Let us calculate the magnitude of the force applied to the shoulder that will topple a person standing at rigid attention purchase fildena overnight delivery impotence depression. In the absence of the force discount fildena online mastercard creatine causes erectile dysfunction, the person is in stable equilibrium because his center of mass is above his feet, which are Section 1. When the person topples, he will do so by pivoting around point A—assuming that he does not slide. The counterclockwise torque Ta about this point produced by the applied force is Ta Fa × 1. The person is on the verge of toppling when the magnitudes of these two torques are just equal; that is, Ta Tw or Fa × 1. This shifts the center of gravity away from the pivot point A, increasing the restoring torque produced by the weight of the body. Stability against a toppling force is also increased by spreading the legs, as shown in Fig. The tendons, which are made of strong tissue, grow into the bone and attach the muscle to the bone. But some muscles end in two or three tendons; these muscles are called, respectively, biceps and triceps. In general, the two bones attached by muscles are free to move with respect to each other at the joints where they contact each other. This arrangement of muscle and bone was noted by Leonardo da Vinci, who wrote, “The muscles always begin and end in the bones that touch one another, and they never begin and end on the same bone.... When ﬁbers in the muscle receive an electrical stimulus from the nerve endings that are attached to them, they contract. This results in a shortening of the muscle and a corresponding pulling force on the two bones to which the muscle is attached. The force of contraction at any time is determined by the number of individual ﬁbers that are contracting within the muscle. When an individual ﬁber receives an electrical stimulus, it tends to contract to its full ability. If a stronger pulling force is required, a larger number of ﬁbers are stimulated to contract. Experiments have shown that the maximum force a muscle is capable of exerting is proportional to its cross section. From measurements, it has been estimated that a muscle can exert a force of about 7 × 106 dyn/cm2 of its area (7 × 106 dyn/cm2 7 × 105 Pa 102 lb/in2). To compute the forces exerted by muscles, the various joints in the body can be conveniently analyzed in terms of levers. We will assume that the tendons are connected to the bones at well-deﬁned points and that the joints are frictionless. Simpliﬁcations are often necessary to calculate the behavior of systems in the real world. Seldom are all the properties of the system known, and even when they are known, consideration of all the details is usually not necessary. Calculations are most often based on a model, which is assumed to be a good representation of the real situation. The position of the fulcrum is ﬁxed so that it is not free to move with respect to 10 Chapter 1 Static Forces the bar. Levers are used to lift loads in an advantageous way and to transfer movement from one point to another. In a Class 1 lever, the fulcrum is located between the applied force and the load. In a Class 2 lever, the fulcrum is at one end of the bar; the force is applied to the other end; and the load is situated in between. As we will see, many of the limb movements of animals are performed by Class 3 levers. It can be shown from the conditions for equilibrium (see Appendix A) that, for all three types of levers, the force F required to balance a load of weight W is given by Wd1 F , (1. If d1 is less than d2, the force required to balance a load is smaller than the load. By placing the load close to the fulcrum, with d1 much smaller than d2, a very large mechanical advantage can be obtained with a Class 1 lever. In a Class 2 lever, d1 is always smaller than d2; therefore, the mechanical advantage of a Class 2 lever is greater than one. Here d1 is larger than d2; therefore, the mechanical advantage is always less than one. As the point at which the force is applied moves through a distance L2, the load moves a distance L1 (see Fig. Thus, it is evident that the excursion and velocity of the load are inversely proportional to the mechanical advantage. The contraction of the triceps causes an extension, or opening, of the elbow, while contraction of the biceps closes the elbow. In our analysis of the elbow, we will consider the action of only these two muscles. This is a simpliﬁcation, as many other muscles also play a role in elbow movement. Some of them stabilize the joints at the shoulder as the elbow moves, and others stabilize the elbow itself. The position of the upper arm is ﬁxed at the shoulder by the action of the shoulder muscles. We will calculate, under the conditions of equilibrium, the pulling force