Chapter 6 The Muscular System Answer Key

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There are two principles that govern the relationship between motor neuron activity and muscle force: the rate code and the size principle. Muscle fibres are the cells that make up skeletal muscle tissue. Coordination of signals to many muscle groups. Additional Practice and Other Resources. In addition to sensory information about the external environment, the motor system also requires sensory information about the current state of the muscles and limbs themselves. Chapter 6 the muscular system answer key figures. The muscular system is the organ system that consists of all the muscles in the body.

Chapter 6 The Muscular System Answers Key

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. Sample answer: The skeletal system and the nervous system. How do we define physical exercise? Skeletal muscles also have connective tissue supporting and protecting the muscle tissue. The task of the motor system is to determine the necessary forces and coordination at each joint in order to produce the final, smooth motion of the arm. Chapter 6 the muscular system answer key strokes. 6 Disorders of the Muscular System: Review Questions and Answers. While the origin of the word "orthopedics" (ortho- = "straight"; paed- = "child"), literally means "straightening of the child, " orthopedists can have patients who range from pediatric to geriatric.

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B. Intrafusal fibers. Define muscle hypertrophy and muscle atrophy. Cat Muscles - Photos of Muscles You Need to Know. Other organ systems rely on this calcium for action (specifically, muscle contraction and neural signaling). The number of fibers innervated by a motor unit is called its innervation ratio.

Chapter 6 The Muscular System Answer Key Strokes

C. Rate code This answer is CORRECT! One of the major principles of the motor system is that motor control requires sensory input to accurately plan and execute movements. An increase in the rate of action potentials fired by the motor neuron causes an increase in the amount of force that the motor unit generates. Identify several other health benefits of physical exercise. Chapter 6 the muscular system answer key.com. If the motor neuron fires after the muscle has returned to baseline, then the magnitude of the next muscle twitch will be the same as the first twitch.

Chapter 6 Muscular System Answer Key

How does a muscle strain occur? The higher-order areas can concern themselves with more global tasks regarding action, such as deciding when to act, devising an appropriate sequence of actions, and coordinating the activity of many limbs. What are the main differences between musculoskeletal disorders and neuromuscular disorders? Through vision, audition, somatosensation, and the other senses, we perceive the world and our relationship to it. What are two examples of flexibility exercises? The skeletal system is the body system composed of bones, cartilages, ligaments and other tissues that perform essential functions for the human body. The large majority of muscle fibers that allow the muscle to do work are termed extrafusal fibers. How Muscles are Named - descriptions / vocab. Crossbridge cycling is the specific mechanism by which the filaments slide past each other, which involves the use of ATP.

Chapter 6 The Muscular System Answer Key Figures

Define neuromuscular disorders. It occurs when a tendon is over-extended or worked too hard without rest. Is the situation described in part (a) more likely to be an isometric or isotonic contraction? People with more slow-twitch fibres may be able to develop greater endurance from aerobic exercise, whereas people with more fast-twitch fibres may be able to develop greater muscle size and strength from anaerobic exercise. These are some of the many components of the motor system that allow us to perform complex movements in a seemingly effortless way. As a result, the afferent is depolarized, and it fires action potentials to signal the amount of force.

Compensation for the physical characteristics of the body and muscles. Why can carpal tunnel syndrome cause muscle weakness in the hands? The motor system must adapt to changing circumstances. 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. The combination of an individual motor neuron and all of the muscle fibers that it innervates is called a motor unit. Raising one's hand from a resting position on a desk, compared to a resting position on top of the head, results in the same final position of the arm, but these two movements require different patterns of muscle activation. Alpha motor neurons (also called lower motor neurons) innervate skeletal muscle and cause the muscle contractions that generate movement. If this does not occur, the myosin head cannot attach to the actin filament and the "power stroke" cannot occur. Musculoskeletal disorders are injuries that occur in muscles or associated tissues such as tendons because of biomechanical stresses. Give three reasons that muscle atrophy may occur. Identify the cause and symptoms of muscular dystrophy. Muscle force is controlled in part by... A. Alpha-gamma coactivation.

Imagine if walking across the room required thinking about planting the foot at each step, paying attention to the movement of each muscle in the leg and making sure that the appropriate forces and contraction speeds are taking place. 5 Physical Exercise: Review Questions and Answers. This nerve is then unable to adequately stimulate the muscles that it innervates, causing muscle weakness. 10 Sensory Innervation of Muscle Spindles. Sample answer: Three reasons that muscle atrophy may occur include lack of physical activity, such as might occur with immobility due to a broken bone or surgery; starvation; and certain diseases, such as AIDS or cancer. Many people who overwork their muscles develop delayed onset muscle soreness (DOMS), which may be caused by tiny tears in muscle fibres.

Why is the heart the muscle that performs the greatest amount of physical work in the course of a lifetime? Physical exercise can also increase factors associated with good cardiovascular health, such as "good" cholesterol level and the mechanical efficiency of the heart. If the triceps were to then contract, which way would the arm move? A muscle strain occurs when muscle fibres tear as a result of overstretching. Semi-rigid connective tissue found on the skeleton in areas where flexibility and smooth surfaces support movement. Yellow bone marrow contains adipose tissue, and the triglycerides stored in the adipocytes of this tissue can be released to serve as a source of energy for other tissues of the body.

Why is padding of a strained muscle part of the typical treatment? Chapter 8: Muscular System. When a light object (a balloon) is placed in the hand, there is little change in the firing rate of either afferent. One of the key questions of research on motor control is to understand the functional roles played by each area.