However order 120 mg silvitra fast delivery, in adults cheap 120 mg silvitra otc, other physiological changes that occur during REM sleep are quite different from those of stage 1 cheap silvitra 120 mg otc. In particular silvitra 120mg otc, there is a flaccid paralysis of the limb muscles together with a loss of fine control of body temperature and other homeostatic mechanisms buy silvitra 120mg line. It is often maintained that dreaming is restricted to these periods of REM sleep, which occur some three or four times during the night, each lasting about 30 min. However, it is now thought that dreams also occur during SWS but that these are more logical and more consistent with normal life events than are those occurring during REM sleep. This sleep pattern, seen in adults, takes some time to develop and appears in infants only around 6 months to one year after birth. Instead, as new parents will testify, young babies have a sleep cycle that lasts only around 3±6 h. The functions of these different phases of sleep are not at all clear but chronic sleep deprivation does eventually lead to death. It seems to be the slow-wave component of sleep (SWS) that is vital and it is thought to serve a restorative purpose. This would be consistent with its greater occurrence during the early stages of the sleep cycle when hormone secretion supports anabolic metabolism. If subjects are wakened every time they enter a period of REM sleep (evidenced by the EEG) there appears to be no overt harmful effect on their behaviour. In fact, REM sleep deprivation has even been used, with some claims of success, as a treatment for minor depression. However, there is an unproven belief that REM sleep is important for memory consolidation. ORIGIN OF THE EEG It appears that the voltage waves recorded in the EEG represent the summation of synaptic potentials in the apical dendrites of pyramidal cells in the cortex. These cells generate sufficient extracellular current for it to reach, and be recorded from, the cranium and scalp. Although these waves originate from the cortex rather than the SCN, the distinctive REM and non-REM phases of sleep still remain after destruction of the SCN but they then occur randomly over the 24-h cycle. This is a further indication that the SCN is at least partly responsible for setting the overall circadian rhythm of the sleep cycle. The more synchronised the activity of the cortical neurons, the greater the summation of currents and the larger and slower the EEG wave, as in the sleep pattern (Fig. While there are some dissociations between EEG pattern and behavioural states, the EEG offers one way of determining experimentally the pathways (and neurotransmitters) that control arousal and sleep, and can be regarded as an important objective measurement of the cortical correlates of sleep and waking. However, the rhythm and appearance of spindles in earlier phases of the sleep cycle do depend on links with the thalamus (see Steriade 1999). Unlike stimulation of the specific sensory relay nuclei in the thalamus, which only affects neurons in the appropriate sensory areas of the cortex, the non- specific nuclei can produce responses throughout the cortex and may not only control, but also generate, cortical activity. Certainly, in vitro studies show that neurons of the non-specific reticular thalamic nucleus (NspRTN) can fire spontaneously at about 8± 12 Hz (equivalent to EEG a-rhythm) or lower, and that low-frequency stimulation of this area can induce sleep. Maintenance of these frequencies relies on the degree of depolarisation of the thalamic neurons (Jahnsen and Llinas 1985) and this, in turn, depends on the nature and intensity of their afferent inputs. The NspRTN and other thalamic nuclei receive reciprocal inputs from the cortex and it is possible that it is the ensuing oscillations in neuronal activity in this circuit between the cortex and thalamus that give rise to the sleep spindle waves in stages 2±4. In fact, it has been suggested that the stronger and clearer these oscillations become, the more likely it is that there will be loss of consciousness. Apart from neuronal inputs originating in the cortex, thalamic afferents (see Fig. Because these neurons are themselves activated by sensory inputs transmitted along the spinothalamic tract, this provides one way in which sensory stimuli can influence cortical activity generally, as well as specifically. As described below, these seem to be particularly important and probably disrupt the thalamo-cortical synchrony. SLEEP AND WAKING CENTRES One of the first experiments