depression on her electrocardiogram without pain during exercise to exhaustion, while having a normal coronary arteriogram and thallium scan. Such clinical observations suggest that some inherent mismatch during exercise can exist between neurohumoral vasconstrictor and local vasodilator factors. Furthermore, although the effects on coronary conductance of conventional experimental stimuli (i.e., those affecting arterial baro- and chemoreceptors) and of cardiac and pulmonary receptors have been investigated, the effects of direct central nervous influences (e.g., emotion) remain largely unknown. Moreover, how the gain of peripheral reflex changes in coronary conductance may be altered by central influences is also unknown. The studies summarized in this chapter were undertaken to investigate the possibility that central nervous μ-opioid agonists such as fentanyl, and monoamines such as 5-hydroxytryptamine (serotonin), can alter vagal vasodilator and sympathetic vasoconstrictor mechanisms in the coronary circulation at rest and during reflex disturbances. Further justification for such studies comes from data showing that humans and other mammals have a distribution of opiate receptors and serotonin-synthesizing neurons concentrated in and around structures known to be part of cardiorespiratory reflex pathways. Questions concerning the power of central nervous factors to significantly regulate coronary conductance receive new impetus each time a patient presents with unexplained chest pain. A familiar story is that of Mrs. V. C., who has bouts of crushing central chest pain at inappropriate times, as well as reproducible progressive and diagnostic ST segment depression on her electrocardiogram without pain during exercise to exhaustion, while having a normal coronary arteriogram and thallium scan. Such clinical observations suggest that some inherent mismatch during exercise can exist between neurohumoral vasconstrictor and local vasodilator factors. Furthermore, although the effects on coronary conductance of conventional experimental stimuli (i.e., those affecting arterial baro- and chemoreceptors) and of cardiac and pulmonary receptors have been investigated, the effects of direct central nervous influences (e.g., emotion) remain largely unknown. Moreover, how the gain of peripheral reflex changes in coronary conductance may be altered by central influences is also unknown. The studies summarized in this chapter were undertaken to investigate the possibility that central nervous μ-opioid agonists such as fentanyl, and monoamines such as 5-hydroxytryptamine (serotonin), can alter vagal vasodilator and sympathetic vasoconstrictor mechanisms in the coronary circulation at rest and during reflex disturbances. Further justification for such studies comes from data showing that humans and other mammals have a distribution of opiate receptors and serotonin-synthesizing neurons concentrated in and around structures known to be part of cardiorespiratory reflex pathways. 2013-04-08T04:53:03.464Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:12711 The nasopharyngeal reflex in the rabbit (respiratory suppression, activation of vagal and sympathetic nerves, and reduction in oxygen usage) is initiated by trigeminal nerves and is enhanced by the arterial baroreceptor and by loss of lung inflation afferent activity. A review of (i) the functional anatomy of central nervous catecholamine and 5-hydroxytryptamine pathways participating in cardiorespiratory regulation, (ii) studies of the reflex in pontine, thalamic, and intact-brain rabbits in which the arterial baroreceptor and lung inflation inputs were manipulated, and (iii) studies of the reflex in rabbits in which central nervous catecholamine and 5-hydroxytryptamine were depleted indicates that the trigeminal nerve can initiate the reflex pattern during maintained ventilation at the ponto-medullo-spinal level through interactions that may include convergence with glossopharyngeal and vagal nerves in the nucleus of the solitary tract. By contrast, loss of lung inflation activity in itself activates vagal and sympathetic pathways through interactions with arterial baroreceptor activity and diencephalic influences. The vagal output component of the reflex is relatively independent of either central nervous monoamine, but the sympathetic vasoconstrictor component appears clearly dependent on central nervous catecholamine and, to a much lesser extent, on 5-hydroxytryptamine. Both monoamines play a role in respiratory suppression. Pentobarbitone blocks centrally the vagal output component of the nasopharyngeal reflex by a monoamine-independent mechanism. The findings provide a framework for testing postulates concerning central nervous catecholamine integration and neurotransmitter control of submergence reflexes in diving species. 2013-03-27T00:04:45.830Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2104 2010-04-27T06:43:41.945Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:2112 This research report on a case study of curriculum development at the school level is very much concerned with the practical aspects of curriculum and change. If things are considered static or lifeless or solitary, then it is hard to imagine change ever occurring within them. Institutions such as schools, and the cultures of those institutions, clearly express relations that are marked by cause and effect. this relational development allows for continuous change and change signified through sudden surges. Such has been the case at (what we will call) Carpenter High School. 2010-04-27T06:43:24.247Z ]]> http://nova.newcastle.edu.au/vital/access/manager/Repository/uon:1056 Writing, for the majority of our students, is a cumbersome task. For most English teachers this is quite a realisation as it cuts across our own disposition to write, to read, and to enjoy doing both well. Writing as a process therefore comes naturally to us, but for many of our students it only adds to the heavy burden they shoulder every time they put pen to paper. Writing on computers provides on means of removing the burden from the writing process, whilst simultaneously opening up to our students the joy of writing we experience. 2010-04-27T06:07:45.251Z ]]>