
	Where results make sense

Topic: Purkinje fibers

Related Topics

Sinoatrial node

Atrioventricular node

Electrical conduction system of the heart

Heart

Sick sinus syndrome

Nervous system

Sarajevo cathedral

Myocardial infarction

Central nervous system

Action potential

Computer software

Neupogen

Software package

Excitable medium

Mountainhome, Pennsylvania

In the News (Fri 27 Nov 09)

Northern Trust

Marvin Harrison

Peter Chernin

Gary Locke

Match Play

Penelope Cruz

Mickey Rourke

AR Rahman

Danny Boyle

Hugh Jackman

	Purkinje fibers - Wikipedia, the free encyclopedia
		These fibers are specialized myocardial fibers that conduct an electrical stimulus or impulse that enables the heart to contract in a coordinated fashion.
		During the ventricular contraction portion of the cardiac cycle, the Purkinje fibers carry the contraction impulse from the left and right bundle branches to the myocardium of the ventricles.
		The impulse through the Purkinje fibers is associated with the QRS complex.
	en.wikipedia.org /wiki/Purkinje_fibers (323 words)

	NASA Neurolab Web: Mission Home Page (Site not responding. Last check: 2007-10-06)
		Purkinje observed the psychological consequences in visual experience after stimulation, including application of pressure and electrical current to the eyeball, alteration in point of light exposure relative to fovea, degree of eye movement and variation in the intensity of light.
		He is also known for his 1839 discovery of Purkinje fibers, the fibrous tissue that conducts the pacemaker stimulus along the inside walls of the ventricles to all parts of the heart.
		Purkinje was the first to use the microtome (to slice thin tissue sections), glacial acetic acid, potassium bichromate and Canada balsam in the preparation of tissue samples for microscopic examination.
	neurolab.jsc.nasa.gov /purkinje.htm (449 words)

	Body Part - Purkinje fibre
		Purkinje fibers are modified cardiac muscle cells located in the bundle of His, in the deepest layer of the endocardium.
		This arrangement ensures that the Purkinje fibers deliver the impulse for contraction such that the ventricular contractions begin at the apex of the heart and then spread up the lateral walls of the ventricles.
		Ventricular depolarization is mainly dependent on Purkinje fibers and ultimately, on the cell-to-cell transmission of the electrical impulse via gap junctions between the ventricular muscle cells.
	www.bioeng.auckland.ac.nz /anatml/anatml/database/cells/cells/parts/part/part_22.html (327 words)

	Nikon MicroscopyU: Confocal Image Gallery - Mammalian Purkinje Fibers
		Purkinje fibers are heart muscle tissues that are specialized to conduct electrical impulses to ventricular cells, which induce the lower chambers of the heart to contract.
		Purkinje fibers are comprised of very large heart cells that are modified to rapidly transmit electrical impulses (action potentials) at a velocity of about five times greater than normal cardiac muscle.
		Impulses from the upper chambers of the heart are relayed by this node to large bundles of Purkinje fibers referred to as the Bundle of His.
	www.microscopyu.com /galleries/confocal/mammalpurkinjefibers40x.html (308 words)

	The Cardiovascular System
		The Purkinje fibers are modified cardiac muscle fibers and have an accumulation of glycogen in the central portions of the cell.
		The elastic fibers are more numerous on the ventricular side of the valve, the side which expands most when the valve is closed and blood in the aorta exerts backward pressure.
		Some elastic fibers may be present in the larger veins; however, at no point are the muscular and elastic components as abundant or as clearly organized as in arteries of comparable size.
	ect.downstate.edu /courseware/histomanual/cardiovascular.html (1687 words)

	Conduction System
		The cause of this reduced negativity is that the cell membranes of the sinus fibers are naturally leaky to sodium ions.
		The fibers located in the purkinje system are very large, even larger than ventricular muscle fibers, and transmit action potentials at a velocity of 1.5 to 4.0 milliseconds.
		Once the impulse reaches the purkinje fibers, it is transmitted through the ventricular muscle mass by the ventricular muscle fibers themselves.
	oak.cats.ohiou.edu /~jr888793/conduction.html (1724 words)

	[No title]
		From the AV node the signal goes into the bundle of His, then to the right and the left bundle branches, and finally to the terminal Purkinje fibers that course along the ventricles.
		Remember the purpose of the Purkinje fibers is to provide rapid conduction of the impulses so that the ventricles can contract synchronously.
		Purkinje fibers on the other hand conduct at a speed between 1 and 2.5 m/s.
	www.uhmc.sunysb.edu /som/students/2001/noteservice/h15.doc (813 words)

	[No title]
		The development of Purkinje fibers is a highly regulated process.
		There is good evidence that during chick embryogenesis Purkinje fibers are recruited from cardiomyocytes located spatially in association with developing coronary arteries.
		The upregulation of Purkinje fiber specific genes and downregulation of cardiomyocyte specific genes in treated cultures will indicate that ET-1 may be involved in the differentiation process of Purkinje fibers.
	www.fiu.edu /~biology1/grad/rpatel.htm (346 words)

