Blood Vessel

The arterial system

The blood vessels are part of the cardiovascular system and function to transport blood throughout the body. The most important types, arteries and veins, carry blood away from or towards the heart, respectively.

Anatomy

All blood vessels have the same basic structure. The inner lining is the endothelium and is surrounded by subendothelial connective tissue. Around this there is a layer of vascular smooth muscle, which is highly developed in arteries. Finally, there is a further layer of connective tissue known as the adventitia, which contains nerves that supply the muscular layer, as well as nutrient capillaries 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.

Laid end to end, the blood vessels in an average human body will stretch approximately 62,000 miles--2.5 times around the earth.

Types

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.

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 70%. (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 and warmth).

Role in disease

Blood vessels play a 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 prime cause of 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 haemorrhage. In contrast, occlusion of the blood vessel (e.g. by a ruptured atherosclerotic plaque, by an embolised blood clot or a foreign body) leads to downstream ischemia (insufficient blood supply) and necrosis (tissue breakdown).

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

HEAD: ARTERIES: carotid - common carotid - internal carotid (ophthalmic, retinal, anterior cerebral, middle cerebral, posterior communicating) - external carotid (facial, maxillary, superficial temporal artery) - posterior cerebral - anterior communicating - basilar - circle of Willis - middle meningeal | VEINS: jugular - vein of Galen
ARMS: ARTERIES: axillary (superior thoracic, thoracoacromial, lateral thoracic, subscapular, anterior circumflex humeral, posterior circumflex humeral) - brachial - radial - ulnar | VEINS: axillary - brachial - radial - ulnar - median cubital - basilic - cephalic
LEGS: ARTERIES: dorsalis pedis - femoral - peroneal - popliteal - profunda femoris - tibial (anterior, posterior) | VEINS: femoral - saphenous (great, small) - peroneal - popliteal - profunda femoris - tibial (anterior tibial, posterior tibial)
THORAX: ARTERIES: aorta - brachiocephalic - bronchial - thoracic (lateral thoracic, internal thoracic) - subclavian - vertebral - axillary - pulmonary | VEINS: venae cavae (superior - inferior) - brachiocephalic - subclavian - portal - ductus venosus - azygos - pulmonary
ABDOMEN: ARTERIES: celiac artery - marginal - artery of Adamkiewicz - gastroduodenal - gastroepiploic - left gastric - umbilical - mesenteric (superior - inferior) | iliac (common - external) - renal - hepatic - common hepatic - splenic | VEINS: mesenteric (inferior, superior) | iliac (common - external) - renal - hepatic - splenic

Circulatory System is a psychedelic rock musical ensemble formed by musician/painter Will Cullen Hart, and featuring Hannah Jones, Derek Almstead, Peter Erchick, John Fernandes, and Heather McIntosh.
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Blood is a specialized biological fluid consisting of red blood cells (also called RBCs or erythrocytes), white blood cells (also called leukocytes) and platelets (also called thrombocytes) suspended in a complex fluid medium known as blood plasma.
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Arteries are muscular blood vessels that carry blood away from the heart.^[1] All arteries, with the exception of the pulmonary and umbilical arteries, carry oxygenated blood.

The circulatory system is extremely important for sustaining life.
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vein is a blood vessel that carries blood toward the heart. The majority of veins in the body carry low-oxygen blood from the tissues back to the heart; the exceptions being the pulmonary and umbilical veins which both carry oxygenated blood.
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heart is a muscular organ responsible for pumping blood through the blood vessels by repeated, rhythmic contractions, or a similar structure in the annelids, mollusks, and arthropods.
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endothelium is the thin layer of cells that line the interior surface of blood vessels, forming an interface between circulating blood in the lumen and the rest of the vessel wall. Endothelial cells line the entire circulatory system, from the heart to the smallest capillary.
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Connective tissue is one of the four types of tissue in traditional classifications (the others being epithelial, muscle, and nervous tissue.) It is largely a category of exclusion rather than one with a precise definition, but all or most tissues in this category are similarly:
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Vascular smooth muscle refers to the particular type of smooth muscle found within, and composing the majority of the wall of blood vessels.

