1、 不同因素对家兔血压的影响实验原理动脉血压主要受心输出量和外周阻力的影响。动脉血压的高低是衡量心血管活动的重要指标。正常情况下，机体的动脉血压保持相对恒定。这种恒定是通过神经体液调节实现的。神经调节主要是心血管反射，其中最重要的是颈动脉窦和主动脉弓压力感受性反射。体液调节最主要的是儿茶酚胺类激素（如肾上腺素和去甲肾上腺素） 。Arterial blood pressure is mainly influenced by cardiac output and peripheral resistance.The discretion of the arterial blood pressure i
2、s the important indicators of cardiovascular events.Under normal circumstances, the bodys arterial blood pressure remained relatively constant.This constant is achieved by neurohumoral regulation.Neuromodulation mainly cardiovascular reflex, one of the most important is the carotid sinus and aortic
3、arch baroreceptor reflex.Humoral regulation is the most important of catecholamine hormone (e.g., epinephrine and norepinephrine).1. 加入去甲肾上腺素后，观察到平均动脉压抬高，心率减慢。这是因为：去甲肾上腺素主要与 受体结合，也可与心肌 1 受体结合，但与血管平滑肌的 2 受体结合的能力较弱。通过 受体的激动，可引起血管极度收缩，使血压升高，冠状动脉血流增加；通过 受体的激动，使心肌收缩加强，心排出量增加。总的来说其作用是使外周大多数血管收缩，外周阻力明显增大，动
4、脉血压明显升高。同时，去甲肾上腺素可作用于心肌 1 受体而使心跳加快加强，但在整体内由于它使动脉血压明显升高，通过降压反射增强而引起心率减慢。 use: norepinephrineMain and alpha receptors, can also be combined with myocardial beta 1 receptor, but the ability to combine the beta 2 receptor and vascular smooth muscle.Excited by alpha receptors, can cause vascular contract
5、ion, blood pressure, coronary blood flow increased;Excited by beta receptors, to reinforce the myocardial contraction and cardiac output increase.Overall its role is to make the most peripheral vasoconstriction, peripheral resistance increases obviously, arterial blood pressure increased significant
6、ly.At the same time, can be applied to norepinephrine myocardial beta 1 receptor and make the heart beat faster to strengthen, but within the overall because it makes the arterial blood pressure increased significantly, caused by depressor reflex slow heart beat.3.2. 加入乙酰胆碱后，观察到心率变慢，平均动脉压下降。这是因为：外源乙
7、酰胆碱作用于血管内皮细胞膜上的 M 受体，引起血管的舒张。 Ach 能使 cAMP 浓度降低，心率减慢，心房收缩力减弱，传导性减弱。心率变慢则流向外周的血量变多，舒张压更低。心房收缩力减弱则收缩压也有下降。平均动脉压降低。但是因为血回心时间变长，因此，回心血量较多，脉压增加。而大多数血管没有 Ach 受体，Ach 对外周阻力影响不大。 On the vascular endothelial cell membrane of M receptor, causing vascular relaxation.Ach can lower the concentration cAMP, the hear
8、t rate slows, atrial contraction force is abate, the conductivity decreased.Heart rate slow moving peripheral blood more, diastolic pressure is lower.Atrial contraction force decreased systolic blood pressure has dropped.Mean arterial pressure decreased.But because blood change time, therefore, the
9、change of blood is more, increased pulse pressure.While most of the blood vessels without Ach receptors, Ach foreign weeks impact resistance.3.3. 夹闭一侧颈总动脉 20s 后，观察到兔动脉血压升高的现象。夹闭颈动脉后，远心端的颈动脉窦张力感受器感受到血压下降，传出神经冲动的频率减慢。使心迷走紧张减弱，心交感和心缩血管紧张加强，作用于心脏，使心率加快，心输出量增加，血管收缩，血管外周阻力增加，从而血压恢复性升高。若血压下降过大，交感缩血管紧张还会扩展到
10、静脉系统，是静脉收缩，促进血液回心，使每博输出量增加。 clipped carotid artery, the carotid sinus on telecentric tension sensor feel blood pressure dropped, the frequency of the efferent nerve impulses slow down.Make heart vagus tension abate, cardiac sympathetic and heart blood vessels was tense, ACTS on the heart, heart rate
