vein
(vān 
)
[L. vena, vein]
A vessel carrying blood toward the heart. Most veins originate in capillaries and drain into increasingly larger veins until their blood is delivered to the right atrium of the heart. Portal veins also originate in capillaries, but their branches decrease in size to pass through another set of capillaries before joining more typical veins on their way toward the heart. For all veins, the precursor veins that empty into a secondary vein are called tributaries of the secondary vein.
SEE: illus.; STRUCTURE OF A VEIN and VENULEcirculation; vena.
The deep veins typically accompany arteries, and artery and vein have the same name, e.g., radial artery and radial vein. In contrast, the superficial or subcutaneous veins typically travel alone. The deep and superficial veins have frequent interconnections, i.e., anastomoses; in general, veins have more anastomoses than do arteries. Throughout the body, the pattern of veins is more variable than is the pattern of arteries.
The walls of most veins have three layers: an endothelial lining, which folds at intervals into leaflets that act as one-way valves, a thin middle layer often containing smooth muscle, and a thin outer layer composed of fibrous connective tissue. In contrast, the veins of the brain have no valves, and the largest venous channels in the brain are not veins but rather endothelial-lined spaces in the dura mater called 'dural sinuses' or 'venous sinuses'; dural sinuses receive blood from cerebral veins and deliver blood to other dural sinuses or to the internal jugular vein.
accessory hemiazygos v.A vein that runs along the posterior wall of the superior aspect of the thorax to the left of the thoracic aorta, passes transversely over the vertebral column at the level of the seventh thoracic vertebra, and drains into the azygos vein. Its tributaries include the left superior intercostal veins and the left bronchial veins.
adrenal v.Either of two veins (right adrenal vein, left adrenal vein) in which blood from the adrenal gland s drains. The right adrenal vein empties into the inferior vena cava; the left, into the left renal vein.SYN: suprarenal vein.
angular v.A tributary of the facial vein, located on the sides of the nose with the angular artery.
anterior cardiac v.Any of the small veins found on the surface of the right ventricle of the heart and draining directly into the right atrium.
anterior facial v.Facial vein.
anterior jugular v.A vein of the neck, descending over the hyoid and infrahyoid muscles, turning laterally behind the sternal head of the sternocleidomastoid muscle, and emptying into the external jugular vein (or, sometimes, into the subclavian vein).
anterior tibial v.A vein that drains blood from the leg and foot and merges with the posterior tibial vein to form the popliteal vein in the popliteal fossa.
ascending lumbar v.A vein that runs along the posterior abdominal wall, connects the common iliac, iliolumbar, and lumbar veins, and empties into the subcostal, azygos, or hemiazygos vein.
axillary v.The continuation of the basilic vein in the upper arm. It accompanies the axillary artery and becomes the subclavian vein at the lateral border of the first rib. Its tributaries include the brachial, the cephalic, and the subscapular veins.
azygos v.A vein running along the back wall of the thorax on the right side of the thoracic aorta. At the level of the fourth thoracic vertebra, the azygos vein curves forward, over the top of the hilum (root) of the right lung, and empties its blood into the superior vena cava. The azygos vein receives blood from the back wall of the trunk via the hemiazygos, accessory azygos, right superior intercostal, right intercostal, mediastinal, pericardial, right subcostal, and right ascending lumbar veins. The patterns and interconnections of the azygos, hemiazygos, and accessory azygos veins are variable.
basal v.A vein that runs along the base of the brain from the cavernous sinus, around the cerebral peduncle, and into the vein of Galen. Its tributaries include the anterior cerebral, deep middle cerebral, and striate veins.
basilic v.A superficial vein running along the lateral side of the upper limb. It begins in the venous network on the dorsum of the hand , continues along the posteromedial side of the anterior forearm, and passes over the anterior aspect of the medial side of the elbow. In the antecubital fossa, it is joined by the median cubital vein. Approx. one third of the way along the medial surface of the arm, the basilic vein descends alongside the medial edge of the biceps brachii to run next to the brachial artery. When the brachial artery becomes the axillary artery, the basilic vein becomes the axillary vein. It is usually chosen for intravenous injection or for the withdrawal of blood.
