Venules vs veins

Vein vs. Venule - What's the difference? Ask Differenc

Veins are part of the closed circulatory system that takes deoxygenated blood from capillaries in tissues to venules, veins, the heart and then the lungs, where the blood is resupplied with oxygen and transferred to arteries, arterioles and then capillaries. Lymph vessels are part of an open-ended system that collects lymph fluid from. Arteries and veins are two of the body's main type of blood vessels. These vessels are channels that distribute blood to the body. Learn the differences between an artery and a vein. Discover.

Varicose Veins Varicose veins Dilated blood vessels- weakening in the vessel wall Swollen, twisted clusters of blue or purple veins Spider Veins or Telangiectasias- Tiny blood vessels close to skin surface & surrounded by thin, red capillarie Arteries are always moving blood away from the heart, while veins are always moving blood towards the heart. Capillaries, on the other hand, act as intermediaries, connecting arterioles and venules. Capillaries connect the arterioles and the venules. Capillaries serve the function in the circulatory system of helping to facilitate the exchange. Venules and veins. The structure of venules and veins is essentially similar structure to arterioles and arteries. In contrast to arteries, the tunica media is considerably thinner and the tunica adventitia may form the thickest wall component. Post capillary venules have a particularly important function in inflammatory responses, contributing. These venules fuse together to form larger veins, which typically have a diameter of 5mm. Veins usually lie between skeletal muscles, which help to squeeze blood during muscular movement. Structure: Veins, much like arteries, have an oval space in the center called the lumen that is covered by the three layers of tissue mentioned above Learn the differences between these blood vessels! Rishi is a pediatric infectious disease physician and works at Khan Academy. These videos do not provide m..

Muscular venules and larger veins (6,18) importantly contribute to venous capacitance, and hence cardiovascular homeostasis. Venular hemodynamic resistance is lower than arteriolar resistance due to the greater number of venules of a given size, relative to comparably sized arterioles (5,13) Main Difference - Veins vs Arteries. Blood Capillaries, Blood Pressure, Closed Circulatory System, Veins, Venules. What are Veins. Veins are a type of blood vessels that carry oxygen-depleted blood towards the heart. A vein is composed of thin, elastic blood vessels. The pressure of the blood carried by a vein is 5 mm Hg post-vapillary venules; Below you can find a collection of videos that can help provide a more visual approach to Blood Vessels including Arteries, Veins and Capillaries. blood vessel layers. 3 types of capillaries. arteries vs veins. Post-capillary venules. Special thanks to the creators of the featured videos on this post, specifically. The terminal hepatic venules and the small zone 3 hepatic veins are sensitive to endothelial damage by alkylating agents that cause intimal edema and subsequent collagen deposition. This can result in hepatic venous outflow tract obstruction, and patients present with painful hepatomegaly, jaundice, and ascites. Venoocclusive disease is. Venule. A venule is a very small blood vessel in the microcirculation that allows blood to return from the capillary beds to drain into the larger blood vessels, the veins. Venules range from 7μm to 1mm in diameter. Veins contain approximately 70% of total blood volume, 25% of which is contained in the venules. Many venules unite to form a vein

term:venules = branches of veins Flashcards. smaller than arterioles, connect capillaries to veins, little. Large diameter, but thin walls, valves allow unidirectional fl. expand with little change in pressure, function as blood reser. one-way valves in peripheral veins, skeletal muscle contracts, Veins are blue blood vessels that carry blood towards the heart. Oxygen Concentration: Arteries carry oxygenated blood (with the exception of the pulmonary artery and umbilical artery). Veins carry deoxygenated blood (with the exception of pulmonary veins and umbilical vein). Direction of Blood Flow: From the heart to various parts of the body Varicose veins are caused by increased blood pressure in the veins. Varicose veins happen in the veins near the surface of the skin (superficial). The blood moves towards the heart by one-way valves in the veins. When the valves become weakened or damaged, blood can collect in the veins. This causes the veins to become enlarged

Main Difference - Capillaries vs Veins. Capillaries and veins are two components of the circulatory system of animals. During systemic circulation, the blood pumped by the heart passes through the aorta to the arteries and arterioles, which drain blood to each of the organs and tissues of the body. Within the tissues, the arterioles produce a fine-branched network called capillaries by which. Venules Venules are the smallest veins and receive blood from capillaries. They also play a role in the exchange of oxygen and nutrients for water products. There are post-capillary sphincters located between the capillaries and venules. The venule is very thin-walled and easily prone to rupture with excessive volume Veins and venules have much thinner, less muscular walls than arteries and arterioles, largely because the pressure in veins and venules is much lower. Veins may dilate to accommodate increased blood volume. If a blood vessel breaks, tears, or is cut, blood leaks out, causing bleeding. Blood may flow out of the body, as external bleeding, or it.

