WordNet

make a veinlike pattern
any of the vascular bundles or ribs that form the branching framework of conducting and supporting tissues in a leaf or other plant organ (同)nervure
one of the horny ribs that stiffen and support the wing of an insect (同)nervure
a layer of ore between layers of rock (同)mineral vein
a blood vessel that carries blood from the capillaries toward the heart; "all veins except the pulmonary vein carry unaerated blood" (同)vena, venous blood vessel
a distinctive style or manner; "he continued in this vein for several minutes"
a craft designed for water transportation (同)watercraft
an object used as a container (especially for liquids)
a tube in which a body fluid circulates (同)vas
of or relating to or having vessels that conduct and circulate fluids; "vascular constriction"; "a vascular bundle"
of or contained in or performing the function of the veins; "venous inflammation"; "venous blood as contrasted with arterial blood"; "venous circulation"
having or showing markings that resemble veins (同)venose, veinlike

PrepTutorEJDIC

〈C〉『静脈』 / 〈C〉(植物の)葉脈;(昆虫の)翅脈;(石の)石理;(木の)木目 / 〈C〉岩脈,鉱脈 / 〈U〉《しばしば a vein》(…の)傾向,性質《+of+名》 / 〈U〉《the vein》(…に対する)気分,気持ち《+for+名(doing)》
(比較的大型の)『船』 / (特に液体を入れる)容器,器 / (動植物の)『管』,導管,脈管
(血液・樹液などを運ぶ)管の,導管の,血管の
静脈[血]の / 葉脈の多い
しも(筋)のある,筋のついた
(葉・昆虫の羽などの)脈模様,すじ

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/02/09 15:39:32」(JST)

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[Wiki en表示]

For other uses, see Vein (disambiguation).

In the circulatory system, veins (from the Latin vena) are blood vessels that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. Veins differ from arteries in structure and function; for example, arteries are more muscular than veins, veins are often closer to the skin and contain valves to help keep blood flowing toward the heart, while arteries carry blood away from the heart.

1 Anatomy
- 1.1 Notable veins and vein systems
- 1.2 Color
2 Function
3 Classification
4 Clinical significance
- 4.1 Phlebology
- 4.2 Venous diseases
  - 4.2.1 Venous insufficiency
  - 4.2.2 Deep vein thrombosis
  - 4.2.3 Thrombophlebitis
5 See also
6 References
7 External links
- 7.1 Scientific publications

Anatomy

Cross section of a vein showing a valve that prevents backflow

In general, veins function to return deoxygenated blood to the heart, and are essentially tubes that collapse when their lumens are not filled with blood. The thick outermost layer of a vein is made of connective tissue, called tunica adventitia or tunica externa. Deeper are bands of smooth muscle called tunica media, which are, in general, thin, as veins do not function primarily in a contractile manner. The interior is lined with endothelial cells called tunica intima. The precise location of veins is much more variable from person to person than that of arteries.^[1] Veins often display a lot of anatomical variation compared with arteries within a species and between species.

Notable veins and vein systems

The great saphenous vein is the most important superficial vein of the lower limb. First described by the Persian physician Avicenna, this vein derives its name from the word safina, meaning "hidden". This vein is "hidden" in its own fascial compartment in the thigh and exits the fascia only near the knee. Incompetence of this vein is an important cause of varicose veins of lower limbs.

The pulmonary veins carry relatively oxygenated blood from the lungs to the heart. The superior and inferior venae cavae carry relatively deoxygenated blood from the upper and lower systemic circulations, respectively.

A portal venous system is a series of veins or venules that directly connect two capillary beds. Examples of such systems include the hepatic portal vein and hypophyseal portal system

The Thebesian veins within the myocardium of the heart are valveless veins that drain directly into the chambers of the heart. The coronary veins all empty into the coronary sinus which empties into the right atrium.

The Dural sinuses within the dura mater surrounding the brain receive blood from the brain and also are a point of entry of cerebrospinal fluid from arachnoid villi absorption. Blood eventually enters the internal jugular vein.