Fm exerted by the biceps muscle and the direction and magnitude of the reaction force Fr at the fulcrum (the joint). The calculations will be performed by con- sidering the arm position as a Class 3 lever, as shown in Fig. In this problem we have three unknown quantities: the muscle force Fm, the reaction force at the fulcrum Fr, and the angle, or direction, of this force φ. The angle θ of the muscle force can be calculated from trigonometric con- siderations, without recourse to the conditions of equilibrium. For equilibrium, the sum of the x and y components of the forces must each be zero. The additional necessary equation is obtained from the torque con- ditions for equilibrium. There are two torques about this point: a clockwise torque due to the weight and a counterclockwise torque due to the vertical y component of the muscle force. Since the reaction force Fr acts at the fulcrum, it does not produce a torque about this point. Assuming as before that the weight supported is 14 kg, these equations become 1440 × cos 72. In these calculations we have omitted the weight of the arm itself, but this eﬀect is considered in Exercise 1-8. Our calculations show that the forces exerted on the joint and by the muscle are large.
Several fetal and neonatal cardiovascular adverse effects are associated with beta-sympathomimetic therapy (Katz and Seeds buy fildena 150 mg erectile dysfunction exercise video, 1989) (Box 15 order fildena no prescription varicocele causes erectile dysfunction. Decreases in the systolic/diastolic ratios of the umbilical artery have been reported in patients using either terbutaline or ritodrine (Brar et al. By 1979, ritodrine was available as a tocolytic agent in 23 foreign countries (Barden, et al. Ritodrine hydrochloride is a beta-adrenergic agonist with beta2-receptor effects that relax smooth muscle in the arterioles, bronchi, and uterus. Although ritodrine use is in widespread use for the inhibition of preterm labor (Leveno et al. No long-term benefi- cial effect of tocolytic therapy (decreased perinatal mortality or severe neonatal respira- tory disorders) was found in meta-analysis of 890 pregnancies in which ritodrine or another beta-mimetic tocolytic agent was used to prevent premature delivery (King et al. Downregulation of beta2-adrenergic receptors following the use of these drugs may explain their poor efficacy because uterine-relaxant effects are short lived (Berg et al. For this indication, a dose of 1–3 mg is usually given over a 2-min period (Smith, 1991). It is possible that a weak effect was pres- ent and the signal could not be separated from background noise. Maternal effects Acute maternal pulmonary edema, in addition to hypokalemia and hyperglycemia, has been reported among women given ritodrine. Steroids administered concomitantly to accelerate fetal lung maturity seem to increase the risk for this maternal complication Tocolytics 283 (see Box 15. Severe maternal cardiovascular complications occurred among nearly 5 percent of women treated with terbutaline (Katz et al. Beta-mimetics also alter glucose tolerance and have been associated with ketoacidosis among women with poorly controlled insulin-dependent diabetes. Fetal effects Fetal tachycardia and arrhythmias are associated with beta-mimetic therapy, including ritodrine (Barden et al. Protracted ritodrine therapy has been associated with increased septal thickness in exposed neonates (Nuchpuckdee et al. However, these do not appear to be frequent complications of ritodrine, or beta-mimetic, therapy in general. Beta-sympathomimetic tocolytic therapy, including ritodrine, was associated with a 2. In another investiga- tion, no association of ritodrine with intraventricular–periventricular hemorrhage was found (Box 15. Beta-mimetics are generally not used during the period of organogenesis, with the exception of terbutaline for asthma. An increased frequency of cardiovascular anomalies in chick embryos exposed to ritodrine and terbutaline was found in one study, and it was concluded that teratogenic effects were secondary to stimulation of beta-2-adrenergic receptors (Lenselink et al. Interestingly, according to its manufacturer, it should not be used for tocolysis. Terbutaline has also been utilized in the management of symptomatic placenta previa in pregnancies remote from term (Besinger et al. Neonatal myocardial dysfunction and necrosis have been associated with terbutaline tocolytic therapy (Fletcher et al. Neonatal hypoglycemia and fetal tachycardia were associated with terbutaline tocolytic therapy late in pregnancy (Peterson et al. Neonatal behavior was transiently altered among the infants of pregnant women who received terbutaline tocolysis (Thayer and Hupp, 1997). One review of car- diopulmonary effects of low-dose continuous terbutaline