sinoatrial node


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Related to sinoatrial node: atrioventricular node, bundle of His

node

 [nōd]
a small mass of tissue in the form of a swelling, knot, or protuberance, either normal or pathological. adj., adj no´dal.
node of Aschoff and Tawara atrioventricular node.
atrioventricular node (AV node) a collection of cardiac fibers at the base of the interatrial septum that transmits the cardiac impulse initiated by the sinoatrial node.
Bouchard's n's cartilaginous and bony enlargements of the proximal interphalangeal joints of the fingers in degenerative joint disease; such nodes on the distal joints are called Heberden's nodes.
Delphian node a lymph node encased in the fascia in the midline just above the thyroid isthmus, so called because it is exposed first at operation and, if diseased, is indicative of disease of the thyroid gland.
Flack's node sinoatrial node.
Heberden's n's nodular protrusions on the phalanges at the distal interphalangeal joints of the fingers in osteoarthritis. Similar nodes on the proximal joints are called bouchard's nodes.
Comparison of Heberden's nodes (seen in patients with osteoarthritis) with Bouchard's nodes (seen in patients with rheumatoid arthritis). From Copstead and Banasik, 2000.
hemal n's nodes with a rich content of erythrocytes within sinuses, found near large blood vessels along the ventral side of the vertebrae and near the spleen and kidneys in various mammals, especially ruminants, having functions probably like those of the spleen; their presence in humans is doubtful.
Keith's node (Keith-Flack node) sinoatrial node.
Legendre's n's Bouchard's nodes.
lymph node see lymph node.
Osler's n's small, raised, swollen, tender areas, bluish or sometimes pink or red, due to inflammation around the site of lodgement of small infected emboli in distal arterioles; they occur commonly in the pads of the fingers or toes, in the palms, or in the soles and are practically pathognomonic for subacute bacterial endocarditis.
Parrot's n's bony nodes on the outer table of the skull of infants with congenital syphilis.
n's of Ranvier constrictions of myelinated nerve fibers at regular intervals at which the myelin sheath is absent and the axon is enclosed only by Schwann cell processes.
Schmorl's node an irregular or hemispherical bone defect in the upper or lower margin of the body of a vertebra into which the nucleus pulposus of the intervertebral disk herniates.
sentinel node
1. the first lymph node to receive drainage from a tumor; used to determine whether there is lymphatic metastasis in certain types of cancer. If this node is negative for malignancy, others “upstream” from it are usually also negative.
signal node an enlarged supraclavicular lymph node; often the first sign of a malignant abdominal tumor.
singer's n's vocal cord nodules.
sinoatrial node a collection of atypical muscle fibers in the wall of the right atrium where the rhythm of cardiac contraction is usually established; therefore also referred to as the pacemaker of the heart. Called also SA node.
syphilitic node a swelling on a bone due to syphilitic periostitis.
node of Tawara atrioventricular node.
teacher's n's vocal cord nodules.
Troisier's node (Virchow's node) sentinel node.

sin·u·a·tri·al node

[TA]
the mass of specialized cardiac muscle fibers that normally acts as the "pacemaker" of the cardiac conduction system; it lies under the epicardium at the upper end of the sulcus terminalis.

sinoatrial node

n.
A small mass of specialized cardiac muscle fibers located in the posterior wall of the right atrium of the heart that acts as a pacemaker by generating at regular intervals the electric impulses of the heartbeat. Also called sinoauricular node, sinus node.

sinoatrial node

SA node, sinuatrial node, sinus node, heart's pacemaker Anatomy A knot of specialized, spontaneously depolarizing cells located at the posterior wall of the upper right atrium, in the sulcus terminalis at the junction between the superior vena cava and right atrium, the heart's natural pacemaker Normal rhythm 70/min; conducts impulses via 3 Purkinje fiber tracts: (1) anterior internodal tract of Bachman; (2) middle internodal tract of Wenckebach; (3) posterior internodal tract of Thorel to AV node–normal rhythm, 45/min–in right posterior portion of interatrial septum; it is continuous with bundle of His–normal rhythm, 35/min Blood supply Rt coronary–65%, circumflex–25%, both in remainder Flow of impulse From the SN through right atrium to AV node in low septal right atrium. See Conduction system. Cf Atrioventricular node.

sin·u·a·tri·al node

, sinoatrial node (sin'yū-ā'trē-ăl nōd, sī'nō-) [TA]
The mass of specialized cardiac muscle fibers that normally acts as the "pacemaker" of the cardiac conduction system; it lies under the epicardium at the upper end of the sulcus terminalis.

sinoatrial node

A small area of specialized muscle cells in the upper right chamber of the heart (right atrium) that acts as the natural pacemaker of the heart, setting the rate in conjunction with other controlling influences, and transmitting impulses throughout the heart muscle.

sinoatrial node (SAN)

see HEART.

sin·u·a·tri·al node

, sinoatrial node (sin'yū-ā'trē-ăl nōd, sī'nō-) [TA]
The mass of specialized cardiac muscle fibers that normally acts as the "pacemaker" of the cardiac conduction system; it lies under the epicardium at the upper end of the sulcus terminalis.
References in periodicals archive ?
Under normal circumstances, the greatest automaticity is in the cells of the sinoatrial node, followed by the cells of the AVN.
The impact disrupted perfectly timed electrical signals emitted from the heart's sinoatrial node, or natural pacemaker--and killed Parman instantly.
The area from which the electrical impulse arises is called the sinoatrial node. During an episode of atrial fibrillation, the function of the sinoatrial node is overtaken and many electrical impulses, greater than 400 per minute, fire off from the upper chambers of the heart.
The beating of the heart is controlled by electrical impulses that originate in a specialized part of the heart called the SA or sinoatrial node. The impulses travel through the atria of the heart, causing them to contract.
SVT is defined as "any abnormally rapid dysrhythmia that originates above the ventricles, that is, any portion of the atrium including the sinoatrial node, the atrioventricular node, or within the bundle of His proximal to its bifurcation" (Ziegler, 1994, p.
Fibrous thickening of the aortal wall can cause interference with the conduction of electrical impulses from the sinoatrial node that coordinate the intrinsic contraction of the heart muscle.[1] This thickening is caused by the spreading of the osteoblastosis from the spine to the aorta and into the ventricular system.
[12] The normally slower heart rate may be due to immaturity of the sinoatrial node early on or the atrial pacemaker may actually be slower in early gestation.
Sick sinus syndrome (SSS) comprises a variety of conditions involving sinus node dysfunction (SND) which occurs as a result of anatomical damage to the sinoatrial node (SAN) of the heart.
(3) Birds have a cardiac conduction system, similar to that of mammals, and consists of a sinoatrial node, an atrioventricular node, and Purkinje fibers.
The heartbeat originates in the sinoatrial node (SAN) of the heart's right upper chamber, where pacemaker cells are clustered.