Color

Vein color is determined in large part by the color of venous blood, which is usually dark red (and not blue as is commonly believed) as a result of its low oxygen content. Veins appear blue because the subcutaneous fat absorbs low-frequency light, permitting only the highly energetic blue wavelengths to penetrate through to the dark vein and reflect back to the viewer. A recent study found the color of blood vessels is determined by the following factors: the scattering and absorption characteristics of skin at different wavelengths, the oxygenation state of blood, which affects its absorption properties, the diameter and the depth of the vessels, and the visual perception process.^[2]

Function

Veins serve to return blood from organs to the heart. Veins are also called "capacitance vessels" because most of the blood volume (60%) is contained within veins. In systemic circulation oxygenated blood is pumped by the left ventricle through the arteries to the muscles and organs of the body, where its nutrients and gases are exchanged at capillaries, the blood then enter venules, then veins filled with cellular waste and carbon dioxide. The de-oxygenated blood is taken by veins to the right atrium of the heart, which transfers the blood to the right ventricle, where it is then pumped through the pulmonary arteries to the lungs. In pulmonary circulation the pulmonary veins return oxygenated blood from the lungs to the left atrium, which empties into the left ventricle, completing the cycle of blood circulation.

The return of blood to the heart is assisted by the action of the skeletal-muscle pump, and by the thoracic pump action of breathing during respiration. Standing or sitting for a prolonged period of time can cause low venous return from venous pooling (vascular) shock. Fainting can occur but usually baroreceptors within the aortic sinuses initiate a baroreflex such angiotensin II and norepinephrine stimulate vasoconstriction and heart rate increases to return blood flow. Neurogenic and hypovolaemic shock can also cause fainting. In these cases, the smooth muscles surrounding the veins become slack and the veins fill with the majority of the blood in the body, keeping blood away from the brain and causing unconsciousness. Jet pilots wear pressurized suits to help maintain their venous return and blood pressure.

The arteries are perceived as carrying oxygenated blood to the tissues, while veins carry deoxygenated blood back to the heart. This is true of the systemic circulation, by far the larger of the two circuits of blood in the body, which transports oxygen from the heart to the tissues of the body. However, in pulmonary circulation, the arteries carry deoxygenated blood from the heart to the lungs, and veins return blood from the lungs to the heart. The difference between veins and arteries is their direction of flow (out of the heart by arteries, returning to the heart for veins), not their oxygen content. In addition, deoxygenated blood that is carried from the tissues back to the heart for reoxygenation in systemic circulation still carries some oxygen, though it is considerably less than that carried by the systemic arteries or pulmonary veins.

Although most veins take blood back to the heart, there is an exception. Portal veins carry blood between capillary beds. For example, the hepatic portal vein takes blood from the capillary beds in the digestive tract and transports it to the capillary beds in the liver. The blood is then drained in the gastrointestinal tract and spleen, where it is taken up by the hepatic veins, and blood is taken back into the heart. Since this is an important function in mammals, damage to the hepatic portal vein can be dangerous. Blood clotting in the hepatic portal vein can cause portal hypertension, which results in a decrease of blood fluid to the liver.

Also transports proteins and other materials throughout the body.

Classification

Image of veins from William Harvey's De Motu Cordis et Sanguinis, 1628

Veins are classified in a number of ways, including superficial vs. deep, pulmonary vs. systemic, and large vs. small.

Superficial veins: Superficial veins are those whose course is close to the surface of the body, and have no corresponding arteries.

Deep veins: Deep veins are deeper in the body and have corresponding arteries.

Communicating veins: Communicating veins (or perforator veins) are veins that directly connect superficial veins to deep veins.

Pulmonary veins: The pulmonary veins are a set of veins that deliver oxygenated blood from the lungs to the heart.

Systemic veins: Systemic veins drain the tissues of the body and deliver deoxygenated blood to the heart.

Clinical significance

Phlebology

Venous valves prevent reverse blood flow.

Phlebology is the medical discipline that involves the diagnosis and treatment of disorders of venous origin. Diagnostic techniques used include the history and physical examination, venous imaging techniques and laboratory evaluation related to venous thromboembolism. The American Medical Association has added phlebology to their list of self-designated practice specialties. A medical specialist in Phlebology is termed a Phlebologist. A related image is called a phlebography

Video of venous valve in action

The American College of Phlebology (ACP) is the largest professional organization in the world dedicated to Phlebology. It is composed of physicians and healthcare professionals from a variety of medical backgrounds and holds an Annual Scientific Congress as well as many symposia that educate and train practitioners in this field in order to enhance the quality of patient care. ACP meetings are conducted to facilitate learning and sharing of knowledge regarding venous disease. The equivalent body for countries in the Pacific is the Australasian College of Phlebology, active in Australia and New Zealand.

