At a stimulation frequency of 15 Hz how many stimuli were there per second? RESULTS See Table 4: Measurement of Threshold Stimulus See Graph: Effect of Stimulation Value on Twitch Contraction Force 1. What is the threshold stimulus? 2. What is the maximum force generated at the threshold stimulus?
Independent Variable. muscle movement 3. Controlled Variables. total number of motor units present in muscle; subject’s physical condition Recruitment during isometric contractions 1. Dependent Variable.
Each time a cross-bridge from the myosin filament releases from an actin filament energy is used. Therefore, the more muscle tissue you have,and the more you use it, the greater your energy expenditure'which is also caloric expenditure. 5.) Define and describe concentric and eccentric muscle actions. Define motor unit.
Finally I will determine which of these three times intervals account for the exercise induced changes in the R-R interval. During the normal cardiac cycle, there is a sequential contraction of the atria and the ventricles, followed by a period of relaxation as the heart fills with blood. Since these sequential contraction are initiated by an action potential, the action potential must first take place in all atria fibers, and then in all ventricular fibers. This synchronous electrical activity in so many cardiac muscle cells produces currents that can be monitored with electrodes placed on the skin; the resulting recording is called electrocardiogram, or ECG. The human ECG consists of five waves, which are expressed as the P-Wave, the QRS complex, and the T-Wave.
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.
The function of these muscles is closely related to their structure and any differences in structure allow these two types of muscle to be identified. Cardiac and skeletal muscle is excitable tissue where stimulation of a single muscle fibre leads to excitation of a whole cell. They undergo contractions in response to an action potential, either resulting in pumping blood into pulmonary and systemic circulation or the movement of limbs. The contractile unit in both tissues is the same, the differences lie in the arrangement of these units and associate structures. The contractile unit consists of myofibrils which encompass repeating units of sarcomeres running end to end giving a striated appearance to the muscle.
| |[pic] |For movement we require skeletal muscles to contract for force and power production. | | |The intensity and duration of the exercise will determine the type of muscle fibres recruited and | | |the force and frequency of the contraction. | | |Type I muscle fibre: Slow twitch. | | |Type II muscle fibre: Fast twitch. | | |Average person has equal amounts of Type I and Type II.
Distention for many involuntary digestive movements. c. What do ANS neurons regulate with regard to mechanical digestion? What are the possible responses? The ANS neurons regulate involuntary smooth muscular movements. The response is either increased or decreased contraction of the muscularis.
Membrane Transport Proteins 4. What three membrane proteins are required if a membrane is to carry electrical impulses? These proteins are pores, gated channels, and ion pumps. 5. Describe the activity of sodium and potassium ion channels.
• Be sure you know the root words and their meanings • Name and describe the three connective tissue layers found in a muscle: These layers allow parts to move on their own and also provide and area for blood vessels and nerves to move through. o Epimysium: The epimysium closely surrounds skeletal muscles. o Perimysium: This connective tissue divides muscle tissue into little segments. o Endomysium: This is a thin covering that houses bundles of muscle fibers called fascicles. • Define: antagonist, synergist, prime mover o Synergist: a muscle that assists the action of a prime mover o Antagonist: A muscle that act in opposition to a prime mover o Prime Mover: muscle primarily responsible for producing an action • List the various ways that muscles are named.