The minor type of vein is venules that have thin walls, enough to store a lot of blood at one time. Veins are classified into four types depending upon their function and location. Deep veins; Superficial veins; Pulmonary veins; Systemic veins; Deep veins are located in muscle tissue and have a corresponding artery near them Postcapillary venules join multiple capillaries exiting from a capillary bed. Multiple venules join to form veins. The walls of venules consist of endothelium, a thin middle layer with a few muscle cells and elastic fibers, plus an outer layer of connective tissue fibers that constitute a very thin tunica externa (Figure 20.7). Venules as well. Veins originate distally as venules in the extremity (hands/feet) and travel to right atrium. Capillary beds are composed of intima only and connect to venules. Venules are composed of intima and adventitia layers only (no media layer) Pressure in the venules normally does not exceed 20mmHg. 80% of the blood in the body is found in the venous. A vein can range in size from 1 millimeter to 1-1.5 centimeters in diameter. The smallest veins in the body are called venules. They receive blood from the arteries via the arterioles and capillaries. The venules branch into larger veins which eventually carry the blood to the largest veins in the body, the vena cava Function & transport: Veins are meant to transport deoxygenated or blood devoid of oxygen from the organs to the heart so that it can gain oxygen again.This blood is usually high in carbon dioxide and must reach the heart for oxygenation. The start of this return journey to the heart begins from smaller vessels called venules (about 20µ diameter), which are located near the organs

What is the difference between a vein and a venule? Socrati

Arterioles are smaller than venules, generally by a ratio of 3:5 to 2:3. If you do the math: 3/5 = .6. 2/3 = .67. So, arterioles are just over half as small venules Valves in these veins allow blood to flow from the superficial veins to your deep veins, but not the other way. Venous system diagram Use this interactive 3-D diagram to explore the venous system

Venules and Veins - Structure And Function of Blood Vessel

  1. Veins vs Venules. vein . English (wikipedia vein) Noun (anatomy) A blood vessel that transports blood from the capillaries back to the heart (used in plural veins ) The entrails of a shrimp (botany) In leaves, a thickened portion of the leaf containing the vascular bundle.
  2. Carbon dioxide and waste substances pass out of the tissue spaces and into the capillary blood where it collects into the venules, empties into the leg veins and returns to the heart. The circulation of blood through the leg is exactly the same as any other part of the peripheral circulation
  3. Capillaries come together to form venules, small blood vessels that carry blood to a vein, a larger blood vessel that returns blood to the heart. Arteries and veins transport blood in two distinct circuits: the systemic circuit and the pulmonary circuit (Figure 20.1.1). Systemic arteries provide blood rich in oxygen to the body's tissues

Venules are the smallest type of vein. They have very thin walls to hold lots of blood. They feed low-oxygen blood through capillaries from arteries directly into veins The main difference between the arteries vs veins is that the arteries carry blood from the heart and in addition to the pulmonary arteries there is oxygenated blood. The color is bright red. When veins carry blood to the heart and there is oxygen-less blood in the blood (except for pulmonary veins and deep red, you cannot feel. Palpitations There are three types of veins in the body, i.e., pulmonary veins, deep veins, and superficial veins. Every vein has its function to perform. The most prominent vein in the body is the inferior vena cava. The smallest vein in the body is the venule. From venules, the blood flows to the larger veins The blood then enters venules, then veins filled with cellular waste and carbon dioxide. The deoxygenated 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 veins return oxygenated blood.


