blood vessels

血管

WordNet

1. smear with blood, as in a hunting initiation rite, where the face of a person is smeared with the blood of the kill
2. temperament or disposition; "a person of hot blood"
3. people viewed as members of a group; "we need more young blood in this organization"
4. the fluid (red in vertebrates) that is pumped through the body by the heart and contains plasma, blood cells, and platelets; "blood carries oxygen and nutrients to the tissues and carries away waste products"; "the ancients believed that blood was the sea
5. a craft designed for water transportation (同)watercraft
6. an object used as a container (especially for liquids)
7. a tube in which a body fluid circulates (同)vas

PrepTutorEJDIC

1. 『血』,『血』液 / 流血(bloodshed);殺人 / 気質,気性,血気,血潮 / 『血統』,血縁(kinship);生まれ,家柄;《the~》王家の血統 / (人種・出身国の)系 / 〈人〉‘に'初めての経験をさせる / 〈猟犬〉‘に'初めて獲物を血を味わわせる
2. (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
3. 純血の,純種の / 《複合語を作って》「…の血(性質)を持った」の意を表す

Wikipedia preview

出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2013/06/30 22:25:49」(JST)

wiki en

[Wiki en表示]

For the singer, see Buster Bloodvessel.

Blood vessel
Simple diagram of the human circulatory system
Latin	vas sanguineum

The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual exchange of water and chemicals between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart.

Anatomy

The arteries and veins have three layers, but the middle layer is thicker in the arteries than it is in the veins:

• Tunica intima (the thinnest layer): a single layer of simple squamous endothelial cells glued by a polysaccharide intercellular matrix, surrounded by a thin layer of subendothelial connective tissue interlaced with a number of circularly arranged elastic bands called the internal elastic lamina.
• Tunica media (the thickest layer in arteries): circularly arranged elastic fiber, connective tissue, polysaccharide substances, the second and third layer are separated by another thick elastic band called external elastic lamina. The tunica media may (especially in arteries) be rich in vascular smooth muscle, which controls the caliber of the vessel.
• Tunica adventitia: (the thickest layer in veins) entirely made of connective tissue. It also contains nerves that supply the vessel as well as nutrient capillaries (vasa vasorum) in the larger blood vessels.

Capillaries consist of little more than a layer of endothelium and occasional connective tissue.

When blood vessels connect to form a region of diffuse vascular supply it is called an anastomosis (pl. anastomoses). Anastomoses provide critical alternative routes for blood to flow in case of blockages.

There is a layer of muscle surrounding the arteries and the veins which help contract and expand the vessels. This creates enough pressure for blood to be pumped around the body.

Types

Blood vessel with an erythrocyte (red blood cell, E) within its lumen, endothelial cells forming its tunica intima (inner layer), and pericytes forming its tunica adventitia (outer layer)

There are various kinds of blood vessels:

• Arteries
  • Aorta (the largest artery, carries blood out of the heart)
  • Branches of the aorta, such as the carotid artery, the subclavian artery, the celiac trunk, the mesenteric arteries, the renal artery and the iliac artery.
• Arterioles
• Capillaries (the smallest blood vessels)
• Venules
• Veins
  • Large collecting vessels, such as the subclavian vein, the jugular vein, the renal vein and the iliac vein.
  • Venae cavae (the 2 largest veins, carry blood into the heart)

They are roughly grouped as arterial and venous, determined by whether the blood in it is flowing away from (arterial) or toward (venous) the heart. The term "arterial blood" is nevertheless used to indicate blood high in oxygen, although the pulmonary artery carries "venous blood" and blood flowing in the pulmonary vein is rich in oxygen. This is because they are carrying the blood to and from the lungs, respectively, to be oxygenated.

Physiology

Blood vessels do not actively engage in the transport of blood (they have no appreciable peristalsis), but arteries—and veins to a degree—can regulate their inner diameter by contraction of the muscular layer. This changes the blood flow to downstream organs, and is determined by the autonomic nervous system. Vasodilation and vasoconstriction are also used antagonistically as methods of thermoregulation.

