间歇性低氧训练对高性能战斗机飞行员脑电复杂度及血氧饱和度的影响

目的 通过动态观察间歇性低氧训练前后高性能战斗机飞行员EEG复杂度和血氧饱和度(arterial oxygen saturation,Sa()2)的变化特征,为低氧适应性训练效果评价提供量化指标.方法 对32名高性能战斗机飞行员进行15 d的间歇性低氧训练(模拟高度3500 m),1次/d,每次25 min.于训练前后,分别检测受试者在模拟7500 m高空环境下的EEG、SaO2、红细胞数及血红蛋白含量,并对受试者低氧训练前后的检测数据进行t检验.结果 间歇性低氧训练后,受试者在模拟7500 m高空环境下的EEG复杂度较训练前显著降低,差异有统计学意义(P＜0.01),Sa()2升高,差异有统计学意义(P＜0.01),红细胞和血红蛋白含量则无明显变化(P＞0.05).结论 模拟3500 m间歇性低氧训练可提高机体高空缺氧耐力水平,EEG复杂度和SaO2可作为评价高性能战斗机飞行员间歇性低氧训练的定量生理指标. Abstract： Objective To explore the quantitative index for evaluating the intermittent hypoxia training effects by analyzing the characteristic changes of electroencephalogram (EEG) complexity and saturation of blood oxygen (SaO2) of high performance fighter pilots. Methods Thirty-two pilots were selected as subjects and undertook a 25 min-training (simulated hypoxia at 3500 m-oxygen concentration 13.1%) with Type DY-84 hypoxia training device once a day for 15 d. Before and after training the subjects were put in simulated 7500 m hypoxia condition (oxygen concentration 7.1%,ventilation volume 15L/min) and their EEG, SaO2, number of red blood cell and hemoglobin level were recorded and analyzed by t-test. Results Training effects showed that the subjects' 7500m EE(G complexity was significantly decreased (P＜0.01), but SaO2 was significantly increased (P＜0.01).Number of red blood cell and hemoglobin level had no obvious change (P＞0.05).Conclusions The simulated 3500 m intermittent hypoxia training could improve pilot's hypoxia tolerance. EEG complexity and SaO2, which are measured under simulated 7500 m hypoxia condition,would be the quantitative indices for evaluating the effects of intermittent hypoxia training for pilot.The results application would be hopefully expanded to the population who work at high altitude or in anoxic environment.     

Ethanol-induced lowering of arterial oxyhemoglobin saturation during hypoxia.

Nine fasting, healthy, adult male volunteers were given oral carbohydrate before exposures to normoxia (PIO2 = 149 torr) and mild hypoxia (PIO2 = 98 torr). Following recovery, they were given oral ethanol before similar exposure to normoxia and mild hypoxia. Repeated measures of arterial blood and expired gases were made. Ethanol diminished respiratory gas exchange (R), causing lower alveolar and arterial oxygen pressures during normoxia and mild hypoxia and a reduction in arterial oxygen saturation from 89.9 to 87.4% during mild hypoxia. It is suggested that carbohydrates are preferable to ethanol and fats as nutrients during limited oxygen transport situations, such as high-altitude, carbon monoxide exposure, or during heavy exertion, and for patients with cardiovascular or pulmonary disease.     

Short-term intermittent normobaric hypoxia-haematological, physiological and mental effects

Effects on erythropoiesis and blood pressure as well as physical performance and mental effects were studied in 15 healthy subjects during intermittent exposure to normobaric hypoxia corresponding to either 2000 m (6 persons) or 2700 m (9 persons) above sea level; another group (5 persons) also served as controls at normoxia. The concept "live hightrain low" was used for 10 d consecutively and the exposure to hypoxia was 12 h/d. Blood pO₂ and oxygen saturation were significantly decreased during the 10 d at hypoxia. [Hb] and Hct decreased significantly after 2 d in hypoxia and then returned to pre-study levels. Erythropoietin was significantly elevated in both hypoxia groups during the initial 3–5 d. Reticulocytes were significantly increased during 7 d of hypoxia. Submaximal and maximal oxygen uptake, blood pressure at rest and during exercise and the profile of mood states (POMS test) did not change during the study. In conclusion, intermittent normobaric hypoxia for 10 d resulted in a significant stimulation of erythropoiesis. Staying at normobaric hypoxia may serve as a complement to an ordinary altitude level sojourn.     