The Venous System Boundless Anatomy and Physiolog

Description of the condition. Telangiectasias, or spider veins, are dilated venules or arterioles (small superficial veins) measuring less than 1.0 mm in diameter and occurring predominantly in the lower extremities (T 2016).Reticular veins have a diameter less than 3 mm and are often tortuous and located in the subdermal or subcutaneous tissue (Eklof 2004; Porter 1995) The four exceptions—the pulmonary veins—transport oxygenated blood from the lungs to the left upper chamber of the heart. The oxygen-depleted blood transported by most veins is collected from the networks of microscopic vessels called capillaries by thread-sized veins called venules Hemangiomas and angiomas, which are made up of very small arteries called arterioles or very small veins called venules. Sometimes, the terms spider veins and telangiectasias are used interchangeably. Symptoms. Red or bluish-purple blood vessels appear, usually on the legs or thighs, but sometimes on the face, forearms or hands.. The capillaries converge again into venules that connect to minor veins, which connect to major veins that take blood high in carbon dioxide back to the heart. The major veins drain blood from the same organs and limbs that the major arteries supply. Fluid is also brought back to the heart via the lymphatic system

Blood is transported in arteries, veins and capillaries. Blood is pumped from the heart in the arteries. It is returned to the heart in the veins. The capillaries connect the two types of blood. Veins ===== Veins and venules are similar in structure to arteries and arterioles, however veins have a wider inner diameter, which means that they can hold a larger volume of blood. Since it would be unworkable to get all the blood back to the heart as quickly as it left the heart (because there is no pumping mechanism to do so); veins have to.

Veins are classified in a number of ways, including superficial vs. deep, pulmonary vs. systemic, and large vs. small. Superficial veins are those closer to the surface of the body, and have no corresponding arteries. The portal venous system is a series of veins or venules that directly connect two capillary beds Venules form larger veins that serve as the primary capacitance vessels of the body - i.e., the site where most of the blood volume is found and where regional blood volume is regulated. For example, constriction of the veins decreases venous volume and increases venous pressure, which alters cardiac output In Sclerotherapy (Fourth Edition), 2007. Venules. Venules in the upper and mid dermis usually run in a horizontal orientation. The diameter of the postcapillary venule ranges from 12 to 35 nm. Collecting venules range from 40 to 60 nm in the upper and mid dermis and enlarge to 100 to 400 nm in diameter in the deeper tissues. 126 One-way valves are found at the subcutis (dermis)-adipose. 67 demonstrated that endothelial cells in veins/venules vs. arteries/arterioles are in distinct cell cycle 68 states during vascular development and in adulthood; early G1 vs. late G1, respectively. Although 69 both early G1 and late G1 represent states of growth arrest, in embryonic stem cells, these state Pathologically enlarged venules are named spider veins , or venous telangiectasia. Advanced form of telangiectasia is commonly referred to as veno-venous malformation. A pathologically enlarged tributary, as it happens during development of superficial venous insufficiency, is a varicose vein. (212) 575-8346 Book Appointment

A telangiectasia is a confluence of dilated intradermal venules of less than 1 mm in caliber. Telangiectasia are more commonly known as spider veins and thread veins. They can be pink, red and have different hues in the red to purple blue range. Answer: Spider Veins vs Varicose Veins--Size matters, among other things. That's a great. Capillaries. Veins. blood moves away from the heart. blood supply at tissue level. blood returned to the heart. thick middle layer of involuntary muscle to increase or decrease diameter. one layer of endothelium with very small diameter. thin middle layer as pressure is reduced. inner layer of endothelium which reduces friction Veins: Capillaries: 1. These are responsible for the transportation of blood from the heart to all parts of the body. These vessels collect blood through capillaries and transport it towards the heart. These vessels connect arteries and veins. 2. All arteries carry oxygenated blood except pulmonary arteries which carry deoxygenated blood Spider telangiectasis is an acquired vascular malformation. It occurs because of the failure of a tiny muscle restricting the size of an arteriole. Increased pulsating flow through the vessel (the central papule) results in the dilatation of distal vessels (the red lines). Spider telangiectasis may arise spontaneously or may be induced by. Arteries and Veins are the major parts of the blood circulation system in any animals on the planet.both play and important role in human body also.the main purpose of these is blood circulation but there is a slight difference between arteries and veins i.e arteries are the blood vessels which take blood away from the heart to the other parts.

