Causes and Prevention / Learn how the heart works
Without stopping, the heart, it pumps oxygen and nutrients for your body to sustain life. The size of a fist, this machine beats 100,000 per day, pumping about five liters of blood per minute or 7,500 gallons per day.
As blood travels through the heart?
As the heart beats, it pumps blood through a system of blood vessels called the circulatory system. They are muscular and elastic tubes that carry blood to all parts of the body. Blood is essential. In addition to carrying fresh oxygen from the lungs and nutrients to body tissues, it also collects the waste from the body, such as carbon dioxide.
There are three main types of blood vessels:
Arteries: They begin with the aorta, the large artery leaving the heart. The arteries carry oxygen-rich blood away from the heart, going to all body tissues. They branch several times, becoming smaller and smaller as they carry the blood to more distant points.
Hair: It’s small and thin blood vessels that connect arteries and veins. Their thin walls allow oxygen, nutrients, carbon dioxide and other harmful substances into and out of cells in organs.
Veins: These are blood vessels that carry blood back to the heart. This blood has low oxygen content and is rich in waste products that will be eliminated by the body. The veins become larger and larger as they get closer to the heart. The superior vena cava is the large vein that brings blood from the head and arms to the heart, and the inferior vena cava is the one that carries blood from the abdomen and legs to the heart.
This vast system of blood arteries, veins and capillaries is nearly 100,000 km. That’s long enough to circle the world more than twice! The blood circulates continuously through the blood vessels of your body. The pump that makes this possible is the heart.
Where Is Your Heart? How is it?
The heart is under the ribs on the left of the breastbone (sternum) and between the lungs. It is a muscle. The strong muscular walls contract, pumping blood throughout the body. On the surface of the heart, there are the coronary arteries, which supply the heart muscle with blood rich in oxygen. The largest vessels entering the heart are the superior vena cava, the inferior vena cava and pulmonary vein. The pulmonary artery and the aorta leave this body and carry oxygenated blood to the rest of the body.
On the inside, the heart is an organ divided into four hollow parts. The sides of the right and left are divided by a muscular wall called the septum.The two sides of the heart are further divided in other two upper chambers called the atria, which receive blood from the veins, and two lower chambers, called ventricles, which pump blood into the arteries. The atria and ventricles work together, contracting and relaxing to pump blood out of the heart. As blood leaves each chamber of the heart, it passes through a valve.
There are four valves within the heart:
The tricuspid and mitral valves lie between the atria and ventricles. Since the aortic and pulmonary valves are between the ventricles and major blood vessels leaving the heart. The heart valves work the same way as the valves of the plumbing of a house. They prevent blood from flowing the wrong way.
As blood flows through the heart?
The right and left sides of the heart work together.
The blood enters the heart through two large veins, the inferior and superior vena cava, eliminating the oxygen-poor blood from the body in the right atrium. As the atrium contracts, blood flows from right atrium to the right ventricle through the tricuspid valve open. When the ventricle is full, the tricuspid valve closes. This prevents blood from flowing backward into the atrium when the ventricle contracts. When the ventricle contracts, blood leaves the heart through the pulmonary valve to the pulmonary artery to the lungs, where it is oxygenated.
The pulmonary vein empties oxygen-rich blood from the lungs into the left atrium. As the atrium contracts, blood flows from left atrium into the left ventricle through the mitral valve open. When the ventricle is full, the mitral valve closes. This prevents blood from flowing backward into the atrium when the ventricle contracts. By contract, the blood leaves the heart through the aortic valve and goes to the aorta and the body.
As blood flows through the lungs?
Pulmonary valve, blood enters the lungs. This is called pulmonary circulation. Through the pulmonary valve, blood travels from the pulmonary artery to the small capillaries of the lung. There, oxygen is transported in bags of thin air through the capillary walls into the blood. At the same time, carbon dioxide, a waste product of metabolism, passes from the blood to air sacs. Carbon dioxide leaves the body when you exhale. Once the blood is purified and oxygenated, it travels back into the left atrium through the pulmonary veins.
What are coronary arteries?
Like all organs, the heart is made of a fabric that requires the supply of oxygen and nutrients. Although its chambers are full of blood, the heart receives no nourishment from this blood. The blood supply to the heart comes through a network of arteries, called coronary arteries. Two main arteries branch off the aorta near the point where the aorta and left ventricle are:
The right coronary artery supplies the right atrium and right ventricle with blood. It branches into the posterior descending artery, which supplies the lower part of the left ventricle and back of the septum with blood.
The main left coronary artery branches into the circumflex artery and left anterior descending artery. The circumflex artery supplies blood to the left atrium, side and back of the left ventricle. Since the left anterior descending artery suppresses the front and lower front of the left ventricle and septum with blood.
These arteries and their branches supply all parts of the coronary muscle with blood.
As the heart beats?
The atria and ventricles work together, alternately contracting and relaxing to pump blood through the heart. It is the heart’s electrical system that makes this possible. The beat of your heart is driven by electrical impulses. The impulse starts in a bundle of specialized cells called the SA node (sinoatrial node), located in the right atrium. The electrical activity is reflected by the walls of the atria, causing them to contract.
A group of cells located in the center of the heart between the atria and ventricles, the AV node (AV node) functions as a gate that slows the electrical impulse before it enters the ventricles. This delay gives the atria time for them to contract before the ventricles do so. The His-Purkinje network is a trail of fibers that send the impulse to the muscular walls of the ventricles, causing them to contract. At rest, the heart beats 50 to 99 times per minute. Physical exercise, strong emotions, fever and some medications can cause your heart to beat faster, to over 100 beats per minute.
