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The cardiac cycle is the sequence of events that occurs in one complete beat of the heart. The pumping phase of the cycle, also known as systole, occurs when heart muscle contracts. The filling phase, which is known as diastole, occurs when heart muscle relaxes. At the beginning of the cardiac cycle, both atria and ventricles are in diastole. During this time, all the chambers of the heart are relaxed and receive blood. The atrioventricular valves are open. Atrial systole follows this phase. During atrial systole, the left and right atria contract at the same time and push blood into the left and right ventricles, respectively. The next phase is ventricular systole. During ventricular systole, the left and right ventricles contract at the same time and pump blood into the aorta and pulmonary trunk, respectively. In ventricular systole, the atria are relaxed and receive blood. The atrioventricular valves close immediately after ventricular systole begins to stop blood going back into the atria. However, the semilunar valves are open during this phase to allow the blood to flow into the aorta and pulmonary trunk. Following this phase,Â the ventricles relax that is ventricular diastole occurs. The semilunar valves close to stop the blood from flowing back into the ventricles from the aorta and pulmonary trunk. The atria and ventricles once again are in diastole together and the cycle begins again.

Components of the Heartbeat

The adult heart beats around 70 to 80 times a minute at rest. When you listen to your heart with a stethoscope you can hear your heart beat. The sound is usually described as “lubb-dupp”. The “lubb” also known as the first heart sound, is caused by the closure of the atrioventricular valves. The “dupp” sound is due to the closure of the semilunar valves when the ventricles relax (at the beginning of ventricular diastole). Abnormal heart sounds are known as murmurs. Murmurs may indicate a problem with the heart valves, but many types of murmur are no cause for concern. (For more information see: (see Valvular Heart Disease)

The Electrocardiogram

The heart has an inbuilt rhythm of contraction and relaxation. A small group of heart muscle cells called the pacemaker help achieve this. The pacemaker generates an electrical impulse which spreads over the atria, making them contract. This impulse then spreads to the ventricles, causing them to contract. The electrical changes that spread through the heart can be detected at the surface of the body by an instrument called the electrocardiograph. Electrodes are placed in a number of positions over the chest and the electrical changes are recorded on moving graph paper as an electrocardiogram (ECG).

Effects of Aging on the Heart in Men and Women

As a part of the normal aging process a number of changes occur to the cardiovascular system.

Our heart rate slows down because the time between heartbeats increases as we age. This is one of the main reasons why the heart is unable to pump out more blood during exercise when we become old.

The amount of blood the heart pumps each minute can change as we age. It decreases slightly in older women. However, it does not change in healthy older men who have no heart disease. The reason for the difference between the sexes is not fully understood.

As we age, our blood pressure falls much more on standing from the sitting position compared to when we are younger. This phenomenon is known as postural hypotension. This explains why elderly people are more likely to feel dizzy or to fall when they stand up quickly from a resting position.

References

1. Beers, M. (editor-in-chief) “Aging and the Cardiovascular System”[online], The Merck Manual of Geriatrics. Merck & Co. Inc. 2006. Available at URL: http://www.merck.com/mrkshared/mmg/search.jsp (last accessed: 30/6/06)

2. Guyton, A and Hall, J. (editors) Textbook of medical physiology. Philadelphia, W. B. Saunders, 2000.

3. Johnson, L. (editor) Essential medical physiology. Philadelphia, Lippincott-Raven, 1998.

4. Saladin, K. Anatomy & physiology: the unity of form and function. Boston, McGraw-Hill, 2001.

5. Talley, N and O’Connor, S. Clinical examination: a guide to physical diagnosis. Sydney, MacLennan & Petty, 2001.

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The average heart is the size of an adult fist.

Your heart will beat about 115,000 times each day.

The beating sound your heart makes is caused by the opening and closing of its valves.

Each day, your heart pumps about 2,000 gallons of blood.

If you were to stretch out your blood vessel system, it would extend over 60,000 miles.

The human heart weighs less than one pound, but a man’s heart is typically two ounces heavier than a woman’s.

A woman’s heart beats slightly faster than a man’s.

There is such a thing as a broken heart. Symptoms are similar to a heart attack but the cause is usually stress and not heart disease.

Laughing is good for your heart. It reduces stress and gives a boost to your immune system.

