There are three types of vessels in the cardiovascular system.
The human heart has four chambers and four valves.
Discuss the control of the heart muscle by the SA and the electrical changes that result in the characteristic patterns seen in an electrocardiogram.
The main force behind the movement of blood in the veins is muscle contraction.
The breastbone is tilted so that the apex is oriented to the left.
The venae cavae is on the right side of the heart.
The left side of the heart contains the aorta and pulmonary veins.
If the blood vessels carry oxygen-rich blood and oxygen-poor blood, they are red and blue, respectively.
The myocardium does not pump blood from the coronary arteries.
The inner surface of the heart is lined with a layer of tissue.
The lining of the blood vessels is continuous.
The wall separates the heart into two parts, one on the right side and one on the left.
There are four chambers in the heart.
The two atria have wrinkled appendages called auricles.
The two chambers on the right are separated from the two chambers on the left by a septum.
Blood passes from the atria to the ventricles when the atrioventricular valves are open.
The cells can bend and stretch at the same location.
The four valves in the heart direct the flow of blood and prevent backward movement.
There are two valves between the atria and the ventricles.
These valves are supported by strings.
The valves are supported by the chordae, which are attached to muscular projections of the ventricular walls.
The tricuspid valve is on the right side and has three flaps.
The valve on the left side has two flaps.
Between the right ventricle and the pulmonary trunk lies the pulmonary semilunar valve.
There is a valve between the left ventricle and the aorta.
Both the atria and the ventricles contract at the same time.
The flow of blood can be traced through the heart and body.
The superior vena cava and the inferior vena cava carry oxygen-poor blood that is high in carbon dioxide into the right atrium.
The blood goes through the atrioventricular valve to the right ventricle.
Four pulmonary veins carry blood from the lungs to the heart.
The blood goes through the atrioventricular valve to the left ventricle.
Oxygen-poor blood never mixes with oxygen-rich blood according to an examination of this pathway.
The left Page 603 ventricle has a harder job of pumping blood to the entire body than the right one.
Oxygen-rich blood is associated with all arteries and oxygen poor blood is associated with all veins.
This is only true in the system circuit.
The arteries and veins carry blood from the lungs to the heart.
The term arteries and veins refers to the direction of blood flow, not the level of oxygenation.
The blood goes into the arteries when the ventricles contract.
The left side of the heart has a stronger pump.
As arterioles increase, blood pressure decreases.
A different mechanism is needed to move blood in the veins.
Each heartbeat lasts about 0.85 seconds, and the average human heart beats about 70 times a minute.
100,000 beats per day is how much this adds up to.
"dilation, spreading" refers to the relaxation of these chambers.
The ventricles fill with blood when the atria contract.
The atrioventricular valves are open and the semilunar valves are closed.
When the ventricles contract, the atrioventricular valves are closed, the semilunar valves are open, and the blood is pumped into the pulmonary trunk and aorta.
The atria and the ventricles fill with blood when the heart is relaxed.
The atrioventricular valves are open and the semilunar valves are closed.
Table 32.1 shows the approximate timing of the cardiac cycle, as well as the condition of the atria and ventricles.
First the atria contract, then the ventricles contract, and then all chambers rest.
About 50% of the time, the heart is in diastole.
The muscular ventricles pump blood into the cardiovascular system.
A person with a heartbeat of 70 beats per minute has a heart rate of 5.25 liters a minute.
It adds up to about 2,000 gallons a day, and is almost equivalent to the amount of blood in the body.
The cardiac output can increase a lot during heavy exercise.
A heart murmur, a slight slush sound after the lub, is often due to ineffective valves, which allow blood to pass back into the atria after the atrioventricular valves have closed.
When the aorta expands, the pulse goes down the walls of the blood vessels.
The heart rate can be determined using the arterial pulse rate.
The contraction of the atria and ventricles is due to the internal system of the heart.
There is a unique type of cardiac muscle located in two regions of the heart.
The ventricles contract by way of large fibers in the Purkinje fibers when the impulse reaches the AV node.