	Jan Evangelista Purkinje (Purkyne) Biography \| World of Biology
		Two years later, as Purkinje was investigating the function of muscular organs, he discovered Purkinje fibers--special muscle fibers in the ventricles of the heart.
		Later it would be shown that Purkinje fibers have an important function: they conduct contraction to all parts of the heart.
		Purkinje also conducted comparative studies of animal and plant tissue, observing that "granules"--now termed cells--were present in both.
	www.bookrags.com /biography/jan-evangelista-purkinje-purkyne-wob (583 words)

	Laboratory Nine: Cardiovascular System
		The epicardium is not evident on this slide.
		Purkinje cells are larger than the cardiac fiber and contain large amounts of glycogen (unstained regions in the cytoplasm).
		Arterioles are easily identified on the slide stained for elastic fibers by the presence of the internal elastic membrane.
	medinfo.ufl.edu /year1/histo/review/lab09.html (1539 words)

	Purkinje fibers (Site not responding. Last check: 2007-10-06)
		The Purkinje fibers are specialized conductive myocardial fibers.
		The combination of the nodal and Purkinje fiber network and intercalated discs enable the heart to contract in a coordinated fashion.
		In Virtual Microscopy, look along the lower edge of the section to find Purkinje fibers.
	www.vetmed.wsu.edu /VAn308/purkinje.htm (61 words)

	Properties of Unitary Granule Cellright-arrowPurkinje Cell Synapses in Adult Rat Cerebellar Slices -- Isope and Barbour ...
		Purkinje cells for which the soma was near the surface and for which the dendrites descended into the pseudo-transverse slice were whole-cell clamped.
		Harvey RJ, Napper RM (1988) Quantitative study of granule and Purkinje cells in the cerebellar cortex of the rat.
		Napper RM, Harvey RJ (1988a) Quantitative study of the Purkinje cell dendritic spines in the rat cerebellum.
	www.jneurosci.org /cgi/content/full/22/22/9668 (8525 words)

	Purkinje Fibers
		In slide #81, look along the wall of the heart and find examples of Purkinje fibers which are modified myofibers that carry the impulse for contraction into the myocardium.
		They are much larger in diameter than the myocytes and often willl have two nuclei and a relatively pale sarcoplasm as myofibrils are displaced by the nuclear and perinuclear organelles.
		This is a slide of the special fibers located in the heart called Purkinje fibers (white arrows).
	www3.umdnj.edu /histsweb/lab6/cardiacmuscle/purkinje.html (223 words)

	Measure effects of drugs on action potential in canine or rabbit Purkinje fibers
		ChanTest conducts action potential measurements using Purkinje fibers isolated from canine or rabbit hearts.
		Purkinje fibers form a multi-cellular tissue that propagates the action potential into the muscular walls of the ventricle and has been shown to be highly sensitive to drugs that produce long QT.
		The measurements are made using conventional intracellular electrophysiological recording to assess drug effects on resting potential, and action potential duration, amplitude and rate-of-rise.
	www.chantest.com /apd.html (317 words)

	Cerebellar Climbing Fibers Modulate Simple Spikes in Purkinje Cells -- Barmack and Yakhnitsa 23 (21): 7904 -- Journal ...
		the midline to synapse on Purkinje neurons in the contralateral
		Circles indicate Purkinje cells with optimal responses in the plane of the ipsilateral posterior-contralateral anterior semicircular canals.
		Magras IN, Voogd J (1985) Distribution of the secondary vestibular fibers in the cerebellar cortex.
	www.jneurosci.org /cgi/content/full/23/21/7904 (7265 words)

	Canine Ventricular KCNE2 Expression Resides Predominantly in Purkinje Fibers -- Pourrier et al. 93 (3): 189 -- ...
		Canine Ventricular KCNE2 Expression Resides Predominantly in Purkinje Fibers -- Pourrier et al.
		Canine Ventricular KCNE2 Expression Resides Predominantly in Purkinje Fibers
		A, Western blots using Purkinje fiber (PF) and ventricular muscle (VM) membrane protein extracts, with identical protein quantities (60 µg) from each of 4 different dog hearts (mass markers are at 23 and 34 kDa).
	circres.ahajournals.org /cgi/content/full/93/3/189 (1974 words)

	Electrotonic suppression of early afterdepolarizations in isolated rabbit Purkinje myocytes -- Huelsing et al. 279 (1): ...
		Single Purkinje myocytes were isolated from rabbit hearts as described previously (18, 19).
		fibers increased the slope of diastolic depolarization and induced
		Purkinje and ventricular activation sequences of canine papillary muscle: effects of quinidine and calcium on Purkinje-ventricular conduction delay.
	ajpheart.physiology.org /cgi/content/full/279/1/H250 (5108 words)

