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All that one could say was that purchase erectafil 20mg on-line impotence quit smoking, in all measurable characteristics trusted 20 mg erectafil impotence signs, two hairs were identical cheap erectafil 20mg on line impotence of organic origin meaning. If death was fairly recent buy generic erectafil 20mg on-line erectile dysfunction natural cures, a hanging drop preparation for motile sperm can be made. Two cotton-tip swabs soaked with material from the vaginal pool should be air dried and placed in card- board boxes (not test tubes). Any apparent seminal stains on the skin of the victim should be recovered with saline-moistened pieces of cloth. Oral and rectal smears and swabs should also be obtained and retained in all autopsy cases. The slides should be placed either in clean plastic slide holders or in new cardboard holders. The latter should not be reused to prevent carryover of vaginal or seminal material to a subsequent slide placed in the cardboard container. Vaginal, rectal and oral slides should be stained in an attempt to identify any spermatozoa. When no sperm are observed, part of each of the swabs from the vagina, rectum, and mouth can be used for presumptive tests for acid phosphatase. If, however, sexual intercourse is still strongly suspected, or if the acid phosphatase test was weakly positive or questionable, an assay for semen-specific protein P30 should be performed. In the latter case, it is probable that the sperm was obtained from cervical mucus. Thus, it is important when searching for motile sperm in an individual alleged to have been raped only a few hours before to obtain this material from the vaginal pool and not from the cervix. Non-motile sperm with tails in the living individual are usually seen up to 26 h, with occasional reports of 2 to 3 days. The identification of only a single sperm on one or two slides should make the examiner wary that he may have one of those cases in which there is unusual prolonged survival of the sperm, that is, sperm from cervical mucus. The presence of several sperm on a slide, with a history of the last voluntary intercourse 2 or 3 days before, would be inconsistent with the sperm’s originating at that time, but would be consistent with a recent rape. Rape 443 The survival time of spermatozoa in the vagina of living individuals as reported in the medical literature is quite variable. This can be explained by two factors: where the sample was collected, and what criteria are used to identify sperm. Swabs should be taken from the vaginal pool and not the cervix, because sperm can survive in cervical mucus much longer than in the vagina. Thus, sperm seen on a cervical swab may not be caused by the rape but by sexual intercourse 2 to 3 days before. Some clinicians identify sperm only when they see a complete spermatozoa — one with a head and tail. This difference in criteria of identification explains some of the differences in reports of the persistence of sperm. The best study of the persistence of sperm in the vagina of living indi- viduals is by Willott and Allard. They found that it was rare to find sperm with tails, especially after more than 6 h. Sperm heads were identified on an anal swab 45 h after intercourse and on a rectal swab 65 h after intercourse. A number of points should be remembered about the identification of sperm in vaginal, rectal, and oral swabs. In addition, the times previously quoted for per- sistence of sperm are for living individuals. Sperm have been identified in the vagina of dead individuals 1 to 2 weeks after death. In dead individuals, the sperm are destroyed by decomposition, not drainage or the action of the vaginal secretions or cells. Sperm that is deposited on material like cotton, cloth, or paper and air dried can be identified years after the event. This could be caused by use of a condom, failure to ejaculate, drainage of semen or aspermia secondary to disease or a vasectomy. Because of this problem, substances were looked for in semen besides sperm that could be identified by biochemical means to indicate recent intercourse. The highest levels are within the first 12 h, with gradual disappearance by 48–72 h. Because it usually disappears in the first 24 h after intercourse, it is most useful as an indicator of recent intercourse, compared with non-motile sperm, which can be identified up to 2–3 days after intercourse. Thus, of 27 females allegedly raped in which acid phosphatase was negative, 26% were positive for P30, thus indicating sexual intercourse had taken place. A number of individuals have been positively identified and convicted on the basis of bite marks. The bite mark should then be documented photographically, with a scale present in the picture. If a forensic odontologist is on call, he should be summoned at the time of the examination to perform the aforementioned steps as well as taking a cast. If a suspect is arrested, a court order can be obtained to get an impression of his teeth to be compared with the injuries on the victim. Homosexual Rape For completeness, we should mention the victims of homosexual rape. Essen- tially