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Venous
Veins () are blood vessels in the circulatory system of humans and most other animals that carry blood towards the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are those of the pulmonary and fetal circulations which carry oxygenated blood to the heart. In the systemic circulation, arteries carry oxygenated blood away from the heart, and veins return deoxygenated blood to the heart, in the deep veins. There are three sizes of veins: large, medium, and small. Smaller veins are called venules, and the smallest the post-capillary venules are microscopic that make up the veins of the microcirculation. Veins are often closer to the skin than arteries. Veins have less smooth muscle and connective tissue and wider internal diameters than arteries. Because of their thinner walls and wider lumens they are able to expand and hold more blood. This greater capacity gives them the term of ''capacitance vessels''. At any time, nearly 70% of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood Vessel
Blood vessels are the tubular structures of a circulatory system that transport blood throughout many Animal, animals’ bodies. Blood vessels transport blood cells, nutrients, and oxygen to most of the Tissue (biology), tissues of a Body (biology), body. They also take waste and carbon dioxide away from the tissues. Some tissues such as cartilage, epithelium, and the lens (anatomy), lens and cornea of the eye are not supplied with blood vessels and are termed ''avascular''. There are five types of blood vessels: 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. Etymology * artery – late Middle English; from Latin ''arteria'', from Gree ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Venous Capacitance
Compliance is the ability of a hollow organ (vessel) to distend and increase volume with increasing transmural pressure or the tendency of a hollow organ to resist recoil toward its original dimensions on application of a distending or compressing force. The reciprocal of compliance is elastance, a measure of the tendency of a hollow organ to recoil toward its original dimensions upon removal of a distending or compressing force. Blood vessels The terms elastance and compliance are of particular significance in cardiovascular physiology and respiratory physiology. In compliance, an increase in volume occurs in a vessel when the pressure in that vessel is increased. The tendency of the arteries and veins to stretch in response to pressure has a large effect on perfusion and blood pressure. This physically means that blood vessels with a higher compliance deform easier than lower compliance blood vessels under the same pressure and volume conditions. Venous compliance is approximatel ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, and hormones. The blood cells are mainly red blood cells (erythrocytes), white blood cells (leukocytes), and (in mammals) platelets (thrombocytes). The most abundant cells are red blood cells. These contain hemoglobin, which facilitates oxygen transport by reversibly binding to it, increasing its solubility. Jawed vertebrates have an adaptive immune system, based largely on white blood cells. White blood cells help to resist infections and parasites. Platelets are important in the clotting of blood. Blood is circulated around the body through blood vessels by the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deoxygenated Blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, and hormones. The blood cells are mainly red blood cells (erythrocytes), white blood cells (leukocytes), and (in mammals) platelets (thrombocytes). The most abundant cells are red blood cells. These contain hemoglobin, which facilitates oxygen transport by reversibly binding to it, increasing its solubility. Jawed vertebrates have an adaptive immune system, based largely on white blood cells. White blood cells help to resist infections and parasites. Platelets are important in the clotting of blood. Blood is circulated around the body through blood vessels by the pump ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oxygenated Blood
Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the Cell (biology), cells, and transports Metabolic waste, metabolic waste products away from those same cells. Blood is composed of blood cells suspended in blood plasma. Plasma, which constitutes 55% of blood fluid, is mostly water (92% by volume), and contains proteins, glucose, mineral ions, and hormones. The blood cells are mainly red blood cells (erythrocytes), white blood cells (leukocytes), and (in mammals) platelets (thrombocytes). The most abundant cells are red blood cells. These contain hemoglobin, which facilitates oxygen transport by reversibly binding to it, increasing its solubility. Gnathostomata, Jawed vertebrates have an adaptive immune system, based largely on white blood cells. White blood cells help to resist infections and parasites. Platelets are important in the Coagulation, clotting of blood. Blood is circu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Skeletal Muscle Pump
The skeletal muscle pump or musculovenous pump is a collection of skeletal muscles that aid the heart in the circulation of blood. It is especially important in increasing venous return to the heart, but may also play a role in arterial blood flow. General The skeletal muscle pump is vital in negating orthostatic intolerance when standing. When moving upright, the blood volume moves to the peripheral parts of the body. To combat this, the muscles involved in standing contract and help to bring venous blood volume to the heart. The pump is important in affecting the central and local supply of blood output. Venous return, cardiac output, and stroke volume were all increased during exercise experiments, as well as affecting the local muscle being used, blood volume. Arterial blood pumping Between muscle relaxations, intramuscular pressure transiently returns to a level below the venous blood pressure. This allows blood from the capillary system to refill the veins until the next c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inferior Vena Cava
