Tubercle
A small tuber, a small lump or bump.
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1. A nodule, especially in an anatomic, not pathologic, sense. 2. A circumscribed, rounded, solid elevation on the skin, mucous membrane, or surface of an organ. 3. A slight elevation from the surface of a bone giving attachment to a muscle or ligament. 4. In dentistry, a small elevation arising on the surface of a tooth. 5. A granulomatous lesion due to infection by Mycobacterium tuberculosis. Although somewhat variable in size (0.5–2 or 3 mm in diameter) and in the proportions of various histologic components, t.'s tend to be fairly well-circumscribed, spheroidal, firm lesions that usually consist of three irregularly outlined but moderately distinct zones: 1) an inner focus of necrosis, coagulative at first, and then becoming caseous; 2) a middle zone that consists of a fairly dense accumulation of large mononuclear phagocytes (macrophages), frequently arranged somewhat radially (with reference to the necrotic material) resembling an epithelium, and hence termed epithelioid cells; multinucleated giant cells of Langhans type may also be present; 3) an outer zone of numerous lymphocytes, and a few monocytes and plasma cells. In instances where healing has begun, a fourth zone of fibrous tissue may form at the periphery. Morphologically indistinguishable lesions may occur in diseases caused by other agents; many observers use the term nonspecifically, i.e., with reference to any such granuloma; others use “t.” only for tuberculous lesions, and then designate those of undetermined causes as epithelioid-cell granulomas. SYN: tuberculum [TA]. [L. tuberculum, dim. of tuber, a knob, a swelling, a tumor]
- accessory t. SYN: accessory process of lumbar vertebra.
- acoustic t. SYN: trigone of auditory nerve.
- adductor t. of femur [TA] the prominence above the medial epicondyle of the femur to which the tendon of the adductor magnus attaches. SYN: tuberculum adductorium femoris [TA].
- amygdaloid t. a projection from the roof of the anterior end-portion of the temporal horn of the lateral ventricle, marking the location of the amygdaloid nucleus.
- anatomic t. SYN: postmortem wart.
- anterior t. of atlas [TA] a conical protuberance on the anterior surface of the arch of the atlas. SYN: tuberculum anterius atlantis [TA].
- anterior t. of cervical vertebrae [TA] the anterior projection from the transverse process. SYN: tuberculum anterius vertebrarum cervicalium [TA].
- t. of anterior scalene muscle SYN: scalene t..
- anterior thalamic t. [TA] a prominence at the anterior extremity of the thalamus which corresponds to the nuclei anteriores. SYN: tuberculum anterius thalami [TA], anterior t. of thalamus.
- areolar tubercles [TA] small elevations on the areola of the female breast, especially prominent during pregnancy and lactation, that are a superficial manifestation of the underlying areolar glands. SYN: tubercula areolae [TA].
- articular t. of temporal bone [TA] articular eminence of the temporal bone which bounds the mandibular fossa anteriorly; it forms the anterior root of the zygomatic process; it is enclosed by the articular capsule of the temporomandibular joint with the articular fossa; the head of the mandible (and intervening articular disc) move onto the articular t. to allow full depression of the mandible (opening of the mouth). SYN: tuberculum articulare ossis temporalis [TA], articular eminence of temporal bone, eminentia articularis ossis temporalis, tuber zygomaticum.
- ashen t. SYN: trigeminal t..
- auricular t. [TA] a small inconstant projection from the upper end of the posterior portion of the incurved free margin of the helix of the auricle. SYN: tuberculum auriculae [TA], darwinian t., tuberculum superius.
- calcaneal t. [TA] the projection, often double, on the inferior aspect of the calcaneus at the anterior end of the area for attachment of the long plantar ligament. SYN: tuberculum calcanei [TA].
- Carabelli t. a small t., resembling a supernumerary cusp, found occasionally on the lingual surface of the mesiolingual cusp of a permanent maxillary first molar.
- carotid t. [TA] the anterior t. of the transverse process of the sixth cervical vertebra, against which the carotid artery may be compressed by the finger. SYN: tuberculum caroticum [TA], Chassaignac t..
- caseous t. SYN: soft t..
- Chassaignac t. SYN: carotid t..
- conoid t. (of clavicle) [TA] the prominence near the lateral end of the inferior surface of the clavicle that gives attachment to the conoid ligament. SYN: tuberculum conoideum (claviculare) [TA], conoid process.
- corniculate t. [TA] the smaller and more medial of the two rounded eminences on the posterior part of the aryepiglottic fold, formed by the underlying corniculate cartilages. SYN: tuberculum corniculatum [TA], Santorini t..
- crown t. SYN: dental t..
- cuneate t. the bulbous rostral extremity of the fasciculus cuneatus corresponding to the position of the cunate nucleus, lying lateral to the clava and separated from the tuberculum cinereum on its lateral side by the posterior lateral sulcus. SYN: tuberculum cuneatum, wedge-shaped t..
- cuneiform t. [TA] the larger, more laterally placed of the two rounded eminences on the posterior part of the aryepiglottic fold, formed by the underlying cuneiform cartilage. SYN: tuberculum cuneiforme [TA], Wrisberg t..
