The heart wall is made up of three layers: the inner endocardium, middle myocardium and outer epicardium. These are surrounded by a double-membraned sac called the pericardium. hypoplastic (say: hi-poh-PLAS-tik) left heart syndrome:When the structures of the left side of the heart (the left ventricle, the mitral valve, and the aortic valve) are underdeveloped, they're unable to pump blood adequately to the entire body. This condition is usually diagnosed within the first few days of life. atria (say: AY-tree-yuh) :The two chambers at the top of the heart are called the atria. The atria are the chambers that fill with the blood returning to the heart from the body and lungs. The heart has a left atrium and a right atrium. In Catholicism, there has been a long tradition of veneration of the heart, stemming from worship of the wounds of Jesus Christ which gained prominence from the mid sixteenth century. [126] This tradition influenced the development of the medieval Christian devotion to the Sacred Heart of Jesus and the parallel veneration of the Immaculate Heart of Mary, made popular by John Eudes. [127] There are also many references to the heart in the Christian Bible, including "Blessed are the pure in heart, for they will see God", [128] "Above all else, guard your heart, for everything you do flows from it", [129] "For where your treasure is, there your heart will be also", [130] "For as a man thinks in his heart, so shall he be." [131]

The heart receives nerve signals from the vagus nerve and from nerves arising from the sympathetic trunk. These nerves act to influence, but not control, the heart rate. Sympathetic nerves also influence the force of heart contraction. [35] Signals that travel along these nerves arise from two paired cardiovascular centres in the medulla oblongata. The vagus nerve of the parasympathetic nervous system acts to decrease the heart rate, and nerves from the sympathetic trunk act to increase the heart rate. [7] These nerves form a network of nerves that lies over the heart called the cardiac plexus. [7] [34] Sacharow, Alla (1993) Classic Russian Cuisine: A Magnificent Selection of More Than 400 Traditional Recipes. ISBN 1-55970-174-9 In the left heart, oxygenated blood is returned to the left atrium via the pulmonary veins. It is then pumped into the left ventricle through the mitral valve and into the aorta through the aortic valve for systemic circulation. The aorta is a large artery that branches into many smaller arteries, arterioles, and ultimately capillaries. In the capillaries, oxygen and nutrients from blood are supplied to body cells for metabolism, and exchanged for carbon dioxide and waste products. [7] Capillary blood, now deoxygenated, travels into venules and veins that ultimately collect in the superior and inferior vena cavae, and into the right heart. Aristotle. On the Parts of Animals. book 3, ch. 4. Archived from the original on 14 August 2016. ( De partibus animalium)Crigg, Gordon; Johansen, Kjell (1987). "Cardiovascular Dynamics in Crocodylus Porosus Breathing Air And During Voluntary Aerobic Dives" (PDF). Journal of Comparative Physiology B. 157 (3): 381–392. doi: 10.1007/BF00693365. S2CID 28733499. Archived (PDF) from the original on 28 August 2021 . Retrieved 20 February 2019. But the things which proceed out of the mouth come forth out of the heart; and they defile the man. Cooley, Denton A. (2011). "Recollections of the Early Years of Heart Transplantation and the Total Artificial Heart". Artificial Organs. 35 (4): 353–357. doi: 10.1111/j.1525-1594.2011.01235.x. PMID 21501184.