The inferior vena cava is a large vein that carries the deoxygenated blood from the lower and middle body into the right atrium of the heart. It is formed by the joining of the right and the left common iliac veins, usually at the level of the fifth Lumbar vertebrae, lumbar vertebra. The inferior vena cava is the lower ("anatomical terms of location#Superior and inferior, inferior") of the two venae cavae, the two large veins that carry deoxygenated blood from the body to the right atrium of the heart: the inferior vena cava carries blood from the lower half of the body whilst the superior vena cava carries blood from the upper half of the body. Together, the venae cavae (in addition to the coronary sinus, which carries blood from the muscle of the heart itself) form the venous counterparts of the aorta. It is a large retroperitoneal vein that lies Posterior (anatomy), posterior to the abdominal cavity and runs along the right side of the vertebral column. It enters the right a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Superior Vena Cava
The superior vena cava (SVC) is the superior of the two venae cavae, the great venous trunks that return deoxygenated blood from the systemic circulation to the right atrium of the heart. It is a large-diameter (24 mm) short length vein that receives venous return from the upper half of the body, above the diaphragm. Venous return from the lower half, below the diaphragm, flows through the inferior vena cava. The SVC is located in the anterior right superior mediastinum. It is the typical site of central venous access via a central venous catheter or a peripherally inserted central catheter. Mentions of "the cava" without further specification usually refer to the SVC. Structure The superior vena cava is formed by the left and right brachiocephalic veins, which receive blood from the upper limbs, head and neck, behind the lower border of the first right costal cartilage. It passes vertically downwards behind the first intercostal space and receives the azygos vei ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart
The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrients to the tissue, while carrying metabolic waste such as carbon dioxide to the lungs. In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the thorax, chest, called the mediastinum. In humans, the heart is divided into four chambers: upper left and right Atrium (heart), atria and lower left and right Ventricle (heart), ventricles. Commonly, the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. In a healthy heart, blood flows one way through the heart due to heart valves, which prevent cardiac regurgitation, backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a sma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunica Externa
The tunica externa (Neo-Latin "outer coat"), also known as the tunica adventitia (Neo-Latin "additional coat"), is the outermost tunica (biology), tunica (layer) of a blood vessel, surrounding the tunica media. It is mainly composed of collagen and, in arteries, is supported by external elastic lamina. The collagen serves to anchor the blood vessel to nearby organs, giving it stability. The three layers of the blood vessels are: an inner tunica intima, a middle tunica media, and an outer tunica externa. Structure The tunica externa is made from collagen and elastic fibers in a loose connective tissue. This is secreted by fibroblasts. This is normally the thickest tunic in veins and may be thicker than the tunica media in some larger arteries. The outer layers of the tunica externa are not distinct but rather blend with the surrounding connective tissue outside the vessel, helping to hold the vessel in relative position. Function The tunica externa provides basic structural s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Figure 40 03 07
Figure may refer to: General *A shape, drawing, depiction, or geometric configuration *Figure (wood), wood appearance *Figure (music), distinguished from musical motif *Noise figure, in telecommunication * Dance figure, an elementary dance pattern *A person's figure, human physical appearance *Figure–ground (perception), the distinction between a visually perceived object and its surroundings Arts *Figurine, a miniature statuette representation of a creature *Action figure, a posable jointed solid plastic character figurine *Figure painting, realistic representation, especially of the human form *Figure drawing *Model figure, a scale model of a creature Writing *figure, in writing, a type of floating block (text, table, or graphic separate from the main text) *Figure of speech, also called a rhetorical figure *Christ figure, a type of character * in typesetting, text figures and lining figures Accounting *Figure, a synonym for number *Significant figures in a decimal numb ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tunica (biology)
In biology, a tunica (, ; : tunicae) is a layer, coat, sheath, or similar covering. The word came to English from the Neo-Latin of science and medicine. Its literal sense is about the same as that of the word ''tunic'', with which it is cognate. In biology, one of its senses used to be the taxonomic name of a genus of plants, but the nomenclature has been revised and those plants are now included in the genus '' Petrorhagia''. In modern biology in general, ''tunica'' occurs as a technical or anatomical term mainly in botany and zoology. It usually refers to membranous structures that line or cover particular organs. In many such contexts, ''tunica'' is used interchangeably with ''tunic'' according to preference. An organ or organism that has a tunic(a) may be said to be ''tunicate'', as in a ''tunicate bulb''. This adjective ''tunicate'' is not to be confused with the noun ''tunicate'', which refers to a member of the subphylum '' Tunicata''. Botanical and related usages In botany ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
