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Tricuspid Valve
The tricuspid valve, or right atrioventricular valve, is on the right dorsal side of the mammalian heart, at the superior portion of the right ventricle. The function of the valve is to allow blood to flow from the right atrium to the right ventricle during diastole, and to close to prevent backflow (Regurgitation (circulation), regurgitation) from the right ventricle into the right atrium during right ventricular contraction (systole). Structure The tricuspid valve usually has three Cusps of heart valves, cusps or leaflets, named the anterior, posterior, and septal cusps. Each leaflet is connected via chordae tendineae to the anterior, posterior, and septal papillary muscles of the right ventricle, respectively. Tricuspid valves may also occur with two or four leaflets; the number may change over a lifetime. Function The tricuspid valve functions as a one-way valve that closes during ventricular systole to prevent regurgitation of blood from the right ventricle back into th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heart
The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrients to the tissue, while carrying metabolic waste such as carbon dioxide to the lungs. In humans, the heart is approximately the size of a closed fist and is located between the lungs, in the middle compartment of the thorax, chest, called the mediastinum. In humans, the heart is divided into four chambers: upper left and right Atrium (heart), atria and lower left and right Ventricle (heart), ventricles. Commonly, the right atrium and ventricle are referred together as the right heart and their left counterparts as the left heart. In a healthy heart, blood flows one way through the heart due to heart valves, which prevent cardiac regurgitation, backflow. The heart is enclosed in a protective sac, the pericardium, which also contains a sma ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bacteria
Bacteria (; : bacterium) are ubiquitous, mostly free-living organisms often consisting of one Cell (biology), biological cell. They constitute a large domain (biology), domain of Prokaryote, prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among the first life forms to appear on Earth, and are present in most of its habitats. Bacteria inhabit the air, soil, water, Hot spring, acidic hot springs, radioactive waste, and the deep biosphere of Earth's crust. Bacteria play a vital role in many stages of the nutrient cycle by recycling nutrients and the nitrogen fixation, fixation of nitrogen from the Earth's atmosphere, atmosphere. The nutrient cycle includes the decomposition of cadaver, dead bodies; bacteria are responsible for the putrefaction stage in this process. In the biological communities surrounding hydrothermal vents and cold seeps, extremophile bacteria provide the nutrients needed to sustain life by converting dissolved compounds, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Right Ventricular Volume Overload
Volume overload refers to the state of one of the Heart#Structure, chambers of the heart in which too large a volume of blood exists within it for it to function efficiently. Ventricle (heart), Ventricular volume overload is approximately equivalent to an excessively high Preload (cardiology), preload. It is a cause of Heart failure, cardiac failure. Pathophysiology In accordance with the Frank–Starling law of the heart, the myocardium contracts more powerfully as the end-diastolic volume increases. Stretching of the myofibrils in cardiac muscle causes them to contract more powerfully due to a greater number of cross-bridges being formed between the myofibrils within cardiac myocytes.Klabunde, Richard E. "Cardiovascular Physiology Concepts". Lippincott Williams & Wilkins, 2011, p. 74. This is true up to a point, however beyond this there is a loss of contractile ability due to loss of connection between myofibrils; see figure. Various pathologies, listed below, can lead to vol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cardiac Muscle
Cardiac muscle (also called heart muscle or myocardium) is one of three types of vertebrate muscle tissues, the others being skeletal muscle and smooth muscle. It is an involuntary, striated muscle that constitutes the main tissue of the wall of the heart. The cardiac muscle (myocardium) forms a thick middle layer between the outer layer of the heart wall (the pericardium) and the inner layer (the endocardium), with blood supplied via the coronary circulation. It is composed of individual cardiac muscle cells joined by intercalated discs, and encased by collagen fibers and other substances that form the extracellular matrix. Cardiac muscle contracts in a similar manner to skeletal muscle, although with some important differences. Electrical stimulation in the form of a cardiac action potential triggers the release of calcium from the cell's internal calcium store, the sarcoplasmic reticulum. The rise in calcium causes the cell's myofilaments to slide past each other i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anatomical Variation
An anatomical variation, anatomical variant, or anatomical variability is a presentation of body structure with Morphology (biology), morphological features different from those that are typically described in the majority of individuals. Anatomical variations are categorized into three types including morphometric (size or shape), consistency (present or absent), and spatial (proximal/distal or right/left). Variations are seen as normal in the sense that they are found consistently among different individuals, are mostly without symptoms, and are termed anatomical variations rather than abnormalities. Anatomical variations are mainly caused by genetics and may vary considerably between different populations. The rate of variation considerably differs between single organ (anatomy), organs, particularly in muscles. Knowledge of anatomical variations is important in order to distinguish them from pathological conditions. A very early paper published in 1898, presented anatomic var ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Framingham Heart Study
