query: what blood vessels carry blood to the heart

pos: Blood vessel between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart. The word "vascular", meaning relating to the blood vessels, is derived from the Latin "vas", meaning vessel. A few structures (such as cartilage and the lens of the eye) do not contain blood vessels and are labeled. The arteries and veins have three layers. The middle layer is thicker in the arteries than it is in the veins: Capillaries consist of little more than a layer of endothelium and occasional connective tissue. When blood vessels connect to form a region of

pos: Vein Vein Veins are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the tissues back to the heart; exceptions are the pulmonary and umbilical veins, both of which carry oxygenated blood to the heart. In contrast to veins, arteries carry blood away from the heart. Veins are less muscular than arteries and are often closer to the skin. There are valves in most veins to prevent backflow. Veins are present throughout the body as tubes that carry blood back to the heart. Veins are classified in a number of ways, including superficial vs. deep, pulmonary

pos: Umbilical cord carries oxygenated, nutrient-rich blood to the fetus, and two arteries that carry deoxygenated, nutrient-depleted blood away. Occasionally, only two vessels (one vein and one artery) are present in the umbilical cord. This is sometimes related to fetal abnormalities, but it may also occur without accompanying problems. It is unusual for a vein to carry oxygenated blood and for arteries to carry deoxygenated blood (the only other examples being the pulmonary veins and arteries, connecting the lungs to the heart). However, this naming convention reflects the fact that the umbilical vein carries blood towards the fetus's heart, while the umbilical arteries

pos: Blood vessel between the blood and the tissues; and the veins, which carry blood from the capillaries back toward the heart. The word "vascular", meaning relating to the blood vessels, is derived from the Latin "vas", meaning vessel. A few structures (such as cartilage and the lens of the eye) do not contain blood vessels and are labeled. The arteries and veins have three layers. The middle layer is thicker in the arteries than it is in the veins: Capillaries consist of little more than a layer of endothelium and occasional connective tissue. When blood vessels connect to form a region of

pos: Vein and veins; these were later discovered by Marcello Malpighi in 1661. In 1956, André Frédéric Cournand, Werner Forssmann and Dickinson W. Richards were awarded the Nobel Prize in Medicine "for their discoveries concerning heart catheterization and pathological changes in the circulatory system." In his Nobel lecture, Forssmann credits Harvey as birthing cardiology with the publication of his book in 1628. In the 1970s, Diana McSherry developed computer-based systems to create images of the circulatory system and heart without the need for surgery. Vein Veins are blood vessels that carry blood toward the heart. Most veins carry deoxygenated blood from the

pos: Vein spleen, where it is taken up by the hepatic veins, and blood is taken back into the heart. Since this is an important function in mammals, damage to the hepatic portal vein can be dangerous. Blood clotting in the hepatic portal vein can cause portal hypertension, which results in a decrease of blood fluid to the liver. The vessels that remove the deoxygenated blood from the heart muscle are known as cardiac veins. These include the great cardiac vein, the middle cardiac vein, the small cardiac vein, the smallest cardiac veins, and the anterior cardiac veins. Coronary veins carry blood

pos: Cardiac output demand pump that does not regulate its own output. When the body has a high metabolic oxygen demand, the metabolically controlled flow through the tissues is increased, leading to a greater flow of blood back to the heart, leading to higher cardiac output. The capacitance, also known as compliance, of the arterio-vascular channels that carry the blood also controls cardiac output. As the body's blood vessels actively expand and contract, the resistance to blood flow increases and decreases respectively. Thin-walled veins have about eighteen times the capacitance of thick-walled arteries because they are able to carry more blood by virtue

pos: Coronary circulation named branches of the coronary circulation in a right-dominant heart: The vessels that remove the deoxygenated blood from the heart muscle are known as cardiac veins. These include the great cardiac vein, the middle cardiac vein, the small cardiac vein, the smallest cardiac veins, and the anterior cardiac veins. Cardiac veins carry blood with a poor level of oxygen, from the myocardium to the right atrium. Most of the blood of the coronary veins returns through the coronary sinus. The anatomy of the veins of the heart is very variable, but generally it is formed by the following veins: heart

pos: Cerebral circulation Cerebral circulation Cerebral circulation is the movement of blood through the network of cerebral arteries and veins supplying the brain. The rate of the cerebral blood flow in the adult is typically 750 milliliters per minute, representing 15% of the cardiac output. The arteries deliver oxygenated blood, glucose and other nutrients to the brain, and the veins carry deoxygenated blood back to the heart, removing carbon dioxide, lactic acid, and other metabolic products. Since the brain is very vulnerable to compromises in its blood supply, the cerebral circulatory system has many safeguards including autoregulation of the blood vessels and the

pos: Artery away from the heart to the tissues, except for pulmonary arteries, which carry blood to the lungs for oxygenation (usually veins carry deoxygenated blood to the heart but the pulmonary veins carry oxygenated blood as well). There are two types of unique arteries. The pulmonary artery carries blood from the heart to the lungs, where it receives oxygen. It is unique because the blood in it is not "oxygenated", as it has not yet passed through the lungs. The other unique artery is the umbilical artery, which carries deoxygenated blood from a fetus to its mother. Arteries have a blood

pos: Coronary circulation can become blocked, causing angina or a heart attack. The coronary arteries that run deep within the myocardium are referred to as subendocardial. The coronary arteries are classified as "end circulation", since they represent the only source of blood supply to the myocardium; there is very little redundant blood supply, that is why blockage of these vessels can be so critical. Coronary circulation Coronary circulation is the circulation of blood in the blood vessels that supply the heart muscle (myocardium). Coronary arteries supply oxygenated blood to the heart muscle, and cardiac veins drain away the blood once it has been

pos: Cardiology in the blood vessels of the heart muscle (myocardium). The vessels that deliver oxygen-rich blood to the myocardium are known as coronary arteries. The vessels that remove the deoxygenated blood from the heart muscle are known as cardiac veins. These include the great cardiac vein, the middle cardiac vein, the small cardiac vein and the anterior cardiac veins. As the left and right coronary arteries run on the surface of the heart, they can be called epicardial coronary arteries. These arteries, when healthy, are capable of autoregulation to maintain coronary blood flow at levels appropriate to the needs of the

pos: Vein pressure. The arteries are perceived as carrying oxygenated blood to the tissues, while veins carry deoxygenated blood back to the heart. This is true of the systemic circulation, by far the larger of the two circuits of blood in the body, which transports oxygen from the heart to the tissues of the body. However, in pulmonary circulation, the arteries carry deoxygenated blood from the heart to the lungs, and veins return blood from the lungs to the heart. The difference between veins and arteries is their direction of flow (out of the heart by arteries, returning to the heart for

