1. [TA] A channel for the passage of blood or lymph, without the coats of an ordinary vessel; e.g., blood passages in the gravid uterus or those in the cerebral meninges. 2. [TA] A cavity or hollow space in bone or other tissue. 3. [TA] A dilation in a blood vessel. 4. A fistula or tract leading to a suppurating cavity. [L. s., cavity, channel, hollow]
- s. alae parvae SYN: sphenoparietal s..
- anal sinuses [TA] 1. the grooves between the anal columns; SYN: Morgagni s. (1). 2. pockets or crypts in the columnar zone of the anal canal between the anocutaneous line and the anorectal line; the sinuses give the mucosa a scalloped appearance. SYN: s. anales [TA], anal crypts, Morgagni crypts, rectal sinuses.
- s. anales [TA] SYN: anal sinuses.
- s. aortae [TA] SYN: aortic s..
- aortic s. [TA] the space between the superior aspect of each cusp of the aortic valve and the dilated portion of the wall of the ascending aorta, immediately above each cusp. SYN: s. aortae [TA], Petit s., Valsalva s..
- Arlt s. an inconstant depression on the lower portion of the internal surface of the lacrimal sac.
- barber pilonidal s. pilonidal s. occurring in barbers, usually in the web between the fingers, due to the burying of exogenous hairs by the alternate loosening and tightening of tissues of the hand by the manipulation of scissors.
- Breschet s. SYN: sphenoparietal s..
- s. caroticus [TA] SYN: carotid s..
- carotid s. [TA] a slight dilation of the common carotid artery at its bifurcation into external and internal carotids; it contains baroreceptors that, when stimulated, cause slowing of the heart, vasodilation, and a fall in blood pressure and is innervated primarily by the glossopharyngeal nerve. SYN: s. caroticus [TA], carotid bulb.
- s. cavernosus [TA] SYN: cavernous s..
- cavernous s. [TA] a paired dural venous s. on either side of the sella turcica, the two being connected by anastomoses, the anterior intercavernosus s. (s. intercavernosus anterior [TA]) and posterior intercavernosus s. [TA] (s. intercavernosus posterior [TA]), in front of and behind the hypophysis, respectively, making thus the circular s.; the cavernous s. is unique among dural venous sinuses in being trabeculated; coursing within the s. are the internal carotid artery and the abducent nerve. SYN: s. cavernosus [TA].
- cervical s. in young mammalian embryos a depression in the nuchal region caudal to the hyoid arch, with the third and fourth branchial arches and ectodermal grooves in its floor; normally it is obliterated after the second month, but occasionally cervical fistulae persist as vestiges of it. SYN: precervical s..
- circular s. 1. dural venous formation that surrounds the hypophysis, composed of right and left cavernous sinuses and the intercavernous sinuses; SYN: circulus venosus ridleyi, Ridley circle. 2. a venous s. at the periphery of the placenta; 3. SYN: scleral venous s..
- s. coronarius [TA] SYN: coronary s..
- coronary s. [TA] a short trunk receiving most of the cardiac veins, beginning at the junction of the great cardiac vein and the oblique vein of the left atrium, running in the posterior part of the coronary sulcus and emptying into the right atrium between the inferior vena cava and the atrioventricular orifice. SYN: s. coronarius [TA].
- costomediastinal s. SYN: costomediastinal recess.
- dermal s. a s. lined with epidermis and skin appendages extending from the skin to some deeper-lying structure, most frequently the spinal cord.
- dural venous sinuses [TA] endothelium-lined venous channels in the dura mater. SYN: s. durae matris [TA], cerebral sinuses, cranial sinuses, sinuses of dura mater, venous sinuses.
- s. epididymidis [TA] SYN: s. of epididymis.
- s. of epididymis [TA] a narrow space between the body of the epididymis and the testis. SYN: s. epididymidis [TA].
- s. ethmoidales SYN: ethmoid cells, under cell.
- frontal s. [TA] a hollow paranasal s. formed on either side in the lower part of the squama of the frontal bone; it communicates by the ethmoidal infundibulum with the middle meatus of the nasal cavity of the same side. SYN: s. frontalis [TA].
- inferior petrosal s. [TA] a paired dural venous s. running in the groove on the petrooccipital fissure connecting the cavernous s. with the superior bulb of the internal jugular vein. SYN: s. petrosus inferior [TA], Englisch s..
- inferior sagittal s. [TA] an unpaired dural venous s. in the lower margin of the falx cerebri, running parallel to the superior sagittal s. and merging with the great cerebral vein to form the straight s.. SYN: s. sagittalis inferior [TA], inferior longitudinal s..
- intercavernous sinuses the anterior and posterior anastomoses between the cavernous sinuses, passing anterior and posterior to the hypophysis and forming, with the cavernous sinuses, the circular s.. SEE ALSO: cavernous s.. SYN: s. intercavernosi anterior et posterior [TA], Ridley s..
