ASCM Exercise Physiology part 2

motor unit

consists of the motor neuron and the muscle fibers it innervates.

concentric contraction

muscle shortens (e.g., the lifting phase of a biceps curl), the muscle action is called

actin and myosin

A sarcomere is composed of two types of muscle protein: ______ (the thin filament) and _____ (the thick filament)

muscle spindles

A sensory receptor called a ___________ is sensitive to the stretch of a muscle and is embedded within the muscle fiber.

recovery

After the exercise stops, the oxygen deficit accumulated will be replenished during _______ by consuming more than usual amounts of oxygen.

cardiac muscle

All internal organs are composed of smooth muscle with the exception of the heart which is composed of ___________

carbohydrates and fats

Although proteins can be used as a fuel for aerobic exercise, ________ and ________ are the primary energy substrates during exercise in a healthy, well-fed individual.

exercise pace or intensity

An additional oxygen deficit accumulates whenever energy demand is abruptly increased, as in sudden increase in _________ or _______

steady state

At the initial stage or transitional stage from rest to submaximal exercise, oxygen consumption builds up gradually until it reaches an optimal level to support the energy demand of the exercise

IIx Fibers

Because force generation is so important, fast-twitch fibers shorten and develop tension considerably faster than type I.These fibers are typically thought of as type

aerobic oxidation

Before steady state , part of the ATP supply relies on the anaerobic metabolism. Once steady state is reached, all the ATP supply is sufficiently provided through aerobic oxidation.

5-10

Creatine Phosphate exists in finite quantities in cells as well, so the total amount of ATP that can be produced is limited, enough for only ______ seconds of strenuous exercise.

static (isometric)

During _____ contractions, the muscle or muscle group maintains a constant length as resistance is applied, and no change in the joint position occurs.

muscle or liver

During recovery, when enough oxygen becomes available, lactate is oxidized and used for ATP production in the _______ or in the ________

muscles

During rest or moderate exercise, lactate is oxidized in ___________with high oxidizing capacity (i.e., heart and ventilatory muscles) In strenuous exercise, when energy demand is high and ventilation is at its peak, lactate accumulates contributing to fatigue

EPOC

EPOC helps to restore Creatine Phosphate in muscles and oxygen in blood and tissues.

True

EPOC remains elevated for longer duration after prolonged exercise than after shorter term exertion.

tendons and ligaments

Hypertrophy is the most prominent adaptation seen with resistance training However, changes to the muscle fibers are not the only adaptations seen with resistance training. _________ , _________ and the muscles' surrounding tissue also undergo hypertrophy and strengthening in order to withstand the greater amount of forces produced by the hypertrophied muscle

Proteins and myofibrils

Hypertrophy, or the increase in muscular size, is thought to occur through the remodeling of ___________ within the muscle cell and an increase in the number of ___________

locomotion and movement

In addition to protecting vital organs, and acting as an important source of nutrients and blood constituents, the primary role of the skeletal system is to provide support for __________

Fasciculi

Individual skeletal muscles are composed of a varying number of muscle bundles referred to as

slow twitch fibers

Individuals most successful at endurance activities generally have a higher proportion of _________ , and this is most likely due to genetic factors supplemented through appropriate exercise training.

high firing rate

Maximal force production requires not only the recruitment of all motor units, including high-threshold motor units, but also recruitment at a sufficiently _____________

True

Metabolically, although type IIa fibers have the ability to generate a moderately large amount of force, they also have some aerobic capacity.

all-or-none principle

Moreover, the nerve impulse that applies to the muscle cell, regardless of its "strength," causes the sarcomere to contract maximally or not all. This is called the

Motor Unit twitch force and recruitment threshold

Motor unit activation is also influenced by the size principle. This principle is based on the observed relationship between ______________ and __________threshold.

creatine phosphate anaerobic glycolysis, and aerobic oxidation

Muscle fibers contain the metabolic machinery to produce ATP by three pathways: ______ , _________ , and ___________ of nutrients to carbon dioxide and water.

Anaerobic

Oxygen is not involved in the rephosphorylation of ADP to ATP, so the Creatine Phosphate system is considered _________ (without oxygen).

sympathetic and parasympathetic

The ANS includes two pathways, the __________pathway and the ________ pathway, which complement each other.

creatine kinase

The Creatine Phosphate system transfers high-energy phosphate from Creatine Phosphate to rephosphorylate ATP from ADP using the enzyme ________ __________

sympathetic

The ________ pathway stimulates visceral activities under stressful (or alarming) conditions, which results in acceleration of metabolism, HR, and breathing and adrenal hormone release..

length of muscle fibers

The _______during a contraction is determined by the number of muscle fibers (cells) being recruited for the contraction.

motor units and fibers

The amount of force that is produced from a muscle contraction is determined by the number of ______ (one motor nerve together with all the muscle fibers that it innervated) that are recruited and the number of ______ contained in each motor unit