pos: Bronchial veins veins. Bronchial veins The bronchial veins are small vessels that return blood from the larger bronchi and structures at the roots of the lungs. The right side drains into the azygos vein, while the left side drains into the left superior intercostal vein or the accessory hemiazygos vein. Bronchial veins are thereby part of the bronchial circulation, carrying waste products away from the cells that constitute the lungs. The bronchial veins are counterparts to the bronchial arteries. However, they only carry ~13% of the blood flow of the bronchial arteries. The remaining blood is returned to the heart via the

pos: Bronchial veins Bronchial veins The bronchial veins are small vessels that return blood from the larger bronchi and structures at the roots of the lungs. The right side drains into the azygos vein, while the left side drains into the left superior intercostal vein or the accessory hemiazygos vein. Bronchial veins are thereby part of the bronchial circulation, carrying waste products away from the cells that constitute the lungs. The bronchial veins are counterparts to the bronchial arteries. However, they only carry ~13% of the blood flow of the bronchial arteries. The remaining blood is returned to the heart via the pulmonary

pos: Human body collection of nerve fibres connecting the brain to the rest of the body. Nerves connect the spinal cord and brain to the rest of the body. All major bones, muscles, and nerves in the body are named, with the exception of anatomical variations such as sesamoid bones and accessory muscles. Blood vessels carry blood throughout the body, which moves because of the beating of the heart. Venules and veins collect blood low in oxygen from tissues throughout the body. These collect in progressively larger veins until they reach the body's two largest veins, the superior and inferior vena cava, which

pos: Blood vessel diffuse vascular supply it is called an anastomosis. 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. Blood vessels are part of the circulatory system, together with the heart and the blood. The biggest difference in the structure of arteries and veins is the presence of valves. Backflow of blood is prevented in arteries by the heart. However in veins, one-direction valves are used to

pos: Smallest cardiac veins contribute to normal physiologic shunting of blood. As a consequence of the input of these vessels, blood in the left heart is less oxygenated than the blood found at the pulmonary capillary beds, albeit to a very small degree. The "openings of smallest cardiac veins" are located in the endocardium. Here the smallest cardiac veins return blood into the heart chambers from the capillary bed in the muscular cardiac wall, enabling a form of collateral circulation unique to the heart. Not every endocardial opening connects to the thebesian veins as some connect to the vessels of Wearn, which are arteries.

pos: Human body include the heart, lungs and liver. Many organs reside within cavities within the body. These cavities include the abdomen and pleura. The circulatory system comprises the heart and blood vessels (arteries, veins and capillaries). The heart propels the circulation of the blood, which serves as a "transportation system" to transfer oxygen, fuel, nutrients, waste products, immune cells and signalling molecules (i.e., hormones) from one part of the body to another. The blood consists of fluid that carries cells in the circulation, including some that move from tissue to blood vessels and back, as well as the spleen and bone marrow.

pos: Heart the heart, ancient Greeks are considered to have been the primary seat of scientific understanding of the heart in the ancient world. Aristotle considered the heart to be organ responsible for creating blood; Plato considered the heart as the source of circulating blood and Hippocrates noted blood circulating cyclically from the body through the heart to the lungs. Erasistratos (304–250 BCE) noted the heart as a pump, causing dilation of blood vessels, and noted that arteries and veins both radiate from the heart, becoming progressively smaller with distance, although he believed they were filled with air and not blood. He

pos: Microcirculation Microcirculation The microcirculation is the circulation of the blood in the smallest blood vessels, the microvessels of the microvasculature present within organ tissues. The microvessels include terminal arterioles, metarterioles, capillaries, and venules. Arterioles carry oxygenated blood to the capillaries, and blood flows out of the capillaries into the venules into the veins. In addition to these blood vessels, the microcirculation also includes lymphatic capillaries and collecting ducts. The main functions of the microcirculation are the delivery of oxygen and nutrients and the removal of carbon dioxide (CO). It also serves to regulate blood flow and tissue perfusion thereby affecting blood

pos: American flamingo volume of lung than a mammal. The American flamingo's four-chambered heart is myogenic, meaning that all the muscle cells and fibers have the ability to contract rhythmically. The rhythm of contraction is controlled by the pace maker cells which have a lower threshold for depolarization. The wave of electrical depolarization initiated here is what physically starts the heart's contractions and begins pumping blood. Pumping blood creates variations in blood pressure and as a result, creates different thicknesses of blood vessels. The Law of LaPlace can be used to explain why arteries are relatively thick and veins are thin. It was

pos: Reindeer by blood returning to the body in a countercurrent heat exchange (CCHE), a highly efficient means of minimizing heat loss through the skin's surface. In the CCHE mechanism, in cold weather, blood vessels are closely knotted and intertwined with arteries to the skin and appendages that carry warm blood with veins returning to the body that carry cold blood causing the warm arterial blood to exchange heat with the cold venous blood. In this way, their legs for example are kept cool, maintaining the core body temperature nearly higher with less heat lost to the environment. Heat is thus recycled

pos: Blood vary somewhat between species. In non-mammalian vertebrates, however, there are some key differences: Blood is circulated around the body through blood vessels by the pumping action of the heart. In humans, blood is pumped from the strong left ventricle of the heart through arteries to peripheral tissues and returns to the right atrium of the heart through veins. It then enters the right ventricle and is pumped through the pulmonary artery to the lungs and returns to the left atrium through the pulmonary veins. Blood then enters the left ventricle to be circulated again. Arterial blood carries oxygen from inhaled

pos: Heart reduced, having no veins or arteries and consisting of two connected tubes. Oxygen travels by diffusion and there are five small muscular vessels that connect these vessels that contract at the front of the animals that can be thought of as "hearts". Squids and other cephalopods have two "gill hearts" also known as branchial hearts, and one "systemic heart". The brachial hearts have two atria and one ventricle each, and pump to the gills, whereas the systemic heart pumps to the body. Heart The heart is a muscular organ in most animals, which pumps blood through the blood vessels of

pos: Microcirculation merge with other vesicles, so their contents are mixed, or can directly go to a specific tissue. This material intermixed increases the functional capability of the vesicle. Microcirculation The microcirculation is the circulation of the blood in the smallest blood vessels, the microvessels of the microvasculature present within organ tissues. The microvessels include terminal arterioles, metarterioles, capillaries, and venules. Arterioles carry oxygenated blood to the capillaries, and blood flows out of the capillaries into the venules into the veins. In addition to these blood vessels, the microcirculation also includes lymphatic capillaries and collecting ducts. The main functions of the microcirculation