Oxygen (bound to hemoglobin in red blood cells) is the most critical nutrient carried by the blood. In all arteries apart from the pulmonary artery, hemoglobin is highly saturated (95-100%) with oxygen. In all veins apart from the pulmonary vein, the hemoglobin is desaturated at about 75%. (The values are reversed in the pulmonary circulation.)

The blood pressure in blood vessels is traditionally expressed in millimetres of mercury (1 mmHg = 133 Pa). In the arterial system, this is usually around 120 mmHg systolic (high pressure wave due to contraction of the heart) and 80 mmHg diastolic (low pressure wave). In contrast, pressures in the venous system are constant and rarely exceed 10 mmHg.

Vasoconstriction is the constriction of blood vessels (narrowing, becoming smaller in cross-sectional area) by contracting the vascular smooth muscle in the vessel walls. It is regulated by vasoconstrictors (agents that cause vasoconstriction). These include paracrine factors (e.g. prostaglandins), a number of hormones (e.g. vasopressin and angiotensin) and neurotransmitters (e.g. epinephrine) from the nervous system.

Vasodilation is a similar process mediated by antagonistically acting mediators. The most prominent vasodilator is nitric oxide (termed endothelium-derived relaxing factor for this reason).

Permeability of the endothelium is pivotal in the release of nutrients to the tissue. It is also increased in inflammation in response to histamine, prostaglandins and interleukins, which leads to most of the symptoms of inflammation (swelling, redness, warmth and pain).

Role in disease

Main article: Vascular disease

Blood vessels play a huge role in virtually every medical condition. Cancer, for example, cannot progress unless the tumor causes angiogenesis (formation of new blood vessels) to supply the malignant cells' metabolic demand. Atherosclerosis, the formation of lipid lumps (atheromas) in the blood vessel wall, is the most common cardiovascular disease, the main cause of death in the Western world.

Blood vessel permeability is increased in inflammation. Damage, due to trauma or spontaneously, may lead to hemorrhage due to mechanical damage to the vessel endothelium. In contrast, occlusion of the blood vessel by atherosclerotic plaque, by an embolised blood clot or a foreign body leads to downstream ischemia (insufficient blood supply) and possibly necrosis. Vessel occlusion tends to be a positive feedback system; an occluded vessel creates eddies in the normally laminar flow or plug flow blood currents. These eddies create abnormal fluid velocity gradients which push blood elements such as cholesterol or chylomicron bodies to the endothelium. These deposit onto the arterial walls which are already partially occluded and build upon the blockage.

Vasculitis is inflammation of the vessel wall, due to autoimmune disease or infection.

References

UpToDate Contents

全文を閲覧するには購読必要です。 To read the full text you will need to subscribe.

• 1. 頚動脈内膜剥離術 carotid endarterectomy
• 2. 冠側副循環 coronary collateral circulation
• 3. 腹壁の解剖学 anatomy of the abdominal wall
• 4. 顔面紅斑が認められる患者に対するアプローチ approach to the patient with facial erythema
• 5. Management of adults with idiopathic cutaneous small vessel vasculitis

English Journal

• The Characteristics of Vascular Growth in VX2 Tumor Measured by MRI and Micro-CT.

• Qi XL, Liu J, Burns PN, Wright GA.SourceImaging Research, Sunnybrook HSC, University of Toronto, 2075 Bayview Avenue, Toronto, ON, Canada M4N 3M5.
• Journal of oncology.J Oncol.2012;2012:362096. Epub 2011 Sep 15.
• Blood supply is crucial for rapid growth of a malignant tumor; medical imaging can play an important role in evaluating the vascular characterstics of tumors. Magnetic resonance imaging (MRI) and micro-computed tomography (CT) are able to detect tumors and measure blood volumes of microcirculation i
• PMID 21941548

• Angiogenesis in acute myeloid leukemia and opportunities for novel therapies.

