CHAPTER 4 CIRCULATION 血液循环

CHAPTER 4 CIRCULATION血液循环 Prof. Wang Ting huai Department of Physiology

SECTION4 REGULATION OF CARDIOVASCULAR ACTIVITY心血管活动的调节

Significance:意义 • To maintain normal blood pressure, blood flow to be relativity constant. 维持正常血压和血流相对恒定 • To redistribute blood supply to different tissues and organs. 在不同的组织和器官重新进行血流分配

Ways of regulation — 调节途径 • Neural control: Cardiovascular reflex 神经调节：心血管反射 • Humoral control：humoral factors 体液调节：体液因素 • Autoregulation: intrinsic regulation 自身调节：内在调节

I. Neural regulation 神经调节(一） Innervation of the heart and the blood vessels心脏和血管的神经支配1. Innervation of the heart心脏的神经支配 dual innervation 双重神经支配 (1) cardiac sympathetic nerve心交感神经(2) cardiac parasympatheticnerve心迷走神经

Cardiac Symp n Cardiac Vagal n IML1-5 Amgiguus N, Dorsal motor N of vagus Preganglionic f Preganglionic f ACh ACh Postganglionic N N receptor Postganglionic f Postganglionic f NE Effects Ach inotropic  receptor chronotropic M receptor dromotropic propranolol Blocker atropine

心交感神经心迷走神经 节前神经元脊髓1～5胸段迷走神经中间外侧柱背核，疑核节前纤维节前纤维 ACh 节后神经元 ACh N型胆碱受体节后纤维节后纤维 NE ACh 效应 β受体变时作用M受体阻断剂：变力作用阻断剂：（心得安）变传导作用（阿托品）

A. Effects of cardiac sympathetic nerve: 心交感神经的作用 Cardiac sympathetic nerve ending → noradrenaline → binds to β- adrenergic receptor→ leads to: 心交感节后神经纤维末梢 → 去甲肾上腺素 → 与β肾上腺素受体结合： positive chronotropic effect 正性变时作用 positive dromotropic effect 正性变传导作用 positive inotropic effect 正性变力作用

Positive chronotropic effect 正性变时作用交感神经兴奋→去甲肾上腺素↑→和β肾上腺素受体结合 →自律细胞4期的跨膜内向电流If↑→ 4期自动除极↑→SN自律性↑，心率↑。

Positive dromotropic effect正性变传导作用 交感N兴奋→ NE与房室交界处细胞β 受体结合 →cAMP ↑ →0期Ca2+内流↑ →AP上升速率, 上升幅度↑ →传导作用↑.

Positive inotropic effect • 正性变力作用交感神经兴奋，释放儿茶酚铵→激活AC →cAMP ↑→ 激活cAMP 依赖性蛋白激酶磷酸化钙通道，↑钙内流，钙诱导钙释放 → ↑肌钙蛋白对的Ca2＋亲和力 →心肌收缩能力↑。

B. Effects of cardiac parasympatheticnerve迷走神经的作用 Vagal nerve ending → ACh → binds to M cholinergic receptor →leads to: 迷走神经末梢 → ACh → 与 M型胆碱能受体结合： negative chronotropic effect 负性变时作用 negative dromotropic effect 负性变传导作用 negative inotropic effect 负性变力作用

Negative chronotropic effect 负性变时作用迷走神经兴奋→Ach ↑→和M型胆碱受体结合→ K＋通道开放速率 ↑ → K＋外流↑ →最大复极电位绝对值↑ ， IK衰减↓ →自动去极化速度↓→SN 自律性↓，心率↓。

Negaitive dromotropic effect负性变传导作用 左侧迷走神经兴奋→Ach ↑ → NOS ↑→ cGMP↑ Ca2+通道开放概率↓→Ca2+内流↓→房室交界0期去极化的速度和幅度↓ →房室传导↓。

Negative inotropic effect 负性变力作用迷走神经兴奋→Ach ↑→结合心肌细胞M 受体→ 平台期Ca2+内流↓ ， Ca2+通道活性 ↓ →胞[Ca2+]i↓→收缩力↓。

Stimulate the left Vagus n: conductivity in A-V node↓. 左侧迷走神经 → 房室结传导性↓Stimulatethe right Vagus n: automaticity in S-A node↓.右侧迷走神经 → 窦房结自律性↓

