List the levels of the muscle (broad to microscope). In () put the CT that surrounds each level.

entire muscle (epimysium) --> muscle fasciculus ( perimysium) --> muscle fiber (endomysium) (sarcolemma) --> myofibril --> myofilaments --> contractile proteins actin (thin) and myosin (thick)

Give a detailed explanation of the excitation-contraction coupling process.

Excitation:

1. AP in motor neuron causes release of acetylcholine (Ach) into synaptic cleft @ NMJ (neuromuscular junction).

2. Ach binds to receptors on motor end plate, leads to depolarization that is conducted down transverse tubules, which causes release of Ca⁺² from sarcoplasmic reticulum (SR)

Contraction:

1. At rest, myosin cross-bridge is in weak binding state.

2. Ca⁺² binds to troponin

* Causes shift in tropomyosin to uncover active sites

* Allows cross-bridge to form strong binding state (actin +myosin)

3. P_i released from myosin. cross-bridge movement occurs

4. ADP released from myosin. cross-bridge movement complete.

POWER STROKE OCCURS

5. ATP attaches to myosin

* Cross-bridge detaches and forms "weak binding state"

* ATP breaks down into ADP+P_i which energizes myosin and recocks the head and prepares it for the next cross-bridge cycle

-Continues as longs as Ca⁺² and ATP are present.

____________ is the contractile unit of the muscle.

sarcomere

What is the NaK pump doing?

Resetting the action potential

___________ blocks the actin site.

tropomyosin

____________ occurs when myosin pull actin.

power stroke

power stroke=contraction

Where is the calcium stored in the muscle?

a. sarcomere

b. sarcolemma

c. sarcoplasmic reticulum

d. golgi tendon organs

c. sarcoplasmic reticulum

Fully explain each step of the cross-bridge cycle. Start where myosin is bound to actin.

1. Cross Bridge Formation: Activated myosin head binds to actin. ADP and P_i remain bound to myosin.

2. Power stroke: Myosin head swivels, which causes the displacement of actin filament. ADP and P_i are released from myosin.

3. Dissociation: ATP binds to myosin. Actin and myosin dissociates (cross-bridge detaches)

4. Activation: Energy from the hydrolysis of ATP used to activate the myosin head. ADP and Pi remain bound to myosin.

An example of an acute response to exercise might be:

a.) a change in resting heart rate from 72 bpm to 60 bpma

b.) change in aerobic capacity

c.) a change in resting respiratory rate from 14 to 8 breaths per minute

d.) a change in heart rate from 62 bpm at rest to 155 bpm during a 220 yd. run

d. a change in heart rate from 62 bpm at rest to 155 bpm during a 220 yd. run

The horizontal axis of every graph is reserved for:

a) the dependent variable

b)the independent variable

c)the variable that changes as a result of the research treatment

d) It does not matter what variable is placed on the horizontal axis.

b. the independent variable

The first director of the Harvard Fatigue Laboratory was D.B. Dill.

a. true

b. false

a. true

A research design examining the effect of a single treatment on groups of participants aged 21 to 30 years, 31 to 40 years, and 41 to 50 years is an example of:

a.) a cross-sectional design

b.) a longitudinal design

c.) a placebo design

d.) a crossover design

a. cross-sectional design

The study of how our bodies' structures and functions are altered when we are exposed to acute and chronic exercise is an appropriate definition of:

a. sport physiology

b.exercise nutrition

c. exercise physiology

d. overtraining

c. exercise physiology

Physical educators in the public school setting may use which of the following to estimate aerobic capacity?

a.) a maximal oxygen consumption treadmill test

b.) a one-mile run test

c.) a maximal oxygen consumption cycle ergometer test

d.) an arm ergometer test

b. a one-mile run

In a cross-sectional research study, participants are tested one or more times after initial testing to determine changes in a particular variable or variables over time.

a. true

b. false

b. false

Homeostasis is best defined as:

a.) a low metabolic rate

b.) a change within the internal environment

c.)organ systems, tissues, cells, and molecules working to regulate our internal environment

d.) a normal external environment

c.) organ systems, tissues, cells, and molecules working to regulate our internal environment

Diurnal variation refers to:

a.) fluctuations in physiological responses that occur during a 24-hour day

b.) variations in physiological responses that occur within a 2-hour time frame

c.) day-to-day variation in the amount of urine expelled over a 24-hour day

d.) seasonal variations in physiological responses

a.) fluctuations in physiological responses that occur during a 24-hour day

Which of the following can alter the body's acute response to exercise?

a.) environmental temperature

b.) the participant's last meal

c.) the menstrual cycle

d.) All of these are correct.

d. all of these are correct

Electrical stimulation provides the most benefit for muscle strength when:

a.) employed during immobilization after an injury

b.) alternated with isokinetic resistance training

c.) used concurrently with eccentric resistance training

d.) substituted for variable-resistance training

a. employed during immobilization after an injury

An increase in the demands on the body beyond that at which it is normally stressed to make further improvement is the principle of:

a. progressive underload

b. overload

c. overtraining

d. specificity

b. overload

Which two factors are most commonly manipulated in training for increased performance?

