HHP 3114 Exam 2 | Questions and Answers

HHP 3114 Exam 2 | Questions and Answers Muscles that constrict or dilate to control blood flow are called smooth muscle Which of the following is also referred to as voluntary muscle? skeletal Muscle The type of muscle that is found in the walls of most internal organs Smooth Muscle The striated appearance of skeletal muscle fiber is mainly due to the arrangement of the actin and myosin myofilaments Which structure within the skeletal muscles stores and releases calcium? Sarcoplasmic reticulum Calcium ions, responsible for turning on muscle contraction, are sarcoplasmic reticulum A sarcomere is the smallest functional unit of skeletal muscle, found between two z lines, and contains actin and myosin The smallest functional unit of a muscle is the Sarcomere The primary contractile proteins in the muscle are actin and myosin A single motor nerve and all of the muscle fibers that it supplies are referred to as motor unit What substance is released at the neuromuscular junction? Acetylcholine What is the trigger mechanism to initiate contraction in skeletal muscle? calcium binding to troponin The active binding sites to which myosin cross-bridges attach during muscle contractions are found on the actin filaments Acetylcholine is the neurotransmitter that is released by motor nerves The energy required for muscle contraction is supplied by ATP Slow-twitch (ST) muscle fibers are also sometimes referred to as type I fibers When a muscle fiber is stimulated by a motor nerve, the muscle fiber either will contract maximally or it will not contract at all. This is referred to as the all-or-none principle What factors influence force production? Number and type of motor units activated, size of muscle, muscles' initial length when activated, and angle of the angle of the joint During a progressive increase in exercise intensity, motor units with small motor neurons are recruited first A muscle that provides most of the force required for a given movement is referred to as an agonist An eccentric muscle contraction is one in which the muscle lengths as contractile force is generated A muscle action in which the muscle generates force but does not change in length is called a static action Isotonic muscle contraction is Dynamic Isometric muscle contraction is Static Skeletal muscle is also referred to as voluntary muscle True In the contraction of a muscle fiber, the tilting of the myosin head is referred to a the power stoke True The motor nerves that innervate skeletal muscles release norepinephrine. False The two main components of the nervous system are