Double circulation occurs in mamamals due to the lungs.The blood passes through the heart in the circuit twice.Blood flows from the main circulation of the body to the heart, then to the lungs and back to the heart again before it is punmped into the main circulation .Veins carry deoxygenated blood from variousparts of the body to theheart. From the heart, the pulmonary arteries carry blood to the lungs. Thge oxygenated blood returns to the heart by the pulmonary veins. Generally, the circulation linking the lungs to the heart is known as the pulmonary circulation. When the oxygenated blood leaves the left side of the heart and is distributed by the arteries to the rest of the body, apart from the lungs. The veins carry the blood from all parts of the body back to the right side of the heart.This circulation is called the systemic circulation. There are many advantages the pulmonary circulation and the systemic circulation allows. Blood entering the lungs is at a low pressure and therefore, it ensures that the blood is well oxygenated before it is returned to the heart. The blood leaving the heart for systemic circulation is at a high pressure. This ensures that the oxygenated blood is well distributed to the parts of the body at a faster rate. Additionally, it helps to maintain a high rate of metalbolic in animals.
Monday, February 15, 2010
Friday, February 12, 2010
Description of the heart
The heart of a mammal is a complicated organ. The size of the heart varies with the animal and in man it is about the size of a clenched fist. It lies in the thorax behind the chest-bone and the two lungs.The heart is surrounded by a two-layed bag known as the pericardium, the inner membrane being in contact with the heart. Right between the two pericardial membranes is the pericardial fluid which helps to reduce friction when the heart is beating.
Generally,the heart heart weighs 0.59% of the total body mass.
More about Coronary artery disease
This happens when most of the heart gets blood it needs through the two coronary arteries. When the arteries are blocked, the heart may die due to the reason of the lack of blood. Coronary artery disease is traceable to atherosclerosis. The arteries changed from being smooth and elastic to rough, inflexible and lastly smaller as compared to before. As a result, being narrow, the volume of blood that can be transported is reduced. Soon, the coronary arteries are clogged by cholesterol and fat deposits and therefore, resulting to the obstruction of the blood flow.During a heart attack, the blood flow to a particular part of the heart that may be blocked, and hence the region of the heart muscle dies. The body can recover if only a small area of muscle dies but extensive muscle damage is fatal.
What causes heart murmurs?
Usually, doctors will call the sound heard with a stethoscope as heart murmurs.They are noises the blood makes as it rushes through the parts of the heart. in some cases, murmurs shows the malfunctioning valves. If a valve does not close properly, it allows some of the blood to leak becomes audible through a stethoscope. Additionally, heart mumurs that are due to disease would occur due to the changes in the mitual valve, a valve that is positioned between the left upper and lower chamber. Babies born with a malfunctioning valve, may have rheumatic fever but these abnormalities can be corrected by surgery.
Parts of the heart
Credits:http://www.biomaterials.org/SIGS/Cardiovascular/images/cv_anatomy_heart.jpgChambers of the heart:The heart id divided into 4 chambers; 2 thin-walled atria, Which receive venous blood, and two larger, thick-walled ventricles, which pump blood into the arterial system.
Aortic valve:Blood is pumped through here from the left ventricle into the aorta.
Superior vena cava (SVC):Drains blood from the head, neck and upper body into the right atrium.
Pulmonary veins:One of four veins draining blood from lungs into left atrium.
Pulmonary artery:Carries deoxyenated blood from right ventricle via the pulmonary trunk to the lungs.
Right atrium:Receives deoxygenated blood from the SVC and IVC.
Left atrium:Receives oxygenated blood from the pulmonary veins.
Tricuspid valve:Prevents backflow of blood into right atrium from right ventricle.
Inferior vena cava (IVC):Drains blood from the lower body into the right atrium.
Conus arteriosus:Smooth-walled exit from right ventricle to the pulmonary valve at the root of the pulmonary artery.
Mitral Vave:Prevents backflow of blood into left atrium from left ventricle.
Interventricular septum:Partition between the ventricles; mostly muscular but thin and membranous in its uppermost part.
Chordae tendineae:Anchor valve flaps to papillary muscles in ventricular wall.Apex of heart:Tip of left ventricle.