pos: Giraffe have unusually high heart rates for their size, at 150 beats per minute. When the animal lowers its head the blood rushes down fairly unopposed and a rete mirabile in the upper neck, with its large cross sectional area, prevents excess blood flow to the brain. When it raises again, the blood vessels constrict and direct blood into the brain so the animal does not faint. The jugular veins contain several (most commonly seven) valves to prevent blood flowing back into the head from the inferior vena cava and right atrium while the head is lowered. Conversely, the blood vessels

pos: Coronary circulation Coronary circulation Coronary circulation is the circulation of blood in the blood vessels that supply the heart muscle (myocardium). Coronary arteries supply oxygenated blood to the heart muscle, and cardiac veins drain away the blood once it has been deoxygenated. Because the rest of the body, and most especially the brain, needs a steady supply of oxygenated blood that is free of all but the slightest interruptions, the heart works constantly and sometimes works quite hard. Therefore its circulation is of major importance not only to its own tissues but to the entire body and even the level of consciousness

pos: Jean Riolan the Younger through the blood vessels to the body's extremities and returned to the heart only two or three times a day. He also postulated that blood often ebbed and flowed in the veins and that it was taken in as nourishment by different parts of the body. Riolan also did not believe that the heart propelled the blood, instead he proposed that the blood kept the heart in motion, analogous to a stream moving the wheel of a water mill. Riolan had other disagreements with Harvey, such as the role of the liver as a blood-manufacturing organ. Riolan was an opponent

pos: Pulmonary circulation pulmonary respiration. The physician Hippocrates (460 - 370 BCE) developed the view that the liver and spleen produced blood, which traveled to the heart to be cooled by the lungs that surrounded it. Hippocrates described the heart as having two ventricles connected by an interventricular septum. He depicted the heart as the connecting point for all the vessels of the body and proposed that some vessels carried only blood, while others also carried air. These air-carrying vessels were the pulmonary veins, which brought air to the left ventricle, and the pulmonary artery, which carried air to the right ventricle and

pos: Biofluid dynamics oxygen. The red blood cells and the hemoglobin present in the blood, which is the main carrier of oxygen in the blood are responsible for this exchange of gases before they are carried to the left ventricle of the heart. The systemic circulation is responsible for taking the oxygenated blood to various organs and tissues via the arterial tree before taking the deoxygenated blood to the right ventricle using the venous system (a network of veins). Arteries carry the oxygenated blood while the veins carry the deoxygenated blood. The fluids associated with the human body include air, oxygen, carbon dioxide,

pos: Medical ultrasound the application of ultrasound technology, such as piezoelectric transducer or CMUT, to see from inside blood vessels out through the surrounding blood column, visualizing the endothelium (inner wall) of blood vessels in living individuals. On the legs, ultrasonography of deep venous thrombosis focuses on the deep veins, while ultrasonography of chronic venous insufficiency of the legs focuses on more superficial veins. Echocardiography is an essential tool in cardiology, to diagnose e.g. dilatation of parts of the heart and function of heart ventricles and valves Point of care emergency ultrasound has many applications in emergency medicine, including the Focused Assessment with

pos: Hemodynamics the "capacitance vessels" of the body because over 70% of the blood volume resides in the venous system. Veins are more compliant than arteries and expand to accommodate changing volume. The blood pressure in the circulation is principally due to the pumping action of the heart. The pumping action of the heart generates pulsatile blood flow, which is conducted into the arteries, across the micro-circulation and eventually, back via the venous system to the heart. During each heartbeat, systemic arterial blood pressure varies between a maximum (systolic) and a minimum (diastolic) pressure. In physiology, these are often simplified into one

pos: Vein person's skin, how much oxygen is being carried in the blood, and how big and deep the vessels are. When a vein is drained of blood and removed from an organism, it appears grey-white. The largest veins in the human body are the venae cavae. These are two large veins which enter the right atrium of the heart from above and below. The superior vena cava carries blood from the arms and head to the right atrium of the heart, while the inferior vena cava carries blood from the legs and abdomen to the heart. The inferior vena cava is

pos: Biofluid dynamics circulates about 5 liters of blood at a rate of approximately 6 l/m. The pulmonary and the systemic circulations are the two parts of the vasculature. The pulmonary circulation system consists of the network of blood vessels from the right heart to the lungs and back to the left heart. The rest of the blood flow loop is called systemic circulation system. The pulmonary and systemic circulations take the blood through large arteries first and then branches into smaller arteries before reaching arterioles and capillaries. After capillaries, the blood enters the venules before joining smaller veins first and then larger

pos: Octopus blood cells, and gives the blood a bluish colour. The systemic heart has muscular contractile walls and consists of a single ventricle and two atria, one for each side of the body. The blood vessels consist of arteries, capillaries and veins and are lined with a cellular endothelium which is quite unlike that of most other invertebrates. The blood circulates through the aorta and capillary system, to the vena cavae, after which the blood is pumped through the gills by the auxiliary hearts and back to the main heart. Much of the venous system is contractile, which helps circulate the

neg: Blood vessel Blood vessel The blood vessels are the part of the circulatory system, and microcirculation, that transports blood throughout the human body. These vessels are designed to transport nutrients and oxygen to the tissues of the body. They also take waste and carbon dioxide and carry them away from the tissues and back to the heart. Blood vessels are needed to sustain life as all of the body’s tissues rely on their functionality.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

neg: Blood vessel prevent blood clots and can also help limit inflammation. Vasculitis is inflammation of the vessel wall, due to autoimmune disease or infection. Blood vessel The blood vessels are the part of the circulatory system, and microcirculation, that transports blood throughout the human body. These vessels are designed to transport nutrients and oxygen to the tissues of the body. They also take waste and carbon dioxide and carry them away from the tissues and back to the heart. Blood vessels are needed to sustain life as all of the body’s tissues rely on their functionality.There are three major types of blood

neg: Pulmonary hypertension heart failure follows. As the blood flowing through the lungs decreases, the left side of the heart receives less blood. This blood may also carry less oxygen than normal. Therefore, it becomes harder and harder for the left side of the heart to pump to supply sufficient oxygen to the rest of the body, especially during physical activity. In PVOD (WHO Group 1'), pulmonary blood vessel narrowing occurs preferentially (though not exclusively) in post-capillary venous blood vessels. PVOD shares several characteristics with PAH, but there are also some important differences, for example differences in prognosis and response to medical therapy.