Histology A560

Structure and Function of Blood Vessels Anatomy and

Venous sinus, in human anatomy, any of the channels of a branching complex sinus network that lies between layers of the dura mater, the outermost covering of the brain, and functions to collect oxygen-depleted blood.Unlike veins, these sinuses possess no muscular coat. Their lining is endothelium, a layer of cells like that which forms the surface of the innermost coat of the veins Varicose Veins Patient - Presentation SYMPTOMS Usually leg symptoms pain ache heavy swelling restless Symptoms possibly venous or not venous restless musculoskletal back joints nerve sometimes pelvis / cycle TAKE A GOOD HISTORY night APPEARANCE Telangiectasias Blue venules Reticular veins Varicosities CEAP classification C1 C2 C3= swellin

Venules are tubes of endothelium. Small venules (up to 40-50 µm diameter) are surrounded by pericytes, contractile cells with long, branching processes that are involved in the control of blood as it flows through the microvasculature. Large venules (50-100 µm diameter) are surrounded by one or two layers of smooth muscle cells venule: 2. one of the branches of a vein in the wing of an insect With every passing second, complex processes take place inside our bodies to keep it both healthy and alive. One of these processes is the transportation of blood to and from the heart - veins and arteries are the major blood vessels charged with this task. Veins typically bring oxygen-depleted blood to the heart, while arteries transport oxygenated blood from the heart to the rest of the body White blood cell (WBC) margination and rolling were studied in venules (20-60 microns in diameter) in rat mesentery to examine the relationship between WBC rolling velocity (Vwbc), flux (Fwbc, cells/min), and deformation; and red blood cell (RBC) velocity (Vrbc), wall shear rate (gamma), and microve Like veins, arteries comprise of three layers; and inner layer made up of epithelial cells, an outer layer of tissue and a layer of muscles between them. In distributing blood and nutrients, all the three vessels supplement each other. Capillaries connect arteries to veins and hence allowing the exchange of products between them

Blood flow must be slower and exert less pressure on fine capillaries. Right Ventricle (low oxygen blood) --> Pulmonary Trunk --> Pulmonary arteries --> lobar arteries --> arterioles --> capillaries surrounding alveolar sacs --> pulmonary venules and veins (high oxygen blood) --> left atrium --> systemic circulation Description of the Blood Vessels: Arteries vs. Veins vs. Capillaries The blood vessel responsible for distributing oxygenated blood throughout the body is the artery. Since the blood is oxygenated, its color is bright red and when an artery gets injured, blood squirts because of arterial pressure is high compared to the vein [ 5,8 ] Venules receive the blood draining out of the capillaries. V enules converge into larger diameter vessels called veins, and finally into the vena cava, the major vessel that empties into the right atrium. The veins are low resistance vessels that serve as capacitance or volume reservoirs. On the right side of the heart, blood ejected from th

Venule definition is - a small vein; especially : any of the minute veins connecting the capillaries with the larger systemic veins 13+ arteries and veins diagram. The coronary arteries wrap around the outside of the heart. Veins and arteries of the neck. We think this is the. The arterioles and venules further divide into the thin walled vessels called. Anatomy of arteries vs veins

Arteries carry oxygenated blood away from the heart, these are the thick-walled muscular tube, while Veins carry deoxygenated blood towards the heart. Though both have the exception of the pulmonary artery and vein, as here the system get opposite and the pulmonary artery carries the deoxygenated blood, and pulmonary vein carries oxygenated blood The blood then enters venules, then veins filled with cellular waste and carbon dioxide. The deoxygenated 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 veins return oxygenated blood from. Venules and Veins • Venules • 8-100 microns in diameter • Join multiple capillaries • Primary site of emigration or diapedesis • Veins • Conduct blood towards heart • Thin walled, irregular lumens • Valve

What Are Some Structural Differences Between Veins & Lymph

Veins. Veins carry blood toward the heart. After blood passes through the capillaries, it enters the smallest veins, called venules. From the venules, it flows into progressively larger and larger veins until it reaches the heart. In the pulmonary circuit, the pulmonary veins transport blood from the lungs to the left atrium of the heart Venules and veins are also richly innervated by sympathetic nerves and smooth muscles within constrict when these nerves are activated. Thus, increased sympathetic nerve activity is associated with a decreased venous volume, which results in increased cardiac filling and therefore an increased cardiac output (via Starling's Law of the Heart)