红景天对急性低压缺氧大鼠内皮素分泌的干预

目的：观察急性中，生度缺氧对大鼠内皮素（ET）的影响及红景天类药物的干预，初步探讨红景天类药物抗缺氧机制，方法：36只雄性SD大鼠，随机分成盐水组，（5000米和8000米）低压缺氧组，三组又各分红景天组和盐水组，盐水组，红景天组每天灌胃生理盐水，红景天浓缩深，共7天。检测盐水和低压暴露5h后缺氧组血浆，脑组织ET含量。结果；急性5000米，8000米缺氧盐水组与地面盐水组比较血浆ET含量显著升高（P＜0．05，P＜0．01），地面药牧组与其盐水组相比血浆ET含量无生差异，急性5000米，80000米缺氧药物组与其盐水组相比血浆ET含量上降（P＜0．05，P＜0．01），急性8000米缺氧药物组与其盐水组相比脑组织ET含量显著下急性中，重度低压缺氧引起机体内皮素的异常升高。     

Central nervous reactions to a 6.5-hour altitude exposure at 3048 meters

In this study of CNS reactions to mild hypoxia, 7 subjects were decompressed to the equivalence of 3048 m altitude breathing air, for 6.5 h. On reaching 3048 m, and for every second h thereafter, a battery of neuropsychological tests were administered. In addition, blood and performance measures were sampled and a symptom check list was administered. The performance tests indicated significant effects of hypoxia. In contrast to earlier studies on grade of hypoxia and performance, no relationship between impaired performance and duration of exposure to hypoxia was found. Repeated testing throughout exposure indicated stable individual reactions. Endocrine variables did not support the hypothesis that activation or 'stress' caused the impairment observed. In addition to impaired neuropsychological test performance and impaired task performance, the subjects reported headache, weakness and some dizziness. Comparisons between different tests confirmed previous results showing that mild hypoxia yields varying degrees of impairment on different cognitive functions.     

急性低压缺氧和间断缺氧习服对血浆与肝肾组织内红细胞生成素的影响

目的　探讨急性低压缺氧和间断缺氧习服对大鼠血液内红细胞数量、红细胞生成素(EPO)浓度以及肝、肾组织内EPO基因表达的影响。　方法　 2 4只Wistar大鼠分为常压空气组 (对照组 )、急性低压缺氧组和间断缺氧习服组。急性低压缺氧组直接在低压舱中模拟海拔 80 0 0m缺氧12h ,间断缺氧习服组模拟海拔 30 0 0m缺氧 2周后 ,再模拟海拔 5 0 0 0m缺氧 2周 ,每天 4h后 ,再在模拟 80 0 0m缺氧 12h。以红细胞计数法检测血液内红细胞数量 ;用MTT法检测血浆内EPO浓度 ,用逆转录 多聚酶链反应 (RT PCR)方法检测肝、肾组织内EPO基因表达。　结果　与对照组相比 ,急性低压缺氧组大鼠血浆内EPO浓度显著升高 (P <0 0 5 ) ,肝、肾组织内该基因表达显著增强 ;间断缺氧习服后的大鼠再经缺氧处理 ,血液内红细胞数量较对照组显著升高 (P <0 0 5 ) ,而血浆内EPO浓度和肝、肾组织中EPO基因的mRNA含量明显低于急性低压缺氧组 (P <0 0 5 )。　结论　急性低压缺氧导致EPO显著升高可能是血液内红细胞数量增加的机制 ;间断缺氧习服大鼠耐缺氧能力增强 ,抑制急性低压缺氧诱导的EPO含量和基因表达升高。     

