The Cardiovascular System: Difference between revisions
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The Cardiovascular System (also called circulatory system) circulates the blood around the body in order to supply all parts with required nutrients and [[Image:Cardiovascularsystem.jpg|frame|right | The Cardiovascular System (also called circulatory system) circulates the blood around the body in order to supply all parts with required nutrients and [[Image:Cardiovascularsystem.jpg|frame|right]][[Oxygen|oxygen]] and to remove waste products such as [[Carbon dioxide|carbon dioxide]] <ref name="parker"> Parker S. (2007) The Human Body Book, 1st edition, London: Dorling Kindersley Limited.</ref>. Consequently it is crucial of the body's maintenance of [[Homeostasis|homeostasis]].<ref name="website">http://stayhealthier.wordpress.com/2010/03/30/cardiovascular-system-understand-it-to-stay-healthy/</ref><br> | ||
In order to carry out its functions, the cardiovascular system pumps blood through the blood vessels. This is done by the pumping of the heart. Furthermore, the circulatory system is associated with other systems in the body, for example the lymphatic system.<ref name="parker" /> | In order to carry out its functions, the cardiovascular system pumps blood through the blood vessels. This is done by the pumping of the heart. Furthermore, the circulatory system is associated with other systems in the body, for example the lymphatic system.<ref name="parker" /><br> | ||
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== Blood and Blood Vessels == | == Blood and Blood Vessels == | ||
'''Blood''' consists of [[White blood cells|white blood cells]], [[Red blood cells|red blood cells]], [[Platelets|platelets]] and liquid plasma. Plasma accounts for about 50% of the total blood content and contains mainly water which has [[Glucose|glucose]], [[Enzymes|enzymes]] and other [[Proteins|proteins]], [[Hormones|hormones]] and waste products dissolved in it. [[Oxygen|Oxygen]] and [[Carbon dioxide|carbon dioxide]] are also present in the blood and are carried by the red blood cells | '''Blood''' consists of [[White blood cells|white blood cells]], [[Red blood cells|red blood cells]], [[Platelets|platelets]] and liquid plasma. Plasma accounts for about 50% of the total blood content and contains mainly water which has [[Glucose|glucose]], [[Enzymes|enzymes]] and other [[Proteins|proteins]], [[Hormones|hormones]] and waste products dissolved in it. [[Oxygen|Oxygen]] and [[Carbon dioxide|carbon dioxide]] are also present in the blood and are carried by the red blood cells <ref name="parker" />. | ||
Within the human body, blood is carried in blood vessels which can differ in size and makeup <ref name="parker" />. | Within the human body, blood is carried in blood vessels which can differ in size and makeup <ref name="parker" />. | ||
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===== Arteries ===== | ===== Arteries ===== | ||
Innitiate from the heart and carry blood to organs and tissues where oyxgen and nutrients are needed. Therefore, they carry blood which is rich in these components. The arteries pump blood by narrowing as the heart relaxes, so that the exerted force pushed the blood forward. Thick walls, muscular (see [[Cardiac muscle|cardiac muscle]]), and elastic layers ensure that the strain due to the blood flow and the contraction of the heart does not damage the walls, which on average are only 1mm thick <ref name="parker" />. | |||
===== Veins ===== | ===== Veins ===== | ||
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== Heart Structure == | == Heart Structure == | ||
The wall of the heart consists of myogenic muscle which is called myocardium. Just like all other tissues in the body, this muscle requires nutrients and oxygen which are supplied by blood vessels called coronary arteries. These originate from the right and the left artery which in turn divide from the aorta. Naturally, waste products must be removed as well which is done by the coronary sinus | The wall of the heart consists of myogenic muscle which is called myocardium. Just like all other tissues in the body, this [[muscle|muscle]] requires nutrients and oxygen which are supplied by blood vessels called coronary arteries. These originate from the right and the left artery which in turn divide from the aorta. Naturally, waste products must be removed as well which is done by the coronary sinus <ref name="parker" />. | ||
Inside the heart, hollow chambers can be found which are filled with blood and emptied again during each contraction cycle. The top chambers are called right and left atrium and receive blood from the body. They are located above the right and left ventricle respectively which pump blood into the arteries to the body. The upper and lower chambers are seperated by valves and the right and left side are seperated by the septum | Inside the heart, hollow chambers can be found which are filled with blood and emptied again during each contraction cycle. The top chambers are called right and left atrium and receive blood from the body. They are located above the right and left ventricle respectively which pump blood into the arteries to the body. The upper and lower chambers are seperated by valves and the right and left side are seperated by the septum <ref name="parker" />. | ||
