Počet záznamů: 1  

A new look at the comparative physiology of insect and human hearts

  1. 1.
    0384155 - BC 2013 RIV GB eng J - Článek v odborném periodiku
    Sláma, Karel
    A new look at the comparative physiology of insect and human hearts.
    Journal of Insect Physiology. Roč. 58, č. 8 (2012), s. 1072-1081. ISSN 0022-1910. E-ISSN 1879-1611
    Institucionální podpora: RVO:60077344
    Klíčová slova: heartbeat reversal * anterograde heartbeat * retrograde heartbeat
    Kód oboru RIV: ED - Fyziologie
    Impakt faktor: 2.379, rok: 2012
    http://www.sciencedirect.com/science/article/pii/S0022191012001035#

    Recent electrocardiographic (ECG) studies of insect hearts revealed the presence of human-like, involuntary and purely myogenic hearts. Certain insects, like a small light-weight species of hoverfly (Episyrphus balteatus), have evolved a very efficient cardiac system comprised of a compact heart ventricle and a narrow tube of aorta, which evolved as an adaptation to sustained hovering flights. Application of thermo-cardiographic and optocardiographic ECG methods revealed that adult flies of this species use the compact muscular heart chamber (heart ventricle) for intensive pumping of insect "blood" (haemolymph) into the head and thorax which is ringed all over with indirect flight musculature. The recordings of these hearts revealed extremely high, record rates of forward-directed, anterograde heartbeat (up to 10 Hz), associated with extremely enhanced synchronic (not peristaltic) propagation of systolic myocardial contractions (32.2 mm/s at room temperature). The relatively slow, backward-directed or retrograde cardiac contractions occurred only sporadically in the form of individual or twinned pulses replacing occasionally the resting periods. The compact heart ventricle contained bi-directional lateral apertures, whose opening and closure diverted the intracardiac anterograde "blood" streams between the abdominal haemocoelic cavity and the aortan artery, respectively. The visceral organs of this flying machine (crop, midgut) exhibited myogenic, extracardiac peristaltic pulsations similar to heartbeat, including the periodically reversed forward and backward direction of the peristaltic waves. The tubular crop contracted with a periodicity of 1 Hz, both forwards and backwards, with propagation of the peristaltic waves at 4.4 mm/s. The air-inflated and blindly ended midgut contracted at 0.2 Hz, with a 0.9 mm/s propagation of the peristaltic contraction waves.
    Trvalý link: http://hdl.handle.net/11104/0213885

     
     
Počet záznamů: 1  

  Tyto stránky využívají soubory cookies, které usnadňují jejich prohlížení. Další informace o tom jak používáme cookies.