| fibrous sheaths | See: fibrous tendon sheath, fibrous digital sheaths of hand, fibrous digital sheaths of foot. (05 Mar 2000) |
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| fibrous skeleton of heart | A complex framework of dense collagen forming four fibrous rings (annuli fibrosi), which surround the ostia of the valves, a right and left fibrous trigone, formed by connecting the rings, and the membranous portions of the interatrial and interventricular septa; it is found in association with the base of the ventricles, i.e., at the level of the coronary sulcus; its functions include: 1) contributing reinforcement of the valvular ostia while providing attachment for the leaflets and cusps of the valves; 2) providing origin and insertion for the myocardium; and 3) serving as a sort of electrical "insulator," separating the electrically conducted impulses of the atria and ventricles and providing passage for the common atrioventricular bundle of conductive tissue through the right fibrous trigone and membranous interventricular septum. Synonym: cardiac fibrous skeleton, cardiac skeleton, skeleton of heart. (05 Mar 2000) |
| fibrous tissue | Although most connective tissue has fibrillar elements, the term usually refers to tissue laid down at a wound site well vascularised at first (granulation tissue) but later avascular and dominated by collagen rich extracellular matrix, forming a scar. Excessive contraction and hyperplasia leads to formation of a keloid. (18 Nov 1997) |
| fibrous trigones of heart | See: right fibrous trigone, left fibrous trigone. (05 Mar 2000) |
| fibrous tubercle | A tubercle 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 tubercle. (05 Mar 2000) |
| fibrous tunic of corpus spongiosum | <anatomy> The thick layer of fibrous tissue surrounding the corpus spongiosum penis. It is thinner than the corresponding layer around each corpus cavernosum. Synonym: tunica albuginea corporis spongiosi, fibrous tunic of corpus spongiosum. (05 Mar 2000) |
| fibrous tunic of eye | The outer layer of the eyeball composed of the sclera and cornea. Synonym: tunica fibrosa bulbi, tunica externa oculi. (05 Mar 2000) |
| fibrous union | Union of fracture by fibrous tissue. See: nonunion. Synonym: faulty union. (05 Mar 2000) |
| fibrous xanthoma | <tumour> A fibrohistiocytic neoplasm. (05 Mar 2000) |
| left fibrous trigone | The part of the fibrous skeleton of the heart located in the interval between the left side of the left atrioventricular ring and the aortic ring. Synonym: trigonum fibrosum sinistrum. (05 Mar 2000) |
| anterior layer of rectus abdominis sheath | The portion of the rectus sheath that lies anterior to the muscle, consisting in its upper two-thirds of contributions from the aponeuroses of the external and internal oblique muscles, and in its lower third (below the arcuralt line) of contributions from the aponeuroses of all three muscles of the anterolateral abdominal wall. Synonym: lamina anterior vaginae musculi recti abdominis. (05 Mar 2000) |
| arcuate line of rectus sheath | A crescentic line, not always clearly defined, which marks the lower limit of the posterior layer of the sheath of the rectus abdominis muscle. Synonym: linea arcuata vaginae musculi recti abdominis, Douglas' line, linea saemicircularis, saemicircular line. (05 Mar 2000) |
| axillary sheath | Fibrous neurovascular sheath, formed as an extension of the prevertebral layer of deep cervical fascia through the cervicoaxillary canal, which enclosed the first part of the axillary artery, the axillary vein, and the brachial plexus. (05 Mar 2000) |
| carotid sheath | The dense fibrous investment of the carotid artery, internal jugular vein, and vagus nerve on each side of the neck, deep to the sternocleidomastoid muscle; the layers of cervical fascia blend with it. Synonym: vagina carotica. (05 Mar 2000) |
| rectus sheath | Sheath of the rectus abdominis, formed by the aponeuroses of the three anterolateral muscles of the abdominal wall that split to enclose the rectus and fuse medially to form the linea alba; it consists of an anterior lamina and a posterior lamina, the latter being absent below the arcuate line. See: aponeurosis of external abdominal oblique muscle, aponeurosis of internal abdominal oblique muscle. Synonym: vagina musculi recti abdominis. (05 Mar 2000) |