Chapter 1 Introduction

1. What are the biological levels of physiology investigate?

(1) Cell and Molecular level

(2) Organ and system level

(3) Integral level

2. What is the internal environment in the body?

Most cells in human body soak in the extracellular fluid, which contains the ions and nutrients needed by the cells to maintain life. Thus the extracellular fluid is also called the internal environment of the body.

3. What is homeostasis of the internal environment?

The stable state of the physical and chemical properties of the internal environment is called homeostasis.

4. Please describe the regulatory system(s) of body functions and their characteristics?

(1)Nervous Regulation: The most important regulation way and realize its regulation by nerve reflex. The structure of the reflex is based on reflex arc. The nervous system regulates many muscular and secretory activities of the body. It response fast; acts exactly or locally, last for a short time.

(2)Hormonal Regulation: Regulate the function of body by hormones secreted by cells. The hormonal system regulates many metabolic functions. It response slowly, acts extensively and lasts for a long time.

(3)Autoregulation: Autoregulation is an adaptive response of tissue cells to environmental stimuli that does not depend on nerve or humoral factors. Impact limited.

The coordination of nerve regulation, humoral regulation and autoregulation can make physiological function more perfect.

5. Please describe the feedback control system(s) of body functions?

Key points: From the viewpoint of cybernetics, Body control system can be divided into three types:

(1)non-automatic control system: is rarely seen in physiological function regulation.

(2)Feedback control system: the control part sends out instructions to control the activities of the controlled part, and the

information emitted by the controlled part in turn affects the activity of the control part. Feedback control system is a closed-loop system, and therefore has the ability of automatic control. Feedback control system Feedback control mechanism consists of two forms, according to the effect of feedback information on the control part.:

Negative feedback control: the feedback information sent by the controlled part adjusts the activity of the control part, and finally the activity of the controlled part in the opposite direction. Its primary role is to maintain homeostasis of the internal environment, such as baroreceptor /depressor reflex, etc.

Positive feedback control: the feedback information sent by the controlled part promotes and strengthens the activity of the control part, and finally makes the activity of the controlled part in the same direction as its original activity, make certain physiological activities continuously enhance until complete, such as childbirth.

(3) Feedforward control system: The control part is affected by the correction information (feedforward information) before the feedback information arrives, correct the deviation in time.


2018年09月20日

Functions of the Nervous System-Review Questions with Reference Answers
Chapter 2 Cell-Review Questions with Reference Answers by Dr. Shuwei Jia

上一篇

下一篇

Chapter 1 Introduction of Physiology-Review Questions with Reference Answers by Dr. Shuwei Jia

For 2017 International Medical Students
姓名、学号
内容
邮箱
本网站由阿里云提供云计算及安全服务