brachial v.Either of a pair of veins accompanying the brachial artery into the upper arm (as venae comitantes) and emptying into the axillary vein.
brachiocephalic v.Either of two veins (left brachiocephalic vein, right brachiocephalic vein) formed by the merger of the subclavian and internal jugular veins in the root of the neck. The right brachiocephalic vein is about 2.5 cm long, the left about 6 cm long. The right and the left brachiocephalic veins join to form the superior vena cava. Their tributaries include the vertebral, internal mammary, and inferior thyroid veins. The left brachiocephalic vein also receives the left superior intercostal, thymic, and pericardial veins.
bronchial v.Any of two pairs of veins (right bronchial veins, left bronchial veins) that collect systemic blood from the bronchi and other lung tissues and return it to the systemic venous pool via the azygos vein on the right and the accessory hemiazygos vein on the left.
cardiac v.Any of the veins that run along the surface of the heart parallel to the coronary arteries, drain the heart muscle, and empty into the coronary sinus or the right atrium.
SEE: coronary artery for illus.
cardinal v.Any of the veins that with the umbilical veins and the vitelline veins form the three venous systems of the early embryo. The cardinal veins return blood to the heart from the body of the embryo. They are the precursors of the major thoracic veins, including the subclavian, brachiocephalic, azygos, internal jugular veins, and the superior vena cava.
central v.The vein that accompanies the central artery inside the optic nerve.
cephalic v.A superficial vein of the upper limb, formed from the dorsal venous network of the hand and running superiorly along the lateral aspect of the upper limb. It enters the deltopectoral triangle to empty into the axillary vein. Over the cubital fossa, the median cubital vein connects the cephalic and basilic veins. This connection is a common site for phlebotomy.
cerebellar v.Either of two veins (superior cerebellar vein, inferior cerebellar vein) that run along the surface of the cerebellum, drain blood from the cerebellum, and empty the blood into nearby dural sinuses.
cerebral v.Any of the veins draining the brain. Cerebral veins differ from veins outside the skull in that 1) cerebral veins do not run with cerebral arteries; 2) cerebral veins do not have valves; and 3) the walls of cerebral veins contain no muscle.
The venous circulation of the brain begins with venules that run from inside the brain to the surface where they run along the pia mater. Anastomosing venous plexuses collect in the pia to form the cerebral veins, which eventually cross the subarachnoid space and empty into dural sinuses. The dural sinuses interconnect and eventually empty into the internal jugular veins.
SEE: dural sinus.
choroidal v.The vein that follows and drains the choroid plexuses in the cerebral ventricles. It merges outside the ventricles with the thalamostriate vein to form the internal cerebral vein.
circumflex iliac nThe vein that accompanies the circumflex iliac artery, supplies blood to the anterior iliac crest, and empties into the external iliac vein. SYN: deep circumflex iliac vein.
common iliac v.The vein accompanying the common iliac artery. It is formed by the union of the external and internal iliac veins and ends by merging with the opposite common iliac vein to form the inferior vena cava. The right iliac vein is shorter than the left. Its tributaries include the iliolumbar, lateral sacral, and median sacral veins.
cranial venous sinus v.Any of the veins between the two layers of the dura mater that drain blood and reabsorbed cerebrospinal fluid from the brain and join the internal jugular vein.
cubital v.Median cubital vein.
deep circumflex iliac v.Circumflex iliac vein.
diploic v.Any of the valveless, thin-walled veins that drain the bones of the skull.
dorsal v. of the penis Either of two veins (superficial vein of the penis, deep dorsal vein of the penis), each of which is an unpaired (single) midline vein. The superficial dorsal vein empties into the external pudendal vein; the deep dorsal vein drains the erectile tissues and empties into the internal pudendal vein.
emissary v.Any of the variable small veins that run through foramina and other apertures in the skull. Emissary veins are valveless and allow the spread of microbes between the outside and inside of the skull.