The muscle wall of the left hand side of the heart is much thicker and stronger due to the fact that it has to pump blood into the whole system that supplies the body with blood and therefore has to supply more powerful contraction. | The muscle wall of the left hand side of the heart is much thicker and stronger due to the fact that it has to pump blood into the whole system that supplies the body with blood and therefore has to supply more powerful contraction. | ||
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This type of disease is caused by insufficient nutrient and oxygen supply to the heart muscle as a consequence of damaged or malfunctional coronary arteries.<ref name="parker" /> | This type of disease is caused by insufficient nutrient and oxygen supply to the heart muscle as a consequence of damaged or malfunctional coronary arteries.<ref name="parker" /> | ||
CHD includes common conditions like Atherosclerosis, Angina or Heart attack | CHD includes common conditions like Atherosclerosis, Angina or Heart attack <ref name="parker" />. | ||
== References == | == References == | ||
<references /> | <references /> | ||
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Revision as of 14:34, 2 December 2011
The Cardiovascular System (also called circulatory system) circulates the blood around the body in order to supply all parts with required nutrients and
oxygen and to remove waste products such as carbon dioxide [1]. Consequently it is crucial of the body's maintenance of homeostasis.[2]
In order to carry out its functions, the cardiovascular system pumps blood through the blood vessels. This is done by the pumping of the heart. Furthermore, the circulatory system is associated with other systems in the body, for example the lymphatic system.[1]
Blood and Blood Vessels
Blood consists of white blood cells, red blood cells, platelets and liquid plasma. Plasma accounts for about 50% of the total blood content and contains mainly water which has glucose, enzymes and other proteins, hormones and waste products dissolved in it. Oxygen and carbon dioxide are also present in the blood and are carried by the red blood cells [1].
Within the human body, blood is carried in blood vessels which can differ in size and makeup [1].
Arteries
Innitiate from the heart and carry blood to organs and tissues where oyxgen and nutrients are needed. Therefore, they carry blood which is rich in these components. The arteries pump blood by narrowing as the heart relaxes, so that the exerted force pushed the blood forward. Thick walls, muscular (see cardiac muscle), and elastic layers ensure that the strain due to the blood flow and the contraction of the heart does not damage the walls, which on average are only 1mm thick [1].
Veins
In contrast to the arteries, veins have thinner walls and are therefore more flexible. These properties arise from the low blood pressure within veins, causing the blood flow to be much slower. A further characteristic of veins are the valves they contain, which are made from endothilium tissue and restrict the blood flow into one direction.[1] Valves contain of two cusps that only open into the direction of blood flow due to pumping of the heart.
This is especially important regarding their function, as this is to return deoxygenated blood to the heart. The main two veins doing this are called superior and inferior venae cavae.[1]
Capillaries
As the distance of the blood vessels to the heart increases, the amount of branching increases and the blood vessels become smaller and finer in order for the blood to reach every part of the body. Starting with large arteries, these blood vessels then further divide into little vessels called capillaries (0.01 mm in diameter). Not only the size decreases but also the thickness of the walls decreases to a layer of only one cell so that a maximum exchange of gases with cells and tissues can be achieved.[1]
The capillaries carrying waste products away from the cells and tissues eventually enlarge into veins which carry the blood back to the heart.[1]
Heart Structure
The wall of the heart consists of myogenic muscle which is called myocardium. Just like all other tissues in the body, this muscle requires nutrients and oxygen which are supplied by blood vessels called coronary arteries. These originate from the right and the left artery which in turn divide from the aorta. Naturally, waste products must be removed as well which is done by the coronary sinus [1].
Inside the heart, hollow chambers can be found which are filled with blood and emptied again during each contraction cycle. The top chambers are called right and left atrium and receive blood from the body. They are located above the right and left ventricle respectively which pump blood into the arteries to the body. The upper and lower chambers are seperated by valves and the right and left side are seperated by the septum [1].
The muscle wall of the left hand side of the heart is much thicker and stronger due to the fact that it has to pump blood into the whole system that supplies the body with blood and therefore has to supply more powerful contraction.
Coronary Heart Disease
This type of disease is caused by insufficient nutrient and oxygen supply to the heart muscle as a consequence of damaged or malfunctional coronary arteries.[1]
CHD includes common conditions like Atherosclerosis, Angina or Heart attack [1].
References