the same procedures as those performed on the female rape victim should be performed on the male. The length, constitution, and number of the repetitive sequences are different for each person. If these match, and the test is done with sufficient probes, there is virtually no doubt that the suspect is the source of the tissue to the exclusion of all other indi- viduals, except for an identical twin. This is possible if the second individual is a monozy- gotic twin, or because an insufficient number of tests were per- formed to differentiate the suspect from the other individual. To determine this, the fre- quency of occurrence of selected alleles in the major population groups is determined, and testing is performed to determine the presence of these selected alleles. If the second allele tested for also occurs and this matches, then 99 out of 100 people are excluded. If sufficient alleles are tested for, the probabilities for exclusion go into the millions or even billions. All nucleated cells in the body contain 23 pairs of chromosomes except for sperm and ova, which contain 23 chromosomes rather than 23 pairs. The sides of the ladder consist of alternating sugar (deoxyribose) and phosphate molecules; the rungs of the ladder consist of nitrogen bases. The weakest part of the helix or ladder is the rungs, where the nitrogen bases are weakly linked by hydrogen bonds. Two of these are purines (adenine and guanine) and two are pyrimidines (thymine and cytosine). In forming the rungs of the ladder, guanine always binds to cytosine and adenine always binds to thymine.
Also present is diastolic fluttering of the mitral leaflets and high-velocity flow detected by Doppler examination in the distal atrial chamber and at the mitral orifice (Videos 75 cheap erectafil 20 mg visa erectile dysfunction bangalore doctor. This technique is usually unnecessary order erectafil 20 mg line erectile dysfunction doctors augusta ga, unless there are concerns regarding the hemodynamic consequences buy 20 mg erectafil overnight delivery erectile dysfunction recovery. Management Options and Outcomes Surgical resection of the membrane is the treatment of choice for patients with significant obstruction buy 20mg erectafil with visa erectile dysfunction doctor type. With the advent of more routine use of echocardiography, a subset of cases with typical but nonobstructive forms has been recognized. Thus far these cases appear to remain asymptomatic, with an infrequent need for surgical intervention. Pulmonary Vein Stenosis Congenital pulmonary vein stenosis may occur as a focal stenosis at the atrial junction or as generalized hypoplasia of one or more pulmonary veins. In other cases the pulmonary vein stenosis is acquired after surgical intervention for a total anomalous pulmonary venous connection. Children frequently present with recurrent respiratory infections, whereas adults exhibit exercise intolerance. Pulmonary hypertension is one of the consequences of pulmonary vein stenosis, whether it is congenital or acquired. In cases with unilateral pulmonary vein stenosis, clinical symptoms are frequently absent because there is pulmonary blood flow redistribution away from the affected lung. With unilateral pulmonary vein stenosis there is oligemia of the affected lung and increased flow to the contralateral side. Assessment of pulmonary artery pressure from tricuspid or pulmonary valve regurgitation is possible. Doppler color flow assessment of the right- and left-sided pulmonary veins is the best screening tool. If there is evidence of turbulence or aliasing in the color flow pattern, then spectral analysis with pulsed Doppler imaging will help confirm the diagnosis. If the pattern is of high velocity and turbulent, there is disturbed pulmonary venous flow. First, the absolute velocity depends on the amount of pulmonary blood flow to that segment of lung. Second, it is often difficult to obtain a parallel line of interrogation of the pulmonary veins that will affect gradient assessment. The absolute velocity is less important than the diagnosis of pulmonary vein stenosis and its effect on pulmonary artery pressure. Velocity assessment is now possible, though this is in the actual veins themselves rather than at the venoatrial junction, which is the site assessed by Doppler echocardiography. Management Options and Outcomes If the patient has unilateral pulmonary vein stenosis and normal pulmonary artery pressure, no treatment may be necessary. Continued follow-up is important because this is often a progressive disease that can subsequently affect both sides. In cases with bilateral stenoses the outlook in the past was believed to be hopeless, with a virtually 100% mortality rate. More recently a pericardial reflection procedure (the “sutureless” repair) using native tissue has resulted in some early success for this lesion. This involves using native atrial tissue, pericardium, and pleura to form a pocket around the surgically resected stenotic region. Pulmonary Arteriovenous Fistula Abnormal development of the pulmonary arteries and veins in a common vascular complex is responsible for this congenital anomaly. A