neg: Channichthyidae of myoglobin gene expression in icefish heart ventricles has occurred at least four separate times. To compensate for the loss of hemoglobin, they have larger blood vessels (including capillaries), greater blood volumes (four times those of other fish), bigger hearts, and greater cardiac outputs (fivefold greater) compared to other fish. Their hearts lack coronary arteries, and the ventricle muscles are very spongy, enabling them to absorb oxygen directly from the blood they pump. Their hearts, large blood vessels and low-viscosity (RBC free) blood are specialized to carry out very high flow rates at low pressures. This helps to reduce the

neg: Syncope (medicine) Causes range from non-serious to potentially fatal. There are three broad categories of causes: heart or blood vessel related, reflex also known as neurally mediated, and orthostatic hypotension. Issues with the heart and blood vessels are the cause in about 10% and typically the most serious while neurally mediated is the most common. Heart related causes may include an abnormal heart rhythm, problems with the heart valves or heart muscle and blockages of blood vessels from a pulmonary embolism or aortic dissection among others. Neurally mediated syncope occurs when blood vessels expand and heart rate decreases inappropriately. This may occur

neg: Coronary thrombosis Coronary thrombosis Coronary thrombosis is the formation of a blood clot inside a blood vessel of the heart. This blood clot restricts blood flow within the heart. It is associated with narrowing of blood vessels subsequent to clotting.<ref name="urlThrombosis/Coronary Thrombosis"></ref> The condition is considered as a type of ischaemic heart disease, also known as a heart attack or myocardial infarction. Thrombosis in the heart can lead to a myocardial infarction. Coronary thrombosis and myocardial infarction are sometimes used as synonyms, although this is technically inaccurate as the thrombosis refers to the blocking of blood vessels, while the infarction refers to

neg: Blood vessel 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 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 where the vessels away from the heart oppose the flow of blood. Resistance is an accumulation of three different factors: blood viscosity, blood vessel length,

neg: Polychaete two main blood vessels furnish smaller vessels to supply the parapodia and the gut. Blood flows forward in the dorsal vessel, above the gut, and returns down the body in the ventral vessel, beneath the gut. The blood vessels themselves are contractile, helping to push the blood along, so most species have no need of a heart. In a few cases, however, muscular pumps analogous to a heart are found in various parts of the system. Conversely, some species have little or no circulatory system at all, transporting oxygen in the coelomic fluid that fills their body cavities. The blood

neg: Verapamil the AV node, thus protecting the ventricles from atrial tachyarrhythmias. Calcium channels are also present in the smooth muscle lining blood vessels. By relaxing the tone of this smooth muscle, calcium channel blockers dilate the blood vessels. This has led to their use in treating high blood pressure and angina pectoris. The pain of angina is caused by a deficit in oxygen supply to the heart. Calcium channel blockers like verapamil dilate blood vessels, which increases the supply of blood and oxygen to the heart. This controls chest pain, but only when used regularly. It does not stop chest pain

neg: Blood vessel dehydration or heart disease while lower proportions could lead to anemia and long-term blood loss. Blood vessels also transport red blood cells which contain the oxygen necessary for daily activities. The amount of red blood cells present in your vessels has an effect on your health. Hematocrit tests can be performed to calculate the proportion of red blood cells in your 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 is

neg: Management of acute coronary syndrome workload of the heart. The pain of myocardial ischemia is likely to respond to any intervention that improves the relationship between oxygen demand and supply, like nitrates, beta blockers and oxygen. Nitrates, like nitroglycerin, dilate blood vessels, which is beneficial against myocardial ischemia in two ways: By increasing blood flow in the coronary arteries and the amount of oxygen that arrives to heart muscle; and by relaxing all blood vessels in the body, thereby reducing the workload that heart needs to produce against them and the oxygen it consumes. The preferred mode of administration is sublingually. By relaxing blood vessels

neg: Brain ischemia blood vessels may also lead to brain ischemia, by blocking the arteries that carry oxygen to the brain. Tumors are one cause of blood vessel compression. Ventricular tachycardia represents a series of irregular heartbeats that may cause the heart to completely shut down resulting in cessation of oxygen flow. Further, irregular heartbeats may result in formation of blood clots, thus leading to oxygen deprivation to all organs. Blockage of arteries due to plaque buildup may also result in ischemia. Even a small amount of plaque build up can result in the narrowing of passageways, causing that area to become more

neg: Circulatory system that is circulated by the heart through the vertebrate vascular system, carrying oxygen and nutrients to and waste materials away from all body tissues. Lymph is essentially recycled excess blood plasma after it has been filtered from the interstitial fluid (between cells) and returned to the lymphatic system. The cardiovascular (from Latin words meaning "heart" and "vessel") system comprises the blood, heart, and blood vessels. The lymph, lymph nodes, and lymph vessels form the lymphatic system, which returns filtered blood plasma from the interstitial fluid (between cells) as lymph. The circulatory system of the blood is seen as having two

neg: Vascular smooth muscle greater wall thickness. This is because they have to carry pumped blood away from the heart to all the organs and tissues that need the oxygenated blood. The endothelial lining of each is similar. Excessive proliferation of vascular smooth muscle cells contributes to the progression of pathological conditions, such as vascular inflammation, plaque formation, atherosclerosis, restenosis, and pulmonary hypertension. Vascular smooth muscle 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 refers to the particular type of smooth muscle found within, and composing

neg: Alcohol (drug) sensory and motor function, slowed cognition, stupefaction, unconsciousness, and possible death. Ethanol is commonly consumed as a recreational substance, especially while socializing, due to its psychoactive effects. Ethanol, alcohol increases levels of high-density lipoproteins (HDLs), which carry cholesterol through the blood. Alcohol is known to make blood less likely to clot, reducing risk of heart attack and stroke. This could be the reason that alcohol produces health benefits when consumed in moderate amounts. Also, alcohol dilates blood vessels. Consequently, a person feels warmer, and their skin may flush and appear pink. Ethanol is a source of energy and pure ethanol

neg: Catheter They include instruments to measure the pressure of blood in each heart chamber and in blood vessels connected to the heart, view the interior of blood vessels, take blood samples from different parts of the heart, or remove a tissue sample (biopsy) from inside the heart.(American Heart Association) The catheter used for hemodialysis is a tunneled catheter because it is placed under the skin. There are two types of tunneled catheters: cuffed or non-cuffed. Non-cuffed tunneled catheters are used for emergencies and for short periods (up to 3 weeks). Tunneled cuffed catheters, a type recommended by the NKF for temporary

