AV node

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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.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

AV node

Abbreviation for atrioventricular node.
Farlex Partner Medical Dictionary © Farlex 2012

atrioventricular node

A microscopic aggregate of specialised cardiac myocytes and neural fibres located in the posterior right atrium between the tricuspid valve and the outlet of the coronary sinus. The AV node is the pacemaker of the heart and an integral part of the normal conduction pathway for impulses originating in the atria and reaching the ventricles.
Blood supply
AV nodal artery (in 80% of patients), a branch of the right coronary artery.

Flow of impulse
The AVN receives an electrical impulse from the sinus node, passes it to the bundle of His, which introduces a delay and passes the impulse over the network of Purkinje fibres in the membranous septum, separating into right and left bundle branches, resulting in (in a normal heart) a co-ordinated cardiac contraction or systole.
Segen's Medical Dictionary. © 2012 Farlex, Inc. All rights reserved.

AV node

Abbreviation for atrioventricular node
Medical Dictionary for the Health Professions and Nursing © Farlex 2012


(nod) [L. nodus, knot]
1. A knot, knob, protuberance, or swelling.
2. A constricted region.
3. A small rounded organ or structure.

Aschoff node

Atrioventricular node.

atrioventricular node

Abbreviation: AV node
A node of specialized cardiac muscle fibers in the lower interatrial septum that receives impulses from the sinoatrial node and transmits them to the bundle of His.
Synonym: Aschoff node See: atrioventricular bundle; conduction system of the heart for illus

Bouchard node

In osteoarthritis, bony enlargement of the proximal interphalangeal joints.

ectopic lymph node

A cluster of immunologically active cells inside a malignant tumor. The node may represent an attempt by the body to destroy foreign antigens on the tumor cell surface.

Haygarth nodes

Joint swelling seen in rheumatoid arthritis.

Heberden nodes

See: Heberden nodes

hemal node

A vascular node that structurally resembles a lymph node, present in certain ungulates. Synonym: hemal gland

Hensen node

See: Hensen, Christian Andreas Victor
Enlarge picture

lymph node

A small encapsulated lymphoid organ that filters lymph. Lymph nodes are found at junctions or branches along the lymphatics. They provide sites where immune responses can be generated through the interaction of antigens, macrophages, dendritic cells and lymphocytes. See: illustration; immune response; inflammation; lymph; lymphocyteLymph nodes are 0.1-2.5 cm long kidney-shaped aggregates of lymphocytes and macrophages embedded in a meshwork reticulum composed of thin collagen fibers. At each lymph node, an artery enters through a surface indentation (the hilum) alongside an exiting vein and an exiting (efferent) lymphatic vessel; a number of afferent lymphatic vessels enter the lymph node at other sites. Inside lymph nodes, lymph slowly flows through endothelial sinuses lined by lymphocytes and macrophages. Macrophages remove macromolecules, particles, debris, and microorganisms from the lymph stream. Lymphocytes and antibodies move through the walls of the sinuses and into the passing lymph, while dendritic cells pass from the lymph into the lymphatic follicles, carrying antigens from the body's epithelia and from infected tissues. In the cortical region of the lymph node, the sinuses wind around lymphatic follicles, which are ovoid germinal centers packed with differentiating and proliferating B lymphocytes and surrounded by loose T lymphocytes. Lymphocytes and antibodies also enter and exit blood capillaries throughout the lymph node. Lymph nodes are most numerous in the neck, mediastinum, abdominal mesenteries, pelvis, the proximal limbs (the axillae and the groin), and along the posterior abdominal wall. Inside the chest and trunk, lymph nodes tend to be found along the veins near viscera.

Meynet nodes

See: Meynet nodes

neurofibril node

Ranvier's node.