variable number of pulmonary arteries communicate directly with branches of the pulmonary veins. Hepatopulmonary syndrome may also be associated with substantial right-to-left intrapulmonary shunting. The amount of right-to-left shunting depends on the extent of the fistulous communications and may result in cyanosis. Paradoxical emboli or a brain abscess may result and cause major neurologic deficits. Patients with hereditary hemorrhagic telangiectasia are often anemic because of repeated blood loss and may have less obvious cyanosis because of anemia. Rounded opacities of various sizes in one or both lungs on chest radiography may suggest the presence of the lesion. Laboratory Investigations Echocardiography is helpful in the initial diagnostic process with the use of a saline contrast injection into a systemic vein. Management Options Unless the lesions are widespread throughout both lungs, surgical treatment aimed at removing the lesions with preservation of healthy lung tissue is commonly indicated to avoid the complications of massive hemorrhage, bacterial endocarditis, and rupture of arteriovenous aneurysms. Transcatheter balloon or plug or coil occlusion embolotherapy may prove to be the therapeutic procedure of choice in some patients. Coronary Arteriovenous Fistula Morphology A coronary arteriovenous fistula is a communication between one of the coronary arteries and a cardiac chamber or vein. The right coronary artery (or its branches) is the site of the fistula in about 55% of patients; the left coronary artery is involved in about 35%; and both coronary arteries are involved in a few. Connections between the coronary system and a cardiac chamber appear to represent persistence of embryonic intertrabecular spaces and sinusoids. Most of these fistulas drain into the right ventricle, right atrium, or coronary sinus. Coronary–to–pulmonary artery fistulas are an occasional and usually incidental finding during coronary angiography. Clinical Features The shunt through the fistula is usually small, and myocardial blood flow is not compromised. Potential complications include pulmonary hypertension and congestive heart failure if a large left-to-right shunt exists, bacterial endocarditis, rupture or thrombosis of the fistula or of an associated arterial aneurysm, and myocardial ischemia distal to the fistula due to a “myocardial steal. The site of maximal intensity of the murmur is related to the site of drainage and is usually away from the second left intercostal space, which is the classic site of the continuous murmur of persistent ductus arteriosus. Radiographic findings are often normal and seldom show selective chamber enlargement. Coronary artery fistulas are now recognized with a high degree of accuracy with the advent of routine coronary artery evaluation during most pediatric echocardiography examinations. A significantly enlarged feeding coronary artery can be detected, and the entire course and site of entry of the arteriovenous fistula can be traced by Doppler color-flow mapping. The shunt entry site is characterized by a continuous turbulent systolic and diastolic flow pattern. If echocardiography demonstrates a significant coronary artery fistula, hemodynamic evaluation and possible intervention are warranted. Standard retrograde thoracic aortography, balloon occlusion angiography of the aortic root with a 45-degree caudal tilt of the frontal camera (“laid back” aortogram), or coronary arteriography can be used reliably to identify the size and anatomic features of the fistulous tract. Management Options and Outcomes Small fistulas have an excellent long-term prognosis. Untreated larger fistulas may predispose the individual to premature coronary artery disease in the affected vessel. Coil embolization at the time of cardiac catheterization is rapidly becoming the treatment of choice (Video 75. Temporal trends in survival to adulthood among patients born with congenital heart disease from 1970 to 1992 in Belgium.
Exercise (see Chapter 54) The conditioning effect of exercise on skeletal muscles allows a greater workload at any level of total- body O consumption buy erectafil 20 mg fast delivery erectile dysfunction treatment lloyds pharmacy. The combination of these two effects of exercise2 conditioning permits patients with chronic stable angina to increase physical performance substantially 111 following institution of a continuing exercise program purchase erectafil 20 mg with amex erectile dysfunction quick remedy. However erectafil 20mg visa impotence following prostate surgery, a single nonrandomized study demonstrated significant improvement in well-being scores and positive affect scores order erectafil 20 mg erectile dysfunction drugs staxyn, as well as a reduction in disability scores, in patients in a structured exercise program. Patients who are involved in exercise programs are also more likely to be health conscious, to pay attention to diet and weight, and to discontinue cigarette smoking. For all these reasons, patients should be urged to 79,112 participate in regular exercise programs, usually walking, in conjunction with their drug therapy. Weight loss 