Isolated sinoatrial node cellsHeart's pacemakerDysfunctionAtrialAtrioventricular nodeTissueMurineArrhythmiaArrhythmiasNodalHeartbeatInvolving the sinus nodePathwaysActivatesCardiac musclePacemaker of the heartPacemakersCellsRight coronaImpulseArteryNerveHeartModulateSuperiorVeinsCardiovascularTravelsHumanActionAtriumRateTechniquesFunction
Isolated sinoatrial node cells2
- These immunocytochemical data, together with morphological and electrophysiological data, obtained from the intact sinoatrial node and isolated sinoatrial node cells support the gradient model of the cellular organisation of the SA node. (ox.ac.uk)
- Selected contribution: axial stretch increases spontaneous pacemaker activity in rabbit isolated sinoatrial node cells. (ox.ac.uk)
Heart's pacemaker2
- The rhythmic contraction of cardiac muscle is regulated by the sinoatrial node, the heart's pacemaker. (britannica.com)
- Each heartbeat begins with an impulse from the heart's pacemaker (sinus or sinoatrial node). (msdmanuals.com)
Dysfunction2
- These findings strongly implicate rs6817105 minor allele in sinus node dysfunction and left atrial enlargement. (nature.com)
- 2000) Congenital deafness and sinoatrial node dysfunction in mice lacking class D L-type Ca2+ channels. (oeaw.ac.at)
Atrial21
- The SA node is located in the wall (epicardium) of the right atrium, laterally to the entrance of the superior vena cava in a region called the sinus venarum (hence sino- + atrial). (wikipedia.org)
- The connective tissue, along with the paranodal cells, insulate the SA node from the rest of the atrium, preventing the electrical activity of the atrial cells from affecting the SA node cells. (wikipedia.org)
- The SA node cells are smaller and paler than the surrounding atrial cells, with the average cell being around 8 micrometers in diameter and 20-30 micrometers in length (1 micrometer= 0.000001 meter). (wikipedia.org)
- Unlike the atrial cells, SA node cells contain fewer mitochondria and myofibers, as well as a smaller sarcoplasmic reticulum. (wikipedia.org)
- This means that the SA node cells are less equipped to contract compared to the atrial and ventricular cells. (wikipedia.org)
- This is again important in insulating the SA node from the surrounding atrial cells. (wikipedia.org)
- Sino-atrial node is called the pacemaker of our heart. (biologydiscussion.com)
- In the mosaic model, there is a variable mix of atrial and sinoatrial node cells from the centre to the periphery. (ox.ac.uk)
- Calcium transients in guinea-pig sino-atrial node cells imaged by confocal microscopy. (ox.ac.uk)
- Electrophysiological features of murine sino-atrial node in relation to the role of i(Na). (ox.ac.uk)
- Raised extracellular potassium attenuates the sympathetic modulation of sino-atrial node pacemaking in the isolated guinea-pig atria. (ox.ac.uk)
- Since changes in [K(+)](o) modulate membrane currents involved in sino-atrial node pacemaking, in particular the voltage-sensitive hyperpolarization-activated current (I(f)), we investigated whether raised [K(+)](o) (from 4 mM to 8 or 12 mM) could directly affect the heart rate response to cardiac sympathetic nerve stimulation (SNS). (ox.ac.uk)
- SAN optical action potentials had diastolic depolarization and multiple upstroke components that corresponded to the separate excitations of the node and surface atrial layers. (wustl.edu)
- After a 49±22 ms conduction delay within the SAN, excitation reached the atrial myocardium via superior and/or inferior sinoatrial exit pathways 8.8±3.2 mm from the leading pacemaker site. (wustl.edu)
- During normal sinus rhythm, the canine SAN is functionally insulated from the surrounding atrial myocardium except for 2 (or more) narrow superior and inferior sinoatrial exit pathways separated by 12.8±4.1 mm. (wustl.edu)
- Inhibition by Compound II, a sotalol analogue, of delayed rectifier current (iK) in rabbit isolated sino-atrial node cells. (ox.ac.uk)
- The effects of Compound II, a sotalol analogue, on spontaneous electrical activity and on three membrane currents (the delayed rectifier current, iK, the long-lasting inward calcium current, i(Ca,L) and hyperpolarization activated inward current, i(f)) were investigated in rabbit isolated sino-atrial node cells by whole cell clamp with amphotericin-permeabilised patches. (ox.ac.uk)
- Sinoatrial node (SAN) and pulmonary veins (PVs) are closely related atrial dysrhythmia. (tmu.edu.tw)
- Following intra-atrial conduction to the area of the lower intra-atrial septum, this wavefront reaches the inputs to the atrioventricular node (AVN). (medscape.com)