	Identification, Tissue-specific Expression, and Subcellular Localization of the 80- and 71-kDa Forms of Myotonic ...
		In cardiac Purkinje fibers the 71-kDa protein was the major form, and in skeletal muscle the 80-kDa protein was the major form.
		Human left ventricular heart samples and cardiac Purkinje fibers were obtained from three normal donor hearts intended for transplantation (recipient not available), three explanted hearts from patients with ischemic cardiomyopathy and idiopathic dilated cardiomyopathy, and one from a patient with Becker muscular dystrophy and severe cardiomyopathy.
		The Purkinje conduction system of the heart is a highly specialized group of cells, which exhibit a 4-fold increase in conduction velocity and a high number of intercellular connections, gap junctions, and desmosomes in the intercalated disc, compared to the disc structure in normal cardiac myocytes(24).
	www.jbc.org /cgi/content/full/270/35/20246 (4516 words)

	Induction of Purkinje fiber differentiation by coronary arterialization -- Hyer et al. 96 (23): 13214 -- Proceedings of ...
		Induction of Purkinje fiber differentiation by coronary arterialization -- Hyer et al.
		Induction of Purkinje fiber differentiation by coronary arterialization
		Purkinje fibers was specifically dependent on the presence of
	www.pnas.org /cgi/content/full/96/23/13214 (3039 words)

	A comparison of transient outward currents in canine cardiac Purkinje cells and ventricular myocytes -- Han et al. 279 ...
		Figure 1 shows the behavior of a typical Purkinje cell AP after the onset of stimulation at 2 Hz.
		Purkinje cells was 55 ± 4% of the value during the first pulse,
		Purkinje cell notch (24), which is due to the slow recovery
	ajpheart.physiology.org /cgi/content/full/279/2/H466 (4486 words)

	CiteULike: Tag purkinje (Site not responding. Last check: 2007-10-06)
		The relationship of excitability to conduction velocity in canine Purkinje tissue.
		Effects of verapamil on electrophysiologic properties of canine cardiac Purkinje fibers.
		The role of synaptic and voltage-gated currents in the control of Purkinje cell spiking: a modeling study.
	www.citeulike.org /tag/purkinje (380 words)

	Dynamics of the Calcium Subsystem in Cardiac Purkinje fibers -- from Mathematica Information Center
		Dynamics of the Calcium Subsystem in Cardiac Purkinje fibers
		A minimal model of the dynamics of internal calcium concentration of the mammalian cardiac Purkinje fiber is examined in order to identify the cause of certain arrhythmias of the heart.
		The effect of inhibition of the sodium/potassium pump is modeled by an elevated value of internal sodium concentration.
	library.wolfram.com /infocenter/Articles/2321 (161 words)

	Hemodynamic-dependent patterning of endothelin converting enzyme 1 expression and differentiation of impulse-conducting ...
		Purkinje fibers of the embryonic chick heart are both diminished
		fibers are nonetheless juxtaposed to coronary vascular tissues
		Purkinje fibers of the avian heart express a myogenic transcription factor program distinct from cardiac and skeletal muscle.
	dev.biologists.org /cgi/content/full/131/3/581 (7462 words)

	Human Mesenchymal Stem Cells Form Purkinje Fibers in Fetal Sheep Heart -- Airey et al. 109 (11): 1401 -- Circulation (Site not responding. Last check: 2007-10-06)
		PAS staining indicates that engrafted human cells are Purkinje fiber cells.
		Purkinje fibers in chimeric fetal hearts and the observation
		Enzymes and metabolites of glycogen metabolism in canine cardiac Purkinje fibers.
	circ.ahajournals.org /cgi/content/full/109/11/1401 (3558 words)

	Purkinje fibers (Site not responding. Last check: 2007-10-06)
		Note - Arrows are pointing to Purkinje fibers which are larger than cardiac muscle fibers.
		Purkinje fibers transmit the action potential through the heart muscle to the heart apex first, which is faster and more direct than cell to cell conduction.
		This allows for the heart to contract as a whole beginning the contraction at the heart apex.
	science.nhmccd.edu /Biol/cardio/purkinje.htm (82 words)

	Endothelin-induced conversion of embryonic heart muscle cells into impulse-conducting Purkinje fibers -- Gourdie et al. ...
		Periarterial differentiation of Purkinje fibers in vivo and ET-dependent induction of the impulse-conducting cells in vitro.
		SAN, the sinuatrial node; AVN, the atrioventricular node; B, the atrioventricular bundle and bundle branches; P, the Purkinje fiber network.
		Induction of Purkinje fiber phenotype in micromass cultures of embryonic myocytes.
	www.pnas.org /cgi/content/full/95/12/6815 (2935 words)

	Topography and Reciprocal Activity of Cerebellar Purkinje Cells in the Uvula-Nodulus Modulated by Vestibular ...
		fiber activity with the CFR of the Purkinje cell.
		fiber projections from the brain stem to the nodulus in the cat.
		of the secondary vestibular fibers in the cerebellar cortex.
	jn.physiology.org /cgi/content/full/78/6/3083 (7262 words)

	AnatomyIntroduction
		The electrical impulse that causes rhythmic contraction of heart muscles arises in the SA node which is the intrinsic pacemaker of the heart.
		From the AV node the electrical impulse is conducted to ventricular muscles via the bundle of His, the bundle branches and the Purkinje fibers.
		AV node, the bundle of His, bundle branches and Purkinje fibers click on these links.
	www.technion.ac.il /~eilamp/anatomyintroduction.html (126 words)

Try your search on: Qwika (all wikis)