- Septum
- A word borrowed from the Latin "saeptum" meaning a "dividing wall or enclosure."
* * *1. [TA] A thin wall dividing two cavities or masses of softer tissue. See septal area, transparent s.. 2. In fungi, a wall; usually a cross-wall in a hypha. [L. saeptum, a partition]- alveolar s. SYN: interalveolar s..- anteromedial intermuscular s. [TA] dense fascial triangle extending from the inferior medial border of the adductor magnus muscle to the vastus medialis muscle. Along with the sartorius muscle, this dense fascia forms the roof of the lower half of the adductor canal and, as the femoral vessels pass deep to it, is often mistaken for the adductor hiatus. SYN: s. intermusculare vastoadductorium [TA], subsartorial fascia, vastoadductor fascia.- aortopulmonary s. the spiral s. which, during development, separates the truncus arteriosus into a ventral pulmonary trunk and dorsal aorta. SEE ALSO: bulbar ridge.- atrioventricular s. [TA] the small part of the membranous s. of the heart just above the septal cusp of the tricuspid valve that separates the right atrium from the left ventricle. SYN: s. atrioventriculare [TA].- s. atrioventriculare [TA] SYN: atrioventricular s..- Bigelow s. SYN: calcar femorale.- bony nasal s. [TA] the bones supporting the bony part of the nasal s.; these are the perpendicular plate of the ethmoid, the vomer, the sphenoidal rostrum, the crest of the nasal bones, the frontal spine, and the median crest formed by the apposition of the maxillary and palatine bones. SYN: s. nasi osseum [TA].- s. bulbi urethrae a fibrous s. in the interior of the bulb of the penis which divides it into two hemispheres.- s. cervicale intermedium [TA] SYN: intermediate cervical s..- comblike s. SYN: pectiniform s..- s. of corpora cavernosa of clitoris [TA] an incomplete fibrous s. between the corpora cavernosa of the clitoris. SYN: s. corporum cavernosorum clitoridis [TA], s. clitoridis.- endovenous s., s. endovenosum a remnant of the primitive separation between veins that fused to form a definitive trunk, such as the trunk leading to the left common iliac and the left renal veins.- femoral s. [TA] mass of connective tissue that occupies the femoral canal, effectively closing the canal but permitting the passage of lymphatics draining the lower limb. SYN: s. femorale [TA], Cloquet s., crural s..- s. femorale [TA] SYN: femoral s..- s. of frontal sinuses [TA] the bony partition between the right and left frontal sinuses; it is often deflected to one side of the middle line. SYN: s. sinuum frontalium [TA].- s. of glans penis [TA] a fibrous partition extending through the glans penis from the lower surface of the tunica albuginea to the urethra. SYN: s. glandis [TA].- hanging s. the deformity caused by an abnormal width of the septal portion of the alar cartilages.- interalveolar s. [TA] 1. the tissue intervening between two adjacent pulmonary alveoli; it consists of a close-meshed capillary network covered on both surfaces by very thin alveolar epithelial cells; 2. one of the bony partitions between the tooth sockets of the mandible and maxilla (septa interalveolare mandibulae et maxillae). SYN: s. interalveolare [TA], alveolar s., septal bone.- s. interalveolare, pl.septa interalveolaria [TA] SYN: interalveolar s..- interatrial s. [TA] the wall between the atria of the heart. SEE ALSO: s. primum, s. secundum. SYN: s. interatriale [TA].- s. interatriale [TA] SYN: interatrial s..- interlobular s. the connective tissue between secondary pulmonary lobules, usually containing a vein and lymphatics; seen radiographically when thickened as a Kerley B or septal line.- intermediate cervical s. [TA] a thin s. composed of glia fiber and leptomeningeal connective tissue in the cervical spinal cord marking the border between the gracile fasciculi and cuneatus of the dorsal funiculus. SYN: s. cervicale intermedium [TA].- s. intermedium old term for the s. of the atrioventricular canal of the embryonic heart formed by the fusion of the dorsal and ventral atrioventricular canal cushions.- intermuscular s. [TA] a term applied to aponeurotic sheets separating various muscles of the limbs; these are anterior and posterior crural intermuscular septa of leg (septa intermuscularis cruris anterius et posterius), lateral and medial femoral intermuscular septa (septa intermuscularis femoris laterale et mediale), lateral and medial intermuscular septa of arm (septa intermuscularis brachii laterale et mediale). SYN: s. intermusculare [TA].- s. intermusculare [TA] SYN: intermuscular s..- s. intermusculare vastoadductorium [TA] SYN: anteromedial intermuscular s..- interpulmonary s. SYN: mediastinum (2).- septa interradicularia mandi′bulae et ma′xillae [TA] SYN: interradicular septa of maxilla and mandible.- interradicular septa of maxilla and mandible [TA] the bony partitions that project into the alveoli between the roots of the molar teeth. SYN: septa interradicularia mandi′bulae et ma′xillae [TA], intra- alveolar septa.- interventricular s. [TA] the wall between the ventricles of the heart. SYN: s. interventriculare [TA], ventricular s..- s. interventriculare [TA] SYN: interventricular s..- s. linguae [TA] SYN: lingual s..- lingual s. [TA] the median vertical fibrous partition of the tongue merging posteriorly into the aponeurosis of the tongue. SYN: s. linguae [TA], s. of tongue.- s. lucidum SYN: s. pellucidum.- s. mediastinale SYN: mediastinum (2).- s. membranaceum ventriculorum SYN: membranous part of interventricular s..- membranous s. 1. SYN: membranous part of nasal s.. 2. SYN: membranous part of interventricular s..- s. mobile nasi SYN: mobile part of nasal s..- s. musculare ventriculorum SYN: muscular part of interventricular s. (of heart).- nasal s. [TA] the wall dividing the nasal cavity into halves; it is composed of a central supporting skeleton covered on each side by a mucous membrane. SYN: s. nasi [TA].- s. nasi [TA] SYN: nasal s..