1. Conductive arteries – Conductive arteries are the most proximal compartment of the coronary arterial system. Their diameter is generally ranging from 500 μm up to 2-5 mm. These are large epicardial coronary arteries that work as a capacitance function for the blood flow. They have very low resistance to blood flow and therefore, the pressure drop along the length of conductive arteries is negligible. The conductive arteries have an inbuilt characteristic of maintaining the shear stress by changing epicardial dilatation. This characteristic is called being responsive to flow-dependent dilatation. They are not very responsive to intravascular pressure or metabolites. [1]
Prearterioles – Prearterioles are the intermediate compartment to conductive arteries. Their diameter ranges from 100-500 μm approximately. The drop in pressure across the prearterioles is large. They have thick walls and extra-myocardial position due to which they do not come across metabolites and hence do not respond to them. The prearterioles are more responsive to flow-dependent dilation than the conductive arteries. [1]
Arterioles - Arterioles are the most distal compartment of the coronary arterial system with diameters of less than 100 μm. The drop in pressure along the arterioles is considerable and maximum of all the three compartments of coronary arterial system. They are also the most responsive to flow-dependent dilatation during epicardial changes due to varying blood flow. They are responsible for the metabolic regulation of coronary blood flow. This is because they are highly responsive to the changes in the concentration of intramyocardial metabolites. They are also highly more responsive to changes in intravascular pressure than the other comp...
... middle of paper ...
...onian_fluid
12. [Online]. FTP Available: http://ocw.usu.edu/Civil_and_Environmental_Engineering/Fluid_Mechanics/CEE3500_L3_Properties2.pdf
13. [Online]. FTP Available: http://en.wikipedia.org/wiki/Coronary_flow_reserve
14. [Online]. FTP Available: http://en.wikipedia.org/wiki/Hemostasis
15. [Online]. FTP Available: https://www.lef.org/protocols/heart_circulatory/blood_clot_01.htm
16. [Online]. FTP Available: http://en.wikipedia.org/wiki/Turbulence
17. [Online]. FTP Available: http://www.britannica.com/EBchecked/topic/609625/turbulent-flow
18. [Online]. FTP Available: http://www.cvphysiology.com/Hemodynamics/H007.htm
19. [Online]. FTP Available: http://link.springer.com/chapter/10.1007/978-1-4419-0730-1_10#page-1
20. [Online]. FTP Available: http://www.heart.org/HEARTORG/Conditions/HeartAttack/SymptomsDiagnosisofHeartAttack/Microvascular-Angina_UCM_450313_Article.jsp
In this experiment the effects of blood vessel radius and blood pressure on glomerular filtration was experimented. The effect of decreasing the afferent arteriole radius on glomerular capillary pressure and filtration rate is as the glomerular capillary pressure decreased; the filtration rate decreased. The effect of increasing the afferent arteriole radius on glomerular capillary pressure and filtration rate is as the glomerular capillary pressure increased; the filtration rate increased. The effect of decreasing the afferent arteriole radius on glomerular capillary pressure and filtration rate is as the glomerular capillary pressure increased; the filtration rate increased. The effect of increasing the afferent arteriole radius on glomerular capillary pressure and filtration rate is that glomerular capillary pressure and filtration rate decreased
Capillaries are very small; in fact, capillaries are the tiniest of all blood vessels. They form the connection between veins and arterioles in the circulatory system. However, capillaries tend to be found everywhere. Unlike veins and arteries, the capillaries main function is not transporting blood. They allow the movement of substances, mainly gases Oxygen and Carbon Dioxide into and out of the capillary. Capillaries have very thin walls that are only one cell thick, which allows substances (such as oxygen) to diffuse through the wall effortlessly. They are also incredibly narrow; so narrow, that blood cells move through it one at a time. As arteries divide into arterioles and continue to diminish in size as they near muscle, they become capillaries. Here, the capillaries form a mesh like structure (capillary bed), forming a network throughout the muscle. This allows a fast and efficient transfer of oxygen-carrying red blood cells to the site where they are needed. With the combined structure of the thin walls and a large surface area, capillaries allow diffusion of oxygen and carbon dioxide with ease. This is ideal for the respiratory system which is in charge of oxidizing the blood
The Mayo Clinic’s book on High Blood Pressure was full of detailed facts about blood pressure and what it is. This is extremely significant to the experiment because blood pressure is one of the variables being tested. Understanding blood pressure is one of the key components to receiving accurate results from this experiment. Most of the book is on high blood pressure, which is not necessary for the experiment, but the book still had plenty of useful information about blood pressure itself. The book explains that when the heart beats, a surge of blood is released from the left ventricle. It also tells of how arteries are blood vessels that move nutrients and oxygenated blood from the heart to the body’s tissues. The aorta, or the largest artery in the heart, is connected to the left ventricle and is the main place for blood to leave the heart as the aorta branches off into many different smaller
The blood that is being carried away is very enriched with oxygen after it leaves the lungs and proceeds to the body’s tissues. The further the arteries get away from the heart they become smaller and more narrow and are eventually called arterioles. Arterioles and arteries just about have the same structure and function. Arterioles have strong, thick muscular walls and a rather small passageway for the blood to travel in and out. Also, they are the most highly regulated blood vessels in the blood and contain blood under high blood
Tortora, G., & Derrickson, B. (2012). The cardiovascular system: The blood. In B. Roesch (Ed.),
...ds a supply of its own blood to function properly. These arteries, called the coronary arteries, are responsible for this. The blockage of these arteries prevents oxygen from reach the heart tissue and leads to what is known as a heart attack.
