atrioventricular node

(redirected from nodus atrioventricularis [TA])
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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.

a·tri·o·ven·tric·u·lar node (AV node),

1. a small node of modified cardiac muscle fibers located near the ostium of the coronary sinus; it gives rise to the atrioventricular bundle of the conduction system of the heart;
2. loosely circumscribed conduction tissue with sparse pacemakerlike (P) cells in the atrioventricular junction.

atrioventricular node

A small mass of specialized cardiac muscle fibers, located in the wall of the right atrium of the heart, that receives electrical impulses from the sinoatrial node and directs them to the conduction system in the walls of the ventricles. Also called A-V node.

atrioventricular (AV) node

an area of specialized cardiac muscle that receives the cardiac impulse from the sinoatrial (SA) node and conducts it to the bundle of His and thence to the Purkinje fibers and walls of the ventricles. The AV node is located in the septal wall between the left and right atria.

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.

atrioventricular node

A ‘junction-box’, between the upper and lower chambers of the heart, in the band of specialized heart muscle fibres which conduct the electrical impulses controlling the contraction of the heart. It assists in the correct timing of the contractions, first of the atria and then of the ventricles.

atrioventricular node (AVN)

see HEART.

Atrioventricular node (AV node)

Highly specialized area of the heart muscle which transmits electrical impulses.
Mentioned in: Heart Block


Karl Ludwig, German pathologist, 1866-1942.
Aschoff bodies - a form of granulomatous inflammation characteristically observed in acute rheumatic carditis. Synonym(s): Aschoff nodules
Aschoff cell - a large-cell component of rheumatic nodules in the myocardium.
Aschoff nodules - Synonym(s): Aschoff bodies
node of Aschoff and Tawara - a small node of modified cardiac muscle that gives rise to the atrioventricular bundle of the conduction system of the heart. Synonym(s): atrioventricular node; Tawara node
Rokitansky-Aschoff sinuses - see under Rokitansky


pertaining to an atrium and ventricle of the heart.

accessory tract atrioventricular conduction
see accessory tract atrioventricular conduction.
atrioventricular block
see atrioventricular heart block.
atrioventricular bundle
bundle of His.
common atrioventricular canal
a congenital cardiac defect in which both sides of the heart share the same atrioventricular orifice. Called also persistent atrioventricular canal, atrioventricularis communis.
atrioventricular node
a mass of cardiac muscle fibers (Purkinje fibers) lying on the right lower part of the interatrial septum of the heart. Its function is the transmission of the cardiac impulse from the sinoatrial node to the muscular walls of the ventricles. The conductive system is organized so that transmission is slightly delayed at the atrioventricular node, thus allowing time for the atria to empty their contents into the ventricles before the ventricles begin to contract.
partitioning atrioventricular canal
during embryological development partitioning of the cardiac chambers and their orifices may be incomplete, leading to fatal cardiac defects, e.g. persistent atrioventricular chamber.
persistent common atrioventricular canal
atrioventricular stenosis
left and right atrioventricular stenosis are recorded; the former is an acyanotic defect, the latter is more serious and a cyanotic defect.
atrioventricular trunk
see bundle of His.
atrioventricular valvular disease
may be identifiable on finding of systolic murmur (incompetent valve) or diastolic murmur (stenotic valve) over the apex of the heart with maximum audibility over the left or right sides, depending on the side involved.
Wenckebach atrioventricular block
see Mobitz atrioventricular heart block.