- jugular s., s. jugularis one of three enlargements of the jugular veins; the external jugular s. is between the two sets of valves; the internal jugular sinuses are at the origin (superior bulb) and near the termination (inferior bulb).
- s. lactiferi [TA] SYN: lactiferous s..
- lactiferous s. [TA] a circumscribed spindle-shaped dilation of the lactiferous duct just before it enters the nipple. In nursing mothers, this dilation stores a droplet of milk that is expressed by compression as the infant begins to suckle; this is thought to encourage continual suckling while the let-down reflex ensues. SYN: s. lactiferi [TA], ampulla lactifera, ampulla of lactiferous duct, ampulla of milk duct, lactiferous ampulla.
- s. laryngeus SYN: laryngeal ventricle.
- lateral s. SYN: transverse s..
- s. lienis SYN: splenic s..
- longitudinal vertebral venous s. large, plexiform veins forming portions of the anterior internal vertebral venous plexus lying on the posterior surfaces of the vertebral bodies on either side of the posterior longitudinal ligament. SYN: s. vertebrales longitudinales.
- lymphatic s. the channels in a lymph node crossed by a reticulum of cells and fibers and bounded by littoral cells; there are subcapsular, trabecular, and medullary sinuses. SYN: lymph s..
- Maier s. an infundibuliform depression on the internal surface of the lacrimal sac which receives the lacrimal canaliculi.
- s. maxillaris [TA] SYN: maxillary s..
- maxillary s. [TA] the largest of the paranasal sinuses occupying the body of the maxilla, communicating with the middle meatus of the nose. SYN: s. maxillaris [TA], antrum of Highmore, genyantrum, maxillary antrum.
- oblique pericardial s. [TA] the recess in the pericardial cavity posterior to the base of the heart bounded laterally by the pericardial reflections on the pulmonary veins and inferior vena cava, and posteriorly by the pericardium overlying the anterior aspect of the esophagus. SYN: s. obliquus pericardii [TA], oblique s. of pericardium.
- occipital s. [TA] an unpaired dural venous s. commencing at the confluence of the sinuses and passing downward in the base of the falx cerebelli to the foramen magnum. SYN: s. occipitalis [TA].
- s. occipitalis [TA] SYN: occipital s..
- Palfyn s. a space within the crista galli of the ethmoid described as communicating with the ethmoidal and frontal sinuses.
- paranasal sinuses [TA] the paired air-filled cavities in the bones of the face lined by mucous membrane continuous with that of the nasal cavity; these sinuses are the frontal, sphenoidal, maxillary, and ethmoidal. SYN: s. paranasales [TA].
- s. paranasales [TA] SYN: paranasal sinuses.
- phrenicocostal s. SYN: costodiaphragmatic recess.
- pilonidal s. a fistula or pit in the sacral region, communicating with the exterior, containing hair which may act as a foreign body producing chronic inflammation. SYN: pilonidal fistula.
- s. pocularis SYN: prostatic utricle.
- posterior s. of tympanic cavity [TA] a deep groove above the pyramidal eminence extending to the incudal fossa in the posterior wall of the tympanic cavity. SYN: s. posterior cavi tympani [TA].
- preauricular s. s. tract or pit in preauricular skin, resulting from developmental defect of the first and second branchial arches. SYN: preauricular pit.
- precervical s. SYN: cervical s..
- prostatic s. [TA] the groove on either side of the urethral crest in the prostatic part of the urethra into which the prostatic ducts open. SYN: s. prostaticus [TA].
- s. prostaticus [TA] SYN: prostatic s..
- s. of pulmonary trunk [TA] the space at the origin of the pulmonary trunk between the dilated wall of the vessel and each cusp of the pulmonic valve. SYN: s. trunci pulmonalis [TA], pulmonary sinuses.
- s. rectus [TA] SYN: straight s..
- renal s. [TA] the cavity of the kidney, containing the calices and pelvis of the ureter and the segmental vesels embedded within a fatty matrix. The renal sinuses cause the kidneys to appear hollow or C-shaped on cross section or medical imaging. SYN: s. renalis [TA].
- s. renalis [TA] SYN: renal s..
- s. reuniens obsolete term for s. venosus.
- rhomboidal s., s. rhomboidalis a dilation of the central canal of the spinal cord in the lumbar region. SYN: rhombocele.
- Ridley s. SYN: intercavernous sinuses.
- Rokitansky-Aschoff sinuses small outpocketings of the mucosa of the gallbladder which extend through the muscular layer; they may be congenital.
- scleral venous s. [TA] the vascular structure encircling the anterior chamber of the eye and through which the aqueous is returned to the blood circulation. SYN: s. venosus sclerae [TA], circular s. (3), Fontana canal, Lauth canal, Schlemm canal, s. circularis, venous s. of sclera.
- sigmoid s. [TA] the S-shaped dural venous s. lying deep to the mastoid process of the temporal bone and immediately posterior to the petrous temporal bone; it is continuous with the transverse s. and empties into the internal jugular vein as it passes through the jugular foramen. SYN: s. sigmoideus [TA].