infusion in 8709 women found 47 women (0. In another review of 1000 women given a combination of intravenous terbutaline and mag- nesium sulfate, the side effects of protracted therapy were negligible (Kosasa et al. Magnesium sulfate has no proven efficacy in delaying delivery beyond 24–48 h (Cotton et al. Maternal effects Hypermagnesemia (cutaneous flushing, nausea, vomiting, respiratory depression, intracar- diac conduction delays) is the major maternal adverse effect of magnesium sulfate therapy. Protracted ther- apy (many days) with magnesium sulfate for preterm labor increases calcium loss and may decrease bone mineralization (Smith et al. Bleeding time during pregnancy may be prolonged with magnesium sulfate therapy, but this is not clinically significant (Fuentes et al. Unlike ritodrine, magnesium sulfate is not associated with a ‘peripheral vascular steal’ syndrome and does not decrease placental perfusion (Dowell and Forsberg, 1995). Fetal effects Magnesium sulfate crosses the placenta and, in extremely large doses, may cause neona- tal cardiorespiratory depression and transient loss of beat-to-beat variability (Hallak et al. Osseous lesions (metaphyses, costochondral junctions, skull) have been reported among infants born to women treated with magnesium sulfate for more than a week prior to delivery (Malaeb et al. Indomethacin is effi- Tocolytics 285 cacious as a tocolytic for short periods of time (Niebyl et al. Maternal effects Indomethacin resulted in few maternal side effects when used as a tocolytic. Potential adverse effects include: interstitial nephritis, acute renal failure, peptic ulcer disease, decrease in platelets, prolonged bleeding time (Clive and Stoff, 1984; Lunt et al. Among 83 women who received indomethacin during pregnancy, no adverse mater- nal or fetal effects were noted, except for oligohydramnios, which resolved sponta- neously (Sibony et al. Fetal effects In a review of 28 studies including 1621 infants exposed to indomethacin for tocolysis, the risk for adverse neonatal outcomes was not increased (Loe et al. However, there were only three randomized clinical trials included and one of them did find an increased risk for adverse neonatal outcomes associated with indomethacin tocolysis. Sulindac was as effective as indomethacin, but with fewer adverse fetal effects in a randomized prospective study of 36 women in preterm labor (Carlan et al. No epidemiological studies of sulindac during pregnancy have been published, but it is probably associated with potential adverse effects similar to indomethacin. Owing to smooth muscle relaxation, there may be maternal hypotension and subsequent decreased uteroplacental perfusion, although in human studies there has been no evidence that nifedipine compromises the fetus (Ray and Dyson, 1995). In a preliminary study of nifedipine versus ritodrine, it was suggested that nifedipine was associated with fewer maternal and fetal side effects (van Dijk et al. A recent case report of severe hypotension and fetal death associated with nifedipine, tocolysis- ascribed causality (van Veen et al. No epidemiologic studies on the safety of this agent during pregnancy have been published. Maternal hypotension and resultant decreased uterine blood flow are the major risks from the use of this agent. Consistent reduction in uterine activity during the infusion of atosiban has been observed (Goodwin et al. No studies regarding the safety of this agent have been published, but a review is available (Shubert, 1995). No difference in tocolytic efficacy was noted in a randomized investigation compar- ing intravenous nitroglycerin with magnesium sulfate (Clavin et al.
It very well may be that one or more of these plays a role in the disease process fildena 100mg free shipping erectile dysfunction doctors in chandigarh. The clinical appearance of alopecia areata varies from small patches of hair loss to total loss of scalp hair (alopecia totalis) to loss of all body hair (alopecia universalis) generic fildena 100 mg impotence low testosterone. It is not usually associated with any symptoms, although some indi- viduals may experience pruritus or paresthesias before or coincident with the loss of hair. A variety of other diseases may also occur in association with alopecia areata, including allergic rhinitis, asthma, atopic dermatitis, diseases of the thy- roid gland, vitiligo, systemic lupus erythematosus, discoid lupus erythematosus, rheumatoid arthritis, pernicious anemia, scleroderma, ulcerative colitis, myasthe- Hair Growth Enhancers 67 nia gravis, and lichen planus. Alopecia areata also may occur in association with Down’s syndrome and Turner’s syndrome, as well as in diabetics and patients with human immunodeﬁciency virus (35). The diagnosis of alopecia areata can be challenging given the