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How does the conduction system of the heart control the cardiac cycle to ensure enough blood is ejected from the heart?
the sinoatrial node (present in the right atrium) starts the cardiac cycle by producing an action potential which is then transmitted rapidly to the left atrium (causing contraction of both atria) & the ventricles during which are relaxed (diastole) then through the atrioventricular node, the impulses are then transmitted from the atria to the ventricles & then through the bundle of Hiss then left & right bundle branches to all of the ventrricular muscle causing contraction of both ventricles & thus systole
Any defect in the conductive system like ectopic foci (focus producing action potential other than the SA node) or AV block (no impulse transmission from atria to ventricles) leads to defective filling of the heart & pumping of blood
What else can I help you with?
What is ischemic heart tissue?
Ischemia occurs when there is not enough oxygenated blood reaching the cardiac muscle cells.
Why does your heart rate level off after cardiac output?
Cardiac output will level off as your heart muscle strengthens and your body becomes accustomed to physical activity. For example, when first getting started, walking 5 minutes may be enough to increase your heart rate, but within a few weeks, you will need to increase the intensity of your walk to increase your heart rate by the same amount.
Why does tachycardia greater than 200 beats per minutes results in decreased coronary perfusion?
The heart does not have enough time between contractions to fill with enough blood to maintain adequate cardiac output. This is especially a concern because the heart itself is perfused during diastole (the period between ventricular contractions).
Can cell phones cause heart attacks?
There is no evidence that cellphones can directly contribute to heart attacks, (unless there is extremely bad news on the other end of the line). To provoke a heart attack, the phone would need to exert enough energy to dislodge a coronary artery plaque, or create a clot to block an artery. The amount of radiant energy produced during a cell phone call is not enough to cross the chest wall, much less have an impact on the cardiac tissues. Persons with pacemakers however, are cautioned to avoid placing any electronic device that might produce a magnetic field, near their pacemaker. Magnets are used to program and control both pacemakers and Automatic Internal Cardiac Defibrillators (AICDs), and there have been reported interference in function of these devices from the magnets from ear-bud speakers and cell phones, when placed in direct proximity of the device.
How does myocardial infarction lead to heart failure?
Myocardial infarction (MI) can lead to heart failure in numerous ways. First of all, early on, the heart muscle does not contract well because it is not receiving enough oxygen and other necessary substrates, so stroke volume is decreased, which may lead to congestive heart failure. Later on, if the MI is aborted with thrombolytics or with a cardiac catheterization and thrombectomy, the myocardium may be stunned, or hibernating, because of the lack of oxygen, and may return to normal function over time. If the MI completes, the portion of cardiac muscle that was affected is dead. Depending on how significant a portion that is, losing the muscle alone may result in heart failure. The dead portion of the heart will later turn into a scar, which is noncontractile and also does not allow for the normal stretch, so it may affect preload and contractility in that way as well, decreasing cardiac output and possibly leading to congestive heart failure.
What determines if electrons are ejected from the surface?
The ejection of electrons from a surface is determined by the energy of the incoming photons or particles. If the energy is high enough, it can overcome the binding energy of the electrons in the material, causing them to be ejected.
How much do cardiac surgeons earn in Idaho?
Enough to get rich in short order.
What is cardiac failure?
Cardiac (pertaing to the heart) failure (no function). The heart stops working and the tissues do not recieve enough oxygen in the blood and a person will die in a few minutes.
Can Conduction take place in a gas?
No it can't because the particles are not close enough for the heat to be transferred
Are there many cardiac surgeons in the world?
There are not enough of them. Their distribution acording to needs and resources is uneven and injust.
Why is cardiac muscle called cardiac muscle?
Cardiac means "of or relating to the heart". Cardiac muscle has that name because it is the specific kind of muscle found only in the heart. It is a very special kind of muscle, very efficient and different from other muscles.
Can you have a heart attack by having not enough oxygen in the cardiac muscle?
Yes, ischemia leads to heart arrest.
What happens when the left ventricle size thins?
If the wall thins enough, the patient goes into cardiac failure.
What is ischemic heart tissue?
Ischemia occurs when there is not enough oxygenated blood reaching the cardiac muscle cells.
If red light can cause an electron to be ejected from the surface of a piece of cobalt statements is most likely true?
Yes, that statement is most likely true as red light has enough energy to cause the photoelectric effect, where electrons are ejected from a material's surface. This phenomenon occurs when photons of light transfer their energy to electrons, allowing them to overcome the material's work function and be ejected.
How does lack of oxygen lead to heart attack or stroke?
The myocard (cardiac muscle), the muscle that makes your heart pump, needs oxygen to function. This oxygen is distributed through the blood that flows in the coronary arteries, which lie around the cardiac muscle. When there is not enough oxygen in your blood, the cardiac muscle does not get enough oxygen to fully function and your heart will not be able to function, over time. This starts at about 3 minutes after stopping to get oxygen.
Why can't a condution occur in a space?
Conduction requires particles to physically touch to transfer heat. In a vacuum (like outer space), there aren't enough particles for conduction to happen efficiently. Heat transfer in space primarily occurs through radiation, where electromagnetic waves carry heat energy.