Vascular smooth muscle contracts or relaxes to both change the volume of blood vessels and the local blood pressure, a mechanism that
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For the botany term, see adventitious.

Adventitia is the outermost connective tissue covering of any organ, vessel, or other structure.
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A nerve is an enclosed, cable-like bundle of axons (the long, slender projection of a neuron). Neurons are sometimes called nerve cells, though this term is technically imprecise since many neurons do not form nerves, and nerves also include the glial cells that
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capillary is used to describe any very narrow tube or channel through which a fluid can pass. See capillary action for details.

Capillaries are the smallest of a body's blood vessels, measuring 5-10 μm, which connect arterioles and venules, and are
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Coronary:

Coronary

Coronary anastomoses are a clinically vital subject: the coronary anastomosis is the blood supply to the heart. The coronary arteries are vulnerable to arteriosclerosis and other effects.
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The aorta (generally pronounced [eɪˈɔːtə] or "ay-orta") is the largest artery in the human body, originating from the left ventricle of the heart and bringing oxygenated blood to all parts of the body in the systemic circulation.
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In human anatomy, the common carotid artery is an artery that supplies the head and neck with oxygenated blood; it divides in the neck to form the external and internal carotid arteries.
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In human anatomy, the subclavian artery is a major artery of the upper thorax that mainly supplies blood to the head and arms. It is located below the clavicle, hence the name. There is a left subclavian and a right subclavian.
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The celiac artery, also known as the celiac trunk and also spelled as coeliac, is the first major branch of the abdominal aorta and branches from the aorta around the level of the T12 vertebra in humans.
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The renal arteries normally arise off the side of the abdominal aorta, immediately below the superior mesenteric artery, and supply the kidneys with blood. Each is directed across the crus of the diaphragm, so as to form nearly a right angle with the aorta.
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In human anatomy, iliac artery refers to several anatomical structures located in the pelvis:

Common iliac artery - forms at terminus of the aorta.
External iliac artery - forms when the common iliac artery bifurcates, continues as the femoral artery at the inguinal

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An arteriole is a small diameter blood vessel that extends and branches out from an artery and leads to capillaries.

Arterioles have thin muscular walls (usually only one to two layers of smooth muscle) and are the primary site of vascular resistance^[1].
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capillary is used to describe any very narrow tube or channel through which a fluid can pass. See capillary action for details.

Capillaries are the smallest of a body's blood vessels, measuring 5-10 μm, which connect arterioles and venules, and are
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A venule is a small blood vessel that allows deoxygenated blood to return from the capillary beds to the larger blood vessels called veins.
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In human anatomy, the subclavian veins are two large veins, one on either side of the body. Its diameter is approximately that of a man's small finger. It is divided into right and left subclavian vein.
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The jugular veins are veins that bring deoxygenated blood from the head back to the heart via the superior vena cava.

Internal and external

There are two sets of jugular veins: external and internal.
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The renal veins are veins that drain the kidney. They connect the kidney to the inferior vena cava.

It is usually singular to each kidney, except in the condition "multiple renal veins".
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In human anatomy, iliac vein refers to several anatomical structures located in the pelvis:

External iliac vein - terminates at the common iliac vein, drains the femoral vein.
Internal iliac vein - terminates at the common iliac vein, drains pelvic organs and perineum.

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The superior and inferior vena cava are collectively called the venae cavae. They are the veins that return de-oxygenated blood from the body into the heart. They both empty into the right atrium.
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2, −1
(neutral oxide)
Electronegativity 3.44 (Pauling scale)
Ionization energies
(more) 1st: 1313.9 kJmol⁻¹
2nd: 3388.3 kJmol⁻¹
3rd: 5300.5 kJmol⁻¹

Atomic radius 60 pm
Atomic radius (calc.
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