CV_Lymphatic_Immune - CV responsibilities include...

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CV responsibilities include: distributing nutrients from the digestive tract to various tissues in the body. It transports metabolic waste products from tissues to the excretory system. Endocrine glands – release their hormones into the bloodstream in order to reach target tissues; thus, the CV system has the responsibility of transporting these hormones to target tissues. Ischemia – inadequate blood flow. - Worse than hypoxia . Why? Because in hypoxia, wastes are still adequately removed, whereas in ischemia, they build up. Portal systems – hepatic portal system; blood passes first through capillaries in the intestine, and then collects in veins to travel to the liver. - After being filtered in the liver, the blood returns to systemic circulation, returning to the heart in the veins. - Hypothalamic-hypophysial portal circulation – blood passes through capillaries in the hypothalamus to the portal veins, then to capillaries in the pituitary . - This system has evolved in order to transport necessary hormones from the hypothalamus to the pituitary . If the hypothalamic-hypophysial portal system were severed, then the pituitary would not receive signals from the hypothalamus; therefore, hormones would take a longer route than normal to reach its target tissues, and they could effectively be degraded along the way. Tricuspid valve – between the right atrium and right ventricle Mitral (Bicuspid) valve – between the left atrium and left ventricle. If the mitral valve were to rupture, then the left ventricle would pump blood in both directions, causing an elevated BP in the left atrium, backflow of blood in pulmonary circulation, and eventual pulmonary edema . When the ventricles are not contracting, they must have low pressure (as opposed to their normally high pressures). This ensures that during ventricular relaxation, the atria fill the ventricles up completely. “Backflow check valves” – found in the veins to ensure that venous BP remains sufficiently high for deoxygenated blood to return back to the heart – skeletal muscle movement is important in this process as well, since it pushes on these backflow check valves to make sure they are functioning properly. In pregnant women, varicose veins develop because the growing fetus presses against the inferior vena cava, causing venous pressure in the legs to rise. General diastole – ventricles are relaxed (atria are contracting, to fill up the ventricles) General systole – ventricles are contracting (atria are relaxed, and AV valves are shut to prevent backflow of blood)
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Think about why athletes have lower heart rates: their stroke volume is generally fairly high, so with each pump of the left ventricle, the left ventricle is pumping a pretty decent amount of oxygenated blood to the arteries. This means that the heart rate doesn’t have to be that high in order to sufficiently provide oxygen to the tissues in order to have a normal cardiac output
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CV_Lymphatic_Immune - CV responsibilities include...

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