Introduction to. Experimental Physiology

Transcription

1 Introduction to Experimental Physiology Experimental Physiology 1. The Purposes of Experimental Physiology 1) Develop students operational skills and ability to write experimental reports. 2) Develop students scientific thinking and ability to ask questions, to analyze problems and to solve problems. 3) Develop students attitude to practical work, normal operational methods, and cooperation based on the division of labor. At the end of the experimental class, students should be able to: (1) Understand the measurement of basic physiological indices; (2) Perform physiological experiments and possess the essential surgical techniques required; (3) Understand the essential techniques of electrophysiology; (4) Analyze experimental results and write experimental reports independently; (5) Understand the general principles and methods of design of physiological experiments. Assessment: emphasis overall performance, which includes attendance, all experiments, the reports. 2. Class Requirements 1) Students should prepare sufficiently before each experiment, by carefully reading the experimental guide, understanding the basic principles and methods, reviewing the relevant anatomy and physiology, and anticipating the results and problems. This is important: avoid blindly following instructions; ensure the experimental class is used for high-quality learning. 2) During experiments, everyone must observe the lab rules, minimal noise, concentrate on the experiment (NO FOOD, NO CELLPHONE). 3) Save the experimental materials. 4) All animals used are provided by the teacher. 5) A single student in each group is responsible for borrowing and returning experimental apparatus. Divide the labor within the group, work seriously and efficiently, observe carefully, record in time and accurately. Tidy up the raw recordings, write the report, and hand it in. 6) After every experiment, each group should clean the experimental bench and return the experimental apparatus. 7) Deposit all dead animals in the assigned place. The assigned group on duty cleans the lab. 1

2 8) Everyone should value the opportunity to carry out experiments and ensure the quality of the results. 9) It is absolutely forbidden to abuse the animals or the apparatus. 3. Experimental Objective: The toad, the rabbit, and the person. 4. Understanding Surgical Instruments and Surgical Methods. (1) Scalpel and blade. the grasp and hold type the bow type the written type the anti-pick type (2) Scissors (straight, curved) Divided into General Scissors, the Tissue Scissors and the Eye Scissors. 2

3 (3) Hemostat or Clamp (straight, curved) Used mainly for clamping blood vessels at the site of bleeding. correct wrong (4) Forceps 1)Toothed Forceps; 2) Eye Forceps (5) Other instruments will be introduced as needed. Frog surgical instruments include pithing probe, general scissors, eye scissors, hemostat or clamp, glass hook, frog board (glass plate), Cu-Zn stimulator, and heart clip. Mammal surgical instruments usually include general scissors, eye scissors, scalpel, hemostat, forceps and eye forceps. 5. Transducers A transducer is an electronic device that converts energy from one form to another. 1) Pressure transducer A pressure transducer converts pressure into an analog electrical signal. Although there are various types of pressure transducers, one of the most common is strain-gage based. The conversion of pressure into an electrical signal is achieved by the physical deformation of strain gages which are bonded into the diaphragm of the pressure transducer and wired into a Wheatstone bridge configuration. Pressure applied to the transducer produces a deflection of the diaphragm which introduces strain to the gages. The strain produces an electrical resistance change proportional to the pressure. 2) Force transducer Force transducer provides an output proportional to the force 3

4 applied. 6. Writing Experimental Reports The experimental reports describes the work done by the experimenter and recreates the experiment, the results, and their meaning. It is one of the important dimensions for assessing the comprehension of the students and measures their abilities. It is also an initial exercise in writing that will be useful in writing scientific papers later. (1) General requirements Use the required report format. Complete each item and mark clearly your name and number. Record the date of the experiment. Leave a space for the signature of the teacher. Please stick to the standard format, provide accurate charts, use legible handwriting or type, and hand the report in on time. (2) Basic format and the writing method Some physiological experiments emphasize surgical methods such as the nerve-muscle preparation; others emphasize measurement of a phenomenon such as gastrointestinal motility; while some lay particular emphasis on the results and analyses, such as the influence of factors on urine formation. Most experiments include all three dimensions. The general experimental report format: Name: Number: Class: Year: Date: Score: Title 1. Purpose 2. Principle 3. Objective 4. Apparatus (list) 5. Methods and Procedures (outline) 6. Results (detailed) 7. Discussion (detailed) 8. Conclusions 4

5 Data Acquisition System Experimental Physiology Data Acquisition System: The RM6240 multi-channel physiological recording and processing system is used in most experiments. 1. General Introduction The RM6240 multi-channel physiological recording and processing system combines software-controlled setting of parameters, extensive signal conditioning options, variable sampling speeds and powerful real-time computations with the advantages of computer-based data display and analysis. It offers the functionality of a chart recorder, XYT plotter, digital voltmeter and storage oscilloscope in one compact unit. Versatile display options and analysis functions are complemented by the ability to export data to other software (such as Microsoft Excel). The RM6240 is a high-performance data acquisition system suitable for a wide range of research applications that require up to 4 input channels. Typical applications include human and animal physiology, pharmacology, neurophysiology, biology, zoology, biochemistry, and biomedical engineering. The unit is capable of recording at speeds of up to 400,000 samples per second continuously to disk, and is compatible with instruments, signal conditioners and transducers. 5

6 2. Working Window All essential controls for recording data are provided within the Chart Application window. Application window Channel 1 Channel 2 Preview Record Pause Stop Amplitude axis Channel 3 Channel separator Channel 4 Data display area Time axis 2) Tool Bar The Tool Bar consists of a row of buttons which provide shortcuts for common tasks. The button functions are displayed if the pointer is held over them. New Save to disk Stimulator 50Hz Notch Filter Help ECG Print 1mV Check Switch Open Zoom View Drop Stimulus Output Display Measuring Information 6

7 3) Data Measurement: After you stop recording, you can use these functions to measure the data and get values. All these values can be output to an EXCEL file. Mobile Measurement Cycle Measurement Derive the Real Time Data Cancel Scribe Line Reginal Measurement Slope Measurement Area measurement Display Measuring Information Conduction Velocity Measurement 4) Hidden function buttons Event marker Close the channel. Channel title Select recording parameter. 7

8 Rate/Time display Sampling Rate 8

9 Range of filter Select filter Alternating Current Direct Current Range/Amplitude display Select a single range 9

10 5) Experiment: There are some ready-made experimental schemes for physiological, pharmacological and pathphysiological experiments. You can select a special experiment from here to start your experiment, because the correct parameters have been preset. If you cannot find the required items, you can use the functions in the create experiment menu to build a new scheme for your own experiment. Ready-made experimental schemes for international students. 5) Save the file when you finish the experiment. Print the results (Excel file, word file or image) if necessary. 10