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Heart & Circulation
CCRI-Newport Q6
Question | Answer |
---|---|
aorta | The great artery that carries blood away from the left ventricle to all the systemic arteries of the circulatory system. The blood in this artery is normally enriched with oxygen and deficient in carbon dioxide. |
apex of the heart | This is the pointed inferior end of the heart. It usually comes in contact with the thoracic wall at intercostal space 5, midclavicular, left side. |
arteries | A thick walled vessel with relatively large numbers of smooth muscle cells in its walls. Arteries carry blood away from the heart CHAMBERS (the mnemonic is aa). |
atria | There are two of these at the superior end of the human heart, a right and a left. Also be called auricles. Referred to as the receiving chambers of the heart. |
atrioventricular sulcus (groove) | A groove between the atria and the ventricles and it is in the posterior part of this sulcus that we find the coronary sinus. Some of the larger coronary arteries and veins also run in this sulcus. It may be called the coronary sulcus. |
atrioventricular valves | There is a valve on each side of the heart. They are found between the atria and the ventricles. They are composed of fibrous connective tissue. Functionally they are important as they prevent backflow of blood from the ventricles to the atria. |
auricles | Also known as the atria or the receiving chambers. |
bicuspid valve | This valve is also called the mitral valve. It is between the left ventricle and the left atrium. It has two cusps. |
bulk flow | Involves the movement of relatively large amounts of materials being moved over relatively large distances in a short period of time. The primary bulk flow system is the circulatory system. It is supplemented by the lymphatic system. |
capillaries | The functional units of the circulatory system with respect to exchange of materials between the blood and the cells. They have a diameter about the size of a red blood cell. No living cell is further than 2/3 cell diameters from a functional capillary. |
closed system | Materials begin within the system and eventually return to the same point, remaining in the system the entire time. A good example of a closed system is the circulatory system. |
chordae tendineae | Tendinous chords that connect the cusps of the atrioventricular valves to the papillary muscles on the walls of the ventricles. Functionally they are important because they help prevent prolapse of the AV valves. |
collateral circulation | Provides for a natural by-pass for blood flow. It usually requires arteriole to arteriole anastomoses. If one of the channels is blocked, the other provides blood to the capillaries. |
coronary arteries | Part of the systemic circulatory system. The coronary arteries are the first two branches of the aorta. Functionally they are very important because they serve the walls of the heart. |
coronary circulation | A special case of the systemic circulation. The coronary arteries are the first two branches of the aorta. The coronary veins drain into the coronary sinus and then to the right atrium. It is the system that delivers blood to the walls of the heart. |
coronary sinus | This is not a vessel. Rather than being tubular, it is shaped like a Quonset hut. The enclosure is made complete by the superficial wall of the heart in the coronary sulcus. It conducts blood from the coronary veins back to the right atrium. |
coronary sulcus | A groove between the atria and the ventricles and it is in the posterior part of this sulcus that we find the coronary sinus. Some of the larger coronary arteries and veins also run in this sulcus. It may be called the atrioventricular sulcus. |
coronary veins | Part of the systemic circulatory system. The coronary veins drain into the coronary sinus, which in turn drains into the right atrium. Functionally they are very important because they serve the walls of the heart. |
diffusion | The random movement of molecules and ions, with a net movement from high to low concentrations. It is only effective over short distances in transport of materials within the body. |
ductus arteriosus | A vessel that connects the pulmonary trunk with the aorta. Functionally it is important because it provides for a bypass of the pulmonary circulation. This bypass is important in order to prevent too much blood from going to the lungs. |
fetal circulation | The arteries of the fetus carry mixed blood rather than oxygen rich blood. Also, there are two major pulmonary bypasses. The functions of many organs such as the lungs and digestive system are performed by the placenta. |
fossa ovalis | An ovale depression in the interatrial septum. At birth changes in pressure within the left atrium cause two flaps to close off the foramen ovale. Scar tissue fix the flaps in position and they become this, preventing the bypass from continuing. |