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The de oxygenated blood travels to the lungs then to collect oxygen

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Heart cells stop dividing , which means heart cancer is extremely rare

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Structure and Function of the Heart

Function and Location of the Heart
The heart’s job is to pump blood around the body. The heart is located in between the two lungs. It lies left of the middle of the chest.
Structure of the Heart
The heart is a muscle about the size of a fist, and is roughly cone-shaped. It is about 12cm long, 9cm across the broadest point and about 6cm thick. The pericardium is a fibrous covering which wraps around the whole heart. It holds the heart in place but allows it to move as it beats. The wall of the heart itself is made up of a special type of muscle called cardiac muscle.
Chambers of the Heart
The heart has two sides, the right side and the left side. The heart has four chambers. The left and right side each have two chambers, a top chamber and a bottom chamber. The two top chambers are known as the left and right atria (singular: atrium). The atria receive blood from different sources. The left atrium receives blood from the lungs and the right atrium receives blood from the rest of the body. The bottom two chambers are known as the left and right ventricles. The ventricles pump blood out to different parts of the body. The right ventricle pumps blood to the lungs while the left ventricle pumps out blood to the rest of the body. The ventricles have much thicker walls than the atria which allows them to perform more work by pumping out blood to the whole body.
Blood Vessels
Blood Vessel are tubes which carry blood. Veins are blood vessels which carry blood from the body back to the heart. Arteries are blood vessels which carry blood from the heart to the body. There are also microscopic blood vessels which connect arteries and veins together called capillaries. There are a few main blood vessels which connect to different chambers of the heart. The aorta is the largest artery in our body. The left ventricle pumps blood into the aorta which then carries it to the rest of the body through smaller arteries. The pulmonary trunk is the large artery which the right ventricle pumps into. It splits into pulmonary arteries which take the blood to the lungs. The pulmonary veins take blood from the lungs to the left atrium. All the other veins in our body drain into the inferior vena cava (IVC) or the superior vena cava (SVC). These two large veins then take the blood from the rest of the body into the right atrium.
Valves
Valves are fibrous flaps of tissue found between the heart chambers and in the blood vessels. They are rather like gates which prevent blood from flowing in the wrong direction. They are found in a number of places. Valves between the atria and ventricles are known as the right and left atrioventricular valves, otherwise known as the tricuspid and mitral valves respectively. Valves between the ventricles and the great arteries are known as the semilunar valves. The aortic valve is found at the base of the aorta, while the pulmonary valve is found the base of the pulmonary trunk. There are also many valves found in veins throughout the body. However, there are no valves found in any of the other arteries besides the aorta and pulmonary trunk.
What is the Cardiovascular System?
The cardiovascular system refers to the heart, blood vessels and the blood. Blood contains oxygen and other nutrients which your body needs to survive. The body takes these essential nutrients from the blood. At the same time, the body dumps waste products like carbon dioxide, back into the blood, so they can be removed. The main function of the cardiovascular system is therefore to maintain blood flow to all parts of the body, to allow it to survive. Veins deliver used blood from the body back to the heart. Blood in the veins is low in oxygen (as it has been taken out by the body) and high in carbon dioxide (as the body has unloaded it back into the blood). All the veins drain into the superior and inferior vena cava which then drain into the right atrium. The right atrium pumps blood into the right ventricle. Then the right ventricle pumps blood to the pulmonary trunk, through the pulmonary arteries and into the lungs. In the lungs the blood picks up oxygen that we breathe in and gets rid of carbon dioxide, which we breathe out. The blood is becomes rich in oxygen which the body can use. From the lungs, blood drains into the left atrium and is then pumped into the left ventricle. The left ventricle then pumps this oxygen-rich blood out into the aorta which then distributes it to the rest of the body through other arteries. The main arteries which branch off the aorta and take blood to specific parts of the body are:

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Laughing is good for your heart. It reduces stress and gives a boost to your immune

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Maer galon yn bwysig heb y galon bydden ni’n marw ✖️❤️😫😵

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The circulatory system is made up of blood vessels that carry blood away from and towards the heart. Arteries carry blood away from the heart and veins carry blood back to the heart. The circulatory system carries oxygen, nutrients, and hormones to cells, and removes waste products, like carbon dioxide.

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Christmas day is the most common day to have a heart attacks to happen

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Most heart attack’s happen on a Monday

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Your ribs protect your Heart from getting damaged

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Heart cells stopped dividing which means heart cancer is extremely rare

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1. The average heart is the size of a fist in an adult.

2. Your heart will beat about 115,000 times each day.

3. Your heart pumps about 2,000 gallons of blood every day.

4. An electrical system controls the rhythm of your heart. It’s called the cardiac conduction system.

5. The heart can continue beating even when it’s disconnected from the body.

6. The first open-heart surgery occurred in 1893. It was performed by Daniel Hale Williams, who was one of the few black cardiologists in the United States at the time.

7. The first implantable pacemaker was used in 1958. Arne Larsson, who received the pacemaker, lived longer than the surgeon who implanted it. Larsson died at 86 of a disease that was unrelated to his heart.

8. The youngest person to receive heart surgery was only a minute old. She had a heart defect that many babies don’t survive. Her surgery was successful, but she’ll eventually need a heart transplant.

9. The earliest known case of heart disease was identified in the remains of a 3,500-year-old Egyptian mummy.

10. The fairy fly, which is a kind of wasp, has the smallest heart of any living creature.

11. The American pygmy shrew is the smallest mammal, but it has the fastest heartbeat at 1,200 beats per minute.

12. Whales have the largest heart of any mammal.

13. The giraffe has a lopsided heart, with their left ventricle being thicker than the right. This is because the left side has to get blood up the giraffe’s long neck to reach their brain.

