Results 151 to 160 of about 9,952 (192)

Functional morphology of the pig sinoatrial node

Journal of Molecular and Cellular Cardiology, 1987
The porcine sinoatrial node in an isolated right atrium preparation is characterized by unifocal impulse generation. It has a rather elongated shape and the larger part of its volume is taken up by collagen and fibroblasts. The impulse appears to emerge from a site where the percentage of myofilaments is relatively low. The impulse is propagated faster
T, Opthof, B, de Jonge, H J, Jongsma, L N, Bouman   +3 more
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Connexins in the Sinoatrial and Atrioventricular Nodes

2006
The sinoatrial node (SAN) and the atrioventricular node (AVN) are specialized tissues in the heart: the SAN is specialized for pacemaking (it is the pacemaker of the heart), whereas the AVN is specialized for slow conduction of the action potential (to introduce a delay between atrial and ventricular activation during the cardiac cycle).
Boyett, M. R., Inada, S., Yoo, S., Li, A. J., Liu, J., Tellez, J., Greener, I. D., Honjo, H., Billeter, R., Lei, M., Zhang, H., Efimov, I. R., Dobrzynski, H.   +12 more
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Sinoatrial node arteriosclerosis in two young dogs

Journal of the American Veterinary Medical Association, 1994
Two 11-month-old 7-kg unrelated female Beagles had clinical signs referable to the cardiovascular system. Histologic studies in both dogs revealed strikingly similar findings of sclerosis of the arteries of the sinoatrial node. Histologic changes included intimal thickening and fibrosis, with marked luminal narrowing; medial hypertrophy, fibrosis, and ...
H J, Hamlen, S A, Kargas, J R, Blum
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Disturbances of Sinoatrial Node Function

2000
The spectrum of human cardiac performance is amazingly broad with cardiac output varying 10–20-fold between that measured during the deepest of sleep to that seen at peak of exercise. In large part this tremendous cardiac reserve is modulated both by cardiac contractility as well as the heart rate itself.
Ruey J. Sung, Michael R. Lauer
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Parasympathetic postganglionic pathways to the sinoatrial node

American Journal of Physiology-Heart and Circulatory Physiology, 1990
Vagal ganglia that innervate the canine sinoatrial node (SAN) have been localized to a fat pad overlying and surrounding the right pulmonary vein complex (PVFP). The ventral epicardial surface of the right atrium was mapped in seven dogs anesthetized with alpha-chloralose after beta-blockade (timolol) and cardiac sympathetic and parasympathetic ...
K M, Bluemel, R D, Wurster, W C, Randall, M J, Duff, M F, O'Toole   +4 more
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Ultrastructure of electrophysiologically identified human sinoatrial nodes

Basic Research in Cardiology, 1988
The ultrastructure of freshly excised human sinus node tissue was studied. In three female patients (ages 20, 30, and 36 years) medically refractory disabling episodes of inappropriate sinus tachycardia were surgically treated by extirpation of the sinus node.
J E, Lowe, T, Hartwich, M, Takla, J, Schaper   +3 more
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Phase Response of Model Sinoatrial Node Cells

Annals of Biomedical Engineering, 2003
When a brief current pulse is incident on excitable cells in cardiac and other nervous tissue, a change in phase of the cell's response is usually observed. In cardiac tissue, the cells are exposed to external stimulation of mainly positive currents, which depolarize the cells.
A C F, Coster, B G, Celler
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The Sinoatrial Node Function

1976
The impulse for the activation of the heart is generated normally in the sinoatrial node (SA node). This structure covers an area of only a few square millimeters. The cells have an irregular contour and are small (diameter less than 10 μ). Furthermore, they contain sparse myofilaments which are often not well organized. The intercellular junctions are
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ICI D7288, a Novel Sinoatrial Node Modulator

Journal of Cardiovascular Pharmacology, 1993
We evaluated the cardiovascular effects of the sinoatrial (SA) node modulating agent, ICI D7288, in guinea pig isolated atria and SA node, anaesthetised and exercising dogs, and conscious rats. ICI D7288 (0.1-100 microM) caused a reduction in spontaneous beating rate in guinea pig isolated right atria without affecting the contractile force of paced ...
P W, Marshall, W, Rouse, I, Briggs, R B, Hargreaves, S D, Mills, B J, McLoughlin   +5 more
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The surgical anatomy of the sinoatrial node

Surgical and Radiologic Anatomy, 1991
The sinoatrial nodes (SAN) were observed, dissected, and measured on 95 adults and 30 child hearts under a dissection microscope. The majority of the SANs in adults are characterized by their pale color, firm consistency, and the location in relation to the penetration of the SAN artery, and they can be located in the superior part of the terminal ...
B M, He, Y X, Tan, M, Cheng, Y Q, Cui
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