foramen ovale | The foramen in the interatrial septum of the fetus. Functionally it is important because it provides for a bypass of the pulmonary circulation, with a little less than half of the blood that enters the right atrium going directly to the left atrium. |
ligamentum arteriosum | Formerly was the ductus arteriosus. It is a fibrous bridge between the pulmonary trunk and the aorta. |
ligamentum teres (round ligament) | What remains of the umbilical vein in postnatal life. It extends from the navel to the liver. It is also another structure found between the head of the femur and the acetabulum of the os coxa. |
lumen | The space inside of a hollow structure such as a blood vessel, organ, or duct. |
mitral valve | This valve is also called the bicuspid valve. It is between the left ventricle and the left atrium. It has two cusps. |
mixed blood | The arteries of the fetus contain blood that is intermediate in oxygen levels. The oxygen rich blood from the placenta mixes with the oxygen deficient blood from the inferior vena cava, superior vena cava, and the coronary sinus. |
moderator band | stretches from a papillary muscle on the interventricular septum to the wall of the right ventricle. Functionally it is important because it conducts impulses between these two regions on the heart, thereby coordinating the contraction of the cells. |
papillary muscles | Raised areas on the walls of the ventricles. The chordate tendineae attach to them. Important because as the chordae tendineae pull on them and cause them to stretch, they contract against the stretch. This prevents prolapse of the av valves. |
pectinate muscles | Ridges on the walls of the atria. They are most easily observed in the right atrium. |
pericardium | Special type of pleura which includes the serous membrane and fibrous tissue. The fibrous tissue helps with strength. |
portal circulation | Occurs when there are two capillary beds in series before the blood goes back to the heart. Normally the blood passes through one capillary bed between the ventricle and atrium. Functional importance: Two changes are made to the blood in these systems. |
pulmonary circulation | Begins with the right ventricle, sends blood to the lungs where the respiratory gases are normally exchanged, and returns the blood to the left atrium. |
sinusoid capillaries | Very wide and porous. This type of capillary is found in bone marrow, the spleen, the liver and the maternal side of circulation within the placenta. |
systemic circulation | Begins with the left ventricle, sends blood to the cells of the body to recondition their environment, and returns the blood to the right atrium. |
tricuspid valve | It is between the right ventricle and the right atrium. It has three cusps. |
tunica adventitia | This is the outermost layer of blood vessel walls. Sometimes it is called tunica externa. It is mostly connective tissue and contains the vasa vasorum. It is usually between half and a third as thick as the tunica media in arteries. |
tunica externa | This is the outermost layer of blood vessel walls. Sometimes it is called tunica adventitia. It is mostly connective tissue and contains the vasa vasorum. It is usually between half and a third as thick as the tunica media in arteries. |
tunica intima | The inner endothelial lining of blood vessels that includes a thin connective tissue layer as well. |
tunica media | The third layer from the lumen of blood vessels. Primarily smooth muscle cells and is much thicker in arteries (about 40 cells in most arteries) than in veins (about 2 to 3 cells in most veins). |
varicose veins | Some veins, especially those of the lower appendage, become over distended due to constant high pressure. When this happens the semilunar valves begin to leak. The blood does not move as it should and potential for abnormal clotting exists. |
vasa vasorum | The blood supply to the outer portion of the walls of large blood vessels. The inner portion of the walls of large blood vessels and smaller vessels don't need this blood supply as the cells get what they require directly from the blood they carry. |
ventricles | They are sometimes referred to as the pumping chambers of the heart. They receive blood from the respective atria and pump the blood into the pulmonary trunk and aorta respectively. The left ventricle has thicker walls than the right ventricle. |
sinusoid capillaries | The fetal capillaries grow into the volume of the maternal sinusoid, but the blood supplies remain separate. This arrangement increases the efficiency of exchange between the maternal and fetal blood. |
systematic circulation | Functional importance: the reconditioning of the interstitial fluid surrounding the cells so that the cells have a favorable environment in which they can live and carry on their specialized functions. |