Credits:
Chambers Of The Heart Pg 74:Name:Handbook Of The Human Body, Author: Professor Peter Abrahams, first published in 2006 by Amber Books Ltd, Bradley's Close, 74-77 White Lion Street, London N1 9PF, United Kingdom
The Circulatory System
Circulatory System:
The heart pumps blood to the lungs. Then it pushes the blood all through the body to deliver oxygen and collect waste. Blood carrying waste from the body cells is drawn through large veins, called the vena cavae, into the right side of the heart. Then the blood is pumped through pulmonary arteries to the lungs. Here it collects oxygen, and is pumped back through pulmonary veins to the left side of the heart.The heart then pumps the oxygen-rich blood out through the main artery, called the aorta. From here, it travels round the body.
Credits:
Circulatory System (page 9), Name: The Human Body (A fascinating see-through view of how our bodies work), Author: Dr. Peter Abrahams, University College London, Text Consultant: Dr. Luisa Dillner, Medical Advisor: Dr. Tom Snow, published in Australia in 1993 by Wishing Well Books, 67 Rushdale Street, Knoxfield, Victoria, 3180.
The heart pumps blood to the lungs. Then it pushes the blood all through the body to deliver oxygen and collect waste. Blood carrying waste from the body cells is drawn through large veins, called the vena cavae, into the right side of the heart. Then the blood is pumped through pulmonary arteries to the lungs. Here it collects oxygen, and is pumped back through pulmonary veins to the left side of the heart.The heart then pumps the oxygen-rich blood out through the main artery, called the aorta. From here, it travels round the body.
Credits:
Circulatory System (page 9), Name: The Human Body (A fascinating see-through view of how our bodies work), Author: Dr. Peter Abrahams, University College London, Text Consultant: Dr. Luisa Dillner, Medical Advisor: Dr. Tom Snow, published in Australia in 1993 by Wishing Well Books, 67 Rushdale Street, Knoxfield, Victoria, 3180.
How does the heart work?
Blood rich in carbon dioxide will enter the right atrium. Blood from the upper parts of the body will drain into the superior vena cave while blood from the lower part of the body will enter through the inferior vena cave. After it enters the right atrium, it wnters the right ventricle through the tricuspid valve. The right ventricle will pump the blood rich in carbon dioxide through the lungs. The blood will then go into the pulmonary arteries to the right lung and the left lung. Gas exchange takes place. The oxygen rich blood flows back into the left atrium through pulmonary veins. Blood from the left atrium flows into the left ventricle through the bicuspid valve. Then, oxygenated blood moves up by the left ventricle though the aortic arch to the rest of the body.The function of the heart
The heart pumps blood to all parts of the body and in the process transports materials to the intended locations. It provides a continuous blood circulation through the cardiac cycle and is one of the most vital organs in the body.
List of Heart Diseases
Coronary Heart Disease:
Coronary Heart Disease, also known as CHD, is the most common of all the heart-related problems. It’s caused by your arteries getting smaller which leads to your heart not getting enough blood supply.
Heart Attack:
A heart attack is also extremely common throughout places like the United States where people engorge upon beefy cheeseburgers, salt-soaked fries, and double decker milkshakes. These types of food aren’t good for you at all and most people who eat these types of food on a regular basis also don’t get much exercise. Another victim of heart attacks is the elderly. As you get older, your body gets weaker and it’s as if your heart has to work double time just to keep up with you anymore. People with heart problems in general should take it easy, lay off the salty/high cholesterol foods, and visit a doctor regularly for checkups. If you’re ever in the unlucky position to be experiencing a heart attack first-hand, sit down immediately and try not to move or stress your body. Take an ibuprofen to reduce inflammation and call 911 within 1-2 minutes of first feeling a heart attack. Heart attacks are generally felt as a shooting pain in your left arm just beforehand, followed by an immense pain in your chest.
High blood pressure:
High blood pressure, also known as hyptertension, is a common thing that effects about 50 millions Americans and countless others worldwide. Once again, it’s generally caused by fatty foods. High blood pressure is often hard to diagnose as it has so few symptoms that you don’t even know that you have it. The best thing to do to avoid high blood pressure is to simply get checked out every six months or so or even just go down to your local Publix and use their blood pressure machine. If you already know that you have high blood pressure, the best thing to do is try to avoid stressful situations as often as possible. Light or mediate exercise is fine, just don’t overdo it. A few ways to know if you may have high blood pressure is if you often wake up with a headache or if headache continues throughout the day, you have a ringing or buzzing noise in your ears, and/or you’re often dizzy or confused.