113,114 can improve or prevent many of the metabolic consequences of obesity. The explanation for the “obesity paradox” by which mild-moderate obesity appears protective in observational studies has not been fully elucidated. Inflammation (See Chapters 44 and 45) 116,117 Atherothrombosis has been recognized as an inflammatory disease. Additional research is ongoing to clarify whether inflammation should be a target for routine strategies of risk reduction or novel therapeutic agents in patients with 119 atherosclerosis. At least one adequately sized outcomes trial has demonstrated the potential for an agent specifically targeting inflammation for secondary prevention. Dosing at 75 to 162 mg daily appears to have comparable effects on secondary prevention as dosing at 160 to 325 mg daily and is associated with lower bleeding risk. Even among patients with intracoronary stenting, low-dose aspirin has been shown to be preferable to 28 higher-dose aspirin. Clopidogrel, a thienopyridine derivative, may be substituted for aspirin in patients with aspirin hypersensitivity or in 28 those who cannot tolerate aspirin (see Chapter 93). However, in the large subgroup of those with established vascular disease, the addition of clopidogrel was associated with a 1% absolute reduction in these events (6. Risk scores weighing these competing risks for ischemic events and bleeding may be useful in decision making. However, a significant increase in the risk for bleeding with vorapaxar underscores the need for tailoring treatment to the individual patient based on the competing risks for increased thrombotic events versus increased bleeding. Direct oral anticoagulants offer the potential for a more favorable balance of efficacy and safety. Rivaroxaban 5 mg twice daily without aspirin did not significantly reduce the primary endpoint compared with aspirin alone. The roles of the available options for long-term antithrombotic therapy in addition to aspirin (e. In addition, a small trial has shown that withdrawing aspirin after coronary stenting is 130 associated with favorable bleeding and efficacy compared with triple therapy. Two subsequent trials have further advanced this strategy using reduced dose direct oral anticoagulants. No differences in ischemic outcomes or stroke were observed for either of the less-intensive regimens. However, such observational studies are limited by the high potential for uncontrolled confounding. Effect of beta-blockade on mortality among high-risk and low-risk patients after myocardial infarction. Beta- blocker use and clinical outcomes in stable outpatients with and without coronary artery disease. Effects of an angiotensin-converting enzyme inhibitor, ramipril, on cardiovascular events in high risk patients. Several additional large randomized trials are ongoing that should provide a clearer picture of the risks and benefits of vitamin D supplementation (www. Certain changes in lifestyle may be helpful, such as modifying strenuous activities if they consistently and repeatedly produce angina. However, isometric activities such as weightlifting and other activities such as snow shoveling, which involves an energy expenditure of 60% to 65% of peak O2 consumption, and cross-country skiing may be undesirable. In addition, these latter activities expose the individual to the detrimental effects of cold on the O demand-and-supply relationship. Patients should avoid sudden bursts of activity, particularly after long periods of rest or inactivity, after meals, and in cold weather. Both chronic angina and unstable angina exhibit a circadian rhythm characterized by a lower angina threshold shortly after arising. Most patients with stable angina are able to continue satisfactory sexual activity. Although from a perspective of both quality of life and avoiding prolonged ischemia, it is desirable to minimize the number of bouts of angina, occasional angina is not to be feared. Indeed, unless patients occasionally reach their angina threshold, they may not appreciate the extent of their exercise capacity. An important dimension to effective angina control relates to the benefits of prophylactic use of short-acting nitrates (either sublingual nitroglycerin or nitrolingual pump spray). If there is a clear pattern of effort angina, prophylactic use of short-acting nitrates several minutes before engaging in the offending activity may provide sufficient vasodilation to prevent an anginal episode. Pharmacologic Management of Angina Beta Adrenoceptor–Blocking Agents 143 Beta-blocking agents constitute a cornerstone of therapy for angina. In addition to their anti-ischemic properties, beta-blocking agents are modestly effective antihypertensives (see Chapter 47) and antiarrhythmics (Chapter 36). Beta blockers reduce the frequency of anginal episodes and raise the anginal threshold, both when given alone and when added to other antianginal agents. The beneficial actions of these drugs depend on their ability to competitively inhibit the effects of neuronally released and circulating catecholamines on beta adrenoceptors (Tables 61. Thus, beta- blocking agents reduce myocardial O demand primarily