multitude of concomitant diseases and conditions; how- ever, it can be absolutely conﬁrmed by biopsy of hair follicles in the area of hair loss. Treatment In some cases of alopecia areata, no therapeutic intervention is necessary because of the patient’s spontaneous regrowth of hair. In many cases, however, long-term therapeutic intervention is necessary in order for patients to see cosmetically acceptable hair regrowth. There are many treatment options available for alopecia areata but no one treatment stands foremost because of the variable nature of the disease and its unpredictable course (Table 1). The beneﬁts and risks of each treatment must be carefully evaluated on a case-by-case basis. However, the differential diagnosis of diffuse alopecia versus androgenetic alopecia, partic- ularly in females, can be difﬁcult because of the similar presentation, and biopsy and histological assessment may be required to conﬁrm the diagnosis. Diffuse alopecia may pres- ent as telogen or anagen efﬂuvium and can be caused by drug and chemical exposure, thyroid disorders, nutritional inﬂuences, and psychological stress. Common causes are childbirth, febrile illnesses, surgery, psychological stress, crash diets, and drug therapy (38). The excessive shedding usually begins 3 to 4 months after the inciting event (39). Anagen efﬂuvium is characterized by widespread or circumscribed loss of anagen hairs from growing follicles. Alopecia due to anagen efﬂuvium is quite obvious because 90% of the hair follicles are in anagen (growing) phase. In contrast with telogen efﬂuvium, loss of anagen hair begins within days to a few weeks after the inciting event. Common causes of anagen efﬂuvium are radiation, toxic drugs, environmental and occupational exposure to hazardous chemicals, and loose anagen syndrome (39). Drug- and chemical- induced hair loss is usually conﬁned to the scalp and is most often diffuse, but it can be patterned or localized. Hypothyroidism is directly correlated with diffuse alopecia, whereas 68 Trancik Hair Growth Enhancers 69 alopecia due to hyperthyroidism is less clearly established (40). Examples of nutritional inﬂuences that can cause diffuse alopecia include caloric deprivation (crash diets), protein-calorie malnutrition, and deﬁciency in zinc, iron, essential fatty acid, and biotin levels (40). Finally, with regard to psychological stress, it is often difﬁcult to determine its role in hair loss because hair loss itself can be very stressful, thus making it nearly impossible to ascertain which is the precipi- tating event, stress or hair loss (40). Once the cause is identiﬁed and eliminated, the prognosis for hair regrowth is usually good (40). In one of the most common causes of diffuse alopecia, chemotherapy, minoxidil topical solution may have utility in reducing the duration of the induced hair loss. In two studies, one controlled (41) and one uncontrolled (42), minoxidil topical solution was not effective in preventing hair loss associated with chemo- therapy. The cross-disciplinary efforts of academia, the pharmaceutical industry, and clini- cians have led to new understanding of hair growth regulation, both biochemi- cally and genetically. Sawaya and Price (8) have recently shown that there are differences in the amounts of steroid-metabolizing enzymes in the hair follicles of males and females with androgenetic alopecia. The recent ﬁnding that the enzyme aromatase is speciﬁcally located in the outer root sheath of hair follicles refocuses our efforts to study the entire hair follicle, not just the dermal papilla cells (8). Based on the numerous patent applications since 1995 (1), it is clear that industry is highly involved in developing hair growth en- hancers. And ﬁnally, Ahmad and colleagues’ (44) discovery of the gene for hair loss in alopecia universalis provides momentous progress at the molecular level. These exciting ﬁndings highlight the great strides that have been made in hair 70 Trancik growth research and provide impetus to researchers in their quest for new and/ or reﬁned therapies for hair loss (45,46). Classiﬁcation of the types of androgenetic alopecia (common baldness) occurring in the female sex. International statistical classiﬁcation of diseases and related health problems, 10th rev ed. General review of the anatomy, growth, and development of hair in Hair Growth Enhancers 71 man. Personality disorders and psychopathologic symptoms in patients with androgenetic alopecia. The psychosocial effects of androgenetic alopecia among women: comparisons with balding men and female controls. Potassium channel conductance: a mechanism affecting hair growth both in vitro and in vivo. Changes in hair weight and hair count in men with androgenetic alopecia, after application of 5% and 2% topical minoxidil, placebo, or no