Peristaltic transport of a biofluid in a pipe of elliptic cross section

Usha, S.; Rao, A. Ramachandra

doi:10.1016/0021-9290(95)80006-9

Cited by 15 publications

(8 citation statements)

References 12 publications

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“…In the OFT the cardiac jelly forms endocardial cushions, which are thickenings of the cardiac wall at opposite sides of the tube that generate an elliptical lumen cross-section. This might be an important role of the OFT cushions, since mathematical analyses have shown that an elliptical tube requires less energy for peristaltic pumping than a circular tube Taber and Perucchio (2000); Usha and Rao (1995). Studies have also suggested that the elliptical lumen cross-section is facilitated by molecules that tether the endocardium to the myocardium at specific locations, so that as the myocardium contracts, the cushions bulge out away from the tethering spots Garita et al (2011).…”

Section: The Developing Heart and Its Outflow Tractmentioning

confidence: 99%

Visualization Techniques for the Developing Chicken Heart

Phan

Grimm

Rugonyi

2015

Advances in Visual Computing

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We present a geometric surface parameterization algorithm and several visualization techniques adapted to the problem of understanding the 4D peristaltic-like motion of the outflow tract (OFT) in an embryonic chick heart. We illustrated the techniques using data from hearts under normal conditions (four embryos), and hearts in which blood flow conditions are altered through OFT banding (four embryos). The overall goal is to create quantitative measures of the temporal heart-shape change both within a single subject and between multiple subjects. These measures will help elucidate how altering hemodynamic conditions changes the shape and motion of the OFT walls, which in turn influence the stresses and strains on the developing heart, causing it to develop differently. We take advantage of the tubular shape and periodic motion of the OFT to produce successively lower dimensional visualizations and quantifications of the cardiac motion.

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“…They acknowledged that biological peristaltic pumps are likely more complex than simple technical peristaltic pumps in an engineering sense (e.g. the roller pump, in which rotating rollers cause the periodic deformation required for pumping (Usha and Rao, 1995)), and that arguments presented by Forouhar et al (2006) in support of impedance pumping are valid only when the comparison of pumping mechanisms relies on observations in impedance pumps versus technical peristaltic pumps. To settle this controversy, it would be necessary to determine whether the tubular heart experiences active contraction throughout the myocardial layer (along the whole heart), as in a peristaltic pump, or if this contraction wave is triggered from a single compression site, as in the impedance pump.…”

Section: Mechanics Of Early Pumpingmentioning

confidence: 99%

Biomechanics of early cardiac development

Goenezen

Rennie

Rugonyi

2012

Biomech Model Mechanobiol

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Biomechanics affect early cardiac development, from looping to the development of chambers and valves. Hemodynamic forces are essential for proper cardiac development, and their disruption leads to congenital heart defects. A wealth of information already exists on early cardiac adaptations to hemodynamic loading, and new technologies, including high resolution imaging modalities and computational modeling, are enabling a more thorough understanding of relationships between hemodynamics and cardiac development. Imaging and modeling approaches, used in combination with biological data on cell behavior and adaptation, are paving the road for new discoveries on links between biomechanics and biology and their effect on cardiac development and fetal programming.

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“…(2) The cardiac jelly shows an uneven spatial distribution, which forces the open lumen of the heart tube to acquire an elliptic cross-section Mä nner et al, 2008). This finding might be interesting because mathematical analyses have shown that tubes of elliptic cross-section have a higher mechanical efficiency of peristaltic pumping compared with tubes of circular crosssection (Usha and Rao, 1995;Taber and Perruchio, 2000). (3) There is evidence that the cardiac jelly is a resilient component of the embryonic heart wall, which becomes deformed during systole and springs back to its original shape during diastolic relaxation and, thereby, might suck the blood into the inflow segment of the heart tube (Barry, 1948;Mä nner et al, 2009).…”

Section: Solid (Morphological) Dynamicsmentioning

confidence: 99%

How does the tubular embryonic heart work? Looking for the physical mechanism generating unidirectional blood flow in the valveless embryonic heart tube