a. intensity and frequency

b. frequency and rest intervals

c. rest intervals and volume

d. volume and intensity

d. volume and intensity

Who would be most likely to have similar responses to a given training program?

a. identical twins

b. two 150 lb, 5' 10" athletes

c. two female swimmers

d. two elite 10 k runners

a. identical twins

Which of these is not a priority when designing a program to increase strength in action-specific movements?

a. engage large muscle groups

b. utilize multiple-joint exercises

c. program high number of reps and sets

d. emphasize higher-intensity efforts

c. program high number of reps and sets

Training adaptations highly specific to type of activity, training volume, and intensity is the principle of:

a. progressive overload

b. recuperation

c. specificity

d. reversibility

c. specificity

Plyometric training takes advantage of the:

a. withdrawal reflex

b. Bainbridge reflex

c. stretch reflex

d. Babinski reflex

c. stretch reflex

As muscles become stronger, what is required to continue gaining strength?

a. higher resistance

b. lower intensity

c. decreased overload

d. continuation of the same training program

a. higher resistance

Which elbow joint angle is associated with the weakest force generated by the biceps?

a. 100°

b. 120°

c. 140°

d. 180°

d. 180°

The loss of exercise capacity, strength, and performance after cessation of training is the principle of:

a. progressive underload

b. periodization

c. microcycling

d. reversibility

d. reversibility

Compared to someone who can squat 75 kg, someone else who can squat 150 kg has:

a. twice the power

b. twice the strength

c. twice the muscular endurance

d. twice the 5-repetition maximum

b. twice the strength

If the rate of oxidative production of ATP is low, then:

a. aerobic power is low

b. aerobic power is high

c. anaerobic power is low

d. anaerobic power is high

a. aerobic power is low

Strength is synonymous with power.

a. true

b. false

b. false

Advanced weight lifters should particularly emphasize:

a. isokinetic resistance training

b. isometric resistance training

c. free-weight resistance training

d. machine resistance training

c. free-weight resistance training

The explosive aspect of strength is:

a. muscle endurance

b. aerobic power

c. maximal anaerobic power

d. power

d. power

Isokinetic training ensures that:

a. resistance remains constant

b. speed remains constant

c. joint angle remains constant

d. number of reps and sets remains constant

b. speed remains constant

Which contractile result of rate coding will produce the most force?

a. twitch

b. summation

c. tetanus

d, all produce the same degree of force

c. tetanus

Type I muscle fibers:

a. have a high oxidative capacity

b. store large quantities of glycogen

c. generate force quickly

d. fatigue quickly

a. have a high oxidative capacity

Why does a sarcomere that is too short or too stretched produce less force?

a. Thick filaments get damaged.

b. Thin filaments become unraveled.

c. Not as many cross-bridges can form.

d. The reduction in force is negligible and can be ignored.

c. Not as many cross-bridges can form

Which protein shields the myosin-binding site, preventing contraction from happening at rest?

a. actin

b. myosin

c. troponin

d. tropomyosin

d. tropomyosin

Muscle found in the walls of the bladder is an example of:

a. cardiac muscle

b. skeletal muscle

c. smooth muscle

c. smooth muscle

Which of these is the correct order of skeletal muscle hierarchical organization, from largest structure to smallest structure?

a. muscle fasciculus, entire muscle, myofibril, muscle fiber

b. entire muscle, muscle fasciculus, muscle fiber, myofibril

c. muscle fiber, myofibril, entire muscle, muscle fasciculus

d. myofibril, muscle fiber, muscle fasciculus, entire muscle

b. entire muscle, muscle fasciculus, muscle fiber, myofibril

Which is the correct order of events in a contraction?

a. T-tubule action potential, Ca2+ gathered in, cross-bridging, Ca2+ released

b. Ca2+ released, cross-bridging, Ca2+ gathered in, T-tubule action potential

c. cross-bridging, Ca2+ released, Ca2+ gathered in, T-tubule action potential

d. T-tubule action potential, Ca2+ released, cross-bridging, Ca2+ gathered in

d. T-tubule action potential, Ca2+ released, cross-bridging, Ca2+ gathered in

According to the size principle, which motor unit will be recruited first for a task?

a. the motor unit with the smallest motor neuron

b. the motor unit with the skinniest muscle fibers

c. the motor unit with the most muscle fibers

d. the motor unit with the largest motor neuron

a. the motor unit wit the smalles motor neuron

For a very heavy lifting task, type IIx fibers are recruited first because they are most appropriate for the job.

a. true

b. false

b. false

Glycogen is stored in which region of a muscle fiber?

a. sarcoplasm

b. sarcolemma

c. sarcoplasmic reticulum

d. T-tubules

a. sarcoplasm

If I need to lift a heavy box of books, I will be most successful if I try to lift it quickly and use momentum to help me.

a. true

b. false

b. false

During concentric contractions, increasing the speed of contraction will:

a. increase the force produced

b. have no effect on the force produced

c. decrease the force produced

c. decrease the force produced

Ca2+ ions (essential for contraction) are stored in the:

a. sarcoplasm

b. sarcolemma

c. sarcoplasmic reticulum

d. T-tubules

c. sarcoplasmic reticulum

Type II fibers:

a. are very fatigue resistant

b. contain high levels of myoglobin

c. are also called slow twitch

d. have more fibers per motor unit

d. have more fibers per motor unit

The process of muscle contraction involves which ion?