The atria contracts when the atria is stimulated by the SA node.
It signals the ventricles to contract when this is reached.
The two branches of the atrioventricular bundle are passed down to the Purkinje fibers.
The rate and strength of heart contractions can be increased or decreased by the input of the brain.
The hormones are released into the blood by the adrenal glands.
The heart pumps faster and stronger when a person is frightened.
There are electrical changes in the myocardium during a cardiac cycle.
Body fluids have electrical currents that can be detected on the body surface.
When an instrument is used to detect the myocardium's electrical changes, wires are placed on the skin.
There is a normal ECG pattern shown in the 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846 888-666-1846
The heart is functioning normally.
The P wave, the QRS complex, and the T wave occur when the ventricles are recovering from contraction.
Ventricular fibrillation can cause an irregularlectrocardiogram.
The P wave is an electrical change.
The atria are about to contract according to the P wave.
The atria are relaxing after the QRS complex signals that the ventricles are about to contract.
The T wave is caused by the electrical changes that occur when the ventricular muscle fibers recover.
An electrocardiogram can be used to detect various types of abnormality.
The cause of ventricular fibrillation is uncoordinated contraction of the ventricles.
Ventricular fibrillation can be caused by an injury or a drug overdose.
It is the most common cause of sudden cardiac death.
When the ventricles are fibrillating, they can be defibrillated by applying a strong electrical current.
SA may be able to reestablish a coordinated beat.
Automatic external defibrillators (AEDs) can be found in many public places and private homes.
These small devices can be used to determine if a person is suffering from a heart problem.
The blood goes between the heart and other parts of the body.
The blood moves between the lungs and the heart.
Oxygen-poor blood from all regions of the body is collected in the right atrium and pumped into the right ventricle.
The right and left pulmonary arteries carry blood to the lungs.
Oxygen and carbon dioxide are given off as blood passes through the lungs.
Oxygen-rich blood returns to the heart through the pulmonary veins.
The majority of the blood vessels in the body belong to the systemic circuit, which is involved in the transportation of blood to and from the organ systems and tissues of the body.
The major blood vessels in the system circuit are the aorta and vena cava.
Oxygen-rich blood is pumped from the left ventricle into the aorta.
Blood arrives at the organ or tissue from smaller arteries and arterioles.
Blood enters the capillary bed from arterioles.
Gas and waste exchange occur here.
The major vein of the body is the vena cava.
The vena cava has poor blood flow.
It will be sent to the lungs via the pulmonary circuit.
The vein that serves the Page 606 region is usually given the same name as the artery.
When viewed through the skin, veins are dull red and arteries are bright red, but they both contain oxygen-rich blood.
The coronary arteries supply oxygen and vitamins to the heart muscle.
Above the semilunar valve is where the coronary arteries come from.
They lie on the exterior surface of the heart.
The blood and the tissues are exchanged in the capillary beds.
The capillary beds join to form the cardiac veins and empty into the right atrium.
There is an exception to the path of blood in the systemic circuit where blood must travel through veins to reach another set of capillaries.
The blood comes from the scuplture to the scuplture to the scuplture to the scuplture to the scuplture to the scuplture to the scuplture to the scupl
Blood is forced into the aorta and other arteries when the left ventricle contracts.
The pressure in the arteries during ventricular diastole is what determines systolic pressure.
Blood pressure can be measured on the brachial arteries.
Digital manometers are often used to take one's blood pressure instead of the older type with a dial.
Blood pressure is measured in grams of mercury.
A blood pressure reading consists of two numbers that represent the pressures of the arteries.
The difference between the two pressure levels gradually decreases.
There is a slow, even flow of blood in the capillaries.
This may be related to the high total crosssectional area of the capillaries.
The large number of capillaries are to blame for most of the distance.
Blood pressure and velocity are related to the cross-sectional area.
Blood in capillaries is under minimal pressure.
capillaries have a bigger total cross-sectional area than arterioles.
Blood pressure in the veins is not high enough to move blood from the limbs to the heart.
