By A. Kippler. Pace University.
In general discount mobic 7.5 mg without prescription, viscosity is a function of temperature and increases as the ﬂuid becomes colder order mobic 15 mg with mastercard. This fact is evident from Bernoulli’s equation generic mobic 15 mg with visa, which shows that if the height and velocity of the ﬂuid remain constant, there is no pressure drop along the ﬂow path. The product of the pressure drop and the area of the pipe is the force required to overcome the frictional forces that tend to retard the ﬂow in the pipe segment. Note that for a given ﬂow rate the pressure drop required to overcome frictional losses decreases as the fourth power of the pipe radius. Thus, even though all ﬂuids are subject to friction, if the area of the ﬂow is large, frictional losses and the accompanying pressure drop are small and can be neglected. The ﬂow becomes turbulent with eddies and whirls disrupting the laminar ﬂow (see Fig. In a cylindrical pipe the critical ﬂow velocity vc above which the ﬂow is turbulent, is given by η vc (8. The symbol is the Reynold’s number, which for most ﬂuids has a value between 2000 and 3000. Therefore, as the ﬂow turns turbulent, it becomes more diﬃcult to force a ﬂuid through a pipe. Blood is not a simple ﬂuid; it contains cells that complicate the ﬂow, especially when the passages become narrow. Furthermore, the veins and arteries are not rigid pipes but are elastic and alter their shape in response to the forces applied by the ﬂuid. Still, it is possible to analyze the circulatory system with reasonable accuracy using the concepts developed for simple ﬂuids ﬂowing in rigid pipes. The blood in the circulatory system brings oxygen, nutrients, and various other vital substances to the cells and removes the metabolic waste products from the cells. The blood is pumped through the circulatory system by the heart, and it leaves the heart through vessels called arteries and returns to it through veins. The mammalian heart consists of two independent pumps, each made of two chambers called the atrium and the ventricle. The entrances to and exits from these chambers are controlled by valves that are arranged to maintain the ﬂow of blood in the proper direction. Blood from all parts of the body except the lungs enters the right atrium, which contracts and forces the blood into the right ventricle. The ventricle then contracts and drives the blood through the pulmonary artery into the lungs. In its passage through the lungs, the blood releases carbon dioxide and absorbs oxygen. The contraction of the left atrium forces the blood into the left ventricle, which on contraction drives the oxygen-rich blood through the aorta into the arteries that lead to all parts of the body except the lungs. Thus, the right side of the heart pumps the blood through the lungs, and the left side pumps it through the rest of the body. The large artery, called the aorta, which carries the oxygenated blood away from the left chamber of the heart, branches into smaller arteries, which lead to the various parts of the body. These in turn branch into still smaller arteries, the smallest of which are called arterioles. As we will explain later, the arte- rioles play an important role in regulating the blood ﬂow to speciﬁc regions in Section 8. The arterioles branch further into narrow capillaries that are often barely wide enough to allow the passage of single blood cells. The capillaries are so profusely spread through the tissue that nearly all the cells in the body are close to a capillary. The exchange of gases, nutrients, and waste products between the blood and the surrounding tissue occurs by diﬀusion through the thin capillary walls (see Chapter 9). The capillaries join into tiny veins called venules, which in turn merge into larger and larger veins that lead the oxygen-depleted blood back to the right atrium of the heart. First the atria contract, forcing the blood into the ventricles; then the ventricles contract, forcing the blood out of the heart. Because of the pumping action of the heart, blood enters the arteries in spurts or pulses. The maximum pressure driving the blood at the peak of the pulse is called the systolic pressure. Ina young healthy individual the systolic pressure is about 120 torr (mm Hg) and the diastolic pressure is about 80 torr. As the blood ﬂows through the circulatory system, its initial energy, pro- vided by the pumping action of the heart, is dissipated by two loss mecha- nisms: losses associated with the expansion and contraction of the arterial walls and viscous friction associated with the blood ﬂow. Due to these energy losses, the initial pressure ﬂuctuations are smoothed out as the blood ﬂows away from the heart, and the average pressure drops. By the time the blood reaches the capillaries, the ﬂow is smooth and the blood pressure is only about 30 torr. The pressure drops still lower in the veins and is close to zero just before returning to the heart. In this ﬁnal stage of the ﬂow, the movement of blood through the veins is aided by the contraction of muscles that squeeze the blood toward the heart. The radius of the aorta, for example, is about 1 cm; therefore, the pressure drop along the arteries is small. The rate of blood ﬂow Q through the body depends on the level of physical activity. Of course, as the aorta branches, the size of the arteries decreases, result- ing in an increased resistance to ﬂow. Although the blood ﬂow in the nar- rower arteries is also reduced, the pressure drop is no longer negligible (see Exercise 8-2). The ﬂow through the arterioles is accompanied by a much larger pressure drop, about 60 torr. Since the pressure drop in the main arteries is small, when the body is horizontal, the average arterial pressure is approximately constant throughout the body. The arterial blood pressure, which is on the average 100 torr, can support a column of blood 129 cm high (see Eq. This means that if a small tube were introduced into the artery, the blood in it would rise to a height of 129 cm (see Fig. If a person is standing erect, the blood pressure in the arteries is not uni- form in the various parts of the body. The weight of the blood must be taken into account in calculating the pressure at various locations. For example, the average pressure in the artery located in the head, 50 cm above the heart (see Exercise 8-4a) is Phead Pheart − ρgh 61 torr. In the feet, 130 cm below the heart, the arterial pressure is 200 torr (see Exercise 8-4b). Thus, a person may feel momentarily dizzy as he/she jumps up from a prone position. This is due to the sudden decrease in the blood pressure of the brain arteries, which results in a temporary decrease of blood ﬂow to the brain. The same hydrostatic factors operate also in the veins, and here their eﬀect may be more severe than in the arteries.
