Muscular System Worksheet Answer Key
What are current recommendations for physical exercise for adults? Chapter 6 the muscular system answers key. Relate physical exercise to cardiovascular disease risk. These fibers do not contribute significantly to the force generated by the muscle. Because of Ohm's Law, a small amount of synaptic current will be sufficient to cause the membrane potential of a small motor neuron to reach firing threshold, while the large motor neuron stays below threshold. Because this low level of the hierarchy takes care of these basic functions, higher levels (such as the motor cortex) can process information related to the planning of movements, the construction of adaptive sequences of movements, and the coordination of whole-body movements, without having to encode the precise details of each muscle contraction.
Chapter 6 The Muscular System Answer Key Strokes
The motor system must generate movements that are adaptive and that accomplish the goals of the organism. How do changes in muscle size affect strength? Even though the motor system is composed of many different types of neurons scattered throughout the CNS, the motor neuron is the only way in which the motor system can communicate with the muscles. Furthermore, if the system were unable to adapt, we would never be able to acquire motor skills, such as playing a piano, hitting a baseball, or performing microsurgery. Because they do not innervate the dynamic nuclear bag fibers, Group II afferents signal information about muscle length only. Physical exercise can reduce risk factors for cardiovascular disease, including hypertension, high levels of "bad" and total cholesterol, and excess body weight. Secondary Parkinson's disease occurs due to some kind of known or suspected cause, such as repeated head trauma or exposure to toxins. It would be hard to do anything else but that one task. Bone (osseous) tissue. They are used when the organism must generate a burst of large amounts of force, such as in an escape mechanism. Can too much physical exercise be harmful? Chapter 6 the muscular system answer key strokes. Some orthopedic problems can be treated with medications, exercises, braces, and other devices, but others may be best treated with surgery (Figure 6. As we age, the distribution of red and yellow bone marrow changes as seen in the figure (Figure 6. Genetic differences in proportions of slow-twitch and fast-twitch skeletal muscle fibres may influence how people respond to physical exercise.
Chapter 6 The Muscular System Answers Key
There are two types of bone marrow: yellow bone marrow and red bone marrow. Suppose your osseous tissue could not store calcium. Because a heavy load is now placed on the biceps, the Ib afferents fire vigorously. Although many of the details are not understood, two broad principles appear to be key concepts toward understanding motor control: - Functional Segregation. Numerous studies suggest that regular aerobic exercise works as well as pharmaceutical antidepressants in treating mild-to-moderate depression, possibly because it increases synthesis of natural euphoriants in the brain. Sample answer:Carpal tunnel syndrome is due to the compression of the median nerve in the wrist. Chapter 6 muscular system answer key. It is more likely to be an isotonic contraction because the muscle is shortening and isotonic contractions involve a change in muscle length. The function of mitochondria in muscle cells is to provide energy for the muscles in the form of ATP, through aerobic respiration. Describe how the terms muscle cells, muscle fibres, and myocytes relate to each other. In order to make a desired movement (e. g., raising your hand to ask a question), it is essential for the motor system to know the starting position of the hand. The sliding filaments increase the tension in, or shorten the length of, the muscle fibres and cause contractions. Group IV afferent fibers are not part of the muscle spindle. Without these automatic adjustments, the simple act of reaching for a cup would cause us to fall, as the body's center of mass shifts to a location in front of the body axis. Sample answer: Two examples of flexibility exercises include stretching and yoga.
They are attached to actin filaments. Although intrafusal fibers do not contribute significantly to muscle contraction, they do have contractile elements at their ends that are innervated by motor neurons. All of the motor neurons in a motor neuron pool innervate a single muscle (Figure 1. With increasing firing rates, the summation grows stronger, up to a limit. Alpha motor neurons innervate extrafusal fibers, the highly contracting fibers that supply the muscle with its power. Explain your answer. Sample answer: Smooth muscles in the blood vessels can contract to cause vasoconstriction, or relax to cause vasodilation. This is because the neurotransmitter acetylcholine is necessary to trigger muscle contractions at the neuromuscular junction by binding to its receptors on the muscle fibres.