• Trujillo A, McGee C, Cogle CR.SourceDivision of Hematology and Oncology, Department of Medicine, College of Medicine, University of Florida, Gainesville, FL 32610-0278, USA.
• Journal of oncology.J Oncol.2012;2012:128608. Epub 2011 Sep 5.
• Acute myeloid leukemia (AML) arises from neoplastic transformation of hematopoietic stem and progenitor cells, and relapsed disease remains one of the greater challenges in treating this hematologic malignancy. This paper focuses on angiogenic aspects of AML including the significance and prognostic
• PMID 21904549

Japanese Journal

• 齧歯類の脳内血管とグリア境界膜との関係について

• 武石 浩之/渡辺 浩太/佐々木 宏
• 東京女子医科大学雑誌 81(4), 259-266, 2011-08-25
• 脳内血管はすべて、アストロサイトが作るグリア境界膜によってほぼ完全に包囲されている.しかしながら、グリア境界膜が血管の種類によって形態的な違いを示すのかどうかについてはほとんど不明である.そこで、私どもは血管色素注入法、レーザー顕微鏡法、透過型電子顕微鏡法、免疫組織化学電子顕微鏡法を用いて、この問題を明らかにしようと試みた.動脈では、外膜を包囲する基底膜が柵状にグリア境界膜に陥入していたが、静脈で …
• NAID 110008604391

• Prediction of outcome of patients with oral squamous cell carcinoma using vascular invasion and the strongly positive expression of vascular endothelial growth factors.

• Seki Sachiko,Fujiwara Mutsunori,Matsuura Masaaki,Fujita Shuichi,Ikeda Hisazumi,Asahina Izumi,Ikeda Tohru
• Oral Oncology 47(7), 588-593, 2011-07
• … In addition to metastatic potential via blood vessels, tumor-induced angiogenesis might also be associated with prognosis. …
• NAID 120003238494

Related Links

• Blood vessel - Wikipedia, the free encyclopedia

The blood vessels are the part of the circulatory system that transports blood throughout the body. There are three major types of blood vessels: the arteries, which carry the blood away from the heart; the capillaries, which enable the actual ...

Related Pictures

---

★リンクテーブル★

リンク元	「血管」
関連記事	「vessel」「blood」

「血管」

　　[★]

英

blood vessel, blood vessels

• 図：M.28

構造

• 内膜

• 内皮細胞(単層扁平上皮細胞)
• 基底板
• 内皮下結合組織(内皮下層 subendothelial layer)：疎性結合組織、縦走平滑筋
• 内弾性板

• 中膜

• 平滑筋
• 外弾性板

• 外膜

• 結合組織に移行

---

動脈	内膜	中膜	外膜
弾性血管	内皮細胞(ワイベル・パラーデ小体を含む) 基底板 内皮下層(少数の線維芽細胞、散在する平滑筋細胞、膠原線維) 不完全な内弾性板	40-70層の有窓性弾性板 弾性板の間に存在する平滑筋細胞 薄い弾性板 外半分には脈管栄養細胞が分布	線維・弾性結合組織 脈管栄養血管 リンパ管 神経細胞
筋性動脈	内皮細胞(ワイベル・パラーデ小体を含む) 基底板 内皮下層(少数の線維芽細胞、散在する平滑筋細胞、膠原線維) 厚い内弾性板	40層に及ぶ平滑筋細胞層 厚い外弾性板	薄い線維・弾性結合組織 脈管栄養血管は著明でない リンパ管 神経線維
細動脈	内皮細胞(ワイベル・パラーデ小体を含む) 基底板 内皮下層：目立たない 内弾性板はなく、弾性線維がある	1-2層の平滑筋細胞	疎性結合組織 神経線維

分類

• 弾性血管 (弾性動脈 elastic artery)
• 筋性動脈 muscular artery
• 細動脈 arteriole

「vessel」

　　[★]

• n.

• 血管、(植物)導管、道管、(一般)容器

関

angio、blood vessel、canal、chamber、conduit、container、duct、sulodexide、vas、vascular、vein

　 　 　 　

「blood」

　　[★] 血液