treatment. Inﬂuence of tretinoin on the percu- taneous absorption of minoxidil from an aqueous topical solution. The use of minoxidil to attempt to prevent alopecia during chemotherapy for gynecologic malignancies. Dry skin might be connected to some in- herited disorders relating to the structure and function of the epidermis (e. Moreover, the condition can occur in response to an environment with low humidity and/or low temperature. Exposure to solvents, cutting ﬂuids, surfactants, acids, and alkalis may also produce dry- ness. The visible and tactile characteristics mentioned below are judged both by the dermatologist and the affected person, while the sensory characteristics are perceived solely by the affected person: 1. Visible characteristics—redness, lackluster surface, dry, white patches, ﬂaky appearance, cracks, and even ﬁssures 2. Sensory characteristics—dry, uncomfortable, painful, itchy, stinging, and tingling sensation 73 74 Loden´ The term ‘‘dry skin’’ is not generally accepted. It has not been conclu- sively shown that the water content of the stratum corneum is reduced in all dry skin conditions. For example, reduced water content has not been detected in the pruritic and dry-looking skin of patients with chronic renal failure (7) or in the clinically dry-looking skin of the elderly (8).
While send more and more pain messages through to the brain purchase fildena 25 mg without prescription erectile dysfunction in diabetes mellitus ppt, you have it purchase fildena 100 mg free shipping erectile dysfunction urethral inserts, your finger will not bend as easily as usual and rather than letting a few slide, as it might do when there are will not feel as flexible. The brain will be assaulted with pain tissue forms on your tendons, ligaments, muscles, or other message after pain message, and there’s no button to silence connective tissues. It’s as if a layer of chicken wire has been attached to various sections of your body, making it The Medical Doctor’s Approach to Inflammation more difficult to bend, twist, and stretch. Excess fibrin can cause arthritis, back pain, fibromyalgia, and pain in any joint. Most doctors approach muscular inflammation, such as The situation worsens if the fibrin attaches itself to blood back pain, by prescribing prescription and over-the-counter vessels. The most popular in this category body to get nutrient-rich blood to the areas that need healing. In addition to regulating First, when your body is in a state of permanent inflammation, they also break down fibrin so it can be inflammation, you can put out the “fire” with these drugs, whisked away with the rest of the waste. When we’re younger, but unless you cut off the source of the fuel, the inflammation we have plenty of these enzymes to do their work, and our will just come back. You could approach this situation by trying many of these enzymes—plus they’re overworked trying to to hose down the fire. However, unless you turn stop the leak deal with all the inflammation inside us—so we have fewer completely, the fire could be sparked again by something as enzymes to break down the fibrin. Your liver, for messengers (prostaglandins), having fewer enzymes means instance— the organ that cleans your blood of things that 71 The 7-Day Back Pain Cure don’t normally belong there (like these drugs)—can tolerate light use of these drugs once in a while, but as the warning labels tell you, it can’t continue doing so for more than a few days at most. Finally, the third limitation of using anti-inflammatories is that you’re not doing anything to increase your body’s natural anti-inflammatory agents—namely, certain foods and enzymes. Unlike the anti-inflammatory drugs, your body can easily handle long-term consumption of anti-inflammatory foods and proteolytic enzyme supplements. In an upcoming section of this book on solutions for living a pain-free life, I’ll talk more about which foods actually calm inflammation and how to naturally supplement your anti- inflammatory proteolytic enzyme levels. Meanwhile, in the next chapter, let’s put everything we’ve learned together and see where you stand on the three areas of pain. Unlike the anti-inflammatory drugs, your body can easily handle long-term consumption of anti-inflammatory foods and proteolytic enzyme supplements. How the Body, Mind, In an upcoming section of this book on solutions for living a pain-free life, I’ll talk more about which foods actually calm and Diet Interact inflammation and how to naturally supplement your anti- inflammatory proteolytic enzyme levels. Meanwhile, in the next chapter, let’s put everything we’ve As you read the preceding chapters, you may have been learned together and see where you stand on the three areas of thinking: Does this apply to me? After all, you’re reading this book to find