2010

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The heart is the first organ to function in vertebrate embryos. The human heart, for example, starts beating around the 21st embryonic day. During the initial phase of its pumping action, the embryonic heart is seen as a pulsating blood vessel that is built up by (1) an inner endothelial tube lacking valves, (2) a middle layer of extracellular matrix, and (3) an outer myocardial tube. Despite the absence of valves, this tubular heart generates unidirectional blood flow. This fact poses the question how it works. Visual examination of the pulsating embryonic heart tube shows that its pumping action is characterized by traveling mechanical waves sweeping from its venous to its arterial end. These traveling waves were traditionally described as myocardial peristaltic waves. It has, therefore, been speculated that the tubular embryonic heart works as a technical peristaltic pump. Recent hemodynamic data from living embryos, however, have shown that the pumping function of the embryonic heart tube differs in several respects from that of a technical peristaltic pump. Some of these data suggest that embryonic heart tubes work as valveless ''Liebau pumps.'' In the present study, a review is given on the evolution of the two above-mentioned theories of early cardiac pumping mechanics. We discuss pros and cons for both of these theories. We show that the tubular embryonic heart works neither as a technical peristaltic pump nor as a classic Liebau pump. The question regarding how the embryonic heart tube works still awaits an answer.

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“…In this respect, it might be of interest that the formation of multiple endocardial spikes has been noted in stage-10/11 embryonic chick hearts subsequent to the injection of vascular endothelial growth factor into the cardiac jelly at initial stages of heart tube formation (Drake et al, 2006 Mathematical models have shown that the mechanical pumping efficiency of tubular peristaltic pumps depends on the cross-sectional shape of its wall. Tubular pumps of elliptic cross-section, for example, work at a higher mechanical efficiency compared with those of circular cross-section (Usha and Rao, 1995;Taber and Perrucchio, 2000). The initially elliptic cross-section of the endocardial lumen of the embryonic heart tube, thus, might be a structural base for the optimization of its pumping function .…”

Section: Which Processes Lead To the Establishment Of The Broad Area mentioning

confidence: 99%

“…The eccentric deformation of the endocardial tube is the consequence of an uneven distribution of cardiac jelly between the myocardium and endocardium. Its implications for the pumping function of the tubular heart seem to be two-fold : (1) It facilitates end-systolic occlusion of the endocardial lumen, and (2) there is evidence that heart tubes of elliptic cross-section might pump blood with a higher mechanical efficiency than those of circular cross-section (Usha and Rao, 1995;Taber and Perrucchio, 2000).…”

Section: Introductionmentioning

confidence: 99%

In vivo imaging of the cyclic changes in cross-sectional shape of the ventricular segment of pulsating embryonic chick hearts at stages 14 to 17: A contribution to the understanding of the ontogenesis of cardiac pumping function

et al. 2009

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The cardiac cycle-related deformations of tubular embryonic hearts were traditionally described as concentric narrowing and widening of a tube of circular cross-section. Using optical coherence tomography (OCT), we have recently shown that, during the cardiac cycle, only the myocardial tube undergoes concentric narrowing and widening while the endocardial tube undergoes eccentric narrowing and widening, having an elliptic cross-section at end-diastole and a slit-shaped cross-section at end-systole. Due to technical limitations, these analyses were confined to early stages of ventricular development (chick embryos, stages 10-13). Using a modified OCT-system, we now document, for the first time, the cyclic changes in cross-sectional shape of beating embryonic ventricles at stages 14 to 17. We show that during these stages (1) a large area of diminished cardiac jelly appears at the outer curvature of the ventricular region associated with formation of endocardial pouches; (2) the ventricular endocardial lumen acquires a bell-shaped cross-section at end-diastole and becomes compressed like a fireplace bellows during systole; (3) the contracting portions of the embryonic ventricles display stretching along its baso-apical axis at end-systole. The functional significance of our data is discussed with respect to early cardiac pumping function. Developmental Dynamics 238:3273-3284,

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Peristaltic transport of a biofluid in a pipe of elliptic cross section

Cited by 15 publications

References 12 publications

Visualization Techniques for the Developing Chicken Heart

Biomechanics of early cardiac development

How does the tubular embryonic heart work? Looking for the physical mechanism generating unidirectional blood flow in the valveless embryonic heart tube

In vivo imaging of the cyclic changes in cross-sectional shape of the ventricular segment of pulsating embryonic chick hearts at stages 14 to 17: A contribution to the understanding of the ontogenesis of cardiac pumping function

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