SEE: inferior epigastric vein.
external iliac v.The continuation of the femoral vein proximal to the inguinal ligament. It accompanies the external iliac artery and joins the internal iliac vein to form the common iliac vein. Its tributaries include the inferior epigastric, deep circumflex iliac, and pubic veins.
external jugular v.A vein that drains blood from the scalp and face. It arises from the merger of the posterior facial and posterior auricular veins posterior to the angle of the mand ible. The external jugular vein runs superficially down the neck, crosses the sternocleidomastoid, and drains into the subclavian vein. Tributaries of the external jugular vein include the posterior external jugular, transverse cervical, suprascapular, and anterior jugular veins.
SEE: jugular vein.
facial v.A vein that runs at an angle, on each side of the face, from the bridge of the nose to halfway along the line of the jaw. The first tributaries of the facial vein include the supratrochlear, supraorbital, and superior ophthalmic veins. Other tributaries include the nasal, deep facial, inferior palpebral, superior and inferior labial, buccinator, parotid, and masseteric veins. Below the jaw and before emptying into the internal jugular vein, the facial vein receives blood from the submental, tonsillar, external palatine, and submand ibular veins. There are no valves in the facial vein, and blood can move backwards into veins with which it anastomoses (such as the ophthalmic veins that connect with the cavernous sinus inside the skull). Microbes from facial infections can use this route to reach intracranial veins.
femoral v.The vein that accompanies the femoral artery. The femoral vein is the continuation of the popliteal vein as it enters the adductor canal of the thigh. As it passes the inguinal ligament, the femoral vein becomes the external iliac vein. Its tributaries include the deep femoral (profunda femoris), the saphenous, and the lateral and medial circumflex femoral veins.
SEE: under Galen, Claudius.
gastric v.Any of three veins (left gastric vein, right gastric vein, short gastric vein). The left gastric vein drains much of the stomach and empties into the portal vein; its tributaries include the esophageal veins. The right gastric vein is a small vein that drains the pyloric region of the stomach and empties into the portal vein. The 4-5 short gastric veins drain part of the greater curvature of the stomach and empty into the splenic vein.
gastroepiploic v.Either of two veins (right gastroepiploic vein, left gastroepiploic vein) accompanying the gastroepiploic (gastro-omental)) arteries. The right gastroepiploic vein drains into the splenic vein; the left gastroepiploic vein, into the superior mesenteric vein.
great cardiac v.A large vein on the anterior surface of the heart. It runs in the anterior interventricular groove along the left anterior descending artery and drains the same area of the heart that is supplied by that artery. It also receives blood from the left marginal vein. The great cardiac vein follows the coronary sulcus to the left to empty into the coronary sinus on the posterior surface of the heart.
great cerebral v.Vein of Galen.
great saphenous v.Long saphenous vein.
greater saphenous v.Long saphenous vein.
hemiazygos v.A vein running along the back wall of the lower thorax on the left side of the thoracic aorta. At the level of the eighth thoracic vertebra, the hemiazygos vein bends to the right, runs behind the aorta, and empties into the azygos vein. Its tributaries include the left bronchial, left lower intercostal, left subcostal, and left ascending lumbar veins; there is often a caudal anastomosis with the left renal vein. The patterns and interconnections of the azygos, hemiazygos, and accessory azygos veins are variable.
hepatic v.Any of the veins that drain the liver sinusoids into the inferior vena cava on the posterior surface of the liver. Inside the liver, the central veins directly drain the sinusoids and then join into the interlobular veins, which merge to become the hepatic veins. All the venous blood that enters the liver from the portal vein and the hepatic artery leaves the liver through the hepatic veins.
inferior epigastric nThe vein that accompanies the inferior epigastric artery and empties into the external iliac vein.
inferior mesenteric nThe vein that accompanies the inferior mesenteric artery, drains the rectum and the sigmoid and descending colon, and empties into the splenic vein.
inferior phrenic nAny of the veins that accompany the inferior phrenic artery. On the right, they empty into the inferior vena cava; on the left, into the left suprarenal vein.