during activity or excitement, when surges of2 increased sympathetic activity occur. In the presence of impaired myocardial perfusion, the effects of beta blockers on myocardial O demand may critically and favorably alter the imbalance between supply and2 demand and thereby mitigate ischemia. Beta blockade has a beneficial effect on ischemic myocardium unless (1) the preload rises substantially, as in left-sided heart failure, or (2) vasospastic angina is present, in which case spasm may be promoted in some patients. Note the suggestion that beta blockade diminishes exercise-induced vasoconstriction. Complications are relatively minor, but in patients with peripheral vascular disease, the reduction in blood flow to skeletal muscles with the use of nonselective beta-blocking agents may decrease maximal exercise capacity. Two major subtypes of beta receptors, designated beta and beta , are present in different proportions in1 2 different tissues. Thus, cardioselective beta blockers reduce2 myocardial O requirements while tending not to block bronchodilation, vasodilation, or glycogenolysis. Because cardioselectivity is only relative, the use of cardioselective beta blockers in doses sufficient to control angina may still cause bronchoconstriction in some susceptible patients. Nevertheless, beta blockers are relatively well tolerated by most patients with obstructive pulmonary disease. Pindolol and acebutolol produce low-grade beta stimulation when sympathetic activity is low (at rest), whereas these partial agonists behave more as conventional beta blockers when sympathetic activity is high. Potency can be measured by the ability of beta blockers to inhibit the tachycardia produced by isoproterenol.
The magnitude of the single-channel current amplitude is dependent generic erectafil 20mg on-line erectile dysfunction treatment houston tx, among other factors 20 mg erectafil overnight delivery erectile dysfunction due to diabetes, on the ionic concentration gradient across the membrane buy erectafil 20mg low price erectile dysfunction nursing interventions. Phases of the Cardiac Action Potential The cardiac transmembrane action potential consists of five phases: phase 0 20 mg erectafil otc impotence leaflets, upstroke or rapid depolarization; phase 1, early rapid repolarization; phase 2, plateau; phase 3, final rapid repolarization; and phase 4, resting membrane potential and diastolic depolarization (Fig. These phases are the result of passive ion fluxes moving down their electrochemical gradients established by active ion pumps and exchange mechanisms. Above and below are the various channels and pumps that contribute the currents underlying the electrical events. Where possible, the approximate time courses of the currents associated with the channels or pumps are shown symbolically, without trying to represent their magnitudes relative to each other. Although it is likely that other ionic current mechanisms exist, they are not shown here because their roles in electrogenesis are not sufficiently well defined. Upper row, Shown are a cell (circle), two microelectrodes, and stages during impalement of the cell and its activation and recovery. Both microelectrodes are extracellular (A), and no difference in potential exists between them (0 potential). The environment inside the cell is negative, and the outside is positive, because the cell is polarized. One microelectrode has pierced the cell membrane (B) to record the intracellular resting membrane potential, which is −90 mV with respect to the outside of the cell. The cell has depolarized (C), and the upstroke of the action potential is recorded. At its peak voltage, the inside of the cell is approximately +30 mV with respect to the outside of the cell. The repolarization phase (D) is shown, with the membrane returning to its former resting potential (E). Ionic fluxes regulate membrane potential in cardiac myocytes in the following fashion. When only one type of ion channel opens, assuming that this channel is perfectly selective for that ion, the membrane potential of the entire cell would equal the Nernst potential of the permeant ion. By solving the Nernst equation for the four major ions across the plasma membrane, the following equilibrium potentials are obtained: sodium, +60 mV; potassium, −94 mV; calcium, +129 mV; and chloride, −83 to −36 mV (Table + + 34. Therefore, if K -selective channels open, such as the inwardly rectifying K (Kir) channel (see + later), the membrane potential approaches E (−94 mV). When two orK more types of ion channels open simultaneously, each channel moves the membrane potential to the equilibrium potential of their respective permeant ions. The contribution of each ion type to the overall membrane potential at any given moment is determined by the instantaneous permeability of the plasma membrane to that ion. For example, deviation of the measured resting membrane potential from E (K see Table 34. With several permeant ion types, V is a weighted mean of all the Nernst potentials. The intracellular potential during electrical quiescence in diastole is −50 to −95 mV, depending on the type of cell (Table 34. Therefore