BIOENGINEERING STUDY ON THE NATURE AND FUNCTION OF THE HUMAN CARDIOVASCULAR SYSTEM

1969 ◽  
Author(s):  
II Hoppmann ◽  
W. H.
2000 ◽  
Vol 39 (02) ◽  
pp. 118-121 ◽  
Author(s):  
S. Akselrod ◽  
S. Eyal

Abstract:A simple nonlinear beat-to-beat model of the human cardiovascular system has been studied. The model, introduced by DeBoer et al. was a simplified linearized version. We present a modified model which allows to investigate the nonlinear dynamics of the cardiovascular system. We found that an increase in the -sympathetic gain, via a Hopf bifurcation, leads to sustained oscillations both in heart rate and blood pressure variables at about 0.1 Hz (Mayer waves). Similar oscillations were observed when increasing the -sympathetic gain or decreasing the vagal gain. Further changes of the gains, even beyond reasonable physiological values, did not reveal another bifurcation. The dynamics observed were thus either fixed point or limit cycle. Introducing respiration into the model showed entrainment between the respiration frequency and the Mayer waves.


Author(s):  
Sherin Saheera ◽  
Vivek P Jani ◽  
Kenneth W Witwer ◽  
Shelby Kutty

Extracellular vesicles (EVs) are nanosized lipid bilayer-delimited particles released from cells that mediate intercellular communications and play a pivotal role in various physiological and pathological processes. Subtypes of EVs may include plasma-membrane ectosomes or microvesicles and endosomal-origin exosomes, although functional distinctions remain unclear. EVs carry cargo proteins, nucleic acids (RNA and DNA), lipids, and metabolites. By presenting or transferring this cargo to recipient cells, EVs can trigger cellular responses. Here, we summarize what is known about EV biogenesis, composition, and function, with an emphasis on the role of EVs in cardiovascular system. Additionally, we provide an update on the function of EVs in cardiovascular pathophysiology, further highlighting their potential for diagnostic and therapeutic applications.


IEEE Access ◽  
2018 ◽  
Vol 6 ◽  
pp. 61896-61903 ◽  
Author(s):  
Andrzej Polanczyk ◽  
Michal Podgorski ◽  
Maciej Polanczyk ◽  
Aleksandra Piechota-Polanczyk ◽  
Christoph Neumayer ◽  
...  

1980 ◽  
Vol 135 (6) ◽  
pp. 1153-1160 ◽  
Author(s):  
TF Meaney ◽  
MA Weinstein ◽  
E Buonocore ◽  
W Pavlicek ◽  
GP Borkowski ◽  
...  

2009 ◽  
Vol 19 (3) ◽  
pp. 033112 ◽  
Author(s):  
A. S. Karavaev ◽  
M. D. Prokhorov ◽  
V. I. Ponomarenko ◽  
A. R. Kiselev ◽  
V. I. Gridnev ◽  
...  

2009 ◽  
Vol 73 (5) ◽  
pp. 636-639 ◽  
Author(s):  
Michael Miller ◽  
William F. Fry

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