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At least 973 records · Page 54Linked to original sources
PubMed1978

Experimentally induced antagonism of chemical and thermal reflexes in the respiratory system of fully conscious chickens.

The joint response of the respiratory and panting centres of fully-conscious unidirectionally-ventilated chickens to simultaneous combinations of hyperthermia and hypo-/hypercapnia was examined. The response was monitored by changes in the rate and amplitude of movements of the body wall and gular apparatus respectively. The response to a combination of hyperthermia plus hypercapnia bore indications of a linear summation of the individual responses of the panting centre and respiratory centre to the respective thermal and chemical stimuli. A more complex response was elicited by a combination of hyperthermia plus hypocapnia. In this case the inhibition of respiratory movements induced by the hypocapnia (hypocapnic apnea) permitted a more forceful manifestation of the component of the thermoreflex which acts via the hyoid muscles and which is responsible for the synchronous 'gular flutterin'. The rate of gular fluttering increased by up to 150% as compared to normal panting. The experimental procedure therefore provided a technique for breaking the central linkage which normally constrains the rhythm of the hyoid muscles to the more dominant rhythm of the respiratory muscles.

Animals↗
PubMed1988

A physical model for the cardiovascular and the respiratory systems.

We propose a two degrees of freedom oscillating system to simulate the working of both respiratory and cardiovascular apparatus and to investigate the physico-mathematical characteristics of a possible decoupling between the physiological systems. We suppose a double mathematical pendulum with forced and damped oscillations, with the first frequency equal to four times the second one; not only, does the system not give resonance or beatings, but it also simulates with reasonable approximation the ratio between natural relative frequencies. The two Langragian equations, that have form: (formula; see text) cannot be solved in an analytical way, even if we suppose an approximation for little oscillations. Now we are studying another two d-o-f mechanical system, with only one suspension point; we are also studying both the electrical equivalent circuits.

Humans↗