Tunica: From 1 Different Sources
n. a covering or layer of an organ or part; for example, a layer of the wall of a blood vessel (see adventitia; intima; media). The tunica albuginea is a fibrous membrane comprising one of the covering tissues of the ovary, penis, and testis.
A circumscribed collection of fluid in the tunica vaginalis testis... hydrocele
The pouch of skin and ?brous tissue, positioned outside the abdomen behind the root of the PENIS, within which the testicles (see TESTICLE) are suspended. It consists of a purse-like fold of skin, within which each testicle has a separate investment of muscle ?bres, several layers of ?brous tissue, and a serous membrane known as the tunica vaginalis. The extra-abdominal site means that the production and storage of sperm (see SPERMATOZOON) in the testicles is at a lower temperature than internal body heat. Temperature control is facilitated by contraction and relaxation of the scrotal muscles.... scrotum
These are smooth, transparent membranes that line certain large cavities of the body. The chief serous membranes are the PERITONEUM, lining the cavity of the abdomen; the pleurae (see PLEURA), one of which lines each side of the chest, surrounding the corresponding lung; the PERICARDIUM, in which the heart lies; and the tunica vaginalis on each side, enclosing a testicle. The name of these membranes is derived from the fact that the surface is moistened by thin ?uid derived from the serum of blood or LYMPH. Every serous membrane consists of a visceral portion, which closely envelops the organs concerned, and a parietal portion, which adheres to the wall of the cavity. These two portions are continuous with one another so as to form a closed sac, and the opposing surfaces are close together, separated only by a little ?uid. This arrangement enables the organs in question to move freely within the cavities containing them. For further details, see under PERITONEUM.... serous membranes
(tunica adventitia) n. 1. the outer coat of the wall of a *vein or *artery. It consists of loose connective tissue and networks of small blood vessels, which nourish the walls. 2. the outer covering of various other organs or parts.... adventitia
n. a *prostaglandin drug (PGE1) administered to improve lung blood flow in newborn babies with congenital heart defects who are awaiting surgery; it acts by preventing the closure of the blood vessel connecting the aorta to the pulmonary artery (see ductus arteriosus). Possible side-effects include diminished respiratory efforts. Alprostadil is also administered to treat *erectile dysfunction in men; it acts by relaxing smooth muscle and dilating the cavernosal arteries, so that blood is trapped when the venules become compressed against the *tunica albuginea. Side-effects may include dizziness and headache.... alprostadil
n. a swelling caused by leakage of blood into a cavity, especially that of the tunica vaginalis, the membrane overlying the front and sides of the *testis. A pelvic haematocoele is a swelling near the uterus formed by the escape of blood, usually from a Fallopian tube in ectopic pregnancy.... haematocoele
(tunica intima) n. 1. the inner layer of the wall of an *artery or *vein. It is composed of a lining of endothelial cells and an elastic membrane. 2. the inner layer of various other organs or parts.... intima
(tunica media) n. 1. the middle layer of the wall of a *vein or *artery. It is the thickest of the three layers, being composed of elastic fibres and smooth muscle fibres in alternating layers. 2. the middle layer of various other organs or parts.... media
the traumatic rupture of the *tunica albuginea of the erect penis (the fibrous covering of the spongy tissue of the penis).... penile fracture
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