out what you can do to get rid of your back pain and live a healthier, more comfortable life. At this point, however, I want to make something clear: You may not find a single, easy answer. In other words, if you could determine that your pain is originating from the emotional burdens in your mind, then you’d have the solution: Create balance in your mind and emotions. That could include adopting stress-management techniques, visiting with a psychiatrist or psychologist, or simplifying your life with fewer demands and activities. While solving back pain may sometimes be this simple, it’s usually a bit more complicated. Some noodles are emotions, some are diet, some are 73 The 7-Day Back Pain Cure the physical body, but they all intertwine, continuously acting on each other and feeding the effects back to you and your life. The demands of their jobs—to say nothing of the demands of insurance companies—mean that they take only a few minutes with you. It’s near impossible to determine in 15 minutes all the different things that may be contributing to your back pain. Second, most medical doctors aren’t aware of how the mind, body, and diet can all affect your condition. Instead, they’re going to follow their training, which is to diagnose the physical source of the pain and address it with drugs, surgery, or a referral to a specialist. Of course, you now know that this approach will only partially (if at all) address the problem. The three areas that contribute to pain—mind, body, and diet—all interact and influence each other. It’s very important to carefully and objectively review all three areas in your life in order to increase your odds of living pain free. An Example: Job Stress Imagine a time when your career was exceptionally stressful and demanding. Maybe you were just promoted and trying to step up to the new position, or perhaps you were concerned about losing your job and were working extra hard to keep it. You put in longer hours than usual, kept breaks short, and ate lunch without getting up. Your time in 73 The 7-Day Back Pain Cure How the Body, Mind, and Diet Interact 74 the physical body, but they all intertwine, continuously acting the sitting position increased—putting you at greater risk for on each other and feeding the effects back to you and your muscle imbalances. The But if you went through several weeks of “crunch time,” demands of their jobs—to say nothing of the demands of your habits may have subtly changed without you realizing it. Maybe you were in sales, coordinating a project, or Second, most medical doctors aren’t aware of how the serving demanding clients. Even if probably spent even more time on the phone than you they are, they may not use that knowledge when treating your normally would have. Instead, they’re going to follow their training, it broke and you didn’t have a chance to get it replaced. Since which is to diagnose the physical source of the pain and you were on a deadline, you used the regular handset and address it with drugs, surgery, or a referral to a specialist. Knowing what you Of course, you now know that this approach will only know now, you can see that the situation set you up for a partially (if at all) address the problem. The awkward position of the neck could contribute to pain—mind, body, and diet—all interact and very easily have pinched a nerve. It’s very important to carefully and time in the sitting position could screw up the natural tilt of objectively review all three areas in your life in order to your pelvis, pressuring nerves in the lower part of your spinal increase your odds of living pain free. At the same time, all those hours of sitting caused the An Example: Job Stress muscles in your rear end to suffer from insufficient blood circulation, which can contribute to the development of a Imagine a time when your career was exceptionally trigger point. Maybe you were just promoted and could have been going on in your life from a mind and diet trying to step up to the new position, or perhaps you were standpoint. The challenges at work most likely increased your concerned about losing your job and were working extra hard stress load. Deep breaths are great at In either of those situations, multiple factors might lead to bringing in more oxygen and helping you to relax, but if back pain. You put in longer hours than usual, kept relaxation, and too little oxygen, contributing to, or breaks short, and ate lunch without getting up. Perhaps you drank more coffee in the morning to get going, increasing your caffeine levels. By lunchtime you were starving, so you snacked on potato chips with their high levels of processed carbohydrates and unhealthful omega- 6 fats. By afternoon, you may have repeated the process of coffee (with lots of sugar), more potato chips, and maybe a cookie.