11、, increased cardiac output, vasoconstriction, blood vessels increase peripheral resistance, and elevated blood pressure recovery.If a drop in blood pressure is too large, the sympathetic vascular tension will also extend to the venous system, is the vein contraction, promote blood change, to make ev
12、ery Po output increase.3.4. 牵拉一侧颈总动脉，血压下降，这是由于颈动脉张力感受器在松开动脉夹时感受到血压突然增大，传出神经冲动的频率增强，信息传到心血管中枢，使心迷走紧张增强，心迷走神经兴奋时，其末梢释放乙酰胆碱，乙酰胆碱与心肌细胞膜上的 M 受体结合，引起心脏负性的变时变力变传导作用及血管的舒张，血管外周阻力减小，从而血压降低。Pull one side of common carotid artery ,drop in blood pressure, back to normal.This is due to the tension of the carotid
13、 arteryTo loosen the artery clamp feel blood pressure suddenly increases, the efferent nerve impulse frequency increases, the information to the cardiovascular center, heart vagus tension, enhance heart vagus nerve excitement, its peripheral release acetylcholine, acetylcholine and myocardial M rece
14、ptors on the cell membrane, causes the heart Negative time-varying force transmission and the diastolic blood vessels, vascular peripheral resistance reduced, thereby reducing blood pressure.3.5. 刺激完整减压神经及其中枢端均可引起血压下降，而刺激该神经外周端基本不变。证明了兔减压神经是传入神经，其作用是将主动脉弓感受器发出的冲动传入延髓心血管中枢，反射性引起血压降低。因此，刺激完整的减压神经或其中枢端
15、，使传入中枢的冲动增加，致血压明显下降，而刺激其外周端虽又冲动传向外周，但不会引起血压变化。 Clear rabbit depressor nerve; depressor afferent nerve, its effect is aortic arch impulse from the receptor into the medulla oblongata cardiovascular center, reflective lead to lower blood pressure.Therefore, stimulate the complete decompression of nerv
16、e or its central, increase the centre of the impulse, to significantly lower blood pressure, and stimulate Zhou Duan is outside its impulse to peripheral, but does not cause the blood pressure changes.3.6. 刺激迷走神经和迷走神经外周端都能引起明显的减压反应，而刺激迷走中枢端则没有减压反应，只是血压稍有轻微抬升变化。证明迷走神经是传出神经。心迷走神兴奋时，其末梢释放乙酰胆碱，乙酰胆碱与心肌细胞
17、膜上的 M 受体结合，引起心脏负性的变时变力变传导作用及血管的舒张。同时，迷走神经中含有从延髓下行的传出纤维，通向心脏。节前纤维末端释放 Ach,节后纤维末端释放 Ach,属于副交感神经纤维，能使 cAMP 浓度降低，心率减慢，心房收缩力减弱，传导性减弱。从而使心输出量变小，平均动脉压降低。此外，还有主动脉体化学感受器的上行纤维在迷走神经中并行，化学感受器受刺激的效应是血压升高。所以，刺激迷走中枢不能引起减压反应，却可以使血压轻微抬高。 Stimulate the vagus nerve and vagus nerve Zhou Duan can cause obvious stress re
18、action, no stress reaction and stimulate the vagus central end, is only slightly raised blood pressure changes.Proved vagal efferent nerve.Cardiac vagus god when excited them to release the acetylcholine endings, acetylcholine and myocardial M receptors on the cell membrane, causing heart negative c
19、hange time varying force conduction of diastolic function and blood vessels.At the same time, the vagus nerve contains the medulla oblongata downward efferent fibers, to the heart.First, release the Ach end of the fibre after fiber end release Ach, belong to the parasympathetic nerve fiber, can lowe
20、r the concentration cAMP, the heart rate slows, atrial contraction force is abate, the conductivity decreased.So that the cardiac output quantity is small, mean arterial pressure decreased.In addition, there are aortic body chemoreceptor upward fibers in the vagus nerve in parallel, chemical sensors by stimulating effect is increased blood pressure.So, stimulate the vagus central cannot cause stress reaction, can make blood pressure slightly raised.