The American Venous Forum (AVF) is the leading academic international consortium of venous and lymphatic specialists dedicated to improving patient care. Research in clinical and basic sciences is reported at the AVF annual meetings, along with the reports on new developments in diagnosis and treatment of venous diseases. The main body of the AVF consists of vascular surgeons and other physicians who specialized in management of not only simple varicose veins but the whole spectrum of venous and lymphatic diseases from congenital abnormalities to deep vein thrombosis to chronic venous diseases.

Venous diseases

Venous insufficiency

Main article: Chronic venous insufficiency

Venous insufficiency is the most common disorder of the venous system, and is usually manifested as spider veins or varicose veins. Several varieties of treatments are used, depending on the patient's particular type and pattern of veins and on the physician's preferences. Treatment can include Endovenous Thermal Ablation using radiofrequency or laser energy, vein stripping, ambulatory phlebectomy, foam sclerotherapy, lasers, or compression.

Postphlebitic syndrome is venous insufficiency that develops following deep vein thrombosis.^[3]

Deep vein thrombosis

Main article: Deep vein thrombosis

Deep-vein thrombosis is a condition in which a blood clot forms in a deep vein, which can lead to pulmonary embolism and chronic venous insufficiency.

Thrombophlebitis

Main article: Thrombophlebitis

Thrombophlebitis is an inflammatory condition of the veins related to blood clots.

References

^ Maton, Anthea; Jean Hopkins, Charles William McLaughlin, Alexandra Senckowski, Susan Johnson, Maryanna Quon Warner, David LaHart, Jill D. Wright (1993). Human Biology and Health. Englewood Cliffs, New Jersey: Prentice Hall. ISBN 0-13-981176-1.
^ Kienle, Alwin; Lilge, Lothar; Vitkin, I. Alex; Patterson, Michael S.; Wilson, Brian C.; Hibst, Raimund; Steiner, Rudolf (1 March 1996). "Why do veins appear blue? A new look at an old question". Applied Optics 35 (7): 1151. doi:10.1364/AO.35.001151.
^ Kahn SR (August 2006). "The post-thrombotic syndrome: progress and pitfalls". British Journal of Haematology 134 (4): 357–65. doi:10.1111/j.1365-2141.2006.06200.x. PMID 16822286.

External links

Look up vein in Wiktionary, the free dictionary.

Merck Manual article on veins
American Venous Forum
American College of Phlebology
American Board of Phlebology
American College of Phlebology Foundation
Australasian College of Phlebology Information from the Australasian College of Phlebology Website
In economics: Arterial and venous industries
Animated Venous Access tutorials

Scientific publications

Phlebology: The Journal of Venous Disease
Phlebology: 1986-1999

UpToDate Contents

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1. 下肢慢性静脈疾患の概要およびマネージメント overview and management of lower extremity chronic venous disease
2. 原発性（特発性）上肢深部静脈血栓症 primary spontaneous upper extremity deep vein thrombosis
3. 下肢静脈治療のための液状硬化療法およびフォーム硬化療法の手技 liquid and foam sclerotherapy techniques for the treatment of lower extremity veins
4. 下肢深部静脈血栓症が疑われた場合の診断 diagnosis of suspected deep vein thrombosis of the lower extremity
5. 下肢慢性静脈疾患の分類 classification of lower extremity chronic venous disorders

English Journal

Freestanding graphene paper decorated with 2D-assembly of Au@Pt nanoparticles as flexible biosensors to monitor live cell secretion of nitric oxide.

Zan X, Fang Z, Wu J, Xiao F, Huo F, Duan H.SourceSchool of Chemical and Biomedical Engineering, Nanyang Technological University, 70 Nanyang Drive, Singapore 637457, Singapore.
Biosensors & bioelectronics.Biosens Bioelectron.2013 Nov 15;49:71-8. doi: 10.1016/j.bios.2013.05.006. Epub 2013 May 9.
We report the development of a new type of flexible electrochemical biosensors based on graphene paper loaded with closely-packed Au@Pt core-shell nanoparticles as a freestanding cell culture substrate for real-time monitoring cell secretion of nitric oxide. The hybrid electrode was fabricated throu
PMID 23722044

Paracrine exchanges of molecular signals between alginate-encapsulated pericytes and freely suspended endothelial cells within a 3D protein gel.

