1. A motor unit is a functional unit formed by a neuron and all the muscle fibres it innervates. II. When a muscle contracts, all motor units within that muscle must contract. III. When lifting heavy object, only larger units will be recruited as they produce larger force than the smaller ones. IV. Muscle tension increases as the number of motor units recruited increases.

1. A motor unit is a functional unit formed by a neuron and all the muscle fibres it innervates. II. When a muscle contracts, all motor units within that muscle must contract. III. When lifting heavy object, only larger units will be recruited as they produce larger force than the smaller ones. IV. Muscle tension increases as the number of motor units recruited increases.

Human Biology (MindTap Course List)

11th Edition

ISBN:9781305112100

Author:Cecie Starr, Beverly McMillan

Publisher:Cecie Starr, Beverly McMillan

Chapter6: The Muscular System

Section: Chapter Questions

Problem 10SQ

See similar textbooks

Similar questions

The muscle relaxes if no new nerve signal arrives. However the neurotransmitter from the previous stimulation is still present in the synapse The activity of helps to remove this neurotransmitter. myosin action potential tropomyosin acetylcholinesterase
The cell membrane of a muscle fiber is called a ___________ . myofibril sarcolemma sarcoplasm myofilament
In the diagram below, label the fine structure of a muscle, down to one of its myofibrils. Identify the basic unit of contraction in a myofibril.
The location of a muscles insertion and origin can determine ________. action the force of contraction muscle name the load a muscle can carry
Figure 38.37 Which of the following statements about muscle contraction is true? The power stroke occurs when ATP is hydrolyzed to ADP and phosphate. The power stroke occurs when ADP and phosphate dissociate from the myosin head. The power stroke occurs when ADP and phosphate dissociate from the actin active site. The power stroke occurs when Ca2+ binds the calcium head.
Watch this video (http://openstaxcollege.org/l/micromacro) to learn more about macro- and microstructures of skeletal muscles. (a) What are the names of the junction points between sarcomeres? (b) What are the names of the subunits within the myofibrils that run the length of skeletal muscle fibers? (c) What is the â€œdouble strand of pearlsâ€� described in the video? (d) What gives a skeletal muscle fiber its striated appearance?
The correct order for the smallest to the largest unit of organization in muscle tissue is ________. fascicle, filament, muscle fiber, myofibril filament, myofibril, muscle fiber, fascicle muscle fiber, fascicle, filament, myofibril myofibril, muscle fiber, filament, fascicle
What is the function of the sarcoplasmic reticulum in muscle cell contraction?
After death, calcium pumps no longer function and the calcium ion concentration of muscle fiber cytoplasm increases. The result is rigor mortis a state or postmortem muscle contraction. Explain why this contraction occurs and why it ends only when myosin heads begin to break down.