- darwinian t. SYN: auricular t..
- deltoid t. (of spine of scapula) [TA] prominence on the dorsum of the scapular spine, lateral to the root of the spine, to which a flat, triangular tendon from the most inferior part of the middle part of the trapezius (muscle) is attached. SYN: tuberculum deltoideum (spinae scapulae) [TA].
- dental t. [TA] a small elevation on some portions of a crown produced by an extra formation of enamel. SYN: tuberculum dentis [TA], crown t., t. of tooth, tuberculum coronae.
- dorsal t. of radius [TA] a small prominence on the dorsal aspect of the distal end of the radius lateral to the groove for the extensor pollicis longus tendon; it serves as a trochlea or pulley for the tendon. SYN: tuberculum dorsale radii [TA], Lister t..
- epiglottic t. [TA] a convexity at the lower part of the epiglottis over the upper part of the thyroepiglottic ligament. SYN: tuberculum epiglotticum [TA], cushion of epiglottis.
- fibrous t. a t. in which fibroblasts proliferate about the periphery (and into the cellular zones), eventually resulting in a rim or wall of cellular fibrous tissue or collagenous material around the t..
- genial t. SYN: mental spine.
- genital t. the median elevation just cephalic to the urogenital orifice of an embryo; it is the primordium of the penis of the male or the clitoris of the female. SYN: phallic t..
- Gerdy t. a t. on the anterolateral side of the upper end of the tibia giving attachment to the iliotibial tract and some fibers of the tibialis anterior muscle.
- Ghon t. calcification seen in pulmonary parenchyma (usually midlung) resulting from earlier, usually childhood, infection with tuberculosis; sometimes confused with a combination of parenchymal lesion and calcified lymph node, which is properly termed a Ranke complex. SYN: Ghon complex, Ghon focus, Ghon primary lesion.
- gracile t. the somewhat expanded upper end of the gracile fasciculus, corresponding to the position of the gracile nucleus. SYN: clava, tuberculum gracile.
- gray t. SYN: trigeminal t..
- greater t. (of humerus) [TA] the larger of the two tubercles next to the head of the humerus; it gives attachment to the supraspinatus, infraspinatus, and teres minor muscles. SYN: tuberculum majus (humeri) [TA], greater tuberosity of humerus.
- hard t. a t. lacking necrosis.
- hyaline t. a form of fibrous t. in which the cellular fibrous tissue and collagenous fibers become altered and merged into a fairly homogeneous, acellular, deeply acidophilic, firm mass.
- iliac t. SYN: t. of iliac crest.
- t. of iliac crest [TA] a prominence on the outer lip of the iliac crest about 5 cm behind the anterior superior iliac spine. SYN: tuberculum iliacum [TA], iliac t..
- inferior thyroid t. [TA] a slight lateral projection from the lower margin of the lamina of the thyroid cartilage on either side, at the inferior end of the oblique line. SYN: tuberculum thyroideum inferius [TA].
- infraglenoid t. (of scapula) [TA] a rough surface below the glenoid cavity of the scapula, giving attachment to the long tendon of the triceps. SYN: tuberculum infraglenoidale (scapulae) [TA], infraglenoid tuberosity.
- intercolumnar t. See subfornical organ.
- intercondylar t. [TA] one of two projections, medial and lateral, springing from the central lip of each articular surface of the tibia on either side of the intercondylar eminence. SYN: tuberculum intercondylare (mediale et laterale) [TA].
- intervenous t. (of right atrium) [TA] the slight projection on the wall of the right atrium between the orifices of the venae cavae. SYN: tuberculum intervenosum (atrii dextri) [TA], Lower t..
- jugular t. of occipital bone [TA] an oval elevation on the cerebral surface of the junction of the lateral and basal parts of the occipital bone, on either side of the foramen magnum medial to the lower border and anterosuperior to the opening of the hypoglossal canal. SYN: tuberculum jugulare ossis occipitalis [TA].
- labial t. SYN: t. of upper lip.
- lateral t. (of posterior process) of talus [TA] the prominence lateral to the groove for the flexor hallucis longus tendon. SYN: tuberculum laterale (processus posterioris) tali [TA].
- lesser t. (of humerus) [TA] the anterior of the two tubercles of the neck of the humerus on which the subscapularis is inserted. SYN: tuberculum minus (humeri) [TA], lesser tuberosity of humerus.
- Lisfranc t. SYN: scalene t..
- Lister t. SYN: dorsal t. of radius.
- Lower t. SYN: intervenous t. (of right atrium).
- mammillary t. SYN: mammillary process of lumbar vertebra.
- marginal t. SYN: marginal t. (of zygomatic bone).
- marginal t. (of zygomatic bone) [TA] an inconstant prominence on the temporal border of the zygomatic bone to which the temporal fascia is attached. SYN: tuberculum marginale (ossis zygomatici) [TA], marginal t..
- medial t. (of posterior process) of talus [TA] the eminence medial to the sulcus for the flexor hallucis longus tendon. SYN: tuberculum mediale (processus posterioris) tali [TA].
- mental t. (of mandible) [TA] a paired eminence on the mental protuberance of the mandible. SYN: tuberculum mentale (mandibulae) [TA], eminentia symphysis.
- molar t. [TA] occasional nonocclusive prominence of variable size on the crown of a molar tooth. SYN: tuberculum molare [TA].
