Anatomy and physiology 1 lab exercise 11 lab document PDF

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Lab document with information filled out as well as correct answers provided. This is for Anatomy and Physiology 1 lab, not Anatomy and Physiology 2....

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BSC1085L Exercise 11 Muscle Physiology Lab Manual pgs 121-26

1. The student needs to be able to describe the gross and microscopic anatomy of a muscle using the terms: Bone, tendon, epimysium, fascicle, perimysium, muscle fiber, endomysium, myofibril, A band, I band, Z line, H zone, myfilaments, actin, myosin, titan, cross bridges. Watch this video : https://www.youtube.com/watch? v=SCznFaTwTPE and use page 125 in your lab manual to label the parts of this muscle picture: A: Tendon B: Epimysium C: Endomysium D: Muscle Fiber E: Perimysium F: Fascicle G: Perimysium H: Bone

2. Now use page 122 in the lab manual and label the next microscopic muscle parts found in the next picture: myofibril, A band, I band, Z disc, M Line H zone, myfilaments, actin, myosin, titan, cross bridges. After filling out those pictures, watch this video on how they operate: https://www.youtube.com/watch?v=GrHsiHazpsw

2 The student needs to know the following anatomical parts of a motor unit: motor neuron, cell body, axon, axon terminal, synapse, muscle fibers. Memorize those parts on this picture.

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Give a written description of these physiological concepts: motor unit recruitment, threshold, graded response, summation, incomplete tetanus, complete tetanus. Motor Unit Recruitment- the activation of additional motor units Threshold-the minimum strength required for stimuli to make a response Graded response-allows variation in muscle tension Summation- successive stimuli are added together to produce a stronger contraction. Incomplete tetanus-frequency permits partial relaxing of muscle between stimuli. Complete tetanus- frequency prohibits any relaxation between stimuli 4. Define: Aponeurosis- sheet of pearly white fibrous tissue that takes the place of a tendon in flat muscles having a wide area of attachment Agonist- movement is the muscle(s) that provides the major force to complete the movement Antagonist- a muscle that opposes the action of another Synergist- muscles perform, or help perform, the same set of joint motion as the agonists Fixator- A muscle that serves as a stabilizer of one part of the body during movement of another part

fascia 5. Identify parts 1-4 of Neuromuscular junction. Use figure 11.4 in your lab manual to help with this labelling. 1. Axon terminal 2. Ach 3. Motor end plate. 4. Synaptic cleft.

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Students will explore the previous concepts using a computer simulation. At the completion of the simulation, there will be a data chart to fill out and a series of questions. Print out the chart, questions and answers and put them in the dropbox MUSCLE STIMULATION How does increased workload affect a skeletal muscle's threshold of stimulation? Go to: http://www.mhhe.com/biosci/genbio/virtual_labs_2K8/labs/BL_13/index.html Click on “laboratory exercise”. Read the information in the INFORMATION box. Close the window when you are finished. You can reopen this information later by clicking the “information” button found at the bottom of the laboratory area. The left side of the page contains background information and instructions in the “Question” area. On the bottom of the page are the following icons for your use: “Journal”, “Calculator” (working calculator function), “Data Table” (where you may be submitting your collected data from the exercise), “Audio” (turns sound on/off) and “Print” (prints the screen).However, the your data and analysis will be recorded on paper. Read the background information found under the “Question” area first, and then continue on to reading the procedure information posted there as well. The procedure is also described below. PROCEDURE:In this exercise, you will use an oscilloscope to examine the effect of varying load (weight) on frog skeletal muscle action.To begin, click on the pull down menu of the “Muscle” button to select the type of muscle you would first like to test. Making sure that the oscilloscope is set to “0V”, click the “Apply Stimulus” button. As you do so, pay close attention to the trace readout on the screen; you are looking specifically for a spike in the straight line to be produced. If no spike is observed, use the upward pointing arrow on the oscilloscope to increase the voltage to the next highest level and then click “Apply Stimulus”. Keep repeating this procedure until you observe the production of a spike in the oscilloscope trace readout. At that point, note the voltage in the “0g” load weight in your “Data Table” and/or in Table I below. NOTE: If no spike is observed, be sure to click “Apply Stimulus” at least 3 times to make sure the muscle received the stimulus properly. When you are through, you will then need to repeat the above steps using the varying loads (weights). To do so, drag the 5g weight to the hook attached to the frog muscle and then proceed as you did to test the muscle action before. When you are through testing the 5g weight, repeat these steps using each of the four remaining loads. When you are completely finished testing all variables for the muscle type selected, you will need to repeat this procedure for ALL three remaining muscle types. Remember, you can always click the “Reset” button to clear your experiment and start fresh. Be sure to appropriately note all of your data in the “Data Table” or Table I below. Please finish this exercise by answering the following questions.

LAB: MUSCLE STIMULATION Fill out this chart as you complete the lab simulation How does increased workload affect a skeletal muscle's threshold of stimulation? Table I: Threshold Stimulus (V)Load Lower Forelimb Upper Forelimb Calf Thigh 0g 2V 3V 5V 6V 5g 3V 4V 5.5V 6.5V 10g 4V 5V 6V 7V 20g None 7V 7V 8V 40g None None 8V 9V 80g None None None 10V

POST LAB: 1. In skeletal muscle:___A__ a.The greater the number of muscle fibers responding to a stimulus, the greater the strength of the contraction b.the fewer the number of muscle fibers responding to a stimulus, the greater the strength of the contraction c.the actual number of muscle fibers responding to a stimulus has no effect on the strength of the contraction 4.An oscilloscope:__C___ a.Provides stimulus to a tested muscle b.Adds weight (load) to a tested muscle c.Measures a twitch response of a tested muscle d.A and C e.All of the above 5.At the point of muscle overload:___C__ a.Skeletal muscle contracts steadily (tetany) b.Skeletal muscle contracts and relaxes repeatedly c.Skeletal muscle does not contract at all 6.A skeletal muscle’s “threshold of stimulation”:__A___ a.Is determined by the lowest voltage stimulus needed to elicit a muscle twitch b.Varies with muscle type c.Is not altered by the application of muscle load d.B and C 7.In response to a stimulus, skeletal muscle fibers:__C___ a.Always contract to 25% of their potential ability b.Always contract to 50% of their potential ability c.Always contract 100% of their potential ability d.None of the above 8.Based upon your experimental data, which muscle type exhibited the lowest __A___Threshold of stimulation in all conditions tested? a.Lower forelimb muscle b.Upper forelimb muscle c.Calf muscle d.Thigh muscle 9.Based upon your experimental data, which muscle type(s) did not reach the __D___point of muscle overload? a.Lower forelimb muscle b.Upper forelimb muscle c.Calf muscle d.Thigh muscle 10.Based upon your experimental data, which muscle tested appears most capable __D___to provide the contraction strength needed for a frog to jump? a.Lower forelimb muscle b.Upper forelimb muscle c.Calf muscle d.Thigh muscle...