The smallest veins in the body are called venules. They receive blood from the arteries via the arterioles and capillaries. The venules branch into larger veins which eventually carry the blood to the largest veins in the body, the vena cava. The blood is then transported from the superior vena cava and inferior vena cava to the right atrium of. Veins • Venules join to form veins. • Veins have three distinct tunics, but their walls are thinner and lumens are larger than arteries. • The tunica adventitia is the heaviest wall layer. Page 24. Blood Pressure in the Veins • Low blood pressure in the veins The smallest veins are called venules. They receive blood from blood vessels and transfer it to bigger veins. Each venule gets blood from numerous capillaries. Capillaries. Capillaries are the smallest blood vessels in the body, connecting the tiniest arteries to the smallest veins. These vessels are often referred to as the microcirculation Commonly Seen Abnormal Veins Caused by Superficial Vein Reflux • Telangiectasia (spider veins) • Confluence of red dilated venules • Intradermal <1 mm in caliber • 15 % of men and 25 % of women • Family hx, sun exposure, pregnancy • Can be caused by Reticular Veins • Reticular Veins (blue veins) • Also called intradermal varices. • Dilated bluish subdermal vein Low-pressure, transports blood from venules to heart Valves present to keep blood flowing toward the heart Capillaries Diffusion of gases and transfer of nutrients and waste products between blood and tissues Smallest and most numerous of all blood vessels Connect the arteries and veins to allow for the exchang

Veins and Venules. Large veins are also composed of the abovementioned tunica layers, but the tunica externa also contains smooth muscle cells, vasa vasorum, and nervi vasorum. A quick-reference guide to blood vessels. In veins the tunica media is much thinner but, unlike the artery, also hosts the vasa vasorum and nervi vasorum When you breath in air they go into small little aveoli and the oxygen from the air enter into small venous capillary beds. These capillaries then move oxygenated blood towards the heart. As the blood is moving the vessels become larger in size. Small vessel vasculitis is the most common form of vasculitis affecting arterioles and venules. In the skin, small vessel vasculitis presents with palpable purpura. Cutaneous small-vessel vasculitis can be idiopathic / primary, or secondary to infection, drug or disease. It may be neutrophilic, lymphocytic or granulomatous on histopathology

Artery vs. Vein: What's the Difference

Venules carry blood from capillary beds to veins. The walls of the venules are very thin and porus, and the tunica media and externa are not present in in small venules and thin and under developed in larger venules •Venules -smallest of all veins -drain capillaries . Arteries vs veins Characteristics Artery Vein Diameter Narrower Wider, often collapsed Wall thickness Thicker Thinner X-section Keeps circular shape collapses Thickest tunic Tunica media Tunica externa Fibers More elastic/collagen Less. Venules are small branches of veins. Arteriovenous Anastomoses . An arteriovenous anastomoses (AV anastomoses or AV shunt) is a direct connection between arteries and veins, bypassing the capillary bed. Portal System . The normal flow of blood in the vasculature is: artery - arteriole - capillary - post capillary venule -vein. However.

What Is Involved in Cannula Insertion? (with pictures)Difference Between Arteries and Arterioles | Definition

What is the Difference Between Arteries, Veins, Blood

So the more muscle you have, the more residual tension at rest you have, which means your veins are become more dilated. Combine that with a low level of body fat and the veins will really 'pop. Arterioles supply capillaries which, in turn, anastomose to form veins. Veins usually accompany similarly sized arteries and are classified as venules and small veins, medium veins, and large veins. 100x. Several characteristics differentiate arteries from their accompanying veins. Proportionally, arteries have narrower lumens and thicker walls. Capillary Blood. Capillary blood is obtained from capillary beds that consist of the smallest veins (venules) and arteries (arterioles) of the circulatory system. The venules and arterioles join together in capillary beds forming a mixture of venous and arterial blood. The specimen from a dermal puncture will therefore be a mixture of arterial. Blood pressure in the veins. When blood leaves the capillaries and enters the venules and veins, little pressure remains to force it along. Blood in the veins below the heart is helped back up to the heart by the muscle pump. This is simply the squeezing effect of contracting muscles on the veins running through them

Venules and veins - Veterinary Histolog

-Veins—carry blood toward the heart and away from capillaries -Capillaries—carry blood from the arterioles to the venules. 5 Blood Vessels •Functions -Arteries—distribution of nutrients, gases, etc., with movement of blood under high pressure; assist in maintaining the arteria Arteries vs. Veins. Arteries and veins are both major components of the cardiovascular system, and both are responsible for transporting blood around the body. to smaller veins (called venules). Capillaries allow the blood to come into close contact with body tissues, and their main function is to supply cells with oxygen and nutrients.