inferior striated v.One of the branches of the basal vein that drain the corpus striatum.
inferior thyroid nA vein draining the venous plexus of the thyroid gland , the trachea, the larynx, and the local esophagus and empties into the brachiocephalic vein or the superior vena cava.
innominate v.Brachiocephalic vein.
intercostal v.Any of the veins that accompany the intercostal arteries and drain blood from the walls of the chest. The upper intercostal vein empties into the ipsilateral brachiocephalic or vertebral vein. Intercostal veins 2-4 merge to form the superior intercostal vein, which drains into the azygos vein on the right and the accessory hemiazygos vein on the left. The lower intercostal veins drain directly into the azygos vein on the right and the hemiazygos vein on the left. SYN: posterior intercostal vein.
internal cerebral v.Either of two veins in each cerebral hemisphere, formed by the merger of the thalamostriate and choroid veins, and draining the deep regions of the hemisphere.
internal iliac v.The vein that accompanies the internal iliac artery and merges with the external iliac vein to form the common iliac vein. Its tributaries include the gluteal, internal pudendal, obturator, lateral sacral, anterior sacral, middle rectal, vesical, uterine, and vaginal veins.
internal jugular v.A large vein in the neck that drains the skull, brain, and parts of the face and neck. It originates in the jugular foramen at the base of the skull and descends vertically in the carotid sheath. At its base, the internal jugular vein merges with the subclavian vein behind the clavicle to form the brachiocephalic vein.
The internal jugular vein forms in the base of the skull by the merger of the inferior petrosal and sigmoid sinuses. As the vein descends through the neck, tributary veins include the facial, lingual, pharyngeal, superior thyroid, and middle thyroid veins.
The right internal jugular vein is often the blood vessel used for medical access to the central venous circulation and to the right side of the heart.
SEE: jugular vein.
internal mammary v.The vein accompanying the internal mammary (internal thoracic) artery. SYN: internal thoracic vein.
internal thoracic v.Internal mammary vein.
jugular v.Any of the two pairs of bilateral veins that return blood to the heart from the head and neck. The external jugular vein receives the blood from the exterior of the cranium and the deep parts of the face. It lies superficial to the sternocleidomastoid muscle as it passes down the neck to join the subclavian vein. The internal jugular vein receives blood from the brain and superficial parts of the face and neck. It is directly continuous with the transverse (sigmoid) sinus, accompanying the internal carotid artery as it passes down the neck, and joins with the subclavian vein to form the innominate vein. The jugular veins are more prominent during expiration than during inspiration and are also prominent during cardiac decompensation.
SEE: illus.
When the patient is sitting or in a semirecumbent position, the height of the jugular veins and their pulsations can provide an accurate estimation of central venous pressure and give important information about cardiac compensation.
SEE: Labbé vein.
lesser saphenous v.Short saphenous vein.
lingual v.Either of two veins (dorsal lingual vein, deep lingual vein) emptying into the internal jugular vein.
long saphenous v.The major superficial vein of the lower leg and the longest vein in the body. It begins in the venous plexus along the medial side of the foot and runs up the medial side of the leg and knee, alongside the saphenous nerve. In the thigh, the vein continues up the medial surface and accompanies the medial femoral cutaneous nerve. Before the long saphenous vein reaches the inguinal ligament, it slips under the deep fascia of the thigh through the saphenous opening and empties into the underlying femoral vein. Its tributaries include the posterior tibial, posteromedial thigh, anterolateral thigh, superficial epigastric, superficial circumflex iliac, and external pudendal veins. SYN: great saphenous vein; greater saphenous vein.
lumbar v.Any of the four veins on each side of the body that accompany the lumbar arteries, run transversely, and drain the posterior abdominal wall. The lumbar veins are connected with one another and with the epigastric veins and empty into the inferior vena cava or the azygos vein.