neg: Fetal circulation circulatory system of the mother is not directly connected to that of the fetus, so the placenta functions as the respiratory center for the fetus as well as a site of filtration for plasma nutrients and wastes. Water, glucose, amino acids, vitamins, and inorganic salts freely diffuse across the placenta along with oxygen. The uterine arteries carry blood to the placenta, and the blood permeates the sponge-like material there. Oxygen then diffuses from the placenta to the chorionic villus, an alveolus-like structure, where it is then carried to the umbilical vein. The heart and blood vessels which form the circulatory

neg: Heart also discovered the heart valves. The Greek physician Galen (2nd century CE) knew blood vessels carried blood and identified venous (dark red) and arterial (brighter and thinner) blood, each with distinct and separate functions. Galen, noting the heart as the hottest organ in the body, concluded that it provided heat to the body. The heart did not pump blood around, the heart's motion sucked blood in during diastole and the blood moved by the pulsation of the arteries themselves. Galen believed the arterial blood was created by venous blood passing from the left ventricle to the right through 'pores' between

neg: Annelid around the gut transfer blood between the main blood vessels and to parts of the segment that need oxygen and nutrients. Both of the major vessels, especially the upper one, can pump blood by contracting. In some annelids the forward end of the upper blood vessel is enlarged with muscles to form a heart, while in the forward ends of many earthworms some of the vessels that connect the upper and lower main vessels function as hearts. Species with poorly developed or no septa generally have no blood vessels and rely on the circulation within the coelom for delivering nutrients

neg: Fimasartan when renin release from the kidney causes the breakdown of angiotensinogen into angiotensin I. Angiotensin-converting enzyme (ACE) then catalyzes the reaction that forms angiotensin II, which acts on AT receptors on the blood vessels, heart, and kidneys. On blood vessels, the AT receptor is coupled to an intracellular pathway that causes smooth muscle contraction (vasoconstriction) of blood vessels. In blocking the AT receptor, fimasartan inhibits vasoconstriction, favouring vasodilation. At the kidney and adrenal gland, AT blockage and prevention of aldosterone formation increase excretion of water and salt by the kidneys, which decreases overall blood volume. At the heart, AT blockage

neg: Vital heat other factors in the body, death its final extinction." According to Ancient Greek physicians, vital heat was produced by the heart, maintained by the "pneuma" (air, breath, spirit or soul), and circulated throughout the body by blood vessels, which were thought to be intact tubes using blood to transmit heat. Aristotle supported this argument by showing that when the heart is made cold compared to other organs, the individual dies. He believed that the heat produced in the heart caused blood to react in a similar way to boiling, expanding out through the blood vessels with every beat. This extreme

neg: Haemodynamic response and prostacyclin, along with overexpression of vasoconstrictors not only affect vascular tone but also promote vascular remodeling. PAH deals with increase blood pressure in pulmonary arteries, which leads to shortness of breath, dizziness, fainting, rarely hemoptysis, and many other symptoms. PAH can be a severe disease, which may lead to decreased exercise tolerance, and ultimately heart failure. It involves vasoconstrictions of blood vessels connected to and within the lungs. As a result, the heart has a hard time pumping blood through the lungs, and the blood vessels eventually undergoes fibrosis. The increased workload on the heart causes hypertrophy of the

neg: Stimulus (physiology) that will restore the body to stasis (such as withdrawal, drinking or resting). Blood pressure, heart rate, and cardiac output are measured by stretch receptors found in the carotid arteries. Nerves embed themselves within these receptors and when they detect stretching, they are stimulated and fire action potentials to the central nervous system. These impulses inhibit the constriction of blood vessels and lower the heart rate. If these nerves do not detect stretching, the body determines perceives low blood pressure as a dangerous stimulus and signals are not sent, preventing the inhibition CNS action; blood vessels constrict and the heart

neg: Necrotizing fasciitis "Clostridium perfringens" produces two deadly toxins: alpha-toxin and theta-toxin. Alpha-toxin causes excessive platelet aggregation which blocks blood vessels and deprives the vital organs of oxygen supply. This creates an acidic, oxygen-deficient environment for the proliferation of bacteria. When alpha-toxin is absorbed by soft tissues, it can inhibit the migration of white blood cells from blood vessels into the soft tissue, thus impairing phagocyte function. The two toxins together can cause destruction of red blood cells in blood vessels, damage to the integrity of the blood vessels, and suppression of heart function. "Clostridium sordellii" can also produce two major toxins: all

neg: Almotriptan adverse effects profile similar to placebo when used following the Summary of Product Characteristics instructions (see references). Like all triptans, almotriptan has a high and specific affinity for serotonin 5-HT receptors. Binding of the drug to the receptor leads to vasoconstriction of the cranial (brain) blood vessels and thus affects the redistribution of blood flow. Almotriptan significantly increases cerebral blood flow and reduces blood flow through extracerebral cranial vessels. Even though it affects cranial blood vessels a single standard dose of almotriptan has no clinically significant effect on blood pressure or heart rate in both young and elderly healthy volunteers.

neg: Ibn al-Nafis the arteria venosa to the left cavity of the two cavities of the heart; and of that mixture is created the animal spirit. Ibn al-Nafis also postulated that nutrients for heart are extracted from the coronary arteries: Again his [Avicenna's] statement that the blood that is in the right side is to nourish the heart is not true at all, for the nourishment to the heart is from the blood that goes through the vessels that permeate the body of the heart. Ibn al-Nafis had an insight into what would become a larger theory of the capillary circulation. He stated

neg: History of anatomy the functions of organs and structures in the body. The study of anatomy begins at least as early as 1600 BC, the date of the Edwin Smith Surgical Papyrus. This treatise shows that the heart, its vessels, liver, spleen, kidneys, hypothalamus, uterus and bladder were recognized, and that the blood vessels were known to emanate from the heart. Other vessels are described, some carrying air, some mucus, and two to the right ear are said to carry the "breath of life", while two to the left ear the "breath of death".The Ebers Papyrus (c. 1550 BC) features a treatise on