the inside of the cell is 50 to 95 mV negative relative to the outside + + − of the cell because of the transmembrane gradients of ions such as K , Na , and Cl. Calcium does not contribute 2+ directly to the resting membrane potential, but changes in intracellular free calcium concentration [Ca ]i can affect other membrane conductance values. Ca and thereby lead to spontaneous transient inward currents and concomitant 2+ + 2+ membrane depolarization. This + 2+ protein exchanges three Na ions for one Ca ion and thus generates a current; the direction depends on + 2+ the [Na ] and [Ca ] on the two sides of the membrane and the transmembrane potential difference (see 2+ Electrogenic Transporters). Another transporter, the Na-K pump, electrogenically pumps Na out of the cell and + + + simultaneously pumps K into the cell (three Na outward and two K inward) against their respective + + chemical gradients, keeping the intracellular K concentration high and the intracellular Na + + concentration low. The rate of Na -K pumping to maintain the same ionic gradients must increase as the + + heart rate increases because the cell gains a small amount of Na and loses a small amount of K with + + each depolarization. A stimulus delivered to excitable tissues can evoke an action potential characterized by a sudden change in voltage caused by transient depolarization followed by repolarization. The action potential is conducted throughout the heart and is responsible for initiating each heartbeat. Electrical changes in the action potential follow a relatively fixed time and voltage relationship that differs according to specific cell types (Fig. In neurons, the entire process takes several milliseconds, whereas action potentials in human cardiac fibers last several hundred milliseconds. Normally, the action potential is independent of the size of the depolarizing stimulus if the latter exceeds a certain threshold potential. Small, subthreshold depolarizing stimuli depolarize the membrane in proportion to the strength of the stimulus. However, when the stimulus is sufficiently intense to reduce membrane potential to a threshold value in the range of −70 to −65 mV for normal Purkinje fibers, an “all-or-none” response results. More intense depolarizing stimuli do not produce larger action potential responses; in contrast, hyperpolarizing pulses, or stimuli that render the membrane potential more negative, elicit a response proportional to the strength of the stimulus. In panels A to F, the top tracing is dV/dt of phase 0, and the second tracing is the action potential. For each panel, the numbers (from left to right) indicate maximum diastolic potential (mV), action potential amplitude (mV), action potential duration at 90% of repolarization (milliseconds), and rate of depolarization of phase 0 (V/sec). Zero potential is indicated by the short horizontal line next to the zero on the upper left of each action potential. Note that the action potentials recorded in A, C, and F have reduced resting membrane potentials and amplitudes relative to the other action potentials. Horizontal calibration on the left: 50 milliseconds for A and C, 100 milliseconds for B, D, E, and F; 200 milliseconds on the right. Vertical calibration on the left: 50 mV; horizontal calibration on the right: 200 milliseconds. The upstroke of the cardiac action potential in atrial and ventricular muscle and His-Purkinje fibers is the + result of a sudden increase in membrane conductance of Na. An externally applied stimulus or a spontaneously generated local membrane circuit current in advance of a propagating action potential + depolarizes a sufficiently large area of membrane at an adequately rapid rate to open the Na channels + + and depolarize the membrane further. When the stimulus activates enough Na channels, Na ions enter + the cell down their electrochemical gradient. The excited membrane no longer behaves like a K + + electrode, that is, exclusively permeable to K , but more closely approximates an Na electrode, and the + membrane voltage moves toward the Na equilibrium potential (+60 mV). The rate at which depolarization occurs during phase 0, that is, the maximum rate of change in voltage over time, is indicated by the expression dV/dtmax or V̇max (see Table 34. As this process is occurring, however, [Na ] and positivei + intracellular charges increase and reduce the driving force for Na flux into the cell. Importantly, Na conductance is time dependent, so when the membrane spends some time at voltages less negative than + the resting potential, Na conductance decreases (inactivation). Therefore an intervention that reduces + membrane potential for a time (acute myocardial ischemia), but not to threshold, partially inactivates Na + channels, and if the threshold is now achieved, the magnitude and rate of Na influx are reduced, which causes conduction velocity to slow. Neuronal Nav channels in the 6 heart have been identified as regulators of contractility. Normal atrial and ventricular muscle cells and fibers in the His-Purkinje system exhibit action potentials with very rapid, large-amplitude upstrokes called fast responses.