to investigate the brain mechanisms that might be involved in regulation of sleep and waking showed that after transection of the brain of cats, so that the cerebrum was separated from the brainstem, the animal displayed continuous sleep. Conversely, transection that separated the entire brain, including the brainstem, from the spinal cord (at the level of Cl) caused continuous arousal. Jouvet (1974) extended this work by showing that a lesion at a specific site in the pons abolished REM sleep, together with the associated muscle atonia and EEG changes, but did not affect SWS. Later studies confirmed the existence of these brain centres in that stimulation of the anterior hypothalamus, at a frequency similar to that of the sleep spindles in the EEG, induced sleep whereas stimulation of a zone of the brainstem, that came to be known as the ascending reticular activating system (ARAS), induced arousal (Moruzzi and Mayoun 1949). The generally accepted view is that the stimulatory drive for the ARAS comes from collaterals of the classical ascending sensory pathways. Indeed, this is another way in which sensory stimuli can affect our state of arousal (Fig.
Check your own records to see what they reveal about the plaintiff and to help refresh your memory order 120 mg silvitra with mastercard. Make cop- ies of these records so that you can review them without getting marks on your originals that could be misconstrued as attempts to alter the records silvitra 120 mg. You will want to have reviewed whatever information you can quickly assemble before you meet with your attorney so that you can share all you recall about your role in treating the plaintiff discount 120 mg silvitra. If there were others involved in the incident of treatment about which plaintiff com- plains discount 120 mg silvitra fast delivery, make some notes as to who they were 120 mg silvitra otc, what role they played in that treatment, and how you know that they were involved or witnessed the treatment. What legal theories, other than negligence, is the plaintiff relying on? What are the necessary elements to those theories and how does your lawyer think the plaintiff will try to satisfy them? Are the theories asserted in the complaint’s various causes of action supported in law? Now, there are two things any good malpractice defense attorney will do to best represent a client: put together a discovery plan and a 32 Hiestand litigation strategy. The two go hand-in-hand, and although not all attorneys put them in writing, you will want a commitment from your attorney to do so for you. These are privileged documents, so your opponent will not be able to force you to disclose them. To be sure, both the initial discovery plan and litigation strategy will change as new information is learned and as there are rulings on motions filed by the parties that affect the course of the litigation. That is understand- able, but it is important for you to have each revised plan because it will keep you informed as to how your defense is progressing, what needs to be done, by when, and whether the case is likely to be resolved without the necessity of trial. Your attorney will also likely work a little harder and maybe smarter for a client who shows interest in his or her own defense. As already mentioned, your objective is to get rid of the case against you at the earliest opportunity, certainly before trial. Ask your attor- ney to explain his litigation strategy for accomplishing that goal. Is the plaintiff asserting any claims that are outside the MICRA defenses available to you? Can those claims be disposed of by legal motions or are you stuck with defending hybrid claims? What evidence must be assembled to file a motion for summary judgment or summary adjudication? Does the discovery plan track with the litigation strategy so as to avoid time barriers that might otherwise preclude those motions from being filed? Once you have a sense of the theories the plaintiff is relying on in suing you, it will be important to find out what evidence the plaintiff has, or must get, to tie you into each theory. Your attorney will develop a discovery plan that seeks to find out what you don’t know and con- firm what you do know. That discovery plan should set forth the facts essential to prove the elements of any theory of liability asserted and of any defense you will assert. Your attorney should seek a stipulation with opposing counsel as to material facts that you believe will not be disputed and put that stipulation in writing. The discovery plan should indicate the discovery device(s) that