Lymph Node: From 2 Different Sources
A small organ lying along the course of a lymphatic vessel (see lymphatic system); commonly but incorrectly called a lymph gland. Lymph nodes vary considerably in size, from microscopic to about 2.5 cm (1 in) in diameter.
A lymph node consists of a thin, fibrous outer capsule and an inner mass of lymphoid tissue. Penetrating the capsule are several small lymphatic vessels (whichcarry lymph into the node). Each node contains sinuses (spaces), in which the lymph is filtered. The flow of the lymph slows as it moves through narrow channels in the sinuses; this reduction in flow allows macrophages (white blood cells that engulf and destroy foreign and dead material) time to filter microorganisms from the lymph. Germinal centres in the lymph node release white blood cells called lymphocytes, which also help to fight infection. A single, larger vessel carries lymph out of the node.
one of a number of small swellings found at intervals along the lymphatic system. Groups of nodes are found in many parts of the body; for example, in the groin and armpit and behind the ear. They are composed of lymphoid tissue and act as filters for the lymph, preventing foreign particles from entering the bloodstream; they also produce lymphocytes.
Pertaining to the lymph system or lymph tissue, the “back alley” of blood circulation. Lymph is the alkaline, clear intercellular fluid that drains from the blood capillaries, where the arterial blood separates into thick, gooey venous blood and lymph. It bathes the cells, drains up into the lymph capillaries, through the lymph nodes for cleaning and checking against antibody templates, up through the body, and back to recombine with the venous blood in the upper chest. Blood in the veins is thick, mainly because part of its fluid is missing, traveling through the tissues as lymph. Lymph nodes in the small intestine absorb most of the dietary fats as well-organized chylomicrons. Lymph nodes and tissue in the spleen, thymus, and tonsils also organize lymphocytes and maintain the software memory of previously encountered antigens and their antibody defense response. Blood feeds the lymph, lymph feeds the cells, lymph cleanses the cells and returns to the blood.... lymph
The term node is widely used in medicine. For instance, the smaller lymphatic glands are often termed LYMPH NODES. It is also applied to a collection of nerve cells forming a subsidiary nerve centre found in various places in the sympathetic nervous system (see NERVOUS SYSTEM), such as the sinuatrial node and the atrioventricular node which control the beating of the HEART.... node
This is the natural pacemaker of the HEART, and comprises a collection of specialised muscle cells in the wall of the upper chamber (atrium) of the heart. The cells initiate electrical impulses at a rate of up to 100 a minute. These impulses stimulate the muscles of the heart to contract. The rate is altered by the effects of certain hormones and various impulses from the nervous system. Damage or disease of the node affects the regular beating of the heart. (See also CARDIAC PACEMAKER.)... sinoatrial node
The central drainage and metabolic organs strung along the lymph vessels. The mesenchymal structure is native, being present at birth. The functional cells have all migrated there, some recently from the marrow, spleen, thymus or blood, others have resided since a few months after birth. Much of the antibody memory is stored in these nodes, and having only venous blood supply, lymph nodes are constantly shunting metabolized substances back into the blood, so the final lymph drainage from the thoracic duct into the left subclavian vein (or the right subclavian) contains fluid already screened and cleansed by many nodes.... lymph nodes
A small knot of specialized muscle cells in the right atrium of the heart. Electrical impulses from the sinoatrial node pass through the atrioventricular node and along conducting fibres to the ventricles, causing them to contract.... atrioventricular node
Small hard knobs which appear at the sides of the last phalanges of the ?ngers in people who have OSTEOARTHRITIS.... heberden’s nodes
Lymph nodes in the groin, next to the genitalia... inguinal nodes
See KAWASAKI DISEASE.... mucocutaneous lymph nodesyndrome
Traps in the lymphatic system that collect byproducts of body infection and which support the immune system in its role as body protector. ... lymph glands
a bony thickening arising at the proximal interphalangeal joint of a finger in osteoarthritis. It is often found together with *Heberden’s nodes. [J. C. Bouchard (1837–1915), French physician]... bouchard’s node
a bony thickening arising at the terminal joint of a finger in *osteoarthritis. It is often inherited, with women most commonly affected. [W. Heberden (1710–1801), British physician]... heberden’s node
(primitive knot) the rounded front end of the embryonic *primitive streak. [V. Hensen (1835–1924), German pathologist]... hensen’s node
one of the gaps that occur at regular intervals in the *myelin sheath of medullated nerve fibres, between adjacent *Schwann cells.... node of ranvier
purplish nodes on the finger pulp or the *thenar or *hypothenar eminence. They are usually tender and a sign of bacterial *endocarditis. [Sir W. Osler]... osler’s nodes
a transparent yellowish liquid produced in a wound or other site of inflammation, in which connective tissue cells and blood vessels develop during healing.... plastic lymph
protrusions of the pulpy inner material of an intervertebral disc into the vertebral body, generally found in the thoracic and lumbar spine. [C. G. Schmorl (1861–1932), German pathologist]... schmorl’s nodes
the first lymph node to show evidence of metastasis (spread) of a malignant tumour (e.g. breast cancer) via the lymphatic system. Absence of cancer cells in the sentinel node indicates that more distal lymph nodes will also be free of metastasis. In breast cancer, the change in practice to perform axillary lymph node dissection only if the sentinel node contains metastatic tumour has reduced the risk of arm lymphoedema. Similarly, in head and neck squamous cell carcinomas, the sentinel lymph node procedure is used as an alternative to neck dissection.... sentinel lymph node
an enlarged lymph node that may be palpated above the left clavicle (the left supraclavicular fossa). It is strongly associated with abdominal malignancy, particularly cancer of the stomach, since the lymphatic drainage from the abdomen is channelled via the thoracic duct to the left side of the neck before it enters the left subclavian vein. Enlargement of the right supraclavicular lymph node is associated with lung and oesophageal cancer.... virchow’s node
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