a b Grimm, Kurt A.; Lamont, Leigh A.; Tranquilli, William J.; Greene, Stephen A.; Robertson, Sheilah A. (2015). Veterinary Anesthesia and Analgesia. John Wiley & Sons. p.418. ISBN 978-1-118-52620-0. Archived from the original on 6 December 2016. Ostchega, Y; Porter, K. S.; Hughes, J; Dillon, C. F.; Nwankwo, T (2011). "Resting pulse rate reference data for children, adolescents and adults, United States 1999–2008" (PDF). National Health Statistics Reports (41): 1–16. PMID 21905522. Archived (PDF) from the original on 23 June 2017. atrioventricular (say: AY-tree-oh-ven-TRIK-yoo-lar) canal defect:This defect — also known as endocardial cushion defect or atrioventricular septal defect — is caused by a poorly formed central area of the heart. Typically there is a large hole between the upper chambers of the heart (the atria) and, often, an additional hole between the lower chambers of the heart (the ventricles). Instead of two separate valves allowing flow into the heart, there is one large common valve that might be quite malformed. Armstrong, William F.; Ryan, Thomas; Feigenbaum, Harvey (2010). Feigenbaum's Echocardiography. Lippincott Williams & Wilkins. ISBN 978-0-7817-9557-9. Archived from the original on 23 April 2016.Many classical philosophers and scientists, including Aristotle, considered the heart the seat of thought, reason, or emotion, often disregarding the brain as contributing to those functions. [119] The identification of the heart as the seat of emotions in particular is due to the Roman physician Galen, who also located the seat of the passions in the liver, and the seat of reason in the brain. [120] veins and arteries:Your body has a highway system all its own that sends blood to and from your body parts. It's called the circulatory system, and the roads are arteries and veins. Arteries, which usually look red, carry blood away from the heart. Veins, which usually look blue, return blood to the heart. a b c "Cardiovascular diseases (CVDs)". World Health Organization. Archived from the original on 10 March 2016 . Retrieved 9 March 2016. CT scans, chest X-rays and other forms of imaging can help evaluate the heart's size, evaluate for signs of pulmonary oedema, and indicate whether there is fluid around the heart. They are also useful for evaluating the aorta, the major blood vessel which leaves the heart. [79] Treatment

Purkinje Fibers". About.com. 9 April 2012. Archived from the original on 14 April 2012 . Retrieved 7 June 2012. The innermost layer of the heart is called the endocardium. It is made up of a lining of simple squamous epithelium and covers heart chambers and valves. It is continuous with the endothelium of the veins and arteries of the heart, and is joined to the myocardium with a thin layer of connective tissue. [7] The endocardium, by secreting endothelins, may also play a role in regulating the contraction of the myocardium. [7] The swirling pattern of myocardium helps the heart pump effectively a b " 'Listen to your heart': Indigenous elders channel tough love in Earth Day film". Reuters. 20 April 2020 . Retrieved 20 December 2022. a b West, J. B. (30 May 2014). "Galen and the beginnings of Western physiology" (PDF). AJP: Lung Cellular and Molecular Physiology. 307 (2): L121–L128. doi: 10.1152/ajplung.00123.2014. PMID 24879053. S2CID 5656712. Archived from the original (PDF) on 2 March 2019.aorta (say: ay-OR-tah) : The aorta is the major blood vessel that carries blood away from the heart to the rest of the body.

Bible Gateway passage: Proverbs 4:23 - New International Version". Bible Gateway . Retrieved 19 December 2022. Long QT Syndrome (LQTS) - Mostly hereditary. On EKG can be observed as longer corrected QT interval (QTc). Characterized by fainting, sudden, life-threatening heart rhythm disturbances - Torsades de pointes type ventricular tachycardia, ventricular fibrillation and risk of sudden cardiac death. [72] The average cardiac output, using an average stroke volume of about 70mL, is 5.25 L/min, with a normal range of 4.0–8.0 L/min. [7] The stroke volume is normally measured using an echocardiogram and can be influenced by the size of the heart, physical and mental condition of the individual, sex, contractility, duration of contraction, preload and afterload. [7]The Sanskrit word for heart is hṛd or hṛdaya, found in the oldest surviving Sanskrit text, the Rigveda. In Sanskrit, it may mean both the anatomical object and "mind" or "soul", representing the seat of emotion. Hrd may be a cognate of the word for heart in Greek, Latin, and English. [117] [118] Silverman, M. E. (13 June 2006). "Why Does the Heart Beat?: The Discovery of the Electrical System of the Heart". Circulation. 113 (23): 2775–2781. doi: 10.1161/CIRCULATIONAHA.106.616771. PMID 16769927. The middle layer of the heart wall is the myocardium, which is the cardiac muscle—a layer of involuntary striated muscle tissue surrounded by a framework of collagen. The cardiac muscle pattern is elegant and complex, as the muscle cells swirl and spiral around the chambers of the heart, with the outer muscles forming a figure 8 pattern around the atria and around the bases of the great vessels and the inner muscles, forming a figure 8 around the two ventricles and proceeding toward the apex. This complex swirling pattern allows the heart to pump blood more effectively. [7] Main article: Cardiac output The x-axis reflects time with a recording of the heart sounds. The y-axis represents pressure. [7]