- Montgomery tubercles elevated reddened areolar glands, usually associated with pregnancy.
- Morgagni t. SYN: cuneiform cartilage.
- Müller t. a median protuberance projecting into the embryonic urogenital sinus from its dorsal wall; it is formed from the fused caudal ends of the paramesonephric ducts and is the first evidence of the embryonic uterus and vagina. SYN: sinus t..
- obturator t. [TA] one of two processes, anterior and posterior, on the margin of the pubic portion of the obturator foramen, bounding the termination of the obturator groove; the posterior obturator t. is inconstant. SYN: tuberculum obturatorium [TA].
- olfactory t. a small, oval area at the base of the cerebral hemisphere, between the diverging medial and lateral olfactory striae, in the anteromedial part of the anterior perforated substance; it is formed by a small area of allocortex characterized by the presence of the islands of Calleja. Corresponding to a much more prominent structure in nonprimate mammals (especially rodents and insectivores), the olfactory t. receives fibers from the olfactory bulb by way of the intermediate olfactory stria; it has efferent connections with the hypothalamus and the mediodorsal nucleus of the thalamus. SYN: tuberculum olfactorium [TA].
- orbital t. (of zygomatic bone) [TA] a small elevation on the orbital surface of the zygomatic bone, just within the orbital margin, about 1 cm below the zygomaticofrontal suture; it gives attachment to the lateral check ligament, the lateral palpebral ligament, and the suspensory ligament of the eyeball. SYN: tuberculum orbitale ossis zygomatici [TA], eminentia orbitalis (ossis zygomatici), orbital eminence of zygomatic bone, Whitnall t..
- phallic t. SYN: genital t..
- pharyngeal t. (of basilar part of occipital bone) [TA] a projection from the undersurface of the basilar portion of the occipital bone, giving attachment to the fibrous raphe of the pharynx. SYN: tuberculum pharyngeum (partis basilaris ossis occipitalis) [TA].
- posterior t. of atlas [TA] a protuberance of the posterior extremity of the arch of the atlas, a rudiment of the spinous process giving attachment to the musculus rectus capitis posterior minor muscle. SYN: tuberculum posterius atlantis [TA].
- posterior t. of cervical vertebrae [TA] a posterior projection from the transverse processes. SYN: tuberculum posterius vertebrarum cervicalium [TA].
- Princeteau t. a slight prominence on the temporal bone near the apex of the petrous part where the superior petrosal sinus commences.
- pterygoid t. a slight prominence on the posterior surface of the medial pterygoid plate, inferior and to the medial side of the pterygoid canal.
- pubic t. [TA] a small palpable projection at the anterior extremity of the crest of the pubis about 2 cm from the symphysis; site of insertion of inguinal ligament. SYN: tuberculum pubicum [TA], pubic spine, spina pubis.
- t. of rib [TA] the knob on the posterior surface of a rib, at the junction of its neck and shaft, which articulates with the transverse process of the vertebra, whch corresponds in number to the rib, forming a costotransverse joint. SYN: tuberculum costae [TA].
- Rolando t. SYN: trigeminal t..
- t. of saddle SYN: tuberculum sellae.
- Santorini t. SYN: corniculate t..
- scalene t. [TA] a small spine on the inner edge of the first rib, giving attachment to the scalenus anterior muscle, lying between and thus demarcating the grooves for the subclavian artery (anteriorly) and vein (posteriorly). SYN: tuberculum musculi scaleni anterioris [TA], Lisfranc t., scalene t. of Lisfranc, t. of anterior scalene muscle.
- scalene t. of Lisfranc SYN: scalene t..
- t. of scaphoid (bone) [TA] a projection at the inferior lateral angle of the scaphoid bone; it can be felt at the root of the thumb; provides attachment for the transverse carpal ligament (flexor retinaculum). SYN: tuberculum ossis scaphoidei [TA].
- sinus t. SYN: Müller t..
- soft t. a t. showing caseous necrosis. SYN: caseous t..
- superior thyroid t. [TA] a blunt lateral projection on the external aspect lamina of the thyroid cartilage on either side at the superior end of the oblique line. SYN: tuberculum thyroideum superius [TA].
- supraglenoid t. (of scapula) [TA] a rough surface above the glenoid cavity of the scapula, giving attachment to the tendon of the long head of the biceps within the articular cavity of the shoulder joint. SYN: tuberculum supraglenoidale (scapulae) [TA].
- supratragic t. [TA] a small inconstant elevation often present on the edge of the upper tragus. SYN: tuberculum supratragicum [TA].
- t. of tooth SYN: dental t..
- t. of trapezium (bone) SYN: tuberculum of trapezium bone.
- trigeminal t. [TA] a longitudinal prominence on the dorsolateral surface of the medulla oblongata along the lateral border of the cuneate t.; it is the surface profile of the spinal tract of trigeminal nerve, continuous caudally with the dorsolateral fasciculus (Lissauer's tract). SYN: tuberculum trigeminale [TA], ashen t., gray t., Rolando t..
- t. of upper lip [TA] the slight projection on the free edge of the center of the upper lip at the lower extent of the philtrum. SYN: tuberculum labii superioris [TA], labial t., procheilon, prochilon.
- wedge-shaped t. SYN: cuneate t..
- Whitnall t. SYN: orbital t. (of zygomatic bone).
- Wrisberg t. SYN: cuneiform t..

