The human heart has four chambers, two atria and two ventricles. the oxygenated blood from the lungs is received by the_______

• 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 heart beats and the animal moves, the hemolymph circulates around th...

When an atrium tells a lie, what do we call it? A fib! Have you ever asked for advice and received the answer, “Listen to your heart?” While well-meaning, if you actually took that advice, all you’d hear is lub dub lub dub lub dub… And though lub dub seems basic, it’s actually incredibly complex and, quite frankly, amazing. In this article, we are delving into the inner workings of the human heart. Ready? Take notes! Here’s the big picture: the human heart is the pump that circulates blood through the body. It pumps blood through the arteries, to arterioles, and then to capillaries. Capillaries are the site of exchange between blood and tissues of the body. What is exchanged? • Gases • Nutrients & Electrolytes • Waste The human heart consists of four-chambers — two atria and two ventricles. The four chambers work in synchronization to contract and relax. During each cardiac cycle (aka heart beat): • Atria contract/ventricles relax (systole). Then, • Ventricles contract/atria relax (diastole). Then, • Both atria and both ventricles relax. The point of all of this? To change pressure within the different chambers to cause the opening and closing of valves. Valves allow the blood to flow in a unidirectional path through the heart. Let’s zoom in from the big picture and examine the path of blood flow This flow of blood is part of what’s called a “closed circuit.” It’s called closed because the blood is enclosed (within vessels) and circuit because it’s a repeating path. • Bloo...

3 Cell Structure and Function • Introduction • 3.1 How Cells Are Studied • 3.2 Comparing Prokaryotic and Eukaryotic Cells • 3.3 Eukaryotic Cells • 3.4 The Cell Membrane • 3.5 Passive Transport • 3.6 Active Transport • Key Terms • Chapter Summary • Visual Connection Questions • Review Questions • Critical Thinking Questions • 4 How Cells Obtain Energy • Introduction • 4.1 Energy and Metabolism • 4.2 Glycolysis • 4.3 Citric Acid Cycle and Oxidative Phosphorylation • 4.4 Fermentation • 4.5 Connections to Other Metabolic Pathways • Key Terms • Chapter Summary • Visual Connection Questions • Review Questions • Critical Thinking Questions • 11 Evolution and Its Processes • Introduction • 11.1 Discovering How Populations Change • 11.2 Mechanisms of Evolution • 11.3 Evidence of Evolution • 11.4 Speciation • 11.5 Common Misconceptions about Evolution • Key Terms • Chapter Summary • Visual Connection Questions • Review Questions • Critical Thinking Questions • 15 Diversity of Animals • Introduction • 15.1 Features of the Animal Kingdom • 15.2 Sponges and Cnidarians • 15.3 Flatworms, Nematodes, and Arthropods • 15.4 Mollusks and Annelids • 15.5 Echinoderms and Chordates • 15.6 Vertebrates • Key Terms • Chapter Summary • Visual Connection Questions • Review Questions • Critical Thinking Questions • 16 The Body’s Systems • Introduction • 16.1 Homeostasis and Osmoregulation • 16.2 Digestive System • 16.3 Circulatory and Respiratory Systems • 16.4 Endocrine System • 16.5 Musculoskeletal ...

Our heart has four chambers, two atria (right and left) and two ventricles (right and left). The right atrium receives the de-oxygenated blood from the body. From the right atrium blood passes to the right ventricle. The right ventricle propels this de-oxygenated blood to the lungs though pulmonary artery, for oxygenation. The deoxygenated blood loses carbon-di-oxide and gains oxygen in the lungs. This process is called gaseous exchange. After the gaseous exchange, blood becomes oxygenated. This oxygenated blood comes to left atrium of the heart through pulmonary veins. From the left atrium blood comes to the left ventricle. Left ventricle sends this oxygenated blood through aorta and arteries to all organs of the body. The following diagram shows blood flow through the heart. Here the blue arrows show the flow of de-oxygenated blood. See, the two blue arrows come to the right atrium (2). This is the chamber, which receives the de-oxygenated blood from the body. The red arrows are representing the oxygenated blood.

The function of the heart is to pump the blood that bathes and nourishes every organ of the body. The blood carries the oxygen and nutrients vital to the tissues, and it also carries waste products away from the tissues. If the pumping action of the heart is disrupted for any reason, the body’s organs begin to fail very quickly. So life itself is dependent on the efficient, continuous operation of the heart. The heart is a muscular organ roughly the size of your fist. As the heart muscle contracts, it propels the blood out into the vascular system. The heart’s chambers and valves are arranged to direct the flow of the blood as the heart beats. Heart’s Chambers and Valves The heart has two “sides.” The right side of the heart accepts “used” blood that is returning from the tissues of the body, and pumps that blood into the lungs, where it is replenished with oxygen. The left side of the heart accepts replenished blood from the lungs, and then pumps that blood out to all the body’s organs. The Right Heart Pump The right heart pump consists of the right atrium, tricuspid valve, right ventricle, pulmonic valve, and pulmonary artery. Its job is to make sure “used” blood gets reloaded with oxygen. Oxygen-poor blood returning to the heart from the body’s tissues enters the right atrium. When the atria contract, the tricuspid valve opens and allows the blood to be pumped from the right atrium to the right ventricle. Then, when the right ventricle contracts, the tricuspid valve clo...

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. The heart beats around 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 • The atria: These are the two upper chambers, which receive blood. • The ventricles: These are the two lower chambers, which discharge blood. 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. The heart’s walls consist of three layers of tissue: • Myocardium: This is the muscular tissue of the heart. • Endocardium: This tissue lines the inside of the heart and protects the valves and chambers. • Pericardium: This is a thin protective coating that surrounds the other parts. • Epicardium: This protective layer consists mostly of connective tissue and forms the innermost layer of the pericardium. The rate at which the heart contracts depends on m...

\( \newcommand\) • • • • • • The heart pumps blood through the body with the help of structures such as ventricles, atria, and valves. Key Points • The heart is divided into four chambers consisting of two atria and two ventricles; the atria receive blood, while the ventricles pump blood. • The right atrium receives blood from the superior and inferior vena cavas and the coronary sinus; blood then moves to the right ventricle where it is pumped to the lungs. • The lungs re-oxygenate the blood and send it to the left atrium. • Blood moves from the left atrium to the left ventricle via the bicuspid valve; blood is pumped out of the left ventricle to the aorta, which sends blood to the organs and muscles of the body. • The heart is composed of three layers: the epicardium (outer layer), the myocardium (middle layer), and the endocardium (inner layer). Key Terms • aorta: the largest artery in the human body which carries the blood from the heart to all parts of the body except the lungs • inferior vena cava: large vein that carries deoxygenated blood from the lower half of the body to the right atrium of the heart • superior vena cava: large vein that carries deoxygenated blood from the upper half of the body to the right atrium of the heart Structure of the Heart The heart is a complex muscle that pumps blood through the three divisions of the circulatory system: the coronary (vessels that serve the heart), pulmonary (heart and lungs), and systemic (systems of the body). Coro...