Circulatory system

Term Meaning Circulatory system The body system responsible for carrying blood, nutrients, and waste throughout the body Cardiac Related to the heart Pulmonary Related to the lungs Artery Blood vessel that moves blood away from the heart Vein Blood vessel that moves blood toward the heart Aorta Major artery that carries blood to the systemic circulatory system Capillary Small blood vessel that allows nutrient exchange Atrium Upper chamber of the heart Ventricle Lower chamber of the heart Blood from the heart is pumped throughout the body using blood vessels. Arteries carry blood away from the heart and into capillaries, providing oxygen (and other nutrients) to tissue and cells. Once oxygen is removed, the blood travels back to the lungs, where it is reoxygenated and returned by veins to the heart. Arteries usually carry oxygenated blood and veins usually carry deoxygenated blood. This is true most of the time. However, the pulmonary arteries and veins are an exception to this rule. Pulmonary veins carry oxygenated blood towards the heart and the pulmonary arteries carry deoxygenated blood away from the heart. • Blood is always red. Veins can appear blue as we see them through our skin, leading some people to believe that deoxygenated blood is blue. However, this is not the case! Blood only appears blue because of the way tissues absorb light and our eyes see color. Although oxygen does have an effect on the brightness of the blood (more oxygen makes a brighter red, less m...

Learning Objectives By the end of this section, you will be able to: • Describe an open and closed circulatory system • Describe interstitial fluid and hemolymph • Compare and contrast the organization and evolution of the vertebrate circulatory system. In all animals, except a few simple types, the circulatory system is used to transport nutrients and gases through the body. Simple diffusion allows some water, nutrient, waste, and gas exchange into primitive animals that are only a few cell layers thick; however, bulk flow is the only method by which the entire body of larger more complex organisms is accessed. Circulatory System Architecture The circulatory system is effectively a network of cylindrical vessels: the arteries, veins, and capillaries that emanate from a pump, the heart. In all vertebrate organisms, as well as some invertebrates, this is a closed-loop system, in which the blood is not free in a cavity. In a closed circulatory system, blood is contained inside blood vessels and circulates unidirectionally from the heart around the systemic circulatory route, then returns to the heart again, as illustrated in a. As opposed to a closed system, arthropods—including insects, crustaceans, and most mollusks—have an open circulatory system, as illustrated in b. In an open circulatory system, the blood is not enclosed in the blood vessels but is pumped into a cavity called a hemocoel and is called hemolymph because the blood mixes with the interstitial fluid. As the...

[ "article:topic", "authorname:openstax", "ostium", "hemocoel", "ventricle", "atrium", "closed circulatory system", "double circulation", "gill circulation", "hemolymph", "interstitial fluid", "open circulatory system", "pulmocutaneous circulation", "pulmonary circulation", "systemic circulation", "unidirectional circulation", "showtoc:no", "license:ccby", "licenseversion:40", "program:openstax" ] Skills to Develop • Describe an open and closed circulatory system • Describe interstitial fluid and hemolymph • Compare and contrast the organization and evolution of the vertebrate circulatory system. In all animals, except a few simple types, the circulatory system is used to transport nutrients and gases through the body. Simple diffusion allows some water, nutrient, waste, and gas exchange into primitive animals that are only a few cell layers thick; however, bulk flow is the only method by which the entire body of larger more complex organisms is accessed. Circulatory System Architecture The circulatory system is effectively a network of cylindrical vessels: the arteries, veins, and capillaries that emanate from a pump, the heart. In all vertebrate organisms, as well as some invertebrates, this is a closed-loop system, in which the blood is not free in a cavity. In a closed circulatory system, blood is contained inside blood vessels and circulates unidirectionally from the heart around the systemic circulatory route, then returns to the heart again, as illustrated in Figure...

Circulatory System All living organisms require a few fundamental elements like food, water, and air to support their life. On a daily basis, we ensure these elements by eating, drinking and breathing. In order to utilize these elements in our body cells, they need to be transported to them. Let’s learn about the human circulatory system and its components which serve as the transportation system in our body. Recommended Video: Circulatory system A network of organs that allow the circulation of blood throughout the body is also known as the cardiovascular system or vascular system. The vital function of the circulatory system is to transport blood to all parts of the body, which is extremely important because it carries It  is a closed network consisting of four major components: • The heart • Blood • Blood vessels These four, with the help of certain other organs such as the lungs, are responsible for the circulation of blood in the human body. Major Components of the human circulatory system are mentioned below. • The Heart The heart is a muscular organ, located roughly at the body’s midline in the thoracic region, and responsible for the pumping of blood in the body. The heart is divided into four chambers: Right atrium, right ventricle, left atrium and left ventricles. The atriums collect the blood in the heart and the ventricles pump it to different organs. • Blood Blood is a fluid connective tissue which plays an essential role in the circulatory system. It ...