- s. nasi osseum [TA] SYN: bony nasal s..- orbital s. [TA] a fibrous membrane attached to the margin of the orbit and extending into the lids, containing the orbital fat and constituting in great part the posterior fascia of the orbicularis oculi muscle. SYN: s. orbitale [TA].- pectiniform s., s. pectiniforme the anterior portion of the s. penis which is broken by a number of slitlike perforations. SYN: comblike s..- s. pellucidum [TA] a thin plate of brain tissue, containing nerve cells and numerous nerve fibers, that is stretched like a flat, vertical sheet between the column and body of fornix below, and the corpus callosum above and anteriorly; it is usually fused in the median plane with its partner on the opposite side so as to form a thin, median partition between the left and right frontal horn of the lateral ventricles; in less than 10% of humans there is a blind, slitlike, fluid-filled space between the two transparent septa, the cavity of s. pellucidum. The transparent s. is continuous ventralward through the interval between the corpus callosum and the anterior commissure with the precommissural s. and subcallosal gyrus. SEE ALSO: cavity of s. pellucidum, septal area. SYN: s. lucidum, transparent s..- s. penis [TA] the portion of the tunica albuginea incompletely separating the two corpora cavernosa of the penis.- s. of pharyngotympanic (auditory) tube [TA] a very thin horizontal plate of bone forming two semicanals, the upper, smaller, for the tensor tympani muscle, and the lower, larger for the pharyngotympanic (auditory) tube; its termination in the middle ear is the processus cochleariformis. SYN: s. canalis musculotubarii, s. of musculotubal canal, s. tubae.- placental septa incomplete partitions between placental cotyledons; they are covered with trophoblast and contain a core of maternal tissue.- precommissural s. septal area.- s. primum a crescentic s. in the embryonic heart that develops on the dorsocephalic wall of the originally single atrium and initiates its partitioning into right and left chambers; the tips of the s. grow toward and fuse with the atrioventricular canal cushions.- rectovaginal s. [TA] the fascial layer between the vagina and the lower part of the rectum. SYN: s. rectovaginale [TA].- s. rectovaginale [TA] SYN: rectovaginal s..- rectovesical s. [TA] a fascial layer that extends superiorly from the central tendon of the perineum to the peritoneum between the prostate and rectum. SYN: s. rectovesicale [TA], Denonvilliers aponeurosis, rectovesical fascia, Tyrrell fascia.- s. rectovesicale [TA] SYN: rectovesical s..- scrotal s. [TA] an incomplete wall of connective tissue and nonstriated muscle (dartos fascia) dividing the scrotum into two sacs, each containing a testis. SYN: s. scroti [TA].- s. scroti [TA] SYN: scrotal s..- s. secundum the second of two major septal structures involved in the partitioning of the atrium, developing later than the s. primum and located to the right of it; like the s. primum, it is crescentic, but its tips are directed toward the sinus venosus, and it is more heavily muscular; it remains an incomplete partition until after birth, with its unclosed area constituting the foramen ovale.- sinus s. a small fold forming the medial end of the valve of the inferior vena cava; it is developed from the dorsal wall of the embryonic sinus venosus.- s. sinuum sphenoidalium [TA] SYN: s. of sphenoidal sinuses.- s. of sphenoidal sinuses [TA] the bony partition between the two sphenoidal sinuses, often deflected to one side of the midline. SYN: s. sinuum sphenoidalium [TA].- spiral s. a s. dividing the embryonic bulbus cordis into pulmonary and aortic outflow tracts from the developing heart; the distal spiral s. is derived from the right and left endocardial cushions and so separates the pulmonary and aortic orifices; the proximal spiral s. is the portion of the s. that is incorporated into the membranous part of the interventricular s..- s. spurium a s. in the right atrium of the embryonic heart formed by the right venous valve and its continuation onto the dorsocephalic wall of the atrium; in human embryos, it reaches its fullest development during the third month and then undergoes regression, taking no part in atrial partitioning (hence its designation as false); reduced portions persist as the valve of the inferior vena cava and the valve of the coronary sinus.- transparent s. SYN: s. pellucidum.- transverse s. 1. SYN: ampullary crest. 2. the mesodermal mass separating the pericardial and peritoneal cavities; it is covered with mesothelium except where intimately associated with the liver, which originally develops within it; the s. is definitively incorporated into the diaphragm as the central tendon.- urogenital s. the coronally placed ridge formed by the caudal portion of the urogenital ridges meeting in the midline of the embryo; it lies between the hindgut dorsally and the bladder ventrally.- urorectal s. in embryos, a partition dividing the cloaca into a dorsal, rectal portion and a ventral portion called the urogenital sinus; reaching the cloacal membrane at about the time of its disintegration, the urorectal s. divides the cloacal exit into an anal and a urogenital orifice. SYN: urorectal fold.- ventricular s. SYN: interventricular s..
* * *
sep·tum 'sep-təm n, pl sep·ta -tə a dividing wall or membrane esp. between bodily spaces or masses of soft tissue: asa) NASAL SEPTUMb) CRURAL SEPTUM* * *
n. (pl. septa)a partition or dividing wall within an anatomical structure. For example, the atrioventricular septum divides the atria of the heart from the ventricles.• septal adj.• septate adj.* * *
sep·tum (sepґtəm) gen. sepґti pl. sepґta [L. saeptum past part. of saepire to fence or wall off] 1. a dividing wall or partition. 2. septal area. 3. s. pellucidum.Descriptions are given on TA terms and include anglicized names of specific anatomic structures.
Medical dictionary. 2011.