缺氧复合氰化钠中毒对家兔动脉血气成分的影响

目的探讨缺氧复合氰化钠(NaCN)中毒对家兔动脉血气成分的影响。方法以人工低压氧舱模拟4 000m高原缺氧环境。20只家兔随机均分为4组:高原高剂量组(2mg/kg),高原低剂量组(1.5mg/kg),平原高剂量组(2mg/kg),平原低剂量组(1.5mg/kg)。高原组动物在低压氧舱内预处理72h后进行实验。以戊巴比妥钠(30mg/kg)麻醉动物后进行股动脉插管,腹腔注射NaCN毒剂(2mg/kg或1.5mg/kg)。分别于NaCN中毒前10min(-10min),中毒后5、10、15、20、30、60、120和180min采血测定动脉血气变化。结果高原缺氧72h后动物的动脉血氧分压(PaO2)和二氧化碳分压(PaCO2)明显降低,与平原组中毒前比较差异有统计学意义(P<0.01),而pH值和碳酸氢根(HCO-3)浓度与平原组中毒前比较,差异无统计学意义(P>0.05)。各组NaCN中毒后动脉血pH值先升高后降低,PaO2显著升高,PaCO2和HCO-3浓度显著降低。结论NaCN中毒后酸碱平衡紊乱,早期表现为呼吸性碱中毒,后期表现为代谢性酸中毒。     

Vascular and oxygenation responses of local ischemia and systemic hypoxia during arm cycling repeated sprints

ObjectivesThe purpose of this study was to investigate the acute vascular and oxygenation responses to repeated sprint exercise during arm cycling with either blood flow restriction (BFR) or systemic hypoxia alone or in combination.DesignThe study design was a single-blinded repeated-measures assessment of four conditions with two levels of normobaric hypoxia (400 m and 3800 m) and two levels of BFR (0% and 45% of total occlusion).MethodsSixteen active participants (eleven men and five women; mean ± SD; 26.4 ± 4.0 years old; 73.8 ± 9.8 kg; 1.79 ± 0.07 m) completed 5 sessions (1 familiarization, 4 conditions). During each test visit, participants performed a repeated sprint arm cycling test to exhaustion (10 s maximal sprints with 20 s recovery until exhaustion) to measure power output, metabolic equivalents, blood flow, as well as oxygenation (near-infrared spectroscopy) of the biceps brachii muscle tissue.ResultsRepeated sprint performance was decreased with both BFR and systemic hypoxia conditions. Greater changes between minimum-maximum of sprints in total hemoglobin concentration (Δ[tHb]) were demonstrated with BFR (400 m, 45% and 3800 m, 45%) than without (400 m, 0% and 3800 m, 0%) (p < 0.001 for both). Additionally, delta tissue saturation index (ΔTSI) decreased more with both BFR conditions than without (p < 0.001 for both). The absolute maximum TSI was progressively reduced with both BFR and systemic hypoxia (p < 0.001).ConclusionsBy combining high-intensity, repeated sprint exercise with BFR and/or systemic hypoxia, there is a robust stimulus detected by increased changes in blood perfusion placed on specific vascular mechanisms, which were more prominent in BFR conditions.     

女飞行学员高空缺氧耐力的实验研究

观察男女飞行学员5000m缺氧的生理反应，旨在从高空缺氧耐力方面探讨我国女性从事歼击机飞行的可能性。以20名男性战斗机高教机飞行学员（21－23岁）和22名女飞行学员（21－23岁）为研究对象。采用DY－84型混氧仪，受受试者吸入10.5%低氧混合气持续15min，模拟高空5000m缺氧耐力检查。在模拟5000缺氧环境中，男女飞行员的心电图、心率、血氧饱和度差异无显著性意义（P＞0.05)，而血压变化差异有显著性意义（P＜0.05)。从缺氧耐力上讲，中国飞行学员可以从事战斗机飞行。     

增氧呼吸器对严重急性低压缺氧的防护作用及氧自由基的影响

目的 探索增氧呼吸器对严重急性低压缺氧的防护作用及氧自由基的影响.方法 30只雄性新西兰大白兔随机分为3组,对照组(Con)暴露在海拔400 m(西安市的平均海拔高度)不佩戴增氧呼吸器;急性低压缺氧组(H)暴露在模拟海拔8 500 m环境180 min,不佩戴增氧呼吸器;急性低压缺氧呼吸器防护组(P)暴露在模拟海拔8 500 m环境180 min,佩戴增氧呼吸器.各组动物均于进舱时、气压降至海拔8500 m即刻、30、60、120、180 min抽取动脉血0.5 mL进行实时血气分析,并于实验结束时抽取动脉血2mL进行超氧化物歧化酶(SOD)活性和丙二醛含量(MDA)测定.结果 H组各时间点PaO2、SaO2及终点SOD活性均低于Con组,P组则均高于H组,两组血气均于8 500 m 30 min时降至最低.血清MDA浓度H组显著高于Con组,P组显著低于H组,各组间比较均P＜0.001.结论 佩戴增氧呼吸器能提高严重急性低压缺氧时PaO2、SaO2及SOD活性,从而在一定程度上防护缺氧所致的自由基损害.     