will be used to prove or disprove the existence of each element of all claims and defenses and the source of proof for each fact pertinent to those elements. The extent of claimed damages is something that you will want to nail the plaintiff down on. Do the local court rules limit the number of experts and, if so, does this hurt your defense? What experts has Chapter 2 / Litigation 33 plaintiff’s counsel used in the past for medical malpractice cases? In doing this, your sense of how the rules and players interact and can affect the outcome of the litigation game will make you a more valuable contributor in preparing to win. Chapter 3 / Risk Reduction 35 3 Risk Reduction From a Plaintiff Attorney’s Perspective David Wm. Horan, MD, JD SUMMARY This chapter looks at malpractice litigation from the unique view- point of the plaintiff attorney. What aspects of the doctor– patient relationship most affect the likelihood of litigation? What aspects of a physician’s care, demeanor, and communication skills make him or her more or less formidable as a defendant? The chapter also discusses the physician’s role in educating his or her own attorney and the preparation needed for a successful defense.
Vestibulocochlear Vestibular portion: Patient asked to walk a straight line order silvitra 120 mg free shipping. Cochlear Not usually tested unless patient complains of dizziness or portion: Tested with tuning fork safe silvitra 120mg. Glossopharyngeal Motor: Examiner notes disturbances in swallowing best silvitra 120mg, talking buy generic silvitra 120 mg on line, Visceral innervation of vagus cannot be examined order 120mg silvitra free shipping, except for and vagus and movement of soft palate; gag reflex tested. Accessory Patient asked to shrug shoulders against resistance of examiner’s Sides should show uniformity of strength. Hypoglossal Patient asked to protrude tongue; tongue thrust may be resisted Tongue should protrude straight out; deviation to side indicates with tongue blade. Which cranial nerves are involved in tasting, chewing and Objective 4 Discuss how the spinal nerves are grouped. Which cranial nerves have to do with the structure, func- Objective 5 Describe the general distribution of a spinal tion, or movement of the eyeball? List the cranial nerves and indicate how each would be tested (both motor and sensory fibers) for possible dysfunction. With the exception of the first cervical nerve, the spinal nerves leave the spinal cord and vertebral canal through intervertebral SPINAL NERVES foramina. The first pair of cervical nerves emerges between the occipital bone of the skull and the atlas. The second through the Each of the 31 pairs of spinal nerves is formed by the union of a seventh pairs of cervical nerves emerge above the vertebrae for posterior and an anterior spinal root that emerges from the which they are named, whereas the eighth pair of cervical nerves spinal cord through an intervertebral foramen to innervate a passes between the seventh cervical and first thoracic vertebrae. Peripheral Nervous © The McGraw−Hill Anatomy, Sixth Edition Coordination System Companies, 2001 414 Unit 5 Integration and Coordination FIGURE 12. The remaining pairs of spinal nerves emerge below the vertebrae ops in adults who were first exposed to the virus as children, and is for which they are named. Treatment may involve large doses of the antiviral drug acyclovir (Zorivax). A spinal nerve is a mixed nerve attached to the spinal cord by a posterior (dorsal) root, composed of sensory fibers, and an A spinal nerve divides into several branches immediately anterior (ventral) root, composed of motor fibers (fig. The small The posterior root contains an enlargement called the spinal meningeal branch reenters the vertebral canal to innervate the (sensory) ganglion, where the cell bodies of sensory neurons are meninges, vertebrae, and vertebral ligaments. The axons of sensory neurons convey sensory impulses called the posterior ramus, innervates the muscles, joints, through the posterior root into the spinal cord, where synapses and skin of the back along the vertebral column (fig. The anterior root consists anterior ramus of a spinal nerve innervates the muscles and skin of axons of motor neurons, which convey motor impulses away on the lateral and anterior side of the trunk. A spinal nerve is formed as the fibers from the anterior rami innervate the limbs. The rami com- The disease herpes zoster, also known as shingles, is a viral infection of the spinal ganglia. Herpes zoster causes painful, municantes are composed of a gray