SEE: internal mammary vein.
maxillary v.A short vein that runs with the first segment of the maxillary artery. It is the merger of veins from the pterygoid venous plexus. It joins the superficial temporal vein to form the posterior facial vein.
median cubital v.A superficial vein running from lateral to medial across the cubital fossa to connect the cephalic vein with the basilic vein. This vein is a common site for phlebotomy.SYN: cubital vein.
median v. of the forearm A vein that begins in the palmar venous plexuses, runs up the forearm along the anterior (ventral) surface to the cubital fossa, where it joins the basilic vein or the median cubital vein.
meningeal v.Any of the veins draining the dura mater. Most meningeal veins empty into the superior sagittal sinus.
SEE: inferior mesenteric vein; superior mesenteric vein.
middle cardiac v.A vein that runs in the posterior interventricular sulcus of the heart. It accompanies the posterior interventricular artery and empties into the coronary sinus.
middle thyroid v.A vein that drains the lower part of the thyroid gland , the larynx, and the trachea and empties into the internal jugular vein.
oblique v.A slender vein that runs along the outer surface of the left atrium of the heart and drains into the coronary sinus. SYN: oblique vein of the left atrium.
oblique v. of the left atrium Oblique vein.
obturator v.The vein that accompanies the obturator artery and empties into the internal iliac vein.
occipital v.A vein formed by the merger of a network of veins along the posterior scalp into a single vein and running down the scalp and under the trapezius muscle. The occipital vein empties into some or all of the following veins: the deep cervical, the vertebral, and the posterior auricular.
ophthalmic v.Either of two veins (superior ophthalmic vein, inferior ophthalmic vein). The superior ophthalmic vein drains the upper portion of the orbit; the inferior ophthalmic vein drains the lower portion. Both veins empty into the cavernous sinus inside the skull. Both veins are valveless, anastomose with the facial vein, and connect the extracranial and intracranial venous systems.
ovarian v.Any of the veins accompanying the ovarian artery and draining the ovary and fallopian tube. Outside the broad ligament, the ovarian veins collect into two veins on each side of the body. These veins accompany the ovarian artery and merge into a single vein: the right ovarian vein then empties into the inferior cava, the left ovarian into the left renal vein.
pancreatic v.Any of the veins draining the body and tail of the pancreas and emptying into the splenic vein.
pancreaticoduodenal v.Either of two veins (superior pancreaticoduodenal vein, inferior pancreaticoduodenal vein) accompanying the pancreaticoduodenal arteries. Usually, the superior pancreaticoduodenal vein empties into the portal vein; the inferior pancreaticoduodenal vein, into the right gastroepiploic vein.
paraumbilical v.Any of the veins connecting the anterior abdominal wall with the portal vein. The paraumbilical veins begin in the region of the umbilicus and run in the ligamentum teres and the median umbilical ligament.
peripheral v.1Any readily accessible vein in an arm or a leg, used esp. in clinical medicine as a site of intravenous access.2Any vein not located in or immediately adjacent to the brain or the visceral organs of the abdomen, chest, or pelvis.
popliteal v.The vein that accompanies the popliteal artery. It is formed by the merger of the anterior and posterior tibial veins and ends by becoming the femoral vein at the distal opening of the adductor canal. The short saphenous vein is a major tributary of the popliteal vein.
portal v.The vein that brings most of the venous blood draining from the absorptive regions of the gastrointestinal tract to the liver. It originates as the merger of the superior mesenteric and splenic veins deep to the neck of the pancreas. It then passes under the duodenum and joins the common bile duct and the hepatic artery as they run inside the right edge of the lesser omentum, over the omental foramen, and into the liver via the porta hepatis. Tributaries of the portal vein include the left gastric, right gastric, paraumbilical, and cystic veins.
posterior facial v.A vein that begins as the merger of the superior temporal and the maxillary veins inside the parotid gland . The vein divides into two branches: an anterior branch that empties into the facial vein, and a posterior branch that joins the posterior auricular vein to form the external jugular vein. SYN: retromand ibular vein.
posterior intercostal v.Intercostal vein.
