Heart Structure And Function Pdf
- and pdf
- Friday, May 14, 2021 12:08:13 AM
- 5 comment
File Name: heart structure and function .zip
If you clench your hand into a fist, this is approximately the same size as your heart. It is located in the middle of the chest and slightly towards the left.
- The heart: All you need to know
- The heart: All you need to know
- Service Unavailable in EU region
- Structure of the Heart
The heart itself is made up of 4 chambers, 2 atria and 2 ventricles.
The heart: All you need to know
The human heart is a finely-tuned instrument that serves the whole body. It is a muscular organ around the size of a closed fist, and it sits in the chest, slightly to the left of center.
This delivers oxygen- and nutrient-rich blood to tissues and organs and carries away waste. The heart sends deoxygenated blood to the lungs, where the blood loads up with oxygen and unloads carbon dioxide, a waste product of metabolism. Together, the heart, blood, and blood vessels — arteries, capillaries, and veins — make up the circulatory system. In this article, we explore the structure of the heart, how it pumps blood around the body, and the electrical system that controls it.
Below is an interactive 3D model of the heart. Explore the model using your mouse pad or touchscreen to learn more. The heart consists of four chambers :. A wall of tissue called the septum separates the left and right atria and the left and right ventricle. Valves separate the atria from the ventricles.
At rest, the heart might beat around 60 times each minute. But this can increase to beats per minute bpm or more. The left and right sides of the heart work in unison. The atria and ventricles contract and relax in turn, producing a rhythmic heartbeat.
Diastole: The ventricles relax and fill with blood as the atria contract, emptying all blood into the ventricles.
Systole: The ventricles contract and pump blood out of the heart as the atria relax, filling with blood again. When a person takes their blood pressure, the machine will give a high and a low number. The high number is the systolic blood pressure, and the lower number is the diastolic blood pressure. Systolic pressure: This shows how much pressure the blood creates against the artery walls during systole.
Diastolic pressure: This shows how much pressure is in the arteries during diastole. The heart enables the body to eliminate the unwanted carbon dioxide. The pulse is the same as the heart rate. When you feel your pulse, you feel the rush of blood as the heart pumps it through the body.
A healthy pulse is usually 60— bpm , and what is normal can vary from person to person. A very active person may have a pulse as low as 40 bpm. People with a larger body size tend to have a faster pulse, but it is not usually over bpm.
Learn how to take the pulse here. The heart has four valves to ensure that blood only flows in one direction:. Most people are familiar with the sound of the heart.
In fact, the heart makes many types of sound , and doctors can distinguish these to monitor the health of the heart. The opening and closing of the valves are key contributors to the sound of the heartbeat. To pump blood throughout the body, the muscles of the heart must work together to squeeze the blood in the right direction, at the right time, and with the right force.
Electrical impulses coordinate this activity. The electrical signal begins at the sino-atrial node, sometimes called the sinus, or SA, node.
The signal causes the atria to contract, pushing blood down into the ventricles. The electrical impulse then travels to an area of cells at the bottom of the right atrium, between the atria and ventricles, called the atrioventricular, or AV, node. These cells act as a gatekeeper. They coordinate the signal so that the atria and ventricles do not contract at the same time. There needs to be a slight delay. From here, the signal travels along fibers, called Purkinje fibers, within the ventricle walls.
The fibers pass the impulse to the heart muscle, causing the ventricles to contract. Arteries : These carry oxygenated blood from the heart to the rest of the body. The arteries are strong, muscular, and stretchy, which helps push blood through the circulatory system, and they also help regulate blood pressure.
The arteries branch into smaller vessels called arterioles. Veins : These carry deoxygenated blood back to the heart, and they increase in size as they get closer to the heart. Veins have thinner walls than arteries. Capillaries : These connect the smallest arteries to the smallest veins. They have very thin walls, which allow them to exchange compounds such as carbon dioxide, water, oxygen, waste, and nutrients with surrounding tissues.
The heart, blood, and blood vessels make up the circulatory, or cardiovascular, system. Here, learn about some diseases that can affect this system. The heart is essential to life — if it stops beating, blood will not reach the brain and other organs, and the person can die within minutes.
This is called cardiac arrest. If a person experiences cardiac arrest, they will be unable to speak or breathe, and they will have no heartbeat. The heart is an essential, powerful organ that constantly pumps oxygen and nutrients around the body.
Here, learn about preventing and treating different types of heart disease. If the heart stops, a person cannot survive for long. Staying active and maintaining a healthful diet are two ways to protect the heart. Learn about foods for a healthy heart here. Statin muscle pain may be the result of tissue damage, or it could be due to the "nocebo" effect.
Read on to learn about some potential ways to…. Full recovery for blood clots in the lungs varies from person to person and can take several months or years.
Read on to learn about the recovery…. The heart: All you need to know. Medically reviewed by Dr. Payal Kohli, M. Anatomy How it works Valves Electrical system Blood vessels Cardiac arrest Summary The human heart is a finely-tuned instrument that serves the whole body.
Anatomy of the heart. How the heart works. Blood vessels. Cardiac arrest: When the heart stops. Latest news Compound isolated from sea sponge fights cancer cells.
Resilience in the age of global crises: How can we cultivate it? Study reveals dietary factors associated with mental health. Related Coverage. What causes statin muscle pain, and will it go away? Recovering from a blood clot in the lungs. Medically reviewed by Raj Dasgupta, MD.
The heart: All you need to know
The human heart is a finely-tuned instrument that serves the whole body. It is a muscular organ around the size of a closed fist, and it sits in the chest, slightly to the left of center. This delivers oxygen- and nutrient-rich blood to tissues and organs and carries away waste. The heart sends deoxygenated blood to the lungs, where the blood loads up with oxygen and unloads carbon dioxide, a waste product of metabolism. Together, the heart, blood, and blood vessels — arteries, capillaries, and veins — make up the circulatory system.
The human heart is a four-chambered muscular organ , shaped and sized roughly like a man's closed fist with two-thirds of the mass to the left of midline. The heart is enclosed in a pericardial sac that is lined with the parietal layers of a serous membrane. The visceral layer of the serous membrane forms the epicardium. Three layers of tissue form the heart wall. The outer layer of the heart wall is the epicardium, the middle layer is the myocardium , and the inner layer is the endocardium. The internal cavity of the heart is divided into four chambers:. The two atria are thin-walled chambers that receive blood from the veins.
Service Unavailable in EU region
- У нас приказ. Мы отчитываемся перед директором Лиландом Фонтейном, и только перед. Фонтейна это позабавило. - Вы знаете, кто. - Какая разница? - огрызнулся светловолосый.
Та показала ему последние строчки текста. Бринкерхофф читал, не веря своим глазам. - Какого чер… В распечатке был список последних тридцати шести файлов, введенных в ТРАНСТЕКСТ.
Structure of the Heart
И сразу же услышала треск. Хейл, сидя на плите и действуя вытянутыми ногами как тараном, сорвал решетчатую дверь с петель, ворвался в комнату и теперь приближался к ней большими прыжками. Сьюзан швырнула ему под ноги настольную лампу, но Хейл легко преодолел это препятствие. Он был уже совсем .
Существовал только один разумный путь - выключить. Чатрукьян знал и то, что выключить ТРАНСТЕКСТ можно двумя способами. Первый - с личного терминала коммандера, запертого в его кабинете, и он, конечно, исключался. Второй - с помощью ручного выключателя, расположенного в одном из ярусов под помещением шифровалки. Чатрукьян тяжело сглотнул. Он терпеть не мог эти ярусы.