As blood travels through the circulatory system, it is first pumped from the right side of the heart to the lungs through the pulmonary arteries and then separates into arterioles which split into capillaries. Here, the deoxygenated blood receives oxygen diffused in the lungs due to large surface area and travel back through venules and then pulmonary veins to the left side of the heart. From here, the oxygen rich blood is pumped throughout the body in arteries, arterioles, and capillaries, providing the body and cells with nutrients through osmosis. Afterwards, the now deoxygenated blood travels back to the right side of the heart containing deoxygenated blood, through venules and vein to repeat the cycle over again. Also, the heart is nourished by coronary circulation through the Right and Left Main Coronary Arteries.
The arteries supply blood rich in oxygen to the body, the veins direct deoxygenated blood from the capillaries back to the heart. These roles make up the circulatory function. Blood flow through these blood vessels can be disrupted resulting in peripheral vascular diseases. These diseases occur as a result of narrowing or blocking of the blood vessels. The risk factors of peripheral vascular diseases include diabetes, smoking, high level of cholesterol, overweight, high blood pressure etc. these risk factors result to aneurysms, Raynaud’s diseases, Buerger’s disease, renal artery disease etc. With this diseases, the peripheral vascular system should be assessed to enable nurses and other health personnel make good
Baroreceptors are sensors in the vascular system that respond to changes in pressure within blood vessels. Baroreceptors are found in the carotid sinus, aorta; the largest artery and the heart’s muscular pumping chamber, and wall of the left ventricle. They monitor the level of arterial pressure and act against in the order to lessen the force in the dilation of blood vessels, which decreases the blood pressure. Chemoreceptors, located in the brain, the two main arteries that carry blood to the head and neck, and aortic body of baroreceptors, are sensitive to changes in concentrations of oxygen, carbon dioxide, and hydrogen ions (Ph) in the blood. A decrease in arterial oxygen concentration or Ph causes a reflexive rise in pressure where an increase in carbon dioxide concentration causes a decrease in blood pressure. Ph is the numeric scale used to identify the basicity and acidity of a solution. Basic is on the top of the scale while acid is on the
Though shear induced cytosolic calcium was increased in normal endothelial cells, diseased artery and mutant endothelial cells did not show any calcium response to shear stress.[5, 7] To verify cilia function specifically against fluid shear stress, a new technique involving artery perfusion in glass capillary was utilized.[7, 120] And it was observed that though cilia react normally when other mechanical stimuli are applied, response to fluid shear stress is highly altered. In these studies, different inhibitors were used to block molecular functions of cells. When EGTA removes extracellular calcium, both cytosolic calcium and nitric oxide production was eradicated. Then L-NAME (NG-nitro-L-arginine methylester), an eNOS inhibitor, was found to block shear induced nitric oxide synthesis but not cytosolic calcium increase. This proved the necessity of cytosolic calcium for production of nitric oxide but not vice-versa. To examine calcium dependent mechanism of nitric oxide biosysnthesis, calphostin C and W7 were employed.
upright. The backflow of blood is prevented by one-way valves. Superficial veins are linked to the
... that sodium ingestion (especially high contents) passes through extracellular compartments including the vascular system before getting eliminated by the kidneys. An acute increase of plasma sodium concentration can alter the mechanical properties of vascular endothelium, as long as aldosterone is present. Aldosterone not only plays a major role in adjusting sodium and potassium transport in kidneys but also on the cardiovascular system. Sodium accumulates in extracellular space when the kidneys cannot adequately adjust salt excretion to salt uptake and/or when the concentration of aldosterone is raised, leading to an increase in plasma sodium concentration. An important finding in these studies was the observed effects of amiloride, which acted to block sodium channels and prevented an increase in stiffness by reversing the increasing in cell volume and pressure.
Elaborate: The cardiac cycle of the heart is divided into diastole and systole stages. Diastole refers to the period of relaxation experienced by the atria and ventricles. Systole is the contraction of the atria and ventricles. The pattern of blood flow starts in the left atrium to right atrium then into the left ventricle and right ventricle. During its course, blood flows through the mitral and tricuspid valves. Simultaneously, the right atrium is granted blood from the veins through the superior and inferior vena cava. The job of the superior vena cava is to transport de-oxygenated blood to
Your Heart and Blood Vessels – Illustrations and facts of the anatomy of the heart.