neg: Berlin Heart unit. It moves the membranes, which draw blood into the blood chamber and push it back into the body. Like the heart, EXCOR blood pumps have valves which ensure that the blood only flows in one direction. The blood pumps are connected to the heart and blood vessels via silicone cannula. The EXCOR product range covers blood pumps and cannula of various sizes and types. While EXCOR Adult is specifically designed for adults, EXCOR Pediatric includes devices for young patients (from newborns to adolescents). In 2018 Chloe Caldwell became the first pediatric patient to be flown for a medical treatment

neg: Bloodless surgery low central venous pressure anesthesia (for select cases), or suture ligation of vessels. Other methods include the use of blood substitutes, which at present do not carry oxygen but expand the volume of the blood to prevent shock. Blood substitutes which do carry oxygen, such as PolyHeme, are also under development. Many doctors view acute normovolemic hemodilution, a form of storage of a patient's own blood, as a pillar of "bloodless surgery" but the technique is not an option for patients who refuse autologous blood transfusions. Intraoperative blood salvage is a technique which recycles and cleans blood from a patient

neg: Blood pressure between a maximum (systolic) and a minimum (diastolic) pressure. The blood pressure in the circulation is principally due to the pumping action of the heart. Differences in mean blood pressure are responsible for blood flow from one location to another in the circulation. The rate of mean blood flow depends on both blood pressure and the resistance to flow presented by the blood vessels. Mean blood pressure decreases as the circulating blood moves away from the heart through arteries and capillaries due to viscous losses of energy. Mean blood pressure drops over the whole circulation, although most of the fall

neg: Fiona pinnata a specialized breathing organ. The oxygenated blood from the heart leads to the aorta, to sinuses where it oxygenates tissues. Deoxygenated blood goes to efferent branchial vessels in cerata. These efferent vessels can be seen in a transverse section of the cerata as widish canal to pass up the opposite margin. From efferent vessels the blood goes into afferent vessel, where is gets an oxygen. Dorsal skin also partly serves as a breathing organ. Excretory system: The renal pore is between heart and anus. Nervous system: The cerebral ganglia are placed at the commencement of the oesophagus. There are as

neg: Coronary thrombosis is treated by taking Aspirin, Nitrates, or Beta Blockers. Coronary thrombosis can be a complication associated with drug-eluting stents. Coronary thrombosis Coronary thrombosis is the formation of a blood clot inside a blood vessel of the heart. This blood clot restricts blood flow within the heart. It is associated with narrowing of blood vessels subsequent to clotting.<ref name="urlThrombosis/Coronary Thrombosis"></ref> The condition is considered as a type of ischaemic heart disease, also known as a heart attack or myocardial infarction. Thrombosis in the heart can lead to a myocardial infarction. Coronary thrombosis and myocardial infarction are sometimes used as synonyms, although

neg: Cardioplegia Blood supply to the heart arises from the aortic root through coronary arteries. Cardioplegia in diastole ensures that the heart does not use up the valuable energy stores (adenosine triphosphate). Blood is commonly added to this solution in varying amounts from 0 to 100%. Blood acts a buffer and also supplies nutrients to the heart during ischemia. Once the procedure on the heart vessels (coronary artery bypass grafting) or inside the heart such as valve replacement or correction of congenital heart defect, etc. is over, the cross-clamp is removed and the isolation of the heart is terminated, so normal blood

neg: Carvedilol Carvedilol Carvedilol, sold under the brand name Coreg among others, is a medication used for treating mild to severe congestive heart failure (CHF), left ventricular dysfunction (LVD) following heart attack in people who are otherwise stable, and for treating high blood pressure. It is a nonselective beta blocker/alpha-1 blocker and belongs to the third generation of beta blockers. Beta blockers block the beta receptors on heart muscle and other cells, making them more relaxed and less responsive to stress hormones. Carvedilol also blocks alpha receptors, which are found on blood vessels, and relaxes the blood vessels, dilating them, which lowers

neg: Great arteries birth. Great arteries The great arteries are the primary arteries that carry blood away from the heart, which include: The great arteries originate from the aortic arches during embryonic development. The aortic arches start as five pairs of symmetrical vessels connecting the heart with the dorsal aorta but then undergo a significant remodelling, in which some of these vessels regress (aortic arches 1 and 2), the 3rd pair of arches contribute to form the common carotids, the right 4th will contribute to the base and central part of the right subclavian artery, while the left 4th will form the central

neg: Great arteries Great arteries The great arteries are the primary arteries that carry blood away from the heart, which include: The great arteries originate from the aortic arches during embryonic development. The aortic arches start as five pairs of symmetrical vessels connecting the heart with the dorsal aorta but then undergo a significant remodelling, in which some of these vessels regress (aortic arches 1 and 2), the 3rd pair of arches contribute to form the common carotids, the right 4th will contribute to the base and central part of the right subclavian artery, while the left 4th will form the central portion

neg: Scimitar oryx to help conduct heat away from the body, enabling them to go for long periods without water. They can allow their body temperature to rise to almost before beginning to perspire. In times of ample supply, oryx can use fluid loss through urination and feces to lower their body temperature to below at night, giving more time before reaching maximum body temperature the following day. They can tolerate high temperatures that would be lethal to most mammals. They have a network of fine blood vessels that carry blood from the heart to the brain, passing close to the nasal passage

neg: Heart in the brainstem that control the sympathetic and parasympathetic influences to the heart through the vagus nerve and sympathetic trunk. These cardiovascular centres receive input from a series of receptors including baroreceptors, sensing stretch the stretching of blood vessels and chemoreceptors, sensing the amount of oxygen and carbon dioxide in the blood and its pH. Through a series of reflexes these help regulate and sustain blood flow. Baroreceptors are stretch receptors located in the aortic sinus, carotid bodies, the venae cavae, and other locations, including pulmonary vessels and the right side of the heart itself. Baroreceptors fire at a rate

neg: Ibn al-Nafis BC) and that the ventricle gets its energy from the blood flowing in the vessels running in the coronary vessels, not from blood deposited in the right ventricle. Based on his anatomical knowledge, Ibn al-Nafis stated: Blood from the right chamber of the heart must arrive at the left chamber, but there is no direct pathway between them. The thick septum of the heart is not perforated and does not have visible pores as some people thought or invisible pores as Galen thought. The blood from the right chamber must flow through the vena arteriosa (pulmonary artery) to the lungs,

neg: Blood vessel 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 the blood vessels is hypertension or high blood pressure. This is caused by an increase in the pressure of the blood flowing through the vessels. Hypertension can lead to more serious conditions such as heart failure and stroke. To prevent these diseases, the most common treatment option is medication as opposed to surgery. Aspirin helps