posterior tibial v.A deep vein in the lower limb that accompanies the posterior tibial artery and drains the region supplied by the artery. The vein merges with the anterior tibial vein to form the popliteal vein in the popliteal fossa behind the knee.
pudendal v.Any of the veins accompanying the external or the internal pudendal artery and emptying into the internal iliac vein.
pulmonary v.Any of the four valveless veins (two from each lung) that return newly oxygenated blood to the left atrium of the heart.
radial v.A vein that drains blood from the forearm and the hand and empties into the brachial vein.
rectal v.Any of the veins (inferior rectal vein, middle rectal vein, superior rectal vein) accompanying the inferior, middle, or superior rectal arteries. The rectal veins originate in a venous plexus that surrounds the rectum and anal canal and connects with the vesical (bladder) venous plexus in males and the vaginal venous plexus in females. The inferior rectal vein empties into the internal pudendal vein; the middle rectal vein empties into the internal iliac vein, and the superior rectal vein empties into the inferior mesenteric vein. The anastomoses in the rectal venous plexus allow back-pressure in the portal system to be transmitted through the inferior mesenteric and superior rectal veins to the inferior and middle rectal veins and into other systemic veins. SYN: hemorrhoidal vein.
renal v.Any of the large veins (left renal vein, right renal vein) that lie on top of (anterior to) the renal arteries, drain blood from the kidney, and empty into the inferior vena cava. The left renal vein is three times as long as the right renal vein so that it may pass over the aorta to the vena cava. Tributaries of the left renal vein include the left testicular vein or the ovarian vein and the left adrenal vein.
retromand ibular v.Posterior facial vein.
SEE: under Retzius, and ers Adolf.
right anterior cardinal v.The embryological blood vessel that gives rise to the superior vena cava in the human infant.
SEE: cardinal vein.
rolling v.A vein that moves to the side during blood collection, generally because it is not anchored properly during the procedure.
sacral v.Any of the veins that accompany the lateral or middle sacral arteries and empty into the internal iliac vein.
SEE: long saphenous vein; short saphenous vein.
short saphenous nA superficial leg vein that begins in the venous plexus that drains the lateral side of the foot. It ascends the lateral side of the calf. As the vein nears the knee, it runs in the midline between the heads of the gastrocnemius muscle and through the popliteal fossa and then empties into the popliteal vein approx. 5 cm above the knee joint.SYN: lesser saphenous vein; small saphenous vein.
small cardiac v.A surface vein of the heart that begins at the apex, runs along the right ventricle, follows the coronary sulcus to the right, and drains into the coronary sinus.
smallest cardiac v.Thebesian vein
small saphenous v.Short saphenous vein.
spermatic v.Any of the veins accompanying the testicular artery and draining the testis and epididymis. In the spermatic cord, the spermatic veins form the pampiniform plexus. After emerging from the deep inguinal ring, the spermatic veins merge into two veins, which continue to accompany the testicular artery. The two spermatic veins eventually merge into a single vein on each side. The right spermatic vein empties into the inferior cava (below the renal vein); the left spermatic vein, into the left renal vein. SYN: testicular vein.
splenic v.A large vein that drains the spleen and empties into the portal vein. Its tributaries include the short gastric, left gastroepiploic, and pancreatic veins.
stellate v.sStarlike venous plexuses on the surface of the kidney below its capsule. SYN: Verheyen stars.
subclavian v.A large vein draining the arm and shoulder. It is the continuation of the axillary vein, beginning at the outer border of the first rib. The thoracic duct empties into the left subclavian vein; the right lymphatic duct empties into the right subclavian vein. The subclavian vein ends by merging with the internal jugular vein to form the brachiocephalic vein. Its tributaries include the external jugular, dorsal scapular, and anterior jugular veins.
superficial temporal v.A vein formed by a network of veins that anastomose across the scalp and collect into a common vein. This vein then merges with the maxillary vein, inside the parotid gland , to form the posterior facial vein.