急性轻中度缺氧条件下心率及收缩压变异性谱变化

目的：应用心率及收缩压变异性（HRV、SBPV）谱分析方法评价急性轻中度缺氧条件下心血管自主神经调节的变化。方法：10名健康男性青年分别吸入氧13．7％（相当于海拔3500m)和11％（相当于海拔5000m）两种氮－氧混合气各20min,将对照和缺氧条件下的HRV和SBPV谱变化进行对比分析。结果：在两种缺氧条件下,受试者均出现血压下降、心率增快反应,HRV谱总功率（TP）和高频成分（HF）功率均显著减小,低频成分（LF）功率与LF／HF功率比值无显著变化,SBPV谱LF功率显著增大,3名缺氧耐力不良受试者尤为明显。不同水平缺氧之间的数值比较差异均无显著性意义。结论：急性轻中度缺氧条件下,人副交感神经抑制,交感神经兴奋,联合应用HRV与SBPV谱分析方法可对心血管自主神经调节活动进行评定;但HRV的LF成分变化机理较为复杂。     

高原缺氧对正常人血浆心钠素的影响

目的 :心钠素是近年来发现从心脏分泌的一种新激素 ,具有强大的利尿、排钠、扩张血管作用。本文观察高原缺氧对人体心钠素含量水平的影响。方法 :血液标本分别取自三个不同海拔地区正常人的空腹静脉血 ,北京地区 (海拔 31m) ;青海省西宁市地区 (海拔 2 2 6 0m) ;青海省果洛州 (海拔 3719m) ;用直接放免法测定血浆中心钠素的含量。结果 :低海拔组 (北京地区 )正常人血浆心钠素含量明显低于中等海拔组 (西宁地区 )及高海拔组 (果洛地区 )正常人 ;其 (P <0 .0 0 1)。结论 :不同海拔高度对正常人体血浆心钠素水平有一定的影响 ,缺氧可能是不同海拔正常人血浆心钠素水平发生的主要原因     

The effects of chronic hypoxia on human auditory system sensitivity.

We have examined the effects of prolonged periods of hypoxia produced at high altitudes on the latency of the auditory brain-stem evoked response (ABER) in 9 subjects at around sea level, 3,500 m, and 4,370 m. Following an ascent from 1,300 m to 3,500 m over 24 h, the mean blood O2 saturation fell to 86.5 +/- 1.2% (+/- S.E.M.) and was associated with a mean prolongation of latency of wave V of the ABER of 0.34 +/- 0.10 ms (p = 0.011 two-tailed paired t-test). Using the stimulus-level/response latency relation determined at around sea-level for each subject, this prolongation of wave V corresponded to a mean reduction in sensitivity of 9.1 dB +/- 1.6 dB. Over a period of 72 h, blood O2 saturation improved slightly (mean 88.1% +/- 1.8%) and mean wave V latency returned to control values. A second rapid ascent to 4,370 m reduced blood O2 to below prerecovery levels (82.5% +/- 1.7%), but in this case there were no significant changes in auditory sensitivity (p = 0.79 two-tailed paired t-test). These data show that mild hypoxia results in an initial decrease in auditory sensitivity. However, the recovery of sensitivity with more prolonged exposure suggests that the auditory system can compensate for chronic mild hypoxia.     

乏氧组织显像剂99Tcm-DTPA-甲硝唑的制备和荷瘤动物实验研究

目的　进行新型乏氧组织显像剂DTPA 甲硝唑的化学合成、药盒制备、99Tcm 标记、质量控制以及药理研究。方法　合成的DTPA 甲硝唑用氯化亚锡作还原剂 ,99Tcm 标记 ,用多元正交法确立99Tcm 标记一步法药盒的最佳配方。纸层析法鉴定99Tcm DTPA 甲硝唑的标记率、标记稳定性 ,完成了H2 2肝癌小鼠体内生物分布实验及显像研究。结果　DTPA 甲硝唑一步法药盒与99TcmO-4 混合 ,沸水浴反应 10min ,放化纯度大于 99%。H2 2肝癌小鼠生物分布显示 ,肿瘤 /血液比值 1、2h分别为3 43、6 40 ,肿瘤 /肌肉比值 1、2h分别为 5 2 4、7 42 ;注射血管舒张药肼苯哒嗪组肿瘤组织摄取明显高于对照组 (P <0 0 1)。结论　研制的99Tcm DTPA 甲硝唑有望成为一种新型的肿瘤乏氧组织显像剂。     

