Ch 5: general muscle biology Flashcards
What is physical activity intended to increase muscle strength and mass?
Strength training
Maintained, enhancing, and regaining strength are critical for?
Improving body function during all phases for recovery
What is any form of active exercise in which a dynamic or static muscle contraction is resisted by an outside force, applied either manually or mechanically?
Resistance exercise
What is resistance training that is applied in a systemic or individualized manner designed to improve, restore, or enhance physical function?
Therapeutic exercise
What are the factors that strength of tension-generating capacity of a muscle?
- Neural control
- Cross sectional area
- Muscle fiber arrangement
- Muscle length
- Angle of pull
- Fiber type distribution
- Energy stores of muscle
- Recovery from exercise
- Fatigue
- Age
- Gender
- State of health of muscle
The body of an individual muscle is surrounded by noncontractile connective tissue called?
Epimysium
With the muscles are bundles of fibers called
Fasciculi
Noncontractile tissue surround fasciculi
Perimysium
What is a noncontractile connective tissue that surrounds each individual muscle fiber?
Endomysium
Individual muscle fibers are composed of?
Myofibrils (parallel to each other)
What are the structural components of myofibrils called?
Myofilaments
What proteins are myofilaments composed of?
Myosin and actin
What is the functional/contractile unit of a muscle fiber cell:
Sarcomere
What is a thick protein actively involved with the muscular contractions which involves a complex and highly structured series of chemical and mechanical events?
Myosin
What is a thin protein actively involved with the muscular contraction which involves a complex and high structured series of chemical and mechanical events?
Actin
Explain the breakdown of muscular contraction
- Neurological stimulus to contract a muscle releases acetylcholine
- Initates release of calcium
- Calcium ions bond with troponin and tropomyosin (actin filament proteins)
- ATP reacts with ATPase producing energy so myosin and actin can slide past each other
- Results in generating tension and producing contraction of muscle
What muscle fiber is type I?
Slow twitch
What muscle fiber is red oxidative?
Slow twitch
What muscle fiber possesses relatively large and numerous mitochondria, triglycerides, and oxidative enzymes to allow for aerobic work?
Slow twitch
Which muscle fiber is aerobic?
Slow twitch
Which muscle fiber has relatively low myosin-ATPase and glycolytic activity as well as slower calcium handing ability and shortening speed?
Slow twitch
What muscle fiber is specialized for muscular endurance?
Slow Twitch
What muscle fiber contract slowly but are highly efficient for prolonged aerobic events
Slow twitch
What muscle fiber is type II?
Fast twitch
What muscle fiber is white glycolytic?
Fast twitch
What muscle fiber is anaerobic?
Fast twitch
What muscle fibers are not vascular?
Fast twitch
What muscle fibers fire/contract at a higher speed and with more force?
Fast twitch
What muscle fibers have high levels of myosin-ATPase, which provides energy for speed of contraction and tension?
Fast twitch
What muscle fibers have low myoglobin content and very few mitochondria?
Fast twitch
What muscle fibers are larger in diameter?
Fast twitch
What muscle fibers are mainly used for speed, strength and power?
Fast twitch
What muscle fiber has a fast contraction speed and moderate capacity for energy transfer from aerobic and anaerobic sources?
Type IIA (fast-oxidative-glycolytic)
What muscle fiber possesses the greatest anaerobic capacity and the fastest shortening speed?
Type IIB (fast-glycolytic)
What muscle fiber is rare and undifferentiated and may contribute to reinnervation and motor unit transformation?
Type IIAB
What is the basic unit of movement?
Motor unit
What consists of the anterior motor neuron and all muscle fibers that innervates it?
Motor unit
What contains only one specific muscle fiber type?
Motor unit
What is the adding of motor units to increase force?
Motor unit recruitment
What proposes an orderly recruitment of motor units within a motor neuron pool during a defined movement task?
Henneman size principle
When a low force is needed, what muscle fibers activate?
Slow twitch (Type I)
What is the orderly recruitment of muscle fibers during contraction?
- Slow Twitch (Type I)
- Fast Twitch (Type II)
- Fast twitch A
- Fast twitch AB
- Fast twitch B
