emissary vein

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Related to emissary vein: mastoid emissary vein


a vessel through which blood passes from various organs or parts back to the heart, in the systemic circulation carrying blood that has given up most of its oxygen. Veins, like arteries, have three coats: an inner coat (tunica intima), middle coat (tunica media), and outer coat (tunica externa); however, in veins these are less thick and collapse when the vessel is cut. Many veins, especially superficial ones, have valves formed of reduplication of their lining membrane. See Appendix 2-6 and see also Plates.
afferent v's veins that carry blood to an organ.
allantoic v's paired vessels that accompany the allantois, growing out from the primitive hindgut and entering the body stalk of the early embryo.
cardinal v's embryonic vessels that include the pre- and postcardinal veins and the ducts of Cuvier (common cardinal veins).
emissary vein one passing through a foramen of the skull and draining blood from a cerebral sinus into a vessel outside the skull. See anatomic Table of Veins in the Appendices.
postcardinal v's paired vessels in the early embryo that return blood from regions caudal to the heart.
precardinal v's paired venous trunks in the embryo cranial to the heart.
pulp v's vessels draining the venous sinuses of the spleen.
subcardinal v's paired vessels in the embryo, replacing the postcardinal veins and persisting to some degree as definitive vessels.
sublobular v's tributaries of the hepatic veins that receive the central veins of hepatic lobules.
supracardinal v's paired vessels in the embryo developing later than the subcardinal veins and persisting chiefly as the lower segment of the inferior vena cava.
thebesian v's smallest cardiac veins; see anatomic Table of Veins in the Appendices.
trabecular v's vessels coursing in splenic trabeculae, formed by tributary pulp veins.
varicose v's see varicose veins.
vitelline v's veins that return the blood from the yolk sac to the primitive heart of the early embryo.
Miller-Keane Encyclopedia and Dictionary of Medicine, Nursing, and Allied Health, Seventh Edition. © 2003 by Saunders, an imprint of Elsevier, Inc. All rights reserved.

em·is·sar·y vein

one of the channels of communication between the venous sinuses of the dura mater and the veins of the diploë and the scalp.
See also: condylar emissary vein, mastoid emissary vein, occipital emissary vein, parietal emissary vein.
Synonym(s): vena emissaria [TA], emissarium, emissary (2)
Farlex Partner Medical Dictionary © Farlex 2012

em·is·sa·ry vein

(em'i-sar-ē vān) [TA]
One of the channels of communication between the venous sinuses of the dura mater and the veins of the diploë and the scalp.
Synonym(s): emissary (2) .
Medical Dictionary for the Health Professions and Nursing © Farlex 2012

em·is·sa·ry vein

(em'i-sar-ē vān) [TA]
A communicating channel between venous sinuses of dura mater and veins of diploë and scalp.
Medical Dictionary for the Dental Professions © Farlex 2012
References in periodicals archive ?
Emissary veins apparently served double duty in the gracile-Homo lineage, says Falk, by helping to drain blood out of the cranium and by cooling the brain when vigorous exercise or heat exposure warnmed up blood flowing into cerebral tissue.
Cabanac and Brinnel placed the tips of ultrasonic probes on the heads of bald male volunteers at sites where emissary veins poke thorugh their tiny cranial conduits.
Since the few emissary veins with impressions remaining on fossil skulls link up to an extensive network of microscopic veins in the cranium, Cabanac and Brinnel's data support her theory that a venous "radiator" cools the human brain, Falk says.
Sustained exercise on the savanna helped to promote the evolution of brain-cooling emissary veins, as well as copious sweat glands in the face and scalp, dark skin and reduced body hair, she notes.
Septicemia and cavernous sinus involvement can develop by way of the emissary veins that drain the nasal septum.
Batson and Eckenhoff showed that there were multiple anastomoses and free connections between this venous plexus and the dural sinuses, the emissary veins of the skull as well as numerous junctions with the cervical plexus.
Cerebral veins are Emissary Veins which lack valves and they allow for BIDIRECTIONAL flow.
3D shaded surface display (Fig-6) and MIP images (Fig-7) showed the lesion was fed from both occipital and right superficial temporal arteries and was draining into scalp veins and dural sinuses through emissary veins.