The Tell Tale Heart ( ANNOTATED )

Product Information

His remark did not seem at all surprising. It was just like Marlow. It was accepted in silence. No one took the trouble to grunt even ; and presently he said, very slow -- He turned to his work. The noise outside had ceased, and presently in going out I stopped at the door. In the steady buzz of flies the homeward-bound agent was lying finished and insensible; the other, bent over his books, was making correct entries of perfectly correct transactions; and fifty feet below the doorstep I could see the still tree-tops of the grove of death. They are the main blood vessels (great vessels) that allow blood to enter and exit the right side of the heart, and enter and exit the left side of the heart. If students receive cuts or scratches during dissection, wash the wound in cold running water. Allow minor wounds to bleed freely and refer to a first aider. Ethical issues

c Decide how the hearts are to be disposed of. This should either be by incineration, or in a dustbin or container used for food wastes that are not to be fed to animals. Sometimes, the pacemaker of the heart stops functioning properly (this can cause an irregular heartbeat) An electrocardiogram (ECG) is a medical device that measures the electrical pulse of the heart. Since the heart undergoes a series of electrical changes related to the waves of excitation, sensors that are connected to a monitor can detect these electrical signals. The ECG produces a trace of electrical activity shown in Figure 6. m Look at the left-hand diagram. Make a long cut down through the aorta and the left ventricle to the tip of the heart (‘apex’), as shown in the diagram. The position of the blood vessels on the surface will help you to make this cut in the right place. Identify the coronary artery that supplies the heart muscle itself with blood. All the events that come and play within the heart come together to become the cardiac cycle. The cardiac cycle is a series of contractions that ensure blood is flowing in the correct direction

Normal CT coronary angiogram

The sino-atrial node sends impulses over the two atria which are then stimulated to contract. When the electrical impulses reach the atrioventricular node (at the junction between the atria and the ventricles), the impulses will spread rapidly through special fibers from the inter-ventricular septum to the walls of both ventricles, where the muscles are stimulated to contract. Relaxation phase: During the relaxation phase, all 4 chambers of the heart are in diastole as blood pours into the heart from the veins. The ventricles fill to about 75% capacity during this phase and will be completely filled only after the atria enter systole. The cardiac muscle cells of the ventricles repolarize during this phase to prepare for the next round of depolarization and contraction. During this phase, the AV valves open to allow blood to flow freely into the ventricles while the semilunar valves close to prevent the regurgitation of blood from the great arteries into the ventricles. Veins are made up of thin layers with a few circular elastic fibres and muscle fibres. This is because blood does not flow in pulses and so the vein walls cannot help pump the blood on. Veins also have thin walls which allows the near by muscles to press against them so that they become flat. This helps the blood to be pushed forwards towards the heart. There is only a thin outer layer of longitudinal collagen and elastic fibres as there is low pressure inside the vein and so little chance of bursting. Finally, a wide lumen is needed to accommodate the slow flowing blood due to the low pressure. Before we dive into what those structures are, let’s briefly review the blood flow through the heart.

The coronary arteries supply heart muscle with oxygen and nutrients. 6.2.3 Explain the action of the heart in terms of collecting blood, pumping blood, and opening and closing of valves. It is impossible to say how first the idea entered my brain; but once conceived, it haunted me day and night. Object there was none. Passion there was none. I loved the old man. He had never wronged me. He had never given me insult. For his gold I had no desire. I think it was his eye! — yes, it was this! He had the eye of a vulture — a pale blue eye, with a film over it. Whenever it fell upon me, my blood ran cold ; and so by degrees — very gradually — I made up my mind to take the life of the old man, and thus rid myself of the eye forever. The two atria (auricles): these are the upper two chambers. They have thin walls which receive blood from veins. All of the deoxygenated blood from the body drains into the venous system and enters the right side of the heart, specifically the right atrium.Cardiac output (CO) is the volume of blood being pumped by the heart in one minute. The equation used to find cardiac output is: CO = Stroke Volume x Heart Rate

The right atrium contracts pushing blood through the right atrioventricular valve into the right ventricle. The right ventricle then contracts passing the blood into the pulmonary trunk via the pulmonary valve to reach the lungs There are a number of different protocols based on patient presentation that can be broken into prospective and retrospective based: mitral valve (aka left atrioventricular valve; aka bicuspid valve) drains blood from the left atrium when it is open during ventricular diastoleAn echocardiogram (or echo) is an ultrasound of the heart. During an echo, we record short videos of the heart as it beats, and from these videos we can learn about the structure and function of the heart. The left ventricle is the main pumping chamber of your heart – it is the one where blood leaves your heart to be pumped around your body. Because it is doing all this work, it is the largest and most muscular of the four chambers of your heart. The bundle of His is a collection of heart muscles cells specialised for electrical conduction. These cells receive input from the AVN. 1,4,5 After this I got embraced, told to wear flannel, be sure to write often, and so on -- and I left. In the street -- I don't know why -- a queer feeling came to me that I was an imposter . Odd thing that I, who used to clear out for any part of the world at twenty-four hours' notice, with less thought than most men give to the crossing of a street, had a moment -- I won't say of hesitation, but of startled pause, before this commonplace affair. The best way I can explain it to you is by saying that, for a second or two, I felt as though, instead of going to the centre of a continent, I were about to set off for the centre of the earth He paused again as if reflecting, then added: "Of course in this you fellows see more than I could then. You see me, whom you know. . . ."