Andrejecsk JW, Cui J, Chang WG, Devalliere J, Pober JS, Saltzman WM.SourceDepartment of Biomedical Engineering, Yale University, New Haven, CT 06511, USA.
Biomaterials.Biomaterials.2013 Nov;34(35):8899-908. doi: 10.1016/j.biomaterials.2013.08.008. Epub 2013 Aug 21.
Paracrine signals, essential for the proper survival and functioning of tissues, may be mimicked by delivery of therapeutic proteins within engineered tissue constructs. Conventional delivery methods are of limited duration and are unresponsive to the local environment. We developed a system for sus
PMID 23973174

Image-guided and tumor-targeted drug delivery with radiolabeled unimolecular micelles.

Guo J, Hong H, Chen G, Shi S, Zheng Q, Zhang Y, Theuer CP, Barnhart TE, Cai W, Gong S.SourceSchool of Chemical Engineering, Tianjin University, Tianjin 300072, China; Department of Biomedical Engineering, University of Wisconsin-Madison, Madison, WI 53706, USA; Wisconsin Institutes for Discovery, University of Wisconsin-Madison, Madison, WI 53715, USA.
Biomaterials.Biomaterials.2013 Nov;34(33):8323-32. doi: 10.1016/j.biomaterials.2013.07.085. Epub 2013 Aug 8.
Unimolecular micelles formed by dendritic amphiphilic block copolymers poly(amidoamine)-poly(l-lactide)-b-poly(ethylene glycol) conjugated with anti-CD105 monoclonal antibody (TRC105) and 1,4,7-triazacyclononane-N, N', N-triacetic acid (NOTA, a macrocyclic chelator for (64)Cu) (abbreviated as PAMAM-
PMID 23932288

Polysaccharide-based biomaterials with on-demand nitric oxide releasing property regulated by enzyme catalysis.

Zhao Q, Zhang J, Song L, Ji Q, Yao Y, Cui Y, Shen J, Wang PG, Kong D.SourceState Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Bioactive Materials, Ministry of Education, Nankai University, Tianjin 300071, PR China.
Biomaterials.Biomaterials.2013 Nov;34(33):8450-8. doi: 10.1016/j.biomaterials.2013.07.045. Epub 2013 Jul 30.
The regulatory role of nitric oxide (NO) in cell signaling has been well recognized. Clinically, NO deficiency is known to be associated with severe vascular disorders, especially in patients with long-term diabetes. Exogenous compensation of NO is a promising therapeutic strategy, although the lack
PMID 23911069

Japanese Journal

膀胱癌に対する長期化学療法施行中に出現した門脈血栓症の1例

上田倫央,中山雅志,松崎恭介,山本致之,武田健,中田渡,新井康之,垣本健一,西村和郎,向井幹夫
泌尿器科紀要 59(7), 449-452, 2013-07-00
… Follow-up computed tomographic scan 3 months after the last chemotherapy showed portal vein thrombosis. …
NAID 120005308131

Thrombosis in the Pulmonary Vein Stump After Left Upper Lobectomy as a Possible Cause of Cerebral Infarction

Ohtaka Kazuto,Hida Yasuhiro,Kaga Kichizo,Kato Tatsuya,Muto Jun,Nakada-Kubota Reiko,Sasaki Tsukasa,Matsui Yoshiro
Annals of Thoracic Surgery 95(6), 1924-1929, 2013-06-00
… Thrombus in the stump of the pulmonary vein (PV) is not a well-known complication after lung resection, and it has the potential to cause embolism to vital organs. …
NAID 120005307924

Relation between bilateral differences in internal jugular vein caliber and flow patterns of dural venous sinuses

Saiki Kazunobu,Tsurumoto Toshiyuki,Okamoto Keishi,Wakebe Tetsuaki
Anatomical Science International 88(3), 141-150, 2013-06-00
We measured the calibers of the left and right internal jugular veins (IJV) and sizes of the left and right transverse sinuses (TS) in 91 cadavers, compared them between the left and right sides, and …
NAID 120005301877

Efficacy and Safety of Preoperative Portal Vein Embolization with Microfibrillar Collagen for Hepatobiliary Malignancy

Shibutani Koichi,Tsushima Fumiyasu,Kakehata Shinya,Miura Hiroyuki,Ono Shuichi,Seino Hiroko,Kakuta Akihisa,Tokuda Toshihide,Toyoki Yoshikazu,Hakamada Kenichi,Takai Yoshihiro
弘前医学 64(1), 1-14, 2013-05-31
… Purpose: To evaluate the clinical efficacy and safety of preoperative percutaneous transhepatic portal vein embolization（PVE） with an ipsilateral approach, using microfibrillar collagen（MFC） as an embolic material for carcinomas of the biliary tract and liver metastases of colorectal carcinoma. …
NAID 120005303550