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Canfitpro Chapter 6

Terms in this set (68)

Myology
The scientific study of the muscular system and muscle tissue
Excitability
is the ability of the muscle/ tissue to carry an electrical impulse called an action potential, which initiates the muscle contraction.
Contractility
refers to the response of the muscle cell to the electrical impulse. The muscle cell responds by shortening, pulling the two ends of the muscle toward each other.
Extensibility
allows the muscle to be length ened without damaging the tissue
Elasticity
allows the muscle to return to its resting length after being either shortened or lengthened
The human body contains three distinct types of muscle tissue:
- skeletal muscle
- cardiac muscle
- smooth muscle
Skeletal Muscle - Location
Attached to bones
Skeletal Muscle - Cell shape and appearance
Single long cylindrical cells with a striated or banded appearance
Skeletal Muscle - Regulation of contraction
Voluntary (can be consciously controlled)
Skeletal Muscle - Arrangement of contractile proteins
Regular, in parallel
Skeletal Muscle - Force production
Along the length of the cell
Cardiac Muscle - Location
Walls of the heart
Cardiac Muscle - Cell shape and appearance
Branched chains of cylindri-lcal cells with striations or bands
Cardiac Muscle - Regulation of contraction
Involuntary (cannot be consciously controlled)
Cardiac Muscle - Arrangement of contractile proteins
Regular, in parallel
Cardiac Muscle - Force production
Along the length of the cell
Smooth Muscle - Location
Walls of the hollow organs such as the stomach, intestines, bladder, and blood vessels
Smooth Muscle - Cell shape and appearance
Irregularly shaped, thin cells with no striations or bands
Smooth Muscle - Regulation of contraction
Involuntary (cannot be consciously controlled)
Smooth Muscle - Arrangement of contractile proteins
Irregular, random
Smooth Muscle - Force production
In all directions equally
concentric contraction
contraction in which the muscle shortens
eccentric contraction
a force exerted by a muscle as it lengthens
Isotonic-concentric
Movement occurs when the muscle contracts Example - Lifting phase of a biceps curl
Three Types Contractions
1. Isotonic-concentric
2. Isotonic-eccentric
3. Isometric
Isotonic-eccentric
The muscle generates tension as it lengthens(e.g., like a braking mechanism)
Example - Lowering phase of a biceps curl
Isometric
In this static contraction, the muscle exerts an opposing force; no change in muscle length occurs.
Example - Holding the arm at a fixed angle of 90° with resistance in the hand
slow twitch fibers - characteristics 4 items
- Best suited for endurance work because they have greater ability to use oxygen and resist fatigue.
- Contain a higher amount of mitochondria compared with fast-twitch fibers
- Contract slowly and produce a smaller amount of force than fast-twitch fibers but are resistant to fatigue
- Work aerobically, for the most part
fast-twitch fibers characteristics 4 items
- Best suited foe exercise that requires short, intense bursts of activity
- Have the ability to produce and use ATP more quickly
- Contract quickly and produce a great deal of force but fatigue quickly
- Work anaerobically, for the most part
Muscle size
The force that a muscle can generate is related to its size
Muscle length
A muscle has the potential to generate its greatest force when it is at its resting length because the actin and myosin filaments lie next to each other and all potential crossbridges are exposed. As the muscle shortens and filaments slide past each other, some of the cross-bridges become fully covered, reducing the amount of additional force that the muscle can generate.
Speed of contraction
For concentric muscle actions, maximal force can be achieved with slower contractions, whereas eccentric muscle actions produce more force with faster movements.
Neural control
Muscle force is generally greater when more motor units are involved in a contraction, the motor units are bigger in size, and the rate at which the motor units fire is faster.
Several factors play a role in the ability of a muscle or muscle group to generate force (strength) 4 items
- Muscle size
- Muscle length
- Speed of contraction
- Neural control
Improvements as a Result of Resistance Training 4 items
- Increases muscular strength, power, and endurance
- Increases core strength
- Increases muscles mass
- Improves bone density and connective tissue strength
Benefits as a Result of Resistance Training 6 items
- Makes everyday activities easier Improves sport performance
- Improves strength for cardiorespiratory exercise Improves posture
- Complements the maintenance of a healthy body weight
- Reduces loss of muscle mass due to inactivity and aging
- Helps prevent osteoporosis
- Reduces the incidence of joint and muscle overuse injury
Muscular endurance - Intensity (% of 1RM)
Less than 70 % of 1RM
Muscular endurance - # of reps
12-15
Muscular endurance - # of sets
1-3
Muscular endurance - Rest between sets
30 sec-1 min
Muscular strength and hypertrophy - Intensity (% of 1RM)
70-80 % of 1RM
Muscular strength and hypertrophy - # of reps
8-12
Muscular strength and hypertrophy - # of sets
1-4
Muscular strength and hypertrophy - Rest between sets
30 sec-2 min
Muscular power and maximal strength - Intensity (% of 1RM)
80-100 % of 1RM
Muscular power and maximal strength - # of reps
1-8
Muscular power and maximal strength - # of sets
1-6
Muscular power and maximal strength - Rest between sets
>2 min
prime mover
The muscle that provides the initial and primary source of a movement.
muscle fiber
The term used to describe the thousands of elongated, rod-shaped muscles cells that make skeletal muscle.
sarcomere
The basic unit of muscular contraction, which is composed of two types of protein: actin and myosin.
concentric contraction
A muscular contraction that involves the shortening of a muscle against a load.
eccentric contraction
A muscular contraction that occurs as a muscle lengthens with a force or load.
Central nervous system (CNS)
Composed of the brain and spinal cord.
peripheral nervous system
Part of the nervous system at lies outside the brain and spinal cord and is made up of nerves that connect the extremities to the brain.
proprioceptors
Specialized sensory receptors found in joints, muscles, and tendons that respond to stimuli produced within the body, allowing maintenance or adjustment of the relative position of the body.
motor unit
Composed of a muscle fiber and a motor neuron, the motor unit is of a group of muscle fibers that contracts when the associated motor neuron is stimulated.
muscular capacity
The full spectrum of muscular capability,including endurance, strength, and power.
muscular endurance
The ability of a muscle to exert or withstand force repeatedly over a period of time.
muscular power
The product of the strength and speed of movement that a muscle can produce. Muscular power is described in terms of explosive muscular contraction.
antagonist
Muscle that performs the opposite move- ment to the primary mover. Antagonist muscles act to stop or slow the moving muscle, assisting in a controlled movement
cam
A component of exercise equipment that varies the resistance of movements performed with pulleys, levers, or belts so that the exerciser maintains a challenging level of tension through the entire phase of an exercise.
Human Skeleton
Summary of Movements Allowed by Major Joints
Level of Organization of Skeletal Muscle
Physical Improvements and Benefits as a Result of Resistance Training
Resistance Training Guidelines for Specific Training Results
Resistance Training Guidelines
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