Progression of Atherosclerotic lesions: Lesions Of Blood Vessels - Andrew Connolly order 15 mg mobic overnight delivery, M buy mobic 7.5 mg amex. Thrombosis is a regular feature of ulcerated plaques generic 15 mg mobic visa, and organization of mural thrombi may contribute to bursts of plaque thickening. Sudden ischemic events are due to thrombosis at sites of atherosclerotic plaque degeneration (Plaque rupture or erosion). Removal of risk factors can slow progression, and convert vulnerable plaques to stable plaques. Fixed Stenosis: critical narrowing with malfunction or atrophy of supplied tissues. If tissue demand for oxygen goes up and supply of oxygen cannot, this can lead to ischemia or infarction (e. Plaque rupture: atherosclerotic plaque ruptures causing immediate thrombosis due to blood mixing with thrombogenic atheromatous debris. Dissection: blood enters intimal defect under pressure and splits tissue planes, often in the media. Statins improve lipoprotein profile and possibly decrease inflammation in atheromas. Surgical management is recommended for larger diameter ones, which are at risk for catastrophic rupture. Stanford (Types A & B): Stanford A originates within or proximal to the aortic arch and usually requires surgery; Stanford B originates after the arch and can usually be managed medically. Intimal tear usually connects with a dissection plane along outer 2/3 of medial layer. Complications include hemorrhage, rupture, compression of nearby viscera, and branch occlusion, leading to the associated signs and symptoms. Rupture: Note: A “false aneurysm” is really a contained perivascular hematoma that communicates with the lumen and mimics an aneurysm. Aortic Dissections Stanford Types A and B: Thromboembolic Disease - Andrew Connolly, M. Some of the consequences of these diseases are due to local changes around the blood vessel, such as edema and hemorrhage, while other consequences are due to changes in tissue perfusion. The most common cause of severe morbidity and mortality in our society is inadequate tissue perfusion due to arterial lesions, causing heart attacks, strokes, pulmonary emboli, renal failure and blindness. As a final common pathway, inadequate tissue perfusion is usually the ultimate cause of death. All tissues require nourishment; hence any may be affected by changes in the blood vessels meant to supply them. In this lecture we will cover obstructions from components of the blood, while obstructions from changes in the vessel wall will be covered more in the second lecture. The steps in hemostasis have negative regulators in the blood and blood vessel wall that limit the extent of propagation, preventing excessive vascular occlusion. Varieties of blood coagulation: Hemostatic Plug Thrombus Hematoma* Blood Clot From blood coagulation From blood coagulation From blood loss into From blood loss to at site of trauma at site of vascular tissues outside the body or into pathology a body cavity Associated with blood Associated with blood Extravascular but in Ex vivo or in a cavity. Vasoconstriction mediated by stimulation of vascular smooth muscle by peripheral nerves and factors released by platelets. Primary Hemostasis mediated by initial platelet deposition on exposed extracellular matrix. Secondary Hemostasis mediated by the coagulation cascade with formation of thrombin and fibrin. Resolution with cessation of hemostatic cascades and lysis of loosely adherent platelets and fibrin. This is abnormal in Thrombosis, leading to pathologic amounts of coagulation in the lumen. Types of emboli: Emboli are classified as solid (detached thrombi, tissue fragments, clumps of tumor cells, etc. A paradoxical embolus is one which arises in the venous circulation but enters the arterial or vice versa, through an Arterio-Venous (A-V) fistula or septal defect in the heart. Pulmonary embolism: Originate commonly from thrombi in veins of lower extremities, pelvis and right heart. These range from tiny, involving arterioles, to massive, involving the main pulmonary artery or its major branches. The possible effects of pulmonary embolism include sudden death, infarction, or hemorrhage of the lung. Systemic arterial emboli: Are usually derived from mural thrombi in the left atrium or left ventricle, vegetations on mitral or aortic valves, atheromatous plaques or aortic aneurysms. Vascular occlusions are most frequent in the spleen, kidneys, brain, bowel, heart, and lower extremities, leading to infarction. Amniotic fluid embolism: An uncommon complication of childbirth which results in embolism of epithelial squamous cells, mucus and lanugo hairs to pulmonary vessels of the mother. Air embolism: Pulmonary air embolism occurs when air is sucked into thoracic veins (at negative pressures during inspiration) as