What Are Arteries, Veins And Capillaries? » Science AB

These venules further converge to form veins. These veins further converge to form the superior and inferior vena cava. These larger veins pour the collected deoxygenated blood into the heart. The heart sends the deoxygenated blood to the lungs through the pulmonary artery Arterioles Venules Size is 20-30µm Micrometer On millionth of a meter. SUPERFICIAL VENOUS ANATOMY Superficial veins flow to the major superficial veins - Saphenous Veins: Greater Lessor / Small Perforators: Hunterian Dodd Boyd Cockett. LOWER EXTREMITY DEEP VENOUS ANATOMY Common Femora Veins and Venules. Veins are the large return vessels of the body and act as the blood return counterparts of arteries. Because the arteries, arterioles, and capillaries absorb most of the force of the heart's contractions, veins and venules are subjected to very low blood pressures. This lack of pressure allows the walls of veins to be much.

The small muscular venules gradually increases in diameter and eventually drain into small veins. Alright, this image is an example of an arteriole from the abdominal mesentery. Similar to most blood vessels, the arteriolar wall has three main layers, the tunica intima , tunica media , and tunica externa Arteries are the blood vessels that carry blood away from the heart, where it branches into even smaller vessels. Finally, the smallest arteries, called arterioles are further branched into small capillaries, where the exchange of all the nutrients, gases and other waste molecules are carried out.. Veins are the blood vessels present throughout the body Types of Veins • Large Veins - Vena cavae - Superior VC and inferior VC - Drain blood from most veins • Medium Veins - Tributaries to the vena cavae - Drain organs and lobes of organs • Venules - Smallest of all veins - Drain capillarie Veins bring blood from different body parts to the heart. The veins have valves to prevent backward flow of blood. In the organs both arteries and veins divide to form arterioles and venules respectively. The arterioles and venules further divide into the thin walled vessels called capillaries. The capillaries of arteries and veins are united Blood Flow Through the Pulmonary and Systemic Cicruit. Self-test: Put this blood flow tracing in correct order STARTING with venules: Check Answers below. A LARGE blood flow graphic is below. 1. Venules. 2. Veins. 3. Inferior vena cava & superior vena cava

Venules are defined as the vessels which empty into small veins. Venules receive blood from smaller vessels, called here post-capillary venules, which in turn originate from the capillary net-work. In the report on arterial vessels from this laboratory,1 a capillary was defined as a distribut-ing vessel whic h aros e as sid branc of Which blood vessels lack elastic tissue? a. muscular arteries and arterioles. b. venules and veins. c. capillaries and venules. d. arterioles and capillaries

Pulmonary Vein - The Definitive Guide | Biology Dictionary

However, they all keep cerebral veins and venules at an arm's length. Neural Vascular Mechanism for the Cerebral Blood Flow Autoregulation after Hemorrhagic Stroke. Circular areas indicate infiltration of venules by leukocytes. Comparative Hepatotoxicity of Fluconazole, Ketoconazole, Itraconazole, Terbinafine, and Griseofulvin in Rats.. Lastly, the smallest arteries, called the arterioles, function to supply blood to the capillary bed.The capillary bed is where the actual gas exchange between cells and tissues occur. Regarding their histology, veins, particularly the venules (smaller veins) serve as the drainage of blood from the capillaries. On their way to the heart, they are transported via larger veins and ultimately to. Veins are blue in colour, since they carry deoxygenated blood: 5: Usually located deep in the body: Usually located close to the skin: 6: Artery is a resistance blood vessel: Vein is a capacitance blood vessel: 7: Middle layer of artery (tunica media) is thick: Tunica media relatively thin in veins: 8: Tunica media composed of elastic and. Superficial veins: These are the veins that are present close to the surface of the skin. Deep veins: These are the veins that are present in the deep muscles of the body. Veins are present in different sizes in the body. The size of veins varies from 1 millimeter to 1.5 centimeters. The vein which is smallest in size is called venules HSP, also known as anaphylactoid purpura and immunoglobulin A (IgA) vasculitis, is a small-vessel leukocytoclastic vasculitis characterized by the perivascular deposition of IgAl-based immune complexes in the walls of arterioles and postcapillary venules. (1) The clinical picture of HSP is palpable purpura, abdominal pain, arthritis, and hematuria 1-2 weeks following an upper respiratory.