The Framingham Heart Study is a long-term, ongoing cardiovascular cohort study of residents of the city of Framingham, Massachusetts. The study began in 1948 with 5,209 adult subjects from Framingham, and is now on its third generation of participants. Prior to the study almost nothing was known about the epidemiology of hypertensive or arteriosclerotic cardiovascular disease. Much of the now-common knowledge concerning heart disease, such as the effects of diet, exercise, and common medications such as aspirin, is based on this longitudinal study. It is a project of the National Heart, Lung, and Blood Institute, in collaboration with (since 1971) Boston University. Various health professionals from the hospitals and universities of Greater Boston staff the project. History In 1948, the study was commissioned by the United States Congress, with multiple communities being considered for study. The final choice was between Framingham, Massachusetts, and Paintsville, Kentucky. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tricuspid Regurgitation
Tricuspid regurgitation (TR), also called tricuspid insufficiency, is a type of valvular heart disease in which the tricuspid valve of the heart, located between the right atrium and right ventricle, does not close completely when the right ventricle contracts (systole). TR allows the blood to flow backwards from the right ventricle to the right atrium, which increases the volume and pressure of the blood both in the right atrium and the right ventricle, which may increase central venous volume and pressure if the backward flow is sufficiently severe. The causes of TR are divided into ''hereditary'' and ''acquired''; and also ''primary'' and ''secondary''. Primary TR refers to a defect solely in the tricuspid valve, such as infective endocarditis; secondary TR refers to a defect in the valve as a consequence of some other pathology, such as left ventricular failure or pulmonary hypertension. The mechanism of TR is either a dilatation of the base (annulus) of the valve due to rig ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cleveland Clinic
Cleveland Clinic is an American Nonprofit organization, nonprofit Academic health science center, academic Medical centers in the United States, medical center based in Cleveland, Ohio. Owned and operated by the Cleveland Clinic Foundation, an Ohio nonprofit corporation, Cleveland Clinic was founded in 1921 by a group of faculty and alumni from the Case Western Reserve University School of Medicine. The Clinic runs a main campus in Cleveland, as well as 15 affiliated hospitals, 20 family health centers in Northeast Ohio, 5 affiliated hospitals in Florida, and cancer center in Nevada. International operations include the Cleveland Clinic Abu Dhabi hospital in the United Arab Emirates and Cleveland Clinic Canada, which has two executive health and sports medicine clinics in Toronto."Facts & Figures" Cleveland Clini ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Serotonin
Serotonin (), also known as 5-hydroxytryptamine (5-HT), is a monoamine neurotransmitter with a wide range of functions in both the central nervous system (CNS) and also peripheral tissues. It is involved in mood, cognition, reward, learning, memory, and physiological processes such as vomiting and vasoconstriction. In the CNS, serotonin regulates mood, appetite, and sleep. Most of the body's serotonin—about 90%—is synthesized in the gastrointestinal tract by enterochromaffin cells, where it regulates intestinal movements. It is also produced in smaller amounts in the brainstem's raphe nuclei, the skin's Merkel cells, pulmonary neuroendocrine cells, and taste receptor cells of the tongue. Once secreted, serotonin is taken up by platelets in the blood, which release it during clotting to promote vasoconstriction and platelet aggregation. Around 8% of the body's serotonin is stored in platelets, and 1–2% is found in the CNS. Serotonin acts as both a vasoconstrictor and vas ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ebstein's Anomaly
Ebstein's anomaly is a congenital heart defect in which the septal and posterior leaflets of the tricuspid valve are displaced downwards towards the apex of the right ventricle of the heart. Ebstein's anomaly has great anatomical heterogeneity that generates a wide spectrum of clinical features at presentation and is complicated by the fact that the lesion is often accompanied by other congenital cardiac lesions. It is classified as a critical congenital heart defect accounting for less than 1% of all congenital heart defects presenting in around 1 per 200,000 live births. Ebstein's anomaly usually presents with a systolic murmur (sometimes diastolic) and frequently with a gallop rhythm. Signs and symptoms The annulus of the valve is still in the normal position. The valve leaflets, however, are to a varying degree, attached to the walls and septum of the right ventricle. A subsequent "atrialization" of a portion of the morphologic right ventricle (which is then contiguous with th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Congenital
A birth defect is an abnormal condition that is present at childbirth, birth, regardless of its cause. Birth defects may result in disability, disabilities that may be physical disability, physical, intellectual disability, intellectual, or developmental disability, developmental. The disabilities can range from mild to severe. Birth defects are divided into two main types: structural disorders in which problems are seen with the shape of a body part and functional disorders in which problems exist with how a body part works. Functional disorders include metabolic disorder, metabolic and degenerative disease, degenerative disorders. Some birth defects include both structural and functional disorders. Birth defects may result from genetic disorder, genetic or chromosome abnormality, chromosomal disorders, exposure to certain medications or chemicals, or certain vertically transmitted infection, infections during pregnancy. Risk factors include folate deficiency, alcohol drink, d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mount Sinai Hospital, New York
Mount Sinai Hospital, founded in 1852, is one of the oldest and largest teaching hospitals in the United States. It is located in East Harlem in the New York City borough of Manhattan, on the eastern border of Central Park stretching along Madison and Fifth Avenues, between East 98th Street and East 103rd Street. The Mount Sinai Hospital is a tertiary and quaternary care facility and as such offers care in all medical and surgical specialties and subspecialties. The hospital is a AIDS center, Sexual Assault Forensic Examiner (SAFE) Program Hospital, Comprehensive Stroke Center, and Regional Perinatal Center. The maternity program is among the busiest in New York State with just over 7,000 deliveries per year. In March 2023, the hospital was ranked 23rd among over 2,300 hospitals in the world and the best hospital in New York state by ''Newsweek.'' Adjacent to the hospital is the Mount Sinai Kravis Children's Hospital which provides comprehensive pediatric specialties an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
