LABORATORY REPORT Activity: Name: Instructor: Date: Twitch Contractions and Summation Predictions Effect of Muscle Fiber Length on Contraction 1. As muscle fiber length increases contraction force decreases Effect of Stimulation Frequency on Contraction 2. As the frequency of stimulation increases, the force of contraction: increases Materials and Methods Measurement of Threshold Stimulus Dependent Variable contraction force Independent Variable stimulation voltage Controlled Variables temperature, frequency of stimulation, muscle fiber length Effect of Muscle Length on Contraction Dependent Variable contraction force Independent Variable muscle fiber length Controlled Variables temperature, stimulation voltage, frequency of stimulation Effect of Stimulation Frequency on Contraction Dependent Variable contraction force Independent Variable frequency of stimulation Controlled Variables temperature, stimulation voltage 4. What structure was stimulated to cause a muscle contraction? The motor unit was stimulated 5.
During arm extension, what type of contraction would the triceps brachii be exhibiting: concentric isotonic contraction, eccentric isotonic contraction, isometric contraction. concentric isotonic contraction 7. As muscle load is increased, which muscle fiber type is recruited first, second, and last? First is the slow oxidative fiber, then is fast oxidative glycolytic fibers, and last is fast glycolytic fibers. 8.
Explain the effect that the flow tube radius change had on flow rate. How well did the results compare with your prediction? The increase of flow tube radius increased the flow rate, as predicted. 3. Describe the effect that radius changes have on the laminar flow of a fluid.
increase See Table 3: Lung Capacities and Minute Ventilation See Graph: Comparison of Resting and Exercising Lung Capacities and Minute Ventilation DISCUSSION 1. Explain the change in ERV with exercise. TV increases with exercise so the ERV decreases too. 2. Explain the change in IRV with exercise.
Experimental Design Focus question: What is the relationship between strain and time? Hypothesis: The more springs added, the mass will vibrate quicker. The more mass added, the longer it will take to vibrate. Vice versa, the more springs taken away, the longer the mass will take to vibrate. The more mass taken away, the quicker it will vibrate.
BIOS 255 Week 4 Lab: #7 Effect of Exercise on Arterial Pressure and Vascular Resistance LABORATORY REPORT Activity 7: Effect of Exercise on Arterial Pressure and Vascular Resistance PREDICTIONS 1. During exercise: MAP will increase 2. During exercise: CO will increase 3: During exercise: SVR will decrease MATERIALS AND METHODS 1. Dependent Variable: heart rate (HR), stroke volume (SV), blood pressure (BP) 2. Independent Variable: level of activity 3.
1 Introduction Acceleration is defined as the rate of change of velocity with respect to time in a given direction. It is a vector quantity that is defined as the rate at which an object changes its velocity [3]. An object is accelerating if it is changing its velocity. The next equations describe velocity and acceleration: a = v/s (1) where v = m/ s (2) where m = distance in meters; s = time in seconds. Since acceleration is a vector quantity it has magnitude and direction [3].
Tidal Volume increases with exercise, which decreases the ERV 2. Explain the change in IRV with exercise. This is the amount of air that can be forcibly inhaled after a normal
A total of 15 oscillations were counted and the time it took to complete those was measured. This was repeated and the average of the two times was taken and divided by the number of oscillations to find the period. The procedure was repeated using masses of 20 g, 30 g, 40 g, 50 g, and 60 g. It was found that as the mass load on the spring increased the period also increased. From the data collected at this point in the experiment, it could be concluded that both period and displacement from the equilibrium position are directly proportional to the mass load on the spring. Following the observation and calculation of the period, the mass load M was plotted against the displacement x with data from the first part of the experiment.
The spring represents the elastic components of the muscle and obeys Hook’s law : F=k*x but in terms of stress the equation turns into : σ=Ε*ε where σ: applied stress, E:Young's Modulus of the material ε: strain. The dashpot represents the viscous components of the muscle and is expressed in differential form by Newton’s law for straight,parallel and uniform flow: σ=η* where η: viscosity and :change of rate of strain (velocity). The important equations that are used in this model are: F=F1+F0 where F0=k0*u and F1=η1*u1=k1*u1’ u=u1+u1’ After long calculations we finally take the differential equation of motion for a standard linear solid: The equation contains F, df/dt ,u ,du/dt functions as well as k0,k1,η constants and is impossible to solve as they are all unknown. For that reason we will use the experimental data from Bobsbooms given paper that will help understand how our functions are supposed to behave during the experiment and thus be able to extract some data and some important initial and boundary conditions, necessary for our model to work. From the Bobsbooms paper ‘Passive transverse mechanical properties of skeletal muscle in compression’ we are supposed to take the ramp and hold data (u versus t graph) and fit it in our model,expecting that our F versus t