2. Innervation of blood vessels血管的神经支配(1) Vasoconstriction fiber交感缩血管神经纤维(2) Vasodilator fiber舒血管神经纤维(3)Non-cholinergic, non-adrenergic fiber非肾上腺素能、非胆碱能纤维

(1) Vasoconstriction fiber交感缩血管神经纤维Preganglionic postganglionic neurons neurons IML T1- L2 N receptorcholinergic f.AChadrenergic f NE receptor activated: vasoconstriction  receptor activated: vasodilation

节前神经元节后神经元 IML T1-L2 N受体α 受体 ●——————〈●———————〈★ NE 胆碱能纤维 ACh 肾上腺素能纤维 β 受体和α 受体结合—血管平滑肌收缩和β 受体结合—血管平滑肌舒张

Density of symp vasoconstriction fiber in organs; 交感缩血管神经纤维在器官分布的密度 Skin > Skeletal ，Visceral organs > Coronary vessels，Cerebral vessels. 皮肤＞骨骼肌，内脏＞冠脉，脑血管

Density of sympathetic vasoconstriction fiber in artery vessels: 交感缩血管神经纤维在动脉血管分布密度 arterioles > arteries > venous capacitance vessels > precapillary sphincters 微动脉＞动脉＞静脉容量血管＞毛细血管前括约肌

Sympathetic vasoconstric tone:in resting state, sympathetic vasoconstrictor fiber continue to release 1~3 t/s low frequency impetus. 交感缩血管紧张: 安静状态下,交感缩血管纤维持续发放1~3次/s的低频冲动。

Sympathetic vasoconstrictor vascular tone effect tone ↑ ↑ vasoconstriction ↓ ↓ vasodilation tonic activity : bidirectional regulation

交感缩血管纤维紧张性血管紧张性 效应 ↑ ↑ 血管收缩 ↓ ↓ 血管舒张交感缩血管紧张性活动：双向调节

excitation of sympathetic vasoconstrictor fibers 器官的交感缩血管神经纤维兴奋，引起： 1） Increasing the resistance of blood flow, decreasing the blood flow; 器官的血管阻力↑，血流量↓；

2） the mean pressure of capillary decreases, that is benefit to the interstitial fluid’s flowing to blood. 毛细血管平均压↓，有利于组织液进入血液； 3）Capacitance vessels constrict, increasing the back flow of venous blood. 容量血管收缩，静脉回流量增加。

(2) Vasodilator fiber 舒血管神经纤维 1 ) Sympathetic vasodilator fiber交感舒血管神经纤维 2） Parasympathetic vasodilator fiber 副交感舒血管神经纤维 3）Non-cholinergic, non-adrenergic fiber 非胆碱能纤维、非肾上腺素能纤维

A. Sympathetic vasodilation fiber交感舒血管神经纤维 Sympathetic vasodilation fiber ending → ACh → Vasodilation in skeletal M. 交感舒血管神经纤维末梢 →ACh→骨骼肌血管舒张 No tonic activity; defense reaction. 无紧张性活动；参与防御反应

B. Parasymp. vasodilation fiber 副交感舒血管神经纤维 Innervation of blood vessels in brain, liver, GI tract, external genitals. 支配脑血管，肝脏，胃肠道外分泌腺，外生殖器 transmitter：Ach combined with M receptor,regulate the Local blood flow. 递质Ach与M受体结合，调节局部血流量

C.Non-cholinergic, non-adrenergic fiber 非肾上腺素能、非胆碱能纤维 NO, peptides NO, 肽类物质

(二) Cardiovascular center心血管中枢 1.Cardiovascular center in medulla oblongata 延髓的心血管中枢 After transection between pon and medulla oblongata, BP remains normal. Stimulation of sciatic nerve induces the increase in BP. 在脑桥和延髓之间横切脑干，血压维持正常。此时刺激坐骨神经，血压下降。

After transection at obex in medulla, BP drops to 40 mmHg, no response of BP to stimulation of sciatic nerve. 横断延髓的闩部，血压降到40mmHg，刺激坐骨神经血压不发生变化。 Medulla can maintain normal BP, and is called basal center of cardiovascular activity integration. 延髓可以维持正常血压，属于心血管活动的基本整合中枢。