a result of cannulation, surgery or injury. The effect depends on the amount: 100-150 cc is required to produce death in an adult. Systemic air embolism occurs when air enters the left-sided circulation during penetrating wounds, surgery, etc. In life this is manifested by bubbles in retinal vessels, skin mottling and tongue pallor. Decompression sickness (“bends”) is due to gas emboli created by desaturation bubbles of nitrogen gas. Other types of embolism: Placental fragments, clumps of tumor cells, bacteria, parasites, foreign bodies, bullets, shrapnel, barium sulfate (from radiology), catheter tips, etc. Some emboli are created purposely in arteries supplying tumors or vascular malformations by interventional radiologists using thrombogenic material. Arterial Embolism: Sources: Infarcts: Thromboembolic Disease - Andrew Connolly, M. Those tissues with higher metabolic rate, like renal tubules and myocardium, are more vulnerable to damage during ischemia, as are those with only terminal vasculature. Morphology of Infarcts: Infarcts may be recent or old, bland or infected (septic). The shape of infarcts depends on the distribution of tissue downstream from the occlude vessel. They are often wedge-shaped with the wide base towards the periphery of the organ. Infarcts are usually pale but may become hemorrhagic if there is either a minor collateral circulation (e. When an infarct extends to a serosal surface, it is covered by fibrinous (fibrin- containing) exudate initially, which may then cause fibrous (collagen- containing) adhesions as it heals. In most infarcts, inflammatory cells are noted in the periphery of large lesions, because that is where the remaining arterial circulation allows delivery of leukocytes. In the first few days neutrophils predominate, and then macrophages and fibroblasts appear until the lesion is replaced by fibrosis (scar). Old infarcts tend to be pale, shrunken and depressed beneath the surface of the organ.
Follow my great-grandmother’s advice: find the internal solution rather than resorting to external prescriptions buy mobic 15mg on-line. My greatest hope is that the information in this book provides a drugless road map that will lead you systematically to increased health and vitality—and that when you achieve this goal discount mobic 7.5mg otc, you’ll be able to reach your fullest potential discount 7.5 mg mobic fast delivery. Synthetic hormones were not just suggested but proselytized to unsuspecting American women prior to 2002, as most baby boomers can attest. The food industry changed our kitchens— instead of stocking our homes with broccoli and pastured eggs, we were convinced that it was healthy to eat packaged and convenience food. We got exposed to hundreds of toxic chemicals, many of which are endocrine disruptors. We have an obesity epidemic, and 70 percent of the costs of our failing healthcare system are for preventable conditions. These insidious factors behind hormonal imbalance affect not just women but also men and children. We’re more stressed and wired, both with electronic gadgets and from the adrenal fallout, than ever before. Lifestyle redesign, as systematized in The Gottfried Protocol, is extremely effective and grounded in robust science, but not yet part of mainstream medicine. After I started medical school in 1989, I was appalled when I became aware of the vast uncontrolled medical experiment that was being performed on American women. It seemed that hormonal imbalance was approached as a business endeavor by pharmaceutical companies, and that most doctors blindly went along, trusting what they heard. Although I was taught to offer women synthetic estrogen and progestin, most commonly Prempro, for their perimenopausal and menopausal symptoms, I realized that the evidence wasn’t there to support the recommendation. In my experience, excess stress is the central story at the root of hormonal imbalance for women over thirty-five. The effects of adrenaline and cortisol have a profound ripple effect on other endocrine organs such as the ovaries and thyroid, yet few practitioners of mainstream medicine seemed to take the female stress response seriously. There are proven methods to preventing and treating hormonal imbalances that originate with stress and cortisol, which typically disrupt hormonal cross talk between your thyroid and ovaries. As I’ve described, chronic stress affects glucocorticoid regulation, which is controlled by the hypothalamus, pituitary, and adrenals. If you’ve been on the path of repair for a while, you know that correcting the adrenals and their control system takes the longest amount of time. As my friend Lisa Byrne, founder of the online community The Well- Grounded Life, says, “It’s a process, not a prescription. As a