50%

The average person has approximately ____ % slow-twitch fibers, and this distribution is generally equal throughout the major muscle groups of the body

postexercise oxygen consumption (EPOC)

The consumption of more than usual amounts of oxygen after exercise is termed

rephosphorylate ADP to form ATP

The electrons from these hydrogens follow a chain of cytochromes (ETC) in the mitochondria, and the energy released from this process is used to _________ ______________

motor units

The greater force production occurring during the eccentric action compared with the concentric action probably results from the greater recruitment of ______ and a slow movement velocity

change in length and tension

The muscle spindles provide sensory information regarding the changes and rate of ______________ of muscle fibers. Their main function is to respond to stretch of a muscle and, through reflex action, to initiate a stronger muscle action to reduce this stretch

conserve and restore

The parasympathetic pathway helps ______ and _______ body resources.

remove hydrogen

The primary function of the Krebs cycle is to ________ _____from four of the reactants involved in the cycle.

anaerobic glycolysis

The rapid breakdown of carbohydrate molecules, either glycogen or glucose, occurring without the presence of oxygen, is called __________ ___________

True

The sliding motion between the actin and myosin causes the shortening of a sarcomere and subsequently the entire muscle fiber..

Sarcomere

The smallest contractile unit of a muscle cell is the

isokinetic

The speed of movement is controlled, and the amount of resistance is proportional to the amount of force produced throughout the full range of motion.

maximal muscle tension

The theoretical advantage of isokinetic exercise is the potential for development of ___________ throughout the range of motion.

Golgi tendon organs

These receptors detect differences in the tension generated by active muscle rather than muscle length.

efferent

To activate muscle contraction a nerve pulse is transmitted to the targeted muscles through an _________ neuron

fat, protein, carbohydrates

Unlike glycolysis, aerobic metabolism can use ________ , _________ , and _________ as substrates to produce ATP.

True

Unlike popular belief, lactate accumulation does not cause soreness after intense exercise .

Type IIa fibers

When an endurance component is introduced, such as in events lasting upward of several minutes (e.g., 800- to 1,500-m races), a second type of fast-twitch fiber, ________, is recruited.

True

When lifting , when maximal force is required, all available motor units are activated.

eccentric muscle action

When the resistance is greater than force applied by the muscle and the muscle lengthens, it is known as _______ (e.g., the lowering phase of the biceps curl).

Higher activation thresholds

Whereas type I motor units are the smallest and possess the lowest recruitment thresholds, type IIa and IIx motor units are larger in size and have ____________ ____________

Lactate

________ a byproduct of anaerobic glycolysis, can also be resynthesized for ATP production during exercise

Type I fibers

________ fibers are selected for activities of low intensity and long duration.

Golgi tendon organs

are another type of specialized proprioceptor that attaches to the tendons near the junction of the muscle

oxygen deficit

describes the difference between the required oxygen amount necessary for meeting the energy demand of the exercise and the actual oxygen consumption.

fat

during prolonged exercise of low to moderate intensity (longer than 30 minutes), a gradual shift occurs from carbohydrate toward an increasing reliance on _______ as a substrate.

True

even though glycolysis does not use oxygen and is considered anaerobic, pyruvate can readily participate in aerobic production of ATP when oxygen is available in the sufficient quantity in the cell.

Overcontraction

excessive tension is detected by the Golgi tendon organs, a continuous reflex inhibition signal is fired to prevent the muscle from contracting. Hence, the Golgi tendon organs serve as a protective sensory system to prevent muscle injury resulting from ___________

Proprioception

is defined as the receipt of information from joints, muscles, and tendons that enables the brain to determine movements and position of the body and its parts

Isokinetic

is the other major type of resistance training and entails a muscular contraction at a constant speed against accommodating resistance.

Eccentric Training

play an important role in preventing or rehabilitating certain musculoskeletal injuries.

oxygen deficit

refers to the lag in oxygen consumption at the beginning of exercise.

delayed onset muscle soreness

soreness, which usually appears after an intense bout of exercise and can last various days, is most commonly due to muscle fiber damage and is referred to as (DOMS)

True

static training is effective in maintaining muscular strength and preventing atrophy associated with the immobilization of a limb

Parasympathetic

the ___________ pathway brings the visceral activities back to normal, for example, decreasing HR and breathing, relaxing the muscles, and increasing gastrointestinal activities.

IIx Fibers

these fibers have minimal aerobic capacity due to a small amount of mitochondria..

fast twitch

those who achieve the greatest success in power and high-intensity speed tasks usually have a greater proportion of ________ muscle fibers distributed through the major muscle groups.

aerobic capacity

type IIa fibers are adaptable with training. For example, with significant endurance training, it is possible for type IIa fibers to increase their __________ such that these type IIa fibers behave much more like type I fibers).