- The SA node is located less than 1 mm from the epicardial surface, laterally in the right atrial sulcus terminalis at the junction of the anteromedial aspect of the superior vena cava (SVC) and the right atrium (RA). (medscape.com)
- The human SA node contains a more than 3-fold greater density of beta-adrenergic and muscarinic cholinergic receptors than the adjacent atrial tissue. (medscape.com)
Atrioventricular node2
- Third-degree atrioventricular (AV) block, also referred to as third-degree heart block or complete heart block (CHB), is an abnormal heart rhythm resulting from a defect in the cardiac conduction system in which there is no conduction through the atrioventricular node (AVN), leading to complete dissociation of the atria and ventricles. (medscape.com)
- The stippled area adjacent to the central fibrous body is the approximate site of the compact atrioventricular node. (medscape.com)
Tissue7
- The cells of the SA node are spread out within a mesh of connective tissue, containing nerves, blood vessels, collagen and fat. (wikipedia.org)
- The sinoatrial (SA) node is a complex and inhomogeneous tissue in terms of cell morphology and electrical activity. (ox.ac.uk)
- This insulation coincided with connexin43-negative regions at the borders of the node, connective tissue, and coronary arteries. (wustl.edu)
- Node of specialized tissue lying near the bottom of the right atrium that fires an electrical impulse across the ventricles, causing them to contract. (encyclopedia.com)
- For example, researchers need to better understand the mechanisms controlling the development and maintenance of pacemaker cells in the sinoatrial node, just as they must develop ways to compare experimental biological pacemaker tissue with bona fide sinoatrial node tissue. (sciencedaily.com)
- The sinus (or sinoatrial) node is a small area of tissue in the wall of the right atrium. (kidshealth.org)
- The sinoatrial (SA) node is a spindle-shaped structure composed of a fibrous tissue matrix with closely packed cells. (medscape.com)
Murine1
- B ) A representative current-clamp recording of spontaneous action potentials from an acutely isolated murine sinoatrial node (SAN) cell. (elifesciences.org)
Arrhythmia1
- The death certificate, completed by the County Coroner, listed "probable arrhythmia due to hypertrophic cardiomyopathy, fibrosis of sinoatrial node" as the immediate cause of death. (cdc.gov)
Arrhythmias1
- iii) it helps protect the sinoatrial node from reentrant arrhythmias. (ox.ac.uk)
Nodal3
- The sinoatrial node receives its blood supply from the sinoatrial nodal artery. (wikipedia.org)
- Despite these many differences, there doesn't appear to be any advantage to how many sinoatrial nodal arteries an individual has, or where they originate. (wikipedia.org)
- Three-dimensional mapping and intracardiac echocardiography in the treatment of sinoatrial nodal tachycardias. (nih.gov)
Heartbeat3
- The human sinoatrial node (SAN) regulates our heartbeat. (wisc-online.com)
- This node is called the pacemaker of the heart because it sets the rate of the heartbeat and causes the rest of the heart to contract in its rhythm. (kidshealth.org)
- Under normal conditions, a group of cells called the "sinoatrial node" innervates the heart and controls the heartbeat. (medicalnewstoday.com)
Involving the sinus node1
- Supraventricular tachyarrhythmias involving the sinus node: clinical and electrophysiologic characteristics. (nih.gov)
Pathways1
- Conduction failure in these sinoatrial exit pathways leads to SAN exit block and is a modulator of heart rate. (wustl.edu)
Activates1
- Upon stimulation, acetylcholine (ACh) released from the vagus nerve binds to and activates M2Rs in sinoatrial node (SAN) pacemaker cells, promoting the engagement of the GDP-bound G protein trimer (Gα i (GDP)βγ). (elifesciences.org)
Cardiac muscle2
- The sinoatrial node (also known as the sinuatrial node, SA node or sinus node) is an oval shaped region of special cardiac muscle in the upper back wall of the right atrium made up of cells known as pacemaker cells. (wikipedia.org)
- The main role of a sinoatrial node cell is to initiate action potentials of the heart that can pass through cardiac muscle cells and cause contraction. (wikipedia.org)
Pacemakers1
- To create biological pacemakers, one approach is to coax stem cells to become specialized cardiac pacemaker cells that are normally found within the sinoatrial node of the heart. (sciencedaily.com)
Cells8
- Immediately surrounding the SA node cells are paranodal cells. (wikipedia.org)
