| 释义 |
SA node
Thesaurus| Noun | 1. | SA node - a specialized bit of heart tissue that controls the heartbeatcardiac pacemaker, sinoatrial node, pacemakercardiac muscle, heart muscle - the muscle tissue of the heart; adapted to continued rhythmic contraction |
SA node
SA node[¦es¦ā ′nōd] (anatomy) sinoauricular node SA node
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 sheath" >myelin sheath is absent and the axon is enclosed only by Schwann cell processes.SA node sinoatrial node.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.2. signal n.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.SA node Sinoatrial node, see there. 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. node (nod) [L. nodus, knot] 1. A knot, knob, protuberance, or swelling.2. A constricted region. 3. A small rounded organ or structure.Aschoff nodeAtrioventricular 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 nodeIn osteoarthritis, bony enlargement of the proximal interphalangeal joints.ectopic lymph nodeA 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 nodesJoint swelling seen in rheumatoid arthritis. Heberden nodes See: Heberden nodeshemal nodeA vascular node that structurally resembles a lymph node, present in certain ungulates. Synonym: hemal glandHensen node See: Hensen, Christian Andreas Victor LYMPH NODElymph nodeA 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 nodesneurofibril nodeRanvier's node.Osler nodes See: Osler nodesParrot nodes See: Parrot nodespiedric nodeA node on the hair shaft seen in piedra. primitive nodeA knoblike structure at the anterior end of the primitive streak. Synonym: Hensen knot; primitive knotRanvier node See: Ranvier nodeSchmorl nodeA node seen in radiographs of the spine. It is caused by prolapse of the nucleus pulposus into the end plate of the vertebra. sentinel node1. 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 nodeEnlargement 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 nodesinger's nodeNoncancerous, 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 nodulesinoatrial 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 nodesinus nodeSinoatrial node.syphilitic nodeCircumscribed 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 nodesTroisier's nodeSignal node.Virchow nodeSignal node.
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 nodeSee also: nodesin·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. SA node
Related to SA node: AV nodeSynonyms for SA nodenoun a specialized bit of heart tissue that controls the heartbeatSynonyms- cardiac pacemaker
- sinoatrial node
- pacemaker
Related Words- cardiac muscle
- heart muscle
|