neg: Coronary circulation vessels (the vessels that run along the outer surface of the heart) remain open. Because of this, blood flow in the subendocardium stops during ventricular contraction. As a result, most myocardial perfusion occurs during heart relaxation (diastole) when the subendocardial coronary vessels are open and under lower pressure. Flow never comes to zero in the right coronary artery, since the right ventricular pressure is less than the diastolic blood pressure. The heart regulates the amount of vasodilation or vasoconstriction of the coronary arteries based upon the oxygen requirements of the heart. This contributes to the filling difficulties of the coronary

neg: Brain ischemia a distinct sub-type of depression, and can be detected with an MRI. Brain ischemia has been linked to a variety of diseases or abnormalities. Individuals with sickle cell anemia, compressed blood vessels, ventricular tachycardia, plaque buildup in the arteries, blood clots, extremely low blood pressure as a result of heart attack, and congenital heart defects have a higher predisposition to brain ischemia in comparison their healthy counterparts. Sickle cell anemia may cause brain ischemia associated with the irregularly shaped blood cells. Sickle shaped blood cells clot more easily than normal blood cells, impeding blood flow to the brain. Compression of

neg: Hypotension from fluids is by doing a passive leg raise followed by measuring the output from the heart. Medium-term (and less well-demonstrated) treatments of hypotension include: "Hypotension", from Ancient Greek "hypo-", meaning "under" or "less" + English "tension", meaning "'strain" or "tightness". This refers to the under-constriction of the blood vessels and arteries which leads to low blood pressure. Hypotension Hypotension is low blood pressure, especially in the arteries of the systemic circulation. Blood pressure is the force of blood pushing against the walls of the arteries as the heart pumps out blood. A systolic blood pressure of less than 90

neg: Lymphatic system Lymphatic system The lymphatic system is part of the vascular system and an important part of the immune system, comprising a large network of lymphatic vessels that carry a clear fluid called lymph (from Latin, "lympha" meaning "water") directionally towards the heart. The lymphatic system was first described in the seventeenth century independently by Olaus Rudbeck and Thomas Bartholin. Unlike the circulatory system, the lymphatic system is not a closed system. The human circulatory system processes an average of 20 litres of blood per day through capillary filtration, which removes plasma while leaving the blood cells. Roughly 17 litres of

neg: Vascular endothelial growth factor A syndrome, also known as Crow-Fukase syndrome. Mutations in this gene have been associated with proliferative and nonproliferative diabetic retinopathy. In ischemic cardiomyopathy, blood flow to the muscle cells of the heart is either partially or completely reduced, leading to cell death and scar tissue formation. Because the muscle cells are replaced with fibrous tissue, the heart loses its ability to contract, compromising heart function. Normally, if blood flow to the heart is compromised, over time, new blood vessels will develop, providing alternative circulation to the affected cells. The viability of the heart following severely restricted blood flow is dependent on

neg: Children's Heart Foundation the heart and great vessels of a newborn. Most heart defects either obstruct blood flow in the heart or vessels near it or cause blood to flow through the heart in an abnormal pattern, although other defects affecting heart rhythm such as long QT syndrome can also occur. Heart defects are among the most common birth defects and congenital birth defects are the leading cause of birth defect-related deaths. As of 2007, The Children’s Heart Foundation has joined forces with the Adult Congenital Heart Association (ACHA) and the Congenital Heart Information Network (CHIN) to form the National Congenital Heart Coalition.

neg: Underage smoking in Australia as blood vessels compact in the fingertips and toes. An example of this is the carbon monoxide in cigarettes, it reduces the ability of blood to carry oxygen, and the ability of muscle cells to take up oxygen. Adolescents who smoke have higher increased stress levels than non-smokers, this is due to re-occurring nicotine withdrawal symptoms, as nicotine makes the heart work harder. There are many long-term health issues that come from the initiation of underage smoking. Adolescents who continue to smoke can develop complications such as: Gum disease, tooth loss, infertility, impotence, chronic lung diseases, hearing loss, vision impairment

neg: Macrovascular disease Macrovascular disease Macrovascular disease is a disease of any large ("macro") blood vessels in the body. It is a disease of the large blood vessels, including the coronary arteries, the aorta, and the sizable arteries in the brain and in the limbs. This sometimes occurs when a person has had diabetes for an extended period of time. Fat and blood clots build up in the large blood vessels and stick to the vessel walls. Three common macrovascular diseases are coronary disease (in the heart), cerebrovascular disease (in the brain), and peripheral vascular disease (in the limbs) Macrovascular disease (macroangiopathy) refers

neg: Artery The elastic tissue allows the artery to bend and fit through places in the body. This layer is mainly made up of endothelial cells (and a supporting layer of elastin rich collagen in elastic arteries). The hollow internal cavity in which the blood flows is called the lumen. Arterial formation begins and ends when endothelial cells begin to express arterial specific genes, such as ephrin B2. Arteries form part of the circulatory system. They carry blood that is oxygenated after it has been pumped from the heart. Coronary arteries also aid the heart in pumping blood. Arteries carry oxygenated blood

neg: Mesoderm the kidneys, gonads, their associated ducts, and the adrenal glands. The lateral plate mesoderm give rise to the heart, blood vessels and blood cells of the circulatory system as well as to the mesodermal components of the limbs. Some of the mesoderm derivatives include the muscle (smooth, cardiac and skeletal), the muscles of the tongue (occipital somites), the pharyngeal arches muscle (muscles of mastication, muscles of facial expressions), connective tissue, dermis and subcutaneous layer of the skin, bone and cartilage, dura mater, endothelium of blood vessels, red blood cells, white blood cells, and microglia, the kidneys and the adrenal cortex.