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tu·ber·cle 't(y)ü-bər-kəl n
1) a small knobby prominence or excrescence: as
a) a prominence on the crown of a molar tooth
b) a small rough prominence (as the greater tubercle or adductor tubercle) on a bone usu. being smaller than a tuberosity and serving for the attachment of one or more muscles or ligaments
c) an eminence near the head of a rib that articulates with the transverse process of a vertebra
d) any of several prominences (as the acoustic tubercle) in the central nervous system that mark the nuclei of various nerves
2) a small discrete lump in the substance of an organ or in the skin esp the specific lesion of tuberculosis consisting of a packed mass of epithelioid cells, giant cells, disintegration products of white blood cells and bacilli, and usu. a necrotic center

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n.
1. (in anatomy) a small rounded protuberance on a bone.
2. the specific nodular lesion of tuberculosis.

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tu·ber·cle (tooґbər-kəl) 1. a nodule or small eminence; in official nomenclature called tuberculum [TA]. Similar structures may be called tubers or tuberosities. 2. the characteristic lesion of tuberculosis, a small round gray translucent granulomatous lesion, usually with central caseation; it is made up of modified macrophages called epithelioid cells, surrounded by a rim of mononuclear cells, principally lymphocytes, and sometimes a center of giant cells called Langhans giant cells.