(1) Rostral ventrolateral medulla(RVLM)延髓头端腹外侧区部（RVLM）(2) Caudal ventrolateral medulla延髓尾端腹外侧部 (CVLM）(3) Nucleus of solitary tract延髓孤束核 (NTS)(4) Cardiac vagal center 心迷走中枢

(1) Rostral ventrolateral medulla (RVLM) 延髓头端腹外侧区的神经元（RVLM） Cardiac sympathetic tone 心交感紧张 Sympathetic vasoconstriction tone 交感缩血管紧张

Stimulation of RVLM→BP ↑, HR ↑. Destruction of RVLM, BP decreases to 40mmHg. 刺激RVLM ，血压 ↑，心率↑，损毁RVLM区，BP降低至40mmHg。 RVLM is very important center in maintain normal BP, it has vasomotor tonity. RVLM是维持正常血压的重要中枢，平时保持一定的血管紧张性活动。

(2) Caudal ventrolateral edulla (CVLM)延髓尾端腹外侧部Receives signals from NTS sends axons to RVLM to inhibit the action of RVLMBP↓HR↓.CVLM接收来自孤束核的直接投射，发出轴突投射到RVLM 抑制后者的活动，导致血压 ↓，心率↓ 。

(3) Nucleus of solitary tract (NTS) 孤束核 Receives signals from arterial baroreceptors and cardiopulmanary receptors sends axons to vagal center and CVLM. 接受来自动脉压力感受器和心肺感受器的传入信号，发出纤维至迷走中枢和CVLM。

(4) Cardiac vagal center 心迷走中枢nucleus ambigus, dorsal motor nucleus of vagus receives axons fom NTS，when excited the cardiac vagal tone ↑ ,HR ↓. 位于迷走神经背核，疑核接受来自孤束核神经元轴突的直接透射，其兴奋后心迷走紧张↑ ，心率↓。

2.Hypothalamus下丘脑 (1)Hypothalamus is higher integrated center of autonomic system, including feeding, regulation of body temperature, fluid balance and endocrine secretion. 下丘脑是自主神经系统的高一级整合中枢，其涉及功能包括摄食，体温调节，体液平衡和内分泌等。

(2). Anterior hypothalamus（AH)下丘脑前部 (AH) AH sends axons directly to SPN of IML in spinal cord.Receives axons of NTS in medulla and plays an important role in arterial baroreflex. Stimulation causes the decrease in BP and HR. AH将轴突直接投射到内侧髓板的节前交感神经元。接受延髓孤束核的轴突投射，在动脉压力感受性反射中起重要作用。刺激AH 可以导致BP和HR↓。

(3)Posterior and lateral hypothalamus下丘脑的后外侧部 Stimulation of defence area cause defensive reaction。 Behavior: Rage, attack reaction or fighting associated with hissing, growling, spitting, piloerection, pupil dilation, biting. 刺激下丘脑后部可引起防御反射，在行为上表现为：愤怒、攻击、战斗，发出嘶嘶声、咆哮、口吐白沫、竖毛肌收缩、瞳孔扩大、撕咬等。

Cardiovascular reactions: 心血管效应： BP ↑, HR ↑, Vasodilation in skeletal muscle and the blood flow increases.Vasoconstriction in skin and splanchnic organs. 心血管效应： BP↑，HR↑，骨骼肌血管舒张，血流量增加，皮肤和内脏血管收缩。

3.Cerebral cortex 大脑皮质 (1) Limbic area regulates the activity of lower centers. 边缘系统调节低级中枢的活动。 (2) Responses of BP to pain, anxiety and during exercise. 调整疼痛，焦虑和运动时的血压反应。

(2) Motor and premotor area causes vasoconstriction of skin, splanchnic and renal vessels, but vasodilation in skeletal muscles. 运动区和运动前区引起皮肤，内脏和肾血管收缩，骨骼肌血管舒张。

（三） Cardiovascular reflex 心血管反射 1.Arterial baroreflexes动脉压力感受性反射2. Cardiopulmonary reflex心肺感受器反射 3. Chemoreceptor reflex化学感受性反射

1. Arterial baroreflexes: 动脉压力感受性反射 Carotid sinus baroreceptor 颈动脉窦压力感受器 Aortic baroreceptor 主动脉弓压力感受器

劲动脉窦和主动脉弓区的压力感受器和化学感受器劲动脉窦和主动脉弓区的压力感受器和化学感受器

CHAPTER 4 CIRCULATION 血液循环