gynecologist, teacher, wife, mom, scientist, and yoga teacher, I spent years formulating, synthesizing, and testing a comprehensive plan for hormonal problems. It’s my life’s mission to bring the fruits of my years of study, inquiry, and obsession with neuroendocrine optimization to other women, and to help them feel balanced again. For more information and to see the schedule of meetups in your town, go to http://thehormonecurebook. Good sources of omega-3s are wild Alaskan salmon and an omega- 3 supplement Omega-3 that’s been shown to be low in mercury and other toxins. Addison’s disease—A disease caused by insufficient production of hormones by the adrenal glands, causing decreased cortisol production and adrenal failure. Over time, cortisol production can’t keep up with demand, which can lead to chronic fatigue syndrome, fibromyalgia, anxiety, insomnia, depression, and more. Adrenal glands—Glands that produce hormones that you can’t live without, including sex hormones and cortisol, which help you respond to stress and have many other functions. Allostasis—The process by which the body responds to stressors in order to regain homeostasis. Amygdala—The part of the temporal lobe of the brain that is the center of vigilance, worry, and fear. It is involved in the assessment of threat-related stimuli and is necessary for the process of fear conditioning. They are the hormones that influence muscular growth; they are sometimes known as anabolic steroids. Androgen—The class of sex hormones that stimulates male characteristics by binding to androgen receptors on cells. Women, even though we have far lower levels of androgens than men, are exquisitely sensitive to androgen levels at the proper amount for vitality, confidence, and maintaining lean body mass. Ovarian overproduction of androgens is a condition in which the female ovaries make too much testosterone, and which is linked to polycystic ovarian syndrome. This condition can lead to the development in a woman of male characteristics, such as rogue hairs, acne, and sometimes hair loss. Anovulation—A lack of egg production in the ovaries, which in turn leads to estrogen dominance. Anti-thyroglobulin—An antibody directed against thyroglobulin, which is a key protein in the thyroid gland essential to the production of thyroid hormones. Apoptosis—Programmed cell death; it is necessary to regulate cell growth and differentiation. Armour (desiccated thyroid hormone)—Individuals with low thyroid function, or hypothyroidism, often benefit from thyroid- replacement therapy. There are many symptoms of low thyroid function, but the top three are weight gain, fatigue, and mood changes such as low-grade depression. In some folks, use of natural desiccated thyroid hormone, such as Armour or Nature-Throid (both bioidentical to human thyroid hormone), results in marked improvement in chronic symptoms that may fail to respond to a wide array of conventional and alternative treatments. Ashwagandha (Withania somnifera)—A popular Ayurvedic herb, often used in formulations prescribed for stress, strain, fatigue, pain, skin diseases, diabetes, gastrointestinal disease, rheumatoid arthritis, and epilepsy. Ashwagandha is also used as a general tonic, to increase energy and improve health and longevity. Ayurveda—The ancient Hindu medical system of India, based on the use of food, movement—such as yoga and meditation—and botanicals. B vitamins are used for treating anemia and depression, preventing cervical cancer, elevating mood, boosting energy, and maintaining fertility. Bioidentical hormones— Interest in a more natural approach to hormone therapy has focused attention on bioidentical hormones—hormones that are identical in molecular structure to the hormones women make in their bodies. They are not found in this form in nature but are made, or synthesized, from a plant chemical extracted from yams and soy. Biomarkers—Biological molecules found in blood, other body fluids, or tissues that are a sign of a normal or abnormal process, or of a condition or disease. A biomarker may be used to see how well the body responds to a treatment for a disease or condition. Botanicals—A botanical is a plant or plant part valued for its medicinal or therapeutic properties, flavor, or scent. Products made from botanicals that are used to maintain or improve health may be called herbal products, botanical products, or phytomedicines. Burnout—A chronic stress state characterized by fatigue, headache, disturbed sleep, pain, attention deficit, feelings of apathy and meaninglessness, and detachment from work. Catabolic dominance—The predominant breaking down of more complex substances into simpler ones in living organisms, often resulting in a release of energy.
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