Osler nodes

See: Osler nodes

Parrot nodes

See: Parrot nodes

piedric node

A node on the hair shaft seen in piedra.

primitive node

A knoblike structure at the anterior end of the primitive streak.
Synonym: Hensen knot; primitive knot

Ranvier node

See: Ranvier node

Schmorl node

A node seen in radiographs of the spine. It is caused by prolapse of the nucleus pulposus into the end plate of the vertebra.

sentinel node

1. A lymph node that receives drainage from a tumor and is likely to harbor metastatic disease before cancer cells have the opportunity to spread elsewhere.
2. Signal node.

signal node

Enlargement of one of the supraclavicular lymph nodes; usually indicative of primary carcinoma of thoracic or abdominal organs. Synonym: sentinel node (2); Troisier's node; Virchow node

singer's node

Noncancerous, callus-like growths on the inner parts of the vocal cords, usually caused by voice abuse or overuse. It is marked by a singer's hoarseness and an inability to produce the desired notes. It is treated by resting the voice. Surgical removal of the nodules is necessary if they do not respond to conservative therapy. Synonym: chorditis nodosa; laryngeal nodule

sinoatrial node

Abbreviation: SA node
A specialized group of cardiac muscle cells in the wall of the right atrium at the entrance of the superior vena cava. These cells depolarize spontaneously and rhythmically to initiate normal heartbeats.
Synonym: pacemaker (2); sinus node

sinus node

Sinoatrial node.

syphilitic node

Circumscribed swelling at the end of long bones due to congenital syphilis. The nodes are sensitive and painful during inflammation, esp. at night.
See: Parrot's nodes

Troisier's node

Signal node.

Virchow node

Signal node.

atrioventricular node

Abbreviation: AV node
A node of specialized cardiac muscle fibers in the lower interatrial septum that receives impulses from the sinoatrial node and transmits them to the bundle of His.
Synonym: Aschoff node See: atrioventricular bundle; conduction system of the heart for illus
See also: node
Medical Dictionary, © 2009 Farlex and Partners

AV node

Collins Dictionary of Medicine © Robert M. Youngson 2004, 2005

Atrioventricular node (AV node)

Highly specialized area of the heart muscle which transmits electrical impulses.
Mentioned in: Heart Block
Gale Encyclopedia of Medicine. Copyright 2008 The Gale Group, Inc. All rights reserved.
References in periodicals archive ?
It is more likely an AVJRT, where block in the AV node caused the tachycardia to terminate.
Antidromic (retrograde) PSVT is due to a reentry circuit conducting from the bundle of Kent to the ventricles, and then retrograde through the His-Purkinje system and AV node to the atria.
Mobitz Type II AV block can occur from age-related degeneration of the conduction system, myocardial ischemia or infarction, or as a result of drugs that block the AV node (e.g., digoxin [Lanoxin[R]], beta blockers, calcium channel blockers).
Because of this rapid, disorganized beating, electrical impulses are only making it through the AV node and down to the ventricles every so often and with irregular timing.
Postoperative JET (Figure 5B) is the most common postoperative malignant tachyarrhythmia and is caused by a focus of increased automaticity in the AV node or His bundle.
It is well-established now that the PR interval is mainly dependent on the slow action potentials elicited on the AV node (Prystowsky, 1988; Golovko and Tipans, 1986; Brown et al., 1986; Gilmour and Zipes, 1985).
Serial sections through the nodule revealed a 1.3 x 1.1 x 1.0-cm, tan mass in the wall of the left atrium at the AV node, which appeared to have numerous vascular channels (Figure 2).
From the AV node, the impulse travels through the bundle of His and Purkinje fibers, which branch extensively and conduct the impulse through the much more massive ventricles, ensuring that the impulse will reach enough cardiac muscle cells to result in a coordinated contraction strong enough to propel blood out of the heart and into circulation.
WPW is one form of AV reentrant tachycardia resulting from "an anomalous conduction pathway (i.e., bundle of Kent) between the atrium and ventricle, bypassing the normal delay of conduction in the AV node" (Park, 1997, p.
In the patients of the control group, the electrophysiological study was indicated to study the AV node and sinus function in 2 patients, atrial flutter in 3 patients, and programmed electrical stimulation in 11 patients.
The AV node connects to a group of special pathways that conduct the signal to the ventricles below.
The impulse then passes through the AV node (in the middle of the heart, between the upper and lower chambers), before spreading through the ventricles so they also contract to pump blood out of your heart and into your body.