英文课件－introduction.ppt

Receptor Afferent nerve Nervous center Efferent nerve Effector ② Structural basis of reflex: Reflex arc (反射弧): 五部分缺一不可 ③ The types of reflex: Unconditioned reflex Conditioned reflex (3) The characteristics of neuroregulation * Rapid, accurate and short 迅速、精确而短暂 2. Humoral regulation * (1) Definition: Regulation fulfilled by special chemicals through body fluid. 体内某些特殊化学物质通过体液途径进行调节. (2) Types: Telecrine (远距分泌) Paracrine (旁分泌) Autocrine (自分泌) Neurocrine (神经分泌) Telecrine (远距分泌) Endocrine cells → hormones→ blood → target tissue or target cell 甲状腺激素 Paracrine (旁分泌) Endocrine cells → local chemicals → Interstitial fluid → surrounding target tissue or target cell 生长抑素 Autocrine (自分泌) Endocrine cells → chemicals → Interstitial fluid → themselves Neurocrine (神经分泌) Neurons → neurohormone → blood → target tissue or target cell Neurohumoral regulation Sympathetic preganglionic nerve fibers Acetylcholine (ACh) The adrenal medulla Epinephrine (E) and Norepinephrine (NE) Target cells Neurohumoral regulation (3) The characteristics of humoral regulation * Slow, diffuse and long 缓慢、弥散而持久 (1) Definition: tissue or cell can respond directly to the stimulation, depending neither on nerves nor on humoral factor. 组织细胞不依赖于神经或体液因素，自身对环境变化发生的适应性反应。 3. Autoregulation (3) The characteristics of autoregulation * Amplitude and range are smaller 调节幅度和范围都较小 Ⅱ. The control system in body Constitution Control part Controlled part Classification Feedback (反馈) control system Feed-forward (前馈) control system 1. Feedback control system * Close-loop (闭环) system Control part Controlled part Output variables 比较器 (调定点) 偏差信息 指令 干扰 信息 Monitor 反馈信息 参考信息 (1) Feedback * (反馈) The effect of the controlled part on the control part. (受控部分发出的信息反过来影响控制部分的活动) (2) Types of feedback * Positive feedback 正反馈 Negative feedback 负反馈 ① Positive feedback a. Definition: The feedback signals enhance the effect of the control part. 受控部分发出的反馈信息促进或加强控制部分的活动，最终使受控部分的活动朝着与它原