26-737: Verhoeff is a surname. Notable people with the surname include: Frederick Herman Verhoeff (1874–1968), American ophthalmic surgeon who developed Verhoeff's stain Hendrik Verhoeff (c. 1645–1680), Dutch silversmith and assassin Jacobus Verhoeff (1927–2018), Dutch mathematician John M. Verhoeff, of the Peary expedition to Greenland of 1891–92 Karl Wilhelm Verhoeff (1867–1944), German zoologist Pieter Verhoeff (1938–2019), Dutch film director Pieter Willemsz. Verhoeff (c. 1573–1609), Dutch captain of
52-478: A bodybuilder ) However, later studies suggest a more conservative figure of 9,000–19,000 kilometres (5,600–11,800 mi) taking into account updated capillary density and average muscle mass in adults. Despite these later studies, many textbooks or other types of media include Krogh's estimates as a fun fact as opposed to the more recent studies. There are various kinds of blood vessels: They are roughly grouped as "arterial" and "venous", determined by whether
78-425: 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). The circulatory system uses the channel of blood vessels to deliver blood to all parts of
104-405: 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. The most common disease of
130-402: A result of the different components of the blood. Blood is 92% water by weight and the rest of blood is composed of protein, nutrients, electrolytes, wastes, and dissolved gases. Depending on the health of an individual, the blood viscosity can vary (i.e., anemia causing relatively lower concentrations of protein, high blood pressure an increase in dissolved salts or lipids, etc.). Vessel length
156-405: Is a staining protocol used in histology , developed by American ophthalmic surgeon and pathologist Frederick Herman Verhoeff (1874–1968) in 1908. The formulation is used to demonstrate normal or pathologic elastic fibers . Verhoeff's stain forms a variety of cationic, anionic and non-ionic bonds with elastin , the main constituent of elastic fiber tissue. Elastin has a strong affinity for
182-633: Is a combination of the following reagents: A common variant is the Masson trichrome and Verhoeff stain , which combines the Masson's trichrome stain and Verhoeff stain. It is sometimes just referred to as a Masson trichrome . This combination is useful for the examination of blood vessels ; the Verhoeff stain highlights elastin (black) and allows one to easily differentiate small arteries (which typically have two elastic laminae) and veins (which have one elastic lamina). Blood vessel Blood vessels are
208-528: 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). 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 . The size of blood vessels
234-481: Is different for each of them. It ranges from a diameter of about 30–25 millimeters for the aorta to only about 5 micrometers (0,005 mm) for the capillaries. 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 can include paracrine factors (e.g., prostaglandins ),
260-430: 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 , an embolised blood clot or a foreign body leads to downstream ischemia (insufficient blood supply) and possibly infarction ( necrosis due to lack of blood supply ). Vessel occlusion tends to be
286-425: Is the total length of the vessel measured as the distance away from the heart. As the total length of the vessel increases, the total resistance as a result of friction will increase. Vessel radius also affects the total resistance as a result of contact with the vessel wall. As the radius of the wall gets smaller, the proportion of the blood making contact with the wall will increase. The greater amount of contact with
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#1732851084365312-438: Is thicker in the arteries than it is in the veins: Capillaries consist of a single layer of endothelial cells with a supporting subendothelium consisting of a basement membrane and connective tissue . When blood vessels connect to form a region of diffuse vascular supply, it is called an anastomosis . Anastomoses provide alternative routes for blood to flow through in case of blockages. Veins can have valves that prevent
338-508: The arteries , which carry the blood away from the heart ; the arterioles ; the capillaries , where the exchange of water and chemicals between the blood and the tissues occurs; the venules ; and the veins , which carry blood from the capillaries back towards the heart. The word vascular , is derived from the Latin vas , meaning vessel , and is mostly used in relation to blood vessels. The arteries and veins have three layers. The middle layer
364-435: The backflow of the blood that was being pumped against gravity by the surrounding muscles. In humans, arteries do not have valves except for the two 'arteries' that originate from the heart's ventricles. Early estimates by Danish physiologist August Krogh suggested that the total length of capillaries in human muscles could reach approximately 100,000 kilometres (62,000 mi). (assuming an ideal human body, like that of