For descriptions of specific anatomic structures not found here, see under tuberculum.


Medical dictionary. 2011.

Look at other dictionaries:

  • Tubercle — Tu ber*cle, n. [L. tuberculum, dim. of tuber: cf. F. tubercule, OF. also tubercle. See {Tuber}.] [1913 Webster] 1. A small knoblike prominence or excrescence, whether natural or morbid; as, a tubercle on a plant; a tubercle on a bone; the… …   The Collaborative International Dictionary of English

  • tubercle — (n.) 1570s, from L. tuberculum a small swelling, dim. of tuber lump (see TUBER (Cf. tuber)) …   Etymology dictionary

  • tubercle — ► NOUN 1) a small rounded projection or protuberance on a bone or on the surface of an animal or plant. 2) a small rounded swelling in the lungs or other tissues, characteristic of tuberculosis. ORIGIN Latin tuberculum small lump or swelling …   English terms dictionary

  • tubercle — [to͞o′bər kəl, tyo͞o′bər kəl] n. [L tuberculum, dim. of tuber: see TUBER] any small, rounded projection or process; specif., a) Bot. any of the wartlike growths on the roots of some plants b) Anat. a knoblike elevation, as on a bone c) Med. any… …   English World dictionary

  • Tubercle — A tubercle is generally a wart like projection, but it has slightly different meaning depending on which family of plants or animals it is used to refer to. In the case of certain orchids and cacti, it denotes a round nodule, small eminence, or… …   Wikipedia

  • tubercle — A small round firm swelling or nodule on the surface of carapace or limbs [Ingle, 1983]. Knoblike process; tip usually blunt [Butler, T.H.]. Low protuberance on exoskeleton [Hobbs and Jass, 1988]. (Class Ostracoda): Type of valve sculpture:… …   Crustacea glossary

  • tubercle — n. 1 a small rounded protuberance esp. on a bone. 2 a small rounded swelling on the body or in an organ, esp. a nodular lesion characteristic of tuberculosis in the lungs etc. 3 a small tuber; a wartlike growth. Phrases and idioms: tubercle… …   Useful english dictionary

  • tubercle — noun Etymology: Latin tuberculum, diminutive of tuber Date: 1578 1. a small knobby prominence or excrescence especially on a plant or animal ; nodule: as a. a protuberance near the head of a rib that articulates with the transverse process of a… …   New Collegiate Dictionary

  • tubercle — a small, usually hard protuberance or excrescence of the skin …   Dictionary of ichthyology

  • tubercle — n. [L. dim. tuber, hump] 1. A small knoblike or rounded protuberance; see torus. 2. (ARTHROPODA: Insecta) In Diptera, sometimes used for an elongate facial swelling …   Dictionary of invertebrate zoology

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