Ischemic heart disease:
Ischemic heart disease is the opposite of hyptertension, in that it is the reduced flow of blood to the heart. The main symptom involved with ischemic heart disease is the concurrent feeling of chest pain, especially pain in the left side of the chest (around the heart). The best thing to do for ischemic heart disease, aside from visiting a doctor, is to start up an exercise routine in order to raise your pulse, thereby making the heart pump faster. If you’re not eating regularly or moving around that much then you may be a candidate for ischemic heart disease. Not only would exerising and developing a routine diet help with your heart troubles but it can also help you lose weight, which is also a common attribute to those with heart disease.
Heart rhythm disorders:
Heart rhymth disorders, also known as heart murmurs, are irregularities in the sound that the heart makes when listened to by a doctor via the means of a stethescope. Sometimes heart murmurs are harmless and are just weird sounds that the heart makes. Other times, however, heart murmurs can be extremely serious and need to be checked out more thoroughly for a deeper analysis.
Tachycardia:
Tachycardia is a very serious matter in which the heart is racing at an extremely high pace. You may be able to diagnose tachycardia yourself if you have shortness of breath, find yourself dizzy for no reason, or you just get that feeling where you can sense your own heartbeat without even checking your pulse and you know it’s extra high. Often times you would experience several of these symptoms at once. If you just got done exercising, running, or do some other strenuous activity (yes, getting mad is included), then don’t worry about it as it’s probably not tachycardia. If, however, your heart keeps racing for more than ten to twenty minutes after you stopped doing these things or just have a rapid pulse for no reason, then you might want to call a doctor as soon as possible. While you’re waiting on the doctor, you need to sit down and relax immediately and calm down. In this case, laughter can really be the best medicine as it takes your mind off of it. So sit on the couch, watch some standup comedy and do your best to get your mind off of your racing heart. Slow, steady breathing can also help so either grab a paper bag or just slow your breathing on your own accord. This is very important and it could possibly mean life or death.
Rheumatic heart disease:
Rheumatic heart disease is a problem associated with heart damage from rheumatic flu. It can be diagnosed by a fever and/or rash along with chest pains or heartburn. This is usually due to a problem with the valves in your heart not being able to close properly which leads to blood spilling out into the wrong parts of the heart. In extreme cases, rheumatic heart disease can lead to heart failure so if you even suspect it (if you notice these symptoms after experiencing rheumatic fever) then go to the doctor’s office or hospital as soon as possible.
Pulmonary heart disease:
Pulmonary heart disease is caused by an abnormal pressure on the lungs due to an improper flow of blood to that region. A diagnosis can be reached if you notice you frequently have shortness of breath, chest pain or faint on occasion. If you have been diagnosed with pulmonary hypertension, cystic fibrosis or advanced emphysema and are now experiencing these symptoms, you may have pulmonary heart disease. There’s nothing you can really do personally to correct pulmonary heart disease as its an actual hardware problem with your body. Go to a doctor and get it checked out and they may be able to fix you up.
Some advice: Whatever you have, or think you have, the best thing you can do is go to the doctor and get checked out. Nothing in this guide should replace information from a educated professional who has studied the field more thoroughly.
Credits: http://www.listofheartdiseases.org/
Coronary Heart Disease, also known as CHD, is the most common of all the heart-related problems. It’s caused by your arteries getting smaller which leads to your heart not getting enough blood supply.
Heart Attack:
A heart attack is also extremely common throughout places like the United States where people engorge upon beefy cheeseburgers, salt-soaked fries, and double decker milkshakes. These types of food aren’t good for you at all and most people who eat these types of food on a regular basis also don’t get much exercise. Another victim of heart attacks is the elderly. As you get older, your body gets weaker and it’s as if your heart has to work double time just to keep up with you anymore. People with heart problems in general should take it easy, lay off the salty/high cholesterol foods, and visit a doctor regularly for checkups. If you’re ever in the unlucky position to be experiencing a heart attack first-hand, sit down immediately and try not to move or stress your body. Take an ibuprofen to reduce inflammation and call 911 within 1-2 minutes of first feeling a heart attack. Heart attacks are generally felt as a shooting pain in your left arm just beforehand, followed by an immense pain in your chest.