- s. sigmoideus [TA] SYN: sigmoid s..
- sphenoidal s. [TA] one of a pair of paranasal sinuses in the body of the sphenoid bone communicating with the upper posterior nasal cavity or sphenoethmoidal recess. SYN: s. sphenoidalis [TA].
- s. sphenoidalis [TA] SYN: sphenoidal s..
- sphenoparietal s. [TA] a paired dural venous s. beginning on the parietal bone, running along the sphenoidal ridges and emptying into the cavernous s.. SYN: s. sphenoparietalis [TA], Breschet s., s. alae parvae.
- s. sphenoparietalis [TA] SYN: sphenoparietal s..
- straight s. [TA] an unpaired dural venous s. in the posterior part of the falx cerebri where it is attached to the tentorium cerebelli; it is formed anteriorly by the merging of the great cerebral vein with the inferior sagittal s., and passes horizontally and posteriorly to the confluence of sinuses. SYN: s. rectus [TA], tentorial s..
- superior petrosal s. [TA] a paired dural venous s. in the groove along the crest of the petrous temporal bone, connecting the cavernous s. with the termination of the transverse s. or beginning of the sigmoid s.. SYN: s. petrosus superior [TA].
- superior sagittal s. [TA] an unpaired dural venous s. in the sagittal groove, beginning at the foramen caecum and terminating at the confluence of sinuses where it merges with the straight s.; receives the superior cerebral veins and has lateral extensions, the lateral venous lacunae. SYN: s. sagittalis superior [TA], superior longitudinal s..
- tarsal s. [TA] a hollow or canal formed by the groove of the talus and the interosseous groove of the calcaneus that is occupied by the interosseous talocalcaneal ligament. SYN: s. tarsi [TA], tarsal canal.
- s. tarsi [TA] SYN: tarsal s..
- tentorial s. SYN: straight s..
- s. tonsillaris SYN: tonsillar fossa.
- Tourtual s. SYN: supratonsillar fossa.
- transverse s. [TA] a paired dural venous s. that drains the confluence of sinuses, running along the occipital attachment of the tentorium cerebelli and terminating in the sigmoid s.. SYN: s. transversus [TA], lateral s..
- transverse pericardial s. [TA] a passage in the pericardial sac between the origins of the great vessels, i.e., posterior to the intrapericardial portions of the pulmonary trunk and ascending aorta and anterior to the superior vena cava and superior to the atria; it is formed as a result of the flexure of the heart tube, partially approximating the great venous and arterial vessels. SYN: s. transversus pericardii [TA], Theile canal, transverse s. of pericardium.
- s. transversus [TA] SYN: transverse s..
- s. transversus pericardii [TA] SYN: transverse pericardial s..
- s. tympani [TA] SYN: tympanic s..
- tympanic s. [TA] a depression in the tympanic cavity posterior to the tympanic promontory. SYN: s. tympani [TA].
- urogenital s. 1. the ventral part of the cloaca after its separation from the rectum by the growth of the urorectal septum; from it develops the lower part of the bladder in both sexes, the prostatic portion of the male urethra, and the urethra and vestibule in the female; 2. SYN: persistent cloaca.
- s. urogenitalis SYN: persistent cloaca.
- uterine s. a small irregular vascular channel in the endometrium, of a type that forms during pregnancy. SYN: uterine sinusoid.
- uteroplacental sinuses irregular vascular spaces in the zone of the chorionic attachment to the decidua basalis.
- s. of the vena cava [TA] the portion of the cavity of the right atrium of the heart that receives the blood from the venae cavae; it is separated from the rest of the atrium by the crista terminalis. SYN: s. venarum cavarum [TA].
- s. venosus [TA] a cavity at the caudal end of the embryonic cardiac tube in which the veins from the intra- and extraembryonic circulatory arcs unite; in the course of development it forms the portion of the right atrium known in adult anatomy as the s. of the vena cava. SYN: saccus reuniens.
* * *
a) a narrow elongated tract extending from a focus of suppuration and serving for the discharge of pus <a tuberculous \sinus>
b ) (1) a cavity in the substance of a bone of the skull that usu. communicates with the nostrils and contains air (2) a channel for venous blood (3) a dilatation in a bodily canal or vessel
* * *
n.
1. an air cavity within a bone, especially any of the cavities within the bones of the face or skull (see paranasal sinuses).
2. any wide channel containing blood, usually venous blood. Venous sinuses occur, for example, in the dura mater and drain blood from the brain.
4. (sinus tract) an infected tract leading from a focus of infection to the surface of the skin or a hollow organ. See pilonidal sinus.
* * *
si·nus (siґnəs) pl. siґnus or sinuses [L. “a hollowâ€] 1. a cavity, channel, or space, such as a venous sinus or paranasal sinus. 2. an abnormal channel or fistula permitting the escape of pus.Descriptions are given on TA terms, and include anglicized names of specific sinuses.
Medical dictionary. 2011.