ramus, containing unmyeli- often unilateral, clusters of fluid-filled vesicles in the skin along the nated fibers, and a white ramus, containing myelinated fibers. The disease devel- This arrangement is described in more detail in chapter 13. Peripheral Nervous © The McGraw−Hill Anatomy, Sixth Edition Coordination System Companies, 2001 Chapter 12 Peripheral Nervous System 415 Lesser occipital nerve Greater auricular nerve Transverse cervical nerve Supraclavicular nerve Phrenic nerve FIGURE 12. Objective 6 List the spinal nerve composition of each of the Knowledge Check plexuses arising from the spinal cord. List the number of nerves in each of the five regions of the Objective 7 List the principal nerves that emerge from the vertebral column. What are the four principal branches, or rami, from a spinal nerve, and what structures does each innervate? It is formed by the anterior rami of the first four cervical nerves Except in thoracic nerves T2 through T12, the anterior rami of (C1–C4) and a portion of C5 (fig. Branches of the cervi- the spinal nerves combine and then split again as networks of cal plexus innervate the skin and muscles of the neck and por- nerve fibers referred to as nerve plexuses. Some fibers of the cervical plexuses of spinal nerves: the cervical, the brachial, the lumbar, plexus also combine with the accessory and hypoglossal cranial and the sacral. Nerves emerging from the plexuses are named nerves to supply dual innervation to some specific neck and pha- according to the structures they innervate or the general course ryngeal muscles (see fig. Peripheral Nervous © The McGraw−Hill Anatomy, Sixth Edition Coordination System Companies, 2001 416 Unit 5 Integration and Coordination TABLE 12. Motor impulses through fibers from the anterior branches of spinal nerves C5 through the paired phrenic nerves cause the diaphragm to contract, mov- T1 and a few fibers from C4 and T2.
How- AGING discount silvitra 120mg online, IMMUNE 120mg silvitra sale, AND ever buy generic silvitra 120 mg on line, it remains unproven that regular exercise over time PSYCHIATRIC RESPONSES can lower the frequency or reduce the intensity of order 120mg silvitra with amex, for ex- ample buy silvitra 120 mg, upper respiratory tract infections. In HIV-positive Maximal dynamic and isometric exercise capacities are men and in men with AIDS and advanced muscle wasting, lower at age 70 than at age 20. There is overwhelming evi- strength and endurance training yield normal gains. There dence, however, that declines in strength and endurance is also incomplete evidence that training may slow progres- with advancing age can be substantially mitigated by train- sion to AIDS in HIV-positive men, with a corresponding ing. Changes in functional capacity, as well as protection increase in CD4 lymphocytes. However, it remains controversial if chronic exercise enhances lifespan, or if exercise boosts the immune Exercise May Help Relieve Depression, but Its system, prevents insomnia, or enhances mood. Efficacy and Neurochemical Effects Are Uncertain In healthy people, prolonged exercise increases subse- As People Age, the Effects of Exercise quent deep sleep, defined as stages 3 and 4 of slow-wave on Functional Capacity Are More Profound sleep (see Chapter 7). This effect is apparently mediated Than Their Effect on Longevity entirely through the thermal effects of exercise, since equivalent passive heating produces the same result. The influence of exercise on strength and endurance at any Whether or not exercise can improve sleep in patients age is dramatic. In fact, a highly active 70-year-old, Whether acute or chronic exercise can help relieve depres- otherwise healthy, will typically display an absolute exer- sion remains unproven. The two most prominent biological cise capacity greater than a sedentary 20-year-old. Aging theories of depression—the dysregulation of central affects all the links in the chain of oxygen transport and use, monoamine activity and dysfunction of the hypothalamic- so aging-induced declines in lung elasticity, lung diffusing pituitary-adrenal axis—have received almost no study with capacity, cardiac output, and muscle metabolic potential regard to the impact of exercise. Consequently, the physiological Panic disorder patients, often characterized by agora- mechanisms underlying fatigue are similar at all ages. Although sodium Regular dynamic exercise, compared with inactivity, in- lactate infusion does provoke panic in these patients, the creases longevity in rats and humans. In descriptive terms, anxiety mediator appears to be