14. Most heart attacks happen on a Monday.

15. Christmas day is the most common day of the year for heart attacks to happen.

16. The human heart weighs less than 1 pound. However, a man’s heart, on average, is 2 ounces heavier than a woman’s heart.

17. A woman’s heart beats slightly faster than a man’s heart.

18. The beating sound of your heart is caused by the valves of the heart opening and closing.

19. It’s possible to have a broken heart. It’s called broken heart syndrome and can have similar symptoms as a heart attack. The difference is that a heart attack is from heart disease and broken heart syndrome is caused by a rush of stress hormones from an emotional or physical stress event.

20. Death from a broken heart, or broken heart syndrome, is possible but extremely rare.

21. The iconic heart shape as a symbol of love is traditionally thought to come from the silphium plant, which was used as an ancient form of birth control.

22. If you were to stretch out your blood vessel system, it would extend over 60,000 miles.

23. Heart cells stop dividing, which means heart cancer is extremely rare.

24. Laughing is good for your heart. It reduces stress and gives a boost to your immune system.

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The heart can continue beating even when when it’s disconnected from the body

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Your ribs protect your heart from getting damaged

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The heart is a size of a  fist I’ll up lord it in a jiffy:)

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Your heart pumps 2,000 gallons of blood every day

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On the rightside  de de oxygenated blood which has circlated your body.

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Death from a broken heart, or broken heart syndrome, is possible but extremely rare

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The heart is placed behind your lungs in your chest

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Your heart will beat about 115,000 times a day

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Smoking 🚬 is bad for the heart 💔

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Endocardium is a another layer surrounding the heart.

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https://upload.wikimedia.org/wikipedia/commons/thumb/1/12/CG_Heart.gif/220px-CG_Heart.gif

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If you were stretched out your blood vessel system it would extend over 60,000 miles

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The heart

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The heart is a symbol of love

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Myocardium isa thick inner layer that contracts that contracts the blood

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Cadw galon yn iach

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Pericardium is one of the layers of the heart it’s a thin outer rim.

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y Galon

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https://www.healthline.com/health/fun-facts-about-the-heart#1

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Divided into 2 there is a border called the  septum

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Depression increases your risk for a heart attack, especially if you’re a woman

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My calon yn size or fist chi

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https://images.agoramedia.com/everydayhealth/gcms/9-amazing-facts-about-your-heart-722x406.jpg?width=722

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The aorta is the biggest arterie and is the first stop on the hearts sensational gurney

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Your activity level is the greatest potential risk factor for heart disease

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Dyma y galon

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the heart that we see everyday is fake

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most heart attacks happen on a Monday

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Death from a broken heart or broken heart syndrome is possible but extremely rare

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laughing is good for your heart. It reduces stress and gives a boost to your immune system

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The youngest person to receive heart surgery was only a minute old.

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らちゆつてんれる.Your ifscrunched your head up it would be the size of your heart

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The heart is not the size of your heaむつへてめ

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The first open heart surgery occurred in 1893.It was performed by Daniel Hale Williams who was one of the few black cardiologist in the United States at the time.

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Heart attack symptoms are different in men and wemen

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The heart pumps oxygen into  other parts of your body.
The red blood sells carry blood into other parts of your body and the blue sells carry oxygen into the lungsq

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Your heart rate drops when your asleep

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Your heart is roughly as big as your fist

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Your heart pumps about 2,000 gallons of blood every day

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The heart is the size of your fist

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Heart disease isn’t one killer for men it is also the number one killer for women

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The average heart is the size of a fist in an adult!

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The hart pumps 1000 taims s day

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The heart is the strongest muscle in your body

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If your fist is small it dosn’t mean your heart is weak

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The Hart is abawt the saus of your fist

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There are many diseases caused by heart there.

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The heart pumps more than 70 a minute

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Age and fitness level affects your heart rate

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Pump ddwbwl

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The hart is locetid buhaund the rub cage

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Your heart is protected by your rib cage

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The Hart is a dubl pump

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The adult heart pumps 100,000 times each day

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My heart is very small because my fist is small but strong

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Fentrigl dde ac y’r fentrigl chwith

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An electrical system controls your heart

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The heart is behind the rib cage

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The heart pumps blood through your body

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Heart is behind the longs

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There are 3 layers to the heart

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The heart pumps blood all around the body

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Dy galon yn cryf iawn

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Your hart will beat 115,000 times a day

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The heart is technically a pump

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Artriwm dde ac yr atrium chwi

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The heart is a muscle

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It’s the hearts job to plumb you blood around your body!

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The heart is the size of your fist

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The heart is a very important organ of your body.

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The heart is the organ that pumps blood around the whole body