Chapter 6

Delayed onset muscle soreness (DOMS) most likely occurs when a person

Runs up and down hills for a half hour

Contractility is strictly defined as the ability to

Shorten

Sarcoplasmic reticulum

Specialized endoplasmic reticulum of muscle cells that surround the myofibrils and stores the calcium needed for the initiation of muscle contraction

All or none principle

The principle that muscle cells always contract completely each time they are stimulated by their motor neuron, and that they do not contract at all if they are not stimulated by their motor neuron

Fatigue

A decline in the muscle performance during exercise

Choose the answer that goes from largest to smallest

Feasible, muscle fiber, myofibril, sarcomere, myosin, myosin head

A sarcomere is defined as ____

Going for Z line to Z line

Neurotrasmitter

A chemical released by a neuron that y stimulate or inhibit other neurons or effector cells

Twitch

A complete cycle of contraction and relaxation in a muscle cell

Actin

A contractile protein of muscle. Forms the thin filaments in myofibrils

What accounts for rigor mortis

A lack of ATP when a person dies

Motor neuron

A neuron in the peripheral nervous system that conducts nerve impulses from the central nervous system to body tissues and organs

A motor unit is best described as ___

A single motor neuron and all the muscle fibers it controls

Motor unit

A somatic motor neuron and all the muscle cells that it stimulates

What causes he myosin head to detach from actin

ATP

Which event is least likely to occur as you enter the second hour of a marathon

ATP is formed from creative phosphate and ADP

Summation

Accumulation of effects, especially those of muscular or neural activity

What is released at the end of the motor neuron

Acetylcholine

The sliding filament model is best described as

Actin fibers sliding over the myosin fibers without actually shortening themselves

The function of the sarcoplasmic reticulum is to store and release _____

Calcium ions

What is tetanus

Continuous contraction without a period of relaxation

Which statement is true concerning summation

Increasing the rate of muscle fiber stimulation creates summmation

Recruitment

Increasing the tone (of force) of muscle by activating more motor units

A fascicles is composed directly of _____

Many muscle fibers surrounded by a connective tissue sheath

Which is not a benefit of aerobic exercise

Muscle enlargement

Choose the correct order of events for the latent period of contraction

Neural impulse travels down axon, acetylcholine is released, pulse travels through sarcoplasmic reticulum releases calcium ions

Which would least likely be associated with muscles associated with maintianing posture

Numerous fast twitch muscle fibers

How do antagonistic pairs operate

One contracts wile the other relaxes

Myosin

One of the principal contractile proteins found in muscle composed of thick filaments with cross-bridges

Myoglobin stores____

Oxygen

What does not characterize fast-twitch muscle fibers

Packed with myoglobin

Oxygen debt

The amount of oxygen required after exercise to oxidize the lactic acid formed by anaerobic metabolism during exercise

The origin is best described as

The least moveable attachment

Sliding filament. Mechanism

The mechanism of muscle contraction. Contract when the thick and thin filaments slide past each other and sarcomeres shorten

Sarcomere

The smallest contractile unit of a muscle myofibril. Extends from one Z-line to the next

_____ prevents myosin heads from attaching to actin

Tropomyosin