What is low blood pressure?
Hypotension is the medical term for low blood pressure, that less than 90/60. The normal pressure that is 120/80 (systolic / diastolic). In healthy people, especially athletes, low blood pressure is a sign of good cardiovascular health (heart and blood vessels). But low blood pressure can also be a sign of other problems, especially in old age: Inadequate blood flow to the heart, brain and other vital organs. The chronic low blood pressure is almost never serious.
But health problems occur when the blood pressure drops suddenly and the brain is deprived of adequate irrigation of blood. This can cause dizziness and blackout. It can occur when a person stands up, which is known as postural or orthostatic hypotension. Postural hypotension is considered a failure in the autonomic nervous system, that part of the nervous system that controls involuntary activities of life such as heartbeat.He can not react appropriately to sudden changes.
When you get up, the blood tends to stay in the lower extremities, leading to pressure to drop. But your body compensates for this by sending messages to your heart beat faster and your veins to constrict. This counteracts the pressure drop. The incidence of both high and low pressure usually increases with age, from natural causes. In addition, blood flow in the brain falls with age, as a response to the plaques that form in blood vessels. So the chances of hypotension also increase.
What causes it?
The cause of low blood pressure is unclear. But it is associated to the following reasons:
Hormonal problems such as hypothyroidism, hyperthyroidism, diabetes and hypoglycemia
Overdose of drugs for high blood pressure
- Cardiac arrest
- Dilation of blood vessels
- Excess heat
- Liver disease
Sudden drop in pressure can be life threatening. The causes of this type of hypotension include:
- Loss of blood
- Low body temperature
- High body temperature
- Heart disease
- Sepsis (generalized infection)
- Severe dehydration
- Reaction to medications
- Severe allergic reaction
Many drugs are usually associated with postural hypotension. These medications can be of two categories:
1. Medications used to treat high blood pressure
2. Drugs that have hypotension as a side effect, such as nitrates, drugs for Parkinson’s disease, antipsychotics, drugs for anxiety, sedatives and antidepressants
Rarer causes of this disease is amyloidosis (accumulation of starch in the tissues), vitamin deficiency, spinal cord injuries and neuropathology associated with cancer, especially lung and pancreas.
Hypertension: high blood pressure symptoms
One of the most dangerous aspects of hypertension is that you may not know about that. In general, there are no symptoms of high blood pressure, so you do not feel it. The only way to discover it is by checking. This is especially important if you have a relative with high blood pressure. If your pressure is extremely high, you may have some symptoms:
- Severe headache
- Fatigue or confusion
- Vision problems
- Chest pain
- Difficulty breathing
- Irregular heartbeat
- Blood in urine and nose
Hypertension abused can lead to serious diseases such as stroke, heart disease, stop the kidneys and eye problems.
When the pressure reaches a certain level, damage to organs.
Occurs when blood pressure rises, but does not bring damage to organs.Within a few hours, the pressure can download again with drugs.
When the pressure brings some damage to the organs, called hypertensive emergency. When this happens, the pressure must be reduced immediately. This is done in an intensive care unit of a hospital.Damage to an organ added to the hypertensive emergency may include:
- Changes in mental status such as confusion and coma
- Infarction in the brain
- Cardiac arrest
- Chest pain
- Fluid in the lungs
Fortunately, hypertensive emergency is rare. When it occurs, is the bearer of hypertension because it was not or did not take the medicine they need.The symptoms of hypertensive emergency are:
- Chest pain
- Shortness of breath
- Swelling or edema (fluid in tissues)
How to diagnose hypertensive emergency?
Your doctor will want to ask you many things to better understand its history. Among them, what medicines you take, even in the form of herbal or dietary supplements. Some tests can also be made:
- Check the pressure
- Examination of the eye to see if it is not swollen or bleeding
- Examination of blood and urine
What are the treatments?
The first goal of the doctor will lower your blood pressure as quickly as possible with intravenous drugs. This will prevent organ damage. If some body has already been damaged, there will be a specific treatment for it.
Hypertension is a silent disease, symptoms almost never there. But if it is not treated, can lead to heart problems and kidney. It is therefore important to check your blood pressure regularly. Especially if she has ever been high, if there is family history and if you’re fat. If you are already treating hypertension and high pressure continues, see a doctor. You may not be responding to medication data and this can bring many dangerous consequences.
Hypertension can be primary, when there is no apparent cause, such as genetics or lifestyle. Or it may be secondary, if it is linked to other disorders. They are: disorders of the adrenal gland (small organs located above the kidneys that produce hormones). These include Cushing’s syndrome (caused by the overproduction of cortisol), the hyper-production of aldosterone and tumors that cause hyper secretion of hormones such as adrenaline
Drugs such as corticosteroids, antiflamatórios, drugs for weight loss, birth control pills, cold medicine and migraine
Apnea, or cessation of breathing during sleep. About half of patients who suffer from sleep apnea have hypertension
Narrowing of the aorta
Thyroid or parathyroid
Because secondary hypertension is diagnosed?
Once you have been diagnosed with hypertension, the doctor may apply other tests such as blood and urine to see if your problem is secondary.
How is it treated?
To treat secondary hypertension, you need to fix the main problem, one that is generating high pressure. This may include surgery or medications.