High blood pressure:
High blood pressure, also known as hyptertension, is a common thing that effects about 50 millions Americans and countless others worldwide. Once again, it’s generally caused by fatty foods. High blood pressure is often hard to diagnose as it has so few symptoms that you don’t even know that you have it. The best thing to do to avoid high blood pressure is to simply get checked out every six months or so or even just go down to your local Publix and use their blood pressure machine. If you already know that you have high blood pressure, the best thing to do is try to avoid stressful situations as often as possible. Light or mediate exercise is fine, just don’t overdo it. A few ways to know if you may have high blood pressure is if you often wake up with a headache or if headache continues throughout the day, you have a ringing or buzzing noise in your ears, and/or you’re often dizzy or confused.
Ischemic heart disease:
Ischemic heart disease is the opposite of hyptertension, in that it is the reduced flow of blood to the heart. The main symptom involved with ischemic heart disease is the concurrent feeling of chest pain, especially pain in the left side of the chest (around the heart). The best thing to do for ischemic heart disease, aside from visiting a doctor, is to start up an exercise routine in order to raise your pulse, thereby making the heart pump faster. If you’re not eating regularly or moving around that much then you may be a candidate for ischemic heart disease. Not only would exerising and developing a routine diet help with your heart troubles but it can also help you lose weight, which is also a common attribute to those with heart disease.
Heart rhythm disorders:
Heart rhymth disorders, also known as heart murmurs, are irregularities in the sound that the heart makes when listened to by a doctor via the means of a stethescope. Sometimes heart murmurs are harmless and are just weird sounds that the heart makes. Other times, however, heart murmurs can be extremely serious and need to be checked out more thoroughly for a deeper analysis.
Tachycardia:
Tachycardia is a very serious matter in which the heart is racing at an extremely high pace. You may be able to diagnose tachycardia yourself if you have shortness of breath, find yourself dizzy for no reason, or you just get that feeling where you can sense your own heartbeat without even checking your pulse and you know it’s extra high. Often times you would experience several of these symptoms at once. If you just got done exercising, running, or do some other strenuous activity (yes, getting mad is included), then don’t worry about it as it’s probably not tachycardia. If, however, your heart keeps racing for more than ten to twenty minutes after you stopped doing these things or just have a rapid pulse for no reason, then you might want to call a doctor as soon as possible. While you’re waiting on the doctor, you need to sit down and relax immediately and calm down. In this case, laughter can really be the best medicine as it takes your mind off of it. So sit on the couch, watch some standup comedy and do your best to get your mind off of your racing heart. Slow, steady breathing can also help so either grab a paper bag or just slow your breathing on your own accord. This is very important and it could possibly mean life or death.
Rheumatic heart disease:
Rheumatic heart disease is a problem associated with heart damage from rheumatic flu. It can be diagnosed by a fever and/or rash along with chest pains or heartburn. This is usually due to a problem with the valves in your heart not being able to close properly which leads to blood spilling out into the wrong parts of the heart. In extreme cases, rheumatic heart disease can lead to heart failure so if you even suspect it (if you notice these symptoms after experiencing rheumatic fever) then go to the doctor’s office or hospital as soon as possible.
Pulmonary heart disease:
Pulmonary heart disease is caused by an abnormal pressure on the lungs due to an improper flow of blood to that region. A diagnosis can be reached if you notice you frequently have shortness of breath, chest pain or faint on occasion. If you have been diagnosed with pulmonary hypertension, cystic fibrosis or advanced emphysema and are now experiencing these symptoms, you may have pulmonary heart disease. There’s nothing you can really do personally to correct pulmonary heart disease as its an actual hardware problem with your body. Go to a doctor and get it checked out and they may be able to fix you up.
Some advice: Whatever you have, or think you have, the best thing you can do is go to the doctor and get checked out. Nothing in this guide should replace information from a educated professional who has studied the field more thoroughly.
Credits: http://www.listofheartdiseases.org/
Where is the heart located?
The heart lies behind the lungs, behind the chest bone. It is slightly tilted to the left.How does the human heart look like?
The human heart is a muscular pump the siza of a clenched fist. It is divided into four chambers. The two upper chambers are the left and right atria and two lower chambers are the right and left ventricles.The human heart has 4 kinds of valves, mitral valve, aortic valve, pulmonic valve and tricuspid valve which prevent the backflow of blood between strokes. The mitral and tricuspid valves are classified as the atrioventricular (AV) valves as they are found between the atria and ventricles.
The interatrioventricular septum separates the left atrium and ventricle from the right atrium and ventricle, dividing the heart into two functionally separate and anatomically distinct units.
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