- These cells have structures intermediate between that of the SA node cells and the rest of the atrium. (wikipedia.org)
- Although iNa has been recorded from sinoatrial (SA) node pacemaker cells, its precise role in SA node pacemaker function remains uncertain. (ox.ac.uk)
- According to the gradient model there is a gradual transition in morphology and electrical properties of SA node cells from the centre to the periphery of the SA node. (ox.ac.uk)
- Isolated, spontaneously beating rabbit sinoatrial node cells were subjected to longitudinal stretch, using carbon fibers attached to both ends of the cell. (ox.ac.uk)
- Which of the following statements describes phase 4 of the action potential of cells in the sinoatrial (SA) node? (nursingessay24x7.com)
- It is concluded that Compound II, a sotalol analogue, slows spontaneous activity of isolated rabbit SA node cells through a selective inhibition of iK. (ox.ac.uk)
- The normal cardiac impulse of the vertebrate heart originates in the pacemaker cells of the sinoatrial node, located in the right atrium. (medscape.com)
Right corona1
- The artery supplying the sinus node branches from the right coronary artery in 55-60% of hearts or the left circumflex artery in 40-45% of hearts. (medscape.com)
Impulse1
- In the heart, normal impulse initiation begins in the sinoatrial node (SAN). (medscape.com)
Artery2
- For example, in most humans, this is a single artery, although in some cases there have been either 2 or 3 sinoatrial node arteries supplying the SA node. (wikipedia.org)
- The artery approaches the node from a clockwise or counterclockwise direction around the SVC-RA junction. (medscape.com)
Nerve1
- The SA node is densely innervated with postganglionic adrenergic and cholinergic nerve terminals. (medscape.com)
Heart2
- In a healthy heart, the SA node continuously produces action potentials, setting the rhythm of the heart (sinus rhythm), and so is known as the heart's natural pacemaker. (wikipedia.org)
- Some cases of PVC occur when a group of fibers called the Purkinje fibers supply nerves to the heart instead of the sinoatrial node. (medicalnewstoday.com)
Modulate1
- Neurotransmitters modulate the SA node discharge rate by stimulation of beta-adrenergic and muscarinic receptors. (medscape.com)
Superior3
- The sinus node is approximately 15 mm long, 3 mm wide, and 1 mm thick, located directly below and to the side of the superior vena cava. (wikipedia.org)
- This band continues to the left atrium (LA), with the anterior internodal pathway entering the superior margin of the AV node. (medscape.com)
- The middle internodal tract begins at the superior and posterior margins of the sinus node, travels behind the SVC to the crest of the interatrial septum, and descends in the interatrial septum to the superior margin of the AV node. (medscape.com)
Veins1
- There are no large veins that drain blood away from the SA node. (wikipedia.org)
Cardiovascular1
- Old age and a variety of cardiovascular disorders may disrupt normal sinus node function. (nih.gov)
Travels1
- The posterior internodal tract starts at the posterior margin of the sinus node and travels posteriorly around the SVC and along the crista terminalis to the eustachian ridge and then into the interatrial septum above the coronary sinus, where it joins the posterior portion of the AV node. (medscape.com)
Human1
- Surface electrode recordings cannot delineate the activation within the human or canine sinoatrial node (SAN) because they are intramural structures. (wustl.edu)
Action1
- however, they do so at a slower rate and therefore, if the SA node is functioning properly, its action potentials usually override those that would be produced by other tissues. (wikipedia.org)
Atrium1
- An abnormality of the sinoatrial (SA) node in the right atrium. (nih.gov)
Rate1
- If the sinoatrial (SA) node fails, then at what rate (depolarizations per minute) can the atrioventricular (AV) node depolarize? (assignmentblock.com)
Techniques1
- Cardiotoxicity studies evaluating conduction node exposure might define dose constraints and criteria for additional cardiac-sparing techniques, such as respiratory techniques or proton therapy, which could benefit patients with underlying rhythmic or conduction disorders. (allenpress.com)
Function3
- SCN5A and sinoatrial node pacemaker function. (ox.ac.uk)
- iii) Experimental and computational evaluations of the functional roles of iNa in SA node pacemaker function. (ox.ac.uk)
- Taken together, these new observations suggest strong correlations between SCN5A-encoded Na+ channel and SA node pacemaker function. (ox.ac.uk)