File Name: anatomy and physiology of the heart and circulatory system .zip
The circulatory system , also called the cardiovascular system or the vascular system , is an organ system that permits blood to circulate and transport nutrients such as amino acids and electrolytes , oxygen , carbon dioxide , hormones , and blood cells to and from the cells in the body to provide nourishment and help in fighting diseases , stabilize temperature and pH , and maintain homeostasis. The circulatory system includes the lymphatic system , which circulates lymph. Lymph is essentially recycled excess blood plasma after it has been filtered from the interstitial fluid between cells and returned to the lymphatic system.
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.
The heart is a muscular organ in most animals, which pumps blood through the blood vessels of the circulatory system. In humans, other mammals, and birds, the heart is divided into four chambers: upper left and right atria and lower left and right ventricles. The wall of the heart is made up of three layers: epicardium , myocardium , and endocardium. The heart pumps blood with a rhythm determined by a group of pacemaking cells in the sinoatrial node. These generate a current that causes contraction of the heart, traveling through the atrioventricular node and along the conduction system of the heart. The heart receives blood low in oxygen from the systemic circulation , which enters the right atrium from the superior and inferior venae cavae and passes to the right ventricle.
The cardiovascular system can be thought of as the transport system of the body. This system has three main components: the heart , the blood vessel and the blood itself. Blood can be thought of as a fluid which contains the oxygen and nutrients the body needs and carries the wastes which need to be removed. The following information describes the structure and function of the heart and the cardiovascular system as a whole. The heart is located in between the two lungs. It lies left of the middle of the chest. Structure of the Heart The heart is a muscle about the size of a fist, and is roughly cone-shaped.
Human cardiovascular system , organ system that conveys blood through vessels to and from all parts of the body, carrying nutrients and oxygen to tissues and removing carbon dioxide and other wastes. It is a closed tubular system in which the blood is propelled by a muscular heart. Two circuits, the pulmonary and the systemic, consist of arterial , capillary , and venous components. The primary function of the heart is to serve as a muscular pump propelling blood into and through vessels to and from all parts of the body. The arteries, which receive this blood at high pressure and velocity and conduct it throughout the body, have thick walls that are composed of elastic fibrous tissue and muscle cells. The arterial tree—the branching system of arteries—terminates in short, narrow, muscular vessels called arterioles , from which blood enters simple endothelial tubes i. These thin, microscopic capillaries are permeable to vital cellular nutrients and waste products that they receive and distribute.
Veins: Blood vessels that carry blood back to the atria; they are less elastic than arteries. Ventricles: The lower chambers of the heart; they receive blood from the.
The cardiovascular system is a closed system if the heart and blood vessels. The heart pumps blood through a closed system of blood vessels. Blood vessels allow blood to circulate to all parts of the body. The vital importance of the heart is obvious.
Like the bustling factory, the body must have a transportation system to carry its various cargos back and forth, and this is where the cardiovascular system steps in. The cardiovascular system can be compared to a muscular pump equipped with one-way valves and a system of large and small plumbing tubes within which the blood travels. The heart muscle has three layers and they are as follows:.
How does the heart work? What does it do? What is it composed of?
Немец называл эту женщину… Беккер слегка потряс Клушара за плечи, стараясь не дать ему провалиться в забытье. Глаза канадца на мгновение блеснули. - Ее зовут… Не отключайся, дружище… - Роса… - Глаза Клушара снова закрылись. Приближающаяся медсестра прямо-таки кипела от возмущения.
Он снова постучал. У него был такой вид, будто он только что увидел Армагеддон. Хейл сердито посмотрел на обезумевшего сотрудника лаборатории систем безопасности и обратился к Сьюзан: - Я сейчас вернусь.
- Сейчас находится в шифровалке. Смотри. Стратмор пришел вчера с самого утра, и с тех пор его лифт не сдвинулся с места.
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The cardiovascular cardio — heart, vascular — blood vessels system is divided for descriptive purposes into two main parts:.Reply
With each heartbeat, blood is sent throughout our bodies, carrying oxygen and nutrients to every cell.Reply