Intermittent hypobaric hypoxia induces altitude acclimation and improves the lactate threshold

The physiological responses to short-term intermittent exposure to hypoxia in a hypobaric chamber were evaluated. The exposure to hypoxia was compatible with normal daily activity. The ability of the hypoxia program to induce hematological and ventilatory adaptations leading to altitude acclimation and to improve physical performance capacity was tested. Six members of a high-altitude expedition were exposed to intermittent hypoxia and low-intensity exercise (in cycle-ergometer) in the INEFC-UB hypobaric chamber over 17 d, 3-5 h x d(-1), at simulated altitude of 4,000 m to 5,500 m. Following this hypoxia exposure program, significant increases were found in packed cell volume (41 to 44.6%; p<0.05), red blood cells count (4.607 to 4.968 10(6) cells x microL(-1); p<0.05), and hemoglobin concentration (14.8 to 16.4 g x dL(-1); p<0.05), thus implying an increase in the blood oxygen transport capacity. Significant differences in exercise blood lactate kinetics and heart rate were also observed. The lactate vs. exercise load curve shifted to the right and heart rate decreased, thus indicating an improvement of aerobic endurance. These results were associated with a significant increase in the ventilatory anaerobic threshold (p<0.05). Significant increases (p<0.05) in pulmonary ventilation, tidal volume, respiratory frequency, O2 uptake, CO2 output and ventilatory equivalents to oxygen (VE/Vo2) and carbon dioxide (VE/co2) were observed at the ventilatory threshold and within the transitional zone of the curves. We conclude that short-term intermittent exposure to moderate hypoxia, in combination with low-intensity exercise in a hypobaric chamber, is sufficient to improve aerobic capacity and to induce altitude acclimation.     

高脂饮食大鼠高住高练模型的建立

目的:建立高脂饮食致肥胖大鼠的高住高练0～4周动物模型,观察高住高练对肥胖大鼠的时序性影响。方法:出生21天离乳SD雄性大鼠280只,体重(42.7±4.7)g,随机选20只普通饲料喂养,其余260只高脂饲料喂养,自由饮食饮水。饲养10周后,随机选取普通饮食大鼠和高脂饮食大鼠各10只,称重、量身长,计算体重指数;取肾周和附睾脂肪垫称重计算脂体比;取血测血脂;从体重、体脂和血脂角度验证肥胖与否。验证肥胖后从高脂饮食组挑选出160只肥胖大鼠,进行适应性训练,确定常氧下训练强度为26 m/min。根据适应训练的情况保留130只大鼠进行正式实验,分成对照组,低住低练1、2、3、4周组,低氧安静1、2、3、4周组,高住高练1、2、3、4周组,保证各组间大鼠体重无显著性差异。用水平动物跑台进行耐力训练,持续运动1 h/d,6 d/w,1～4 w。低氧氧浓度为13.6%(约相当于3500 m高度)。根据血乳酸确定低氧下训练强度。结果:饲养10周后,普通饮食大鼠体重(425.1±54.2g)和身长(24.0±1.3cm)均显著(P<0.05)高于高脂饮食大鼠(362.7±37.9 g;22.3±0.7 cm),两组大鼠肾周脂肪和附睾脂肪重绝对值之间无显著差异,高脂饮食大鼠体重指数(320.39±13.55)和脂体比(0.99±0.15)%均高于普通饮食组(305.48±11.49,0.61%±0.29%),且具有显著性(P<0.05)和高度显著性(P<0.01)差异。高脂饮食大鼠胆固醇(1.91±0.26 mmol/L)、甘油三酯(0.59±0.25mmol/L)水平显著性(P<0.05)和高度显著性(P<0.01)高于普通饮食组(1.58±0.21 mmol/L、0.40±0.14 mmol/L),高脂饮食组大鼠低密度脂蛋白(0.20±0.04 mmol/L)与普通饮食组大鼠(0.15±0.03mmol/L)比较,高度显著性升高(P<0.01)。常氧26 m/min与低氧21 m/min运动后大鼠血乳酸较为接近。结论:(1)高脂饮食大鼠具有体脂比例、大鼠体重指数和血脂代谢紊乱的多重表现,可视为肥胖造模成功。(2)常氧下25～26 m/min的训练强度和13.6%低氧下20～21 m/min的训练强度相对于高脂饮食大鼠的代谢反应来说是相同的。     