390-405: The heartbeat . Blood vessels also transport red blood cells. Hematocrit tests can be performed to calculate the proportion of red blood cells in the blood. Higher proportions result in conditions such as dehydration or heart disease, while lower proportions could lead to anemia and long-term blood loss. Permeability of the endothelium is pivotal in the release of nutrients to the tissue. It
416-448: The pulmonary vein , the saturation of hemoglobin is about 75%. (The values are reversed in the pulmonary circulation .) In addition to carrying oxygen, blood also carries hormones , and nutrients to the cells of a body and removes waste products . Blood vessels do not actively engage in the transport of blood (they have no appreciable peristalsis ). Blood is propelled through arteries and arterioles through pressure generated by
442-458: The Admiralty of Amsterdam See also [ edit ] Verhoeff algorithm , a check digit algorithm invented by Jacobus Verhoeff Verhoef , a related surname Verhoeven [REDACTED] Surname list This page lists people with the surname Verhoeff . If an internal link intending to refer to a specific person led you to this page, you may wish to change that link by adding
468-525: 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. Blood vessels function to transport blood to an animal's body tissues. In general, arteries and arterioles transport oxygenated blood from
494-403: The blood to receive oxygen through tiny air sacs in the lungs. This is also the site where carbon dioxide exits the blood. This all occurs in the lungs where blood is oxygenated. 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
520-439: The body. This is a result of the left and right sides of the heart working together to allow blood to flow continuously to the lungs and other parts of the body. Oxygen-poor blood enters the right side of the heart through two large veins. Oxygen-rich blood from the lungs enters through the pulmonary veins on the left side of the heart into the aorta and then reaches the rest of the body. The capillaries are responsible for allowing
546-425: The heart) and 80 mmHg diastolic (low pressure wave). In contrast, pressures in the venous system are constant and rarely exceed 10 mmHg. Vascular resistance occurs when the vessels away from the heart oppose the flow of blood. Resistance is an accumulation of three different factors: blood viscosity, blood vessel length and vessel radius. Blood viscosity is the thickness of the blood and its resistance to flow as
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#1732851084365572-546: The iron-hematoxylin complex formed by the reagents in the stain and will hence retain dye longer than other tissue elements . This allows elastin to remain stained while the remaining tissue elements are decolorized. Sodium thiosulfate is used to remove excess iodine and a counterstain (most often Van Gieson's stain ) is used to contrast the principal stain. Elastic fibers and cell nuclei are stained black, collagen fibers are stained red, and other tissue elements including cytoplasm are stained yellow. Verhoeff's stain
598-428: The lungs to the body and its organs , and veins and venules transport deoxygenated blood from the body to the lungs. Blood vessels also circulate blood throughout the circulatory system . 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
624-530: The person's given name (s) to the link. Retrieved from " https://en.wikipedia.org/w/index.php?title=Verhoeff&oldid=965703473 " Categories : Surnames Dutch-language surnames Hidden categories: Articles with short description Short description is different from Wikidata All set index articles Verhoeff%27s stain Verhoeff's stain , also known as Verhoeff's elastic stain ( VEG ) or Verhoeff–Van Gieson stain ( VVG ),
650-463: The tubular structures of a circulatory system that transport blood throughout a vertebrate 's body. Blood vessels transport blood cells , nutrients, and oxygen to most of the tissues of a body . They also take waste and carbon dioxide away from the tissues. Some tissues such as cartilage , epithelium , and the lens and cornea of the eye are not supplied with blood vessels and are termed avascular . There are five types of blood vessels:
676-753: The wall will increase the total resistance against the blood flow. 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 represents around 85% of all deaths from cardiovascular diseases due to the buildup of plaque . Coronary artery disease that often follows after atherosclerosis can cause heart attacks or cardiac arrest , resulting in 370,000 worldwide deaths in 2022. In 2019, around 17.9 million people died from cardiovascular diseases. Of these deaths, around 85% of them were due to heart attack and stroke. Blood vessel permeability
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