When the valves of the veins become weak, they can't prevent the backward flow of blood.
Blood flow is regulated by valves.
When external pressure is not applied to the vein, back pressure causes the valve to close.
The blood can't flow in the opposite direction if the valves are closed.
Cardiovascular disease is the leading cause of death in Western countries.
According to the American Heart Association, cardiovascular disease has been the most common cause of death in the United States since 1900.
The worst year of a global flu epidemic was 1918.
According to statistics from the American Heart Association, about 2,250 Americans die of CVD each day, which is an average of one death every 40 seconds, and about one out of every three deaths overall.
The recent findings about preventing cardiovascular disease are examined in the Nature of Science feature.
About 30% of Americans suffer from Page 607 hypertension, which is high blood pressure.
Prehypertension is a condition that can lead to hypertension.
Table 32.2 shows the blood pressure levels associated with hypertension.
"Understanding Blood Pressure Readings" was published by the American Heart Association.
A narrowing of arteries is the most common cause of hypertension.
The heart has to work harder to get enough blood.
Increased blood pressure can cause damage to the heart, arteries, and other organs.
Only about two-thirds of people with hypertension seek medical help for their condition, and it is likely that many people with high blood pressure are unaware of it.
The flow of blood is disrupted by an accumulate of soft materials in the vessel.
A clot can form on the wall.
A stroke or heart attack can occur if thromboembolism is not treated.
Atherosclerotic plaque accumulates cholesterol and fat.
A heart attack is more likely to occur when plaque is present in a coronary arteries.
Page 608 has been associated with an increased risk of cardiovascular disease.
Increasing age, male gender, family history of heart disease, and belonging to certain races, such as African American, Mexican American, and American Indian, cannot be avoided.
Smoking, high cholesterol, hypertension, diabetes, and physical activity can be avoided by changing one's behavior or taking medication.
Other factors have been considered in recent years.
Alcohol abuse can destroy every organ in the body.
According to recent research, a moderate level of alcohol intake can improve cardiovascular health by decreasing unwanted clot formation, increasing blood flow in the heart, and reducing blood pressure.
According to the American Heart Association, people who consume one or two drinks per day have a 50% reduction in cardiovascular disease compared to nondrinkers.
The risk of many alcohol-related problems is increased if you consume more than one or two drinks per day.
Wine is often consumed with meals.
Red wine has high levels of anti-oxidants, including resveratrol.
Resveratrol can be found in grape juice.
There are supplements for Resveratrol at health food stores.
The benefits of resveratrol alone are questionable, and most controlled studies have shown no beneficial effects.
The French have a lower incidence of CVD due to lifestyle and genetic differences.
The influence that diet has on cholesterol levels has been studied.
It is beneficial to limit our intake of foods high in trans fats and saturated fat.
Replacing harmful fats with healthier ones is beneficial.
Salmon, mackerel, herring, lake trout, sardines, and albacore tuna are some of the fish that the American Heart Association recommends being eaten at least two times a week.
The growth rate of atherosclerotic plaque can be slowed with the help of essential fatty acids.
Children and pregnant women are advised to limit their fish consumption due to high levels of mercury in some fishes.
The benefits of fish consumption far outweigh the risks for older men and women.
Symptoms of atherosclerosis may not appear until an individual is 50 or older.
There are strokes and heart attacks associated with hypertension.
When a small cranial arteriole bursts or is blocked by an embolus, a stroke can happen.
A lack of oxygen can cause the brain to die.
A person can sometimes be warned of a stroke by a feeling of weakness in their hands, face, or eye.
Angina pectoris, also known as a squeezing sensation or a flash of burning, is a symptom of a partially blocked coronary arteries.
A portion of the heart muscle can be killed by a lack of oxygen due to a blocked coronary arteries.
This is a heart attack.
It is possible to place a self-expanding wire mesh tube inside a blocked arteries to keep it open.
If this approach isn't successful, a surgery may be needed to replace one or more blocked arteries with a new one from elsewhere in the patient's body.