neg: Eicosanoid on heart, kidney, and other blood vessels as well as on the kidney's reabsorption of sodium and water, and act to reduce blood pressure and ischemic and other injuries to the heart, brain, and other tissues; they may also act to reduce inflammation, promote the growth and metastasis of certain tumors, promote the growth of new blood vessels, in the central nervous system regulate the release of neuropeptide hormones, and in the peripheral nervous system inhibit or reduce pain perception. Arachidonic acid (AA; 20:4 ω-6) sits at the head of the "arachidonic acid cascade" – more than twenty eicosanoid-mediated signaling

neg: Atrial septostomy and is pumped through the aorta to the rest of the body, including the heart muscle itself. This is the systemic circulation part of blood flow, the other loop of an interconnected normal cardio-pulmonary system. With d-TGA, certain major blood vessels are connected improperly, so oxygen-poor blood from the right heart is pumped immediately through the aorta and circulated to the body and the heart itself, bypassing the lungs altogether, while the left heart pumps oxygen-rich blood continuously back into the lungs through the pulmonary artery. This is a life-threatening situation due to the resultant low oxygen levels throughout the

neg: Earthworm vessel, which runs below the ventral nerve cord; and two lateroneural vessels on either side of the nerve cord. The dorsal vessel moves the blood forward, while the other four longitudinal vessels carry the blood rearward. In segments seven through eleven, a pair of aortic arches rings the coelom and acts as hearts, pumping the blood to the ventral vessel that acts as the aorta. The blood consists of ameboid cells and hemoglobin dissolved in the plasma. The second circulatory system derives from the cells of the digestive system that line the coelom. As the digestive cells become full, they

neg: Polyarteritis nodosa with highly oxygenated blood, often leads to high blood pressure in about one-third of cases. deposition of protein or blood in the urine may also be seen. Involvement of the arteries of the heart may cause a heart attack, heart failure, and inflammation of the sac around the heart (pericarditis). There is no association with ANCA, but about 30% of people with PAN have chronic hepatitis B and deposits containing HBsAg-HBsAb complexes in affected blood vessels, indicating an immune complex–mediated cause in that subset. Infection with the Hepatitis C virus and HIV are occasionally discovered in people affected by PAN.

neg: Tarantula lung, oxygen is taken into the blood stream through the blood vessels in the lungs. Needed moisture may also be absorbed from humid air by these organs. A tarantula’s blood is unique (not only by appearance); an oxygen-transporting protein is present (the copper-based hemocyanin), but not enclosed in blood cells such as the erythrocytes of mammals. A tarantula’s blood is not true blood, but rather a liquid called haemolymph, or hemolymph. At least four types of hemocytes, or hemolymph cells, are known. The tarantula’s heart is a long, slender tube located along the top of the opisthosoma. The heart is

neg: Circulatory system which specialise in the heart, and cardiothoracic surgeons specialise in operating on the heart and its surrounding areas. Vascular surgeons focus on other parts of the circulatory system. The essential components of the human cardiovascular system are the heart, blood and blood vessels. It includes the pulmonary circulation, a "loop" through the lungs where blood is oxygenated; and the systemic circulation, a "loop" through the rest of the body to provide oxygenated blood. The systemic circulation can also be seen to function in two parts–a "macrocirculation" and a microcirculation. An average adult contains five to six quarts (roughly 4.7 to

neg: Complications of hypertension blood pressure in diabetes is associated with a 4 fold increase in death chiefly from heart disease and strokes. The chief reason why people with diabetes develop high blood pressure is hardening of the arteries. Diabetes tends to speed up the process of atherosclerosis. The other fact about diabetes is that it affects both large and small blood vessels in the body. Over time, blood vessels become clogged with fatty depots, become non-compliant and lose their elasticity. The process of atherosclerosis is a lot faster in diabetic individuals whom do not have good control of their blood sugars. The high

neg: Raymond P. Ahlquist on several organs, including blood vessels and the heart. He found that the six substances possessed different rank orders of potency that differed depending on the tissue. For example, the rank order of potency was "adrenaline > noradrenaline > α-methyl noradrenaline > isoprenaline" in promoting contraction of blood vessels, but the rank order was "isoprenaline > adrenaline > α-methyl noradrenaline > norepinephrine" in the heart. Ahlquist concluded that there are two different receptors for agonists. The receptors with the first rank order (that is, for example, for blood vessel contraction), he called α-adrenoceptors (alpha adrenotropic receptor) receptors while the second

neg: Diffusion compared to the blood in the body. The pumping action of the heart then transports the blood around the body. As the left ventricle of the heart contracts, the volume decreases, which increases the pressure in the ventricle. This creates a pressure gradient between the heart and the capillaries, and blood moves through blood vessels by bulk flow down the pressure gradient. As the thoracic cavity contracts during expiration, the volume of the alveoli decreases and creates a pressure gradient between the alveoli and the air outside the body, and air moves by bulk flow down the pressure gradient. The

neg: Epaulette shark °F), which is also unusual in that most animals capable of tolerating oxygen deprivation do so at low temperatures. The physiological responses of the epaulette shark to low oxygen are mediated by the nucleoside adenosine. In hypoxic conditions, the heart and ventilation rates drop sharply. The shark's blood pressure falls by half as the blood vessels dilate to deliver more blood to the brain and heart. Unlike in bony fishes and tetrapods, the blood flow rate remains constant and there is no elevation of blood glucose levels. The brains of sharks only consume a third as much ATP as those

neg: Major aortopulmonary collateral artery with congenital heart diseases with decreased pulmonary blood flow like tetralogy of Fallot or pulmonary atresia it may be seen sometimes in isolation i.e. not associated with any congenital heart disease in that case it is termed as isolated aortopulmonary collateral artery. In these cases it may be one of the cause of congestive cardiac failure in neonates. Pulmonary arteries come from the right side of the heart, and usually carry deoxygenated blood from the body. These collateral arteries carry blood which has already been oxygenated by the lungs, so are of little use in helping the body to get

neg: Blood vessel prevent backflow as a result of a decrease in blood pressure as the blood passes through the circulatory system. There are various kinds of blood vessels: 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. Blood

neg: Heart Heart The heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system. Blood provides the body with oxygen and nutrients, as well as assists in the removal of metabolic wastes. In humans, the heart is located between the lungs, in the middle compartment of the chest. In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria; and lower left and right ventricles. Commonly the right atrium and ventricle are referred together as the "right heart" and their left counterparts as the "left heart".

neg: Circulatory system of the horse Circulatory system of the horse The circulatory system of the horse consists of the heart, the blood vessels, and the blood. The equine heart is a muscular pump that circulates blood throughout the body. It is more glenoid in shape than the human heart and consists of four chambers: the left and right atria, and the left and right ventricles. The average adult horse has a heart, although it can be more than twice this size. The heart grows until the horse is 4 years of age, although it can increase slightly in size as a response to conditioning. Heart

neg: Circulatory system of the horse Circulatory system of the horse The circulatory system of the horse consists of the heart, the blood vessels, and the blood. The equine heart is a muscular pump that circulates blood throughout the body. It is more glenoid in shape than the human heart and consists of four chambers: the left and right atria, and the left and right ventricles. The average adult horse has a heart, although it can be more than twice this size. The heart grows until the horse is 4 years of age, although it can increase slightly in size as a response to conditioning. Heart