The circulatory system, also known as the cardiovascular system, is a simple loop which starts, and ends, with your heart. It is a closed system, meaning blood does not enter or leave the system during its journey from your heart to your body and back again. In such a system, a continuous flow of the same liquid can be pumped through the loop again and again. Circulation Begins in Your Heart The circulatory system begins in your right atrium, the upper right-hand chamber of your heart. Blood moves from the right side of your heart through your lungs to get rid of carbon dioxide and pick up oxygen, and then returns to the left side of your heart, ending up in the left ventricle. The left ventricle is the strongest part of the heart, since it must pump blood out to the rest of the body. From Your Aorta to Your Capillaries Your blood travels from your aorta through a series of smaller blood vessels until it reaches your capillaries. Before reaching your capillaries, however, blood must travel through the arterioles, where its speed and pressure are constantly adjusted as different segments of the arterioles change diameter in response to pressure and chemical sensors positioned nearby. These sensors adjust Because of arteriole action, by the time your blood reaches your capillaries, it is no longer traveling in a pulsing fashion. Blood flows continuously through the capillaries, it does not "squirt" and "pause" as your heart beats. This continuous flow is necessary because th...

4 Cell Structure • Introduction • 4.1 Studying Cells • 4.2 Prokaryotic Cells • 4.3 Eukaryotic Cells • 4.4 The Endomembrane System and Proteins • 4.5 The Cytoskeleton • 4.6 Connections between Cells and Cellular Activities • Key Terms • Chapter Summary • Visual Connection Questions • Review Questions • Critical Thinking Questions • 6 Metabolism • Introduction • 6.1 Energy and Metabolism • 6.2 Potential, Kinetic, Free, and Activation Energy • 6.3 The Laws of Thermodynamics • 6.4 ATP: Adenosine Triphosphate • 6.5 Enzymes • Key Terms • Chapter Summary • Visual Connection Questions • Review Questions • Critical Thinking Questions • 7 Cellular Respiration • Introduction • 7.1 Energy in Living Systems • 7.2 Glycolysis • 7.3 Oxidation of Pyruvate and the Citric Acid Cycle • 7.4 Oxidative Phosphorylation • 7.5 Metabolism without Oxygen • 7.6 Connections of Carbohydrate, Protein, and Lipid Metabolic Pathways • 7.7 Regulation of Cellular Respiration • Key Terms • Chapter Summary • Visual Connection Questions • Review Questions • Critical Thinking Questions • 14 DNA Structure and Function • Introduction • 14.1 Historical Basis of Modern Understanding • 14.2 DNA Structure and Sequencing • 14.3 Basics of DNA Replication • 14.4 DNA Replication in Prokaryotes • 14.5 DNA Replication in Eukaryotes • 14.6 DNA Repair • Key Terms • Chapter Summary • Visual Connection Questions • Review Questions • Critical Thinking Questions • 15 Genes and Proteins • Introduction • 15.1 The Genetic Code • 15.2...

About the size of two adult hands held together, the Heart wall There are three layers of the heart wall. The epicardium is the heart wall’s outer layer, the myocardium is the middle — and muscular — layer, and the endocardium is the heart’s innermost layer. Chambers The heart has four chambers: the The four chambers play an important role in circulation. The atria receive blood from the veins, while the ventricles push blood out of the heart. Because the ventricles have to be much stronger to perform this pumping activity, their myocardial layers are thicker than those of the atria. The artery walls have three layers: tunica intima (inner), tunica media (middle), and tunica externa (outer). The middle layer is usually the thickest. It’s made up of smooth muscle that changes the size of the artery to regulate blood flow. There are three main types of arteries. They get smaller and smaller the further they are from the heart. Elastic arteries The aorta and pulmonary arteries are the elastic arteries. They receive blood directly from the heart and need to be elastic to accommodate the surge and contraction as blood pushes through with each heartbeat. The aorta is the body’s most important artery. Pulmonary arteries take deoxygenated blood from the right ventricle to the Muscular arteries The muscular arteries move blood from the elastic arteries through the body. They’re made of smooth muscle, which can expand and contract as blood flows. The Arterioles The smallest arteries...