superior mesenteric v.The vein that accompanies the superior mesenteric artery and drains the small intestine, cecum, ascending colon, and transverse colon. Under the neck of the pancreas, this vein joins the splenic vein to form the portal vein. Its tributaries include the jejunal, ileal, ileocolic, right and middle colic veins, right gastroepiploic, and pancreaticoduodenal veins.
superior thyroid v.The vein that accompanies the superior thyroid artery and empties into the internal jugular vein (or, occasionally, the facial vein). Its tributaries include the superior laryngeal and cricothyroid veins.
systemic v.A vein that carries deoxygenated blood and is not a vein of the portal system or a pulmonary vein.
thalamostriate v.The major vein draining the caudate nucleus and the thalamus of the brain. It merges with the choroid vein to form the internal cerebral vein.
thebesian v.Any of the venules conveying blood from the myocardium to the atria or ventricles. SYN: smallest cardiac vein.
SEE: inferior thyroid vein; middle thyroid vein; superior thyroid vein.
SEE: anterior tibial vein; posterior tibial vein.
ulnar v.A vein that drains blood from the forearm and the hand and empties into the brachial vein.
umbilical v.Either of the two veins (right umbilical vein, left umbilical vein) that with the cardinal veins and the vitelline veins form the three venous systems of the early embryo. The umbilical vein passes oxygenated blood from outside the embryo to the embryonic heart. In the fetus, deoxygenated blood is carried to the placenta from the internal iliac arteries via the right and left umbilical arteries. Oxygenated blood from the placenta is returned to the fetus in the umbilical vein, which empties into the ductus venosus. The umbilical vein and the umbilical arteries are the main contents of the umbilical cord.
varicose v.A dilated vein. The dilation may occur in almost any part of the body but is most common in the lower extremities and in the esophagus.
The development of varicose veins of the legs is promoted and aggravated by pregnancy, obesity, genetics, chronic constipation, straining at stool, and occupations requiring prolonged stand ing. Esophageal varices are caused by portal hypertension that accompanies cirrhosis or by mechanical obstruction and occlusion of hepatic veins.
Esophageal varices and hemorrhoidal varices may bleed profusely. Most varicose veins of the legs are asymptomatic but also may be cosmetically undesirable.
SEE: illus.
In hemorrhage from esophageal varices, elevation of the extremity and firm, gentle pressure over the wound will stop the bleeding. The patient should not be permitted to walk until the acute condition is controlled. Sclerotherapy, rubber band ligation, or octreotide may be used to control bleeding.
The patient with lower extremity varicosities is taught to avoid anything that impedes venous return, such as wearing garters and tight girdles, crossing the legs at the knees, and prolonged sitting. After the legs have been elevated for 10 to 15 min, support hose is applied. The patient should not sit in a chair for longer than 1 hr at a time. Walking is encouraged for at least 5 min every hour. The patient should elevate the legs whenever possible, but no less than twice a day for 30 min each time, and should avoid prolonged stand ing. Exercise, esp. walking, is encouraged to promote the muscular contraction that moves blood through the veins and minimizes venous stasis. Signs of thrombophlebitis, a complication of varicose veins, include heat and local pain. If surgery is performed, elastic stockings or antithrombotic devices are applied postoperatively, and the foot of the bed is elevated above the level of the heart. Analgesics are prescribed and administered as needed. Circulatory assessment (color and temperature of toes, pedal pulses) is carried out according to protocol or the surgeon’s orders. The patient is watched for complications such as bleeding, infection, and neurosensory problems. Overweight patients must lose weight.
vertebral v.A vein that drains the venous plexus surrounding each vertebral artery. It leaves the sixth cervical transverse foramen and empties into the brachiocephalic vein.
SEE: under Vesalius, and reas.
vitelline v.Any of veins that with the cardinal veins and the umbilical veins form the three venous systems of the early embryo. The vitelline veins return blood from the yolk sac, are the precursors of many of the veins of the gut (including the portal system), and are focal structures in the developing liver.
vorticose v.Any of two pairs of veins (superior vorticose veins, inferior vorticose veins) that receive blood from all parts of the choroid of the eye and empty into the superior ophthalmic vein.