hypernatremia, not lactate; the effects of exercise are modest; all-cause mortality is re- even strenuous exercise with substantial lactic acidosis will duced, but only in amounts sufficient to increase longevity not trigger panic attacks in these individuals. CHAPTER 30 Exercise Physiology 563 REVIEW QUESTIONS DIRECTIONS: Each of the numbered (E) Will be balanced by local dilation (D) Reduce risk of myocardial items or incomplete statements in this in these vascular beds infarction despite elevated total section is followed by answers or by 5. A young, healthy, highly trained cholesterol levels completions of the statement. Select the individual enters a marathon (40 km) (E) Elevate HDL and lower LDL ONE lettered answer or completion that is run on a warm, humid day (32 C, 70% 9. The best medical advice for completes a 500 m freestyle swim this individual is to be concerned about at an age-group competition. In an effort to strengthen selected the possibility for Breathing hard after the race, she muscles after surgery and (A) Heat exhaustion explains that her increased immobilization has led to muscle (B) Coronary ischemia ventilation is a normal response to atrophy, isometric exercise is (C) Renal ischemia and anoxia heavy, dynamic exercise. The intensity of (D) Hypertension increased ventilation results in isometric exercise is best quantified (E) Gastric mucosal ischemia and (A) Clinically significant systemic (A) Relative to the maximal oxygen increased risk for gastric ulceration arterial hypoxemia uptake 6. An individual with hypertension has (B) Normal or reduced arterial PCO2 (B) As mild, moderate, or strenuous been advised to increase physical (C) Respiratory alkalosis (C) As percentage of the maximum activity. At the same time, this person (D) Respiratory acidosis voluntary contraction has been counseled to avoid activities (E) Dizziness and decreased cerebral (D) In terms of anaerobic metabolism that substantially increase the systemic blood flow (E) On the basis of the total muscle arterial blood pressure. A 33-year-old woman embarks on an mass involved dynamic exercise, this individual extensive program of daily exercise, 2. Two people, one highly trained and should avoid exercise that with both strenuous dynamic and one not, each exercising at 75% of the (A) Causes fatigue isometric exercise included. After two maximal oxygen uptake, become (B) Is prolonged years, her maximal voluntary fatigued (C) Uses untrained muscle groups contraction of many major muscle (A) For similar physiological reasons (D) Is substituted for isometric exercise groups and her maximal oxygen (B) Very slowly (E) Involves an intermediate muscle mass uptake, are both increased 30%. In a patient with heart disease, a Predictably, pulmonary function tests (D) While performing equally well for treadmill test involving graded show at least a short period of time dynamic exercise results in falling (A) A 30% rise in vital capacity (E) Despite much higher circulating blood pressure at each exercise level. These vital capacity exercise test on a treadmill while results arise from inadequate cardiac (C) An increase in resting pulmonary showing a modest rise (25%) in mean output during exercise because the diffusing capacity of 30 to 50% arterial blood pressure. In contrast, baroreceptors, during exercise, (D) A 25% increase in maximal forced during the highest level of exercise at (A) Reset blood pressure to a lower expiratory flow rate the end of the test, an indirect method level (E) Decreases in residual volume and shows that cardiac output has risen (B) Are “turned off” airways resistance at rest 300% from rest. In older adults at risk for falls, that during graded, dynamic exercise training osteoporosis, and fractures, a program to exhaustion, systemic vascular (D) Are decreased in sensitivity by of weight-bearing exercise resistance training (A) Increases the risk of hip fracture (A) Is constant (E) Reset blood pressure to a higher (B) Decreases bone mineral density (B) Rises slightly level (C) Leaves gait, coordination, (C) Falls only if work is prolonged 8. A man with a family history of heart proprioception, and reaction time (D) Falls dramatically disease has both diabetes and unaltered (E) Cannot be measured hypertension. In addition, falls, and fractures disease and compromised kidney his LDL cholesterol is elevated and his (E) Is less valuable than dynamic function asks if exercise will alter blood HDL cholesterol is reduced, compared exercise during water immersion flow to either the gastrointestinal tract with individuals with low 12.