Reaction of respiration neurons in the medulla on locus coeruleus irritation by hypoxia]

Effects of locus coeruleus (LC) stimulation on the impulse activity of bulbar respiration neurons in rats were studied on a background of varying hypoxia. Different levels of hypoxia were used as an experiment model for ensuing summation of the LC effect. At the normal atmospheric pressure, LC electrical stimulation had an alleviating and also inhibiting effect on the impulse activity of these medulla neurons; however, the former effect was dominant. During the initial hypoxia simulating the altitude of 4000-5000 m, LC stimulation had a weak alleviating effect. On this level of hypoxia such effect is highly important, as unchecked strengthening of respiration activating mechanisms may result in excessive hyperventilation and consequent respiration slowing down to standstill because of low blood content of carbonic acid. During heavy hypoxia simulating the altitude of 7500-8000 m LC electrical stimulation had an intrinsic to this structure activating effect on markedly inhibited respiratory neurons. In the event of acute hypoxia the highly sensitive cortical component lose their inhibitory effect on the bulbar respiratory center and suprabulbary formations. However, this favours startup of the activating systems and enhancement of the respiration ventilatory function.     

高原高空及坑洞施工现场长管道吸氧效果研究

目的:研究分析高原高空及坑洞内施工现场长管道吸氧的效果。方法:在海拔约3 600、4 200、4 800 m的施工现场,各随机选取高原高空及坑洞作业者40名(高空及坑洞作业者各20名),吸氧前先测血氧饱和度3次,计算出平均值,再用50 m长管道,连接40 L氧气瓶以10、5、2.5 MPa压力,4 L/min的氧流量吸氧3 min后测量血氧饱和度3次,每次间隔1 min,计算出平均值,并进行对比分析。结果:在高原不同海拔高度的高空及坑洞内用长管道、以不同供氧压力、相同氧流量吸氧后血氧饱和度都显著提高,有统计学意义(P<0.01)。结论:高原高空及坑洞内施工现场长管道吸氧能显著提高血氧饱和度,改善缺氧,是解决高原高空及坑洞内作业缺氧的一种简单、易行、安全、有效的方法。     

模拟飞行缺氧与吸氧对小鼠脏器自由基代谢的影响

目的 观察了两种模拟飞行条件（１５００ｍ轻度低压缺氧和５５００ｍ中度低压吸氧重复暴露下小鼠多脏器自由基代谢变化的特点。方法 昆明种小鼠６０只,随机分为６组（ｎ＝１０）进行缺氧与吸氧实验,实验完毕后,取小鼠尾血做血常规检查。次日,将小鼠断头处死,取脑、心、肺、肝、肾制备匀浆,测定丙二醛（ＭＤＡ）含量和超氧化物歧化酶（ＳＯＤ）活性。结果 １５００ｍ轻度低压缺氧重复暴露８ｗｋ使肺ＭＤＡ含量显著增高,提示     

Reduced systolic blood pressure elevations during maximum exercise at simulated altitudes

Ten healthy female subjects performed maximum exercise on a bicycle in an altitude chamber during normoxia and hypobaric hypoxia simulating altitudes of 2,450, 3,700 and 4,600 m. The increases in systolic blood pressure responses were reduced with the degree of hypobaric hypoxia, whereas heart rate and diastolic pressure responses were unchanged. The increases in blood levels of aldosterone, plasma renin activity, adrenaline, noradrenaline, neuropeptide-Y and vasoactive intestinal peptide were similar at the different simulated altitudes. Angiotensin-converting enzyme and vasoactive intestinal peptide levels were not affected by hypoxia or maximum exercise. The present results suggest that the decreases in systolic blood pressure responses during hypobaric hypoxia could not be explained by altered responses of the measured vasoactive substances from the renin-angiotensin, gastrointestinal, and autonomic nervous systems.