a. Na+

b. K+

c. Ca2+

d. Cl-

c. Ca2+

Genetic factors appear to be most influential in determining the percentage of type I versus type II fibers.

a. true

b. false

a. true

According to the length-tension relationship, a muscle will be functionally weaker if it is too stretched or too short.

a. true

b. false

a. true

Thick filaments are primarily made of which protein?

a. actin

b. myosin

c. troponin

d. tropomyosin

b. myosin

Both type II fibers and type II motor units tend to be larger compared to type I fibers and motor units.

a. true

b. false

a. true

As intensity increases, in which order are fibers recruited?

a. type IIx, type IIa, type I

b. type IIa, type I, type IIx

c. type I, type IIx, type IIa

d. type I, type IIa, type IIx

d. type I, type IIa, type IIx

During _____________, a neuron can only be stimulated by a stronger-than-normal stimulus.

a. the absolute refractory period

b. depolarization

c. the relative refractory period

d. rest

c. the relative refractory period

In a resting neuron, the intracellular environment is more negative compared to the extracellular environment.

a. true

b. false

a. true

If membrane potential changes from -40 mV to 30 mV, this is an example of:

a. depolarization

b. repolarization

c. hyperpolarization

d. threshold polarization

a. depolarization

Which receptors would tell the brain that the elbow was fully extended but is now bending quickly?

a. muscle spindles

b. Golgi tendon organs

c. chemoreceptors

d. joint kinesthetic receptors

d. joint kinesthetic receptors

The cerebellum consciously controls movement.

a. true

b. false

b. false

( it unconsciously controls fine movement)

The sympathetic nervous system would contribute to:

a. increased heart rate

b. skeletal muscle contraction

c. skeletal muscle inhibition

d. increased energy conservation

a. increased heart rate

*Remember sympathetic is "flight or fight" and parasympathetic is "rest and digest"

If someone is having trouble passing a roadside sobriety test (walk the line, touch the nose, etc.), which region of the brain is affected?

a. diencephalon

b. cerebellum

c. midbrain

d. medulla oblongata

b. cerebellum

A reflex is a fast, involuntary response to a stimulus.

a. true

b. false

a. true

The membrane potential at which an action potential will definitely occur is the:

a. allowance potential

b. permissive voltage

c. threshold

d. fulfilled potential

c. threshold

_____ is most important for depolarization; _____ is most important for repolarization.

a. Na+ , K+

b. K+ , Na+

c. Cl- , K+

d. Na+, Cl-

a. Na+, K+

A motor unit with a neuron:fiber ratio of 1:20 might be found innervating the:

a. tensor tympani muscle of the eardrum

b. biceps brachii muscle of the upper arm

c. quadriceps muscles of the thigh

d. abdominal muscles

a. tensor tympani muscle of the eardrum

Which neurotransmitter binds to receptors on the motor end plate of a neuromuscular junction?

a. norepinephrine

b. acetylcholine

c. serotonin

d. dopamine

b. acetylcholine

The job of an afferent neuron is to:

a. send impulses from the body to the brain

b. send impulses from the brain to the body

c. send impulses to skeletal muscle

d. send impulses to the viscera (heart, lungs, etc.)

a. send impulses from the body to the brain

If membrane potential changes from -70 mV to -55 mV, what will happen?

a. An inhibitory postsynaptic potential (IPSP) will be generated.

b. An excitatory postsynaptic potential (EPSP) will be generated.

c. An action potential will be generated.

d. Nothing will happen. This change in millivolts is negligible.

c. An action potential will be generated

Motor units can contain multiple types of muscle fibers.

a. true

b. false

b. false

The fastest impulses travel on axons that are:

a. myelinated and large

b. unmyelinated and large

c. myelinated and small

d. unmyelinated and small

a. myelinated and large

_____________ training is critical in developing fiber hypertrophy.

a. Concentric

b. Anaerobic

c. Variable-resistance

d. Eccentric

d. Eccentric

In untrained individuals, motor units are recruited asynchronously.

a. true

b. false

a. true

Acute muscle soreness is caused by edema formation and muscle swelling.

a. true

b. false

a. true

What role do white blood cells play in the development of DOMS?

a. They phagocytose cell membranes, causing muscle enzymes to leak into the bloodstream.

b. They destroy sarcomere structural proteins, leading to excitation-contraction problems.

c. They fight muscle infections that cause DOMS.

d. They secrete inflammatory substances that activate pain nerves in muscle.

d. They secrete inflammatory substances that activate pain nerves in muscle

It is unsafe for children and adolescents to engage in a resistance training program.

a. true

b. false

b. false

Resistance training can decrease inhibitory impulses to agonist muscles by reducing:

a. frequency of stimulation

b. coactivation

c. asynchronization

d. autogenic inhibition

d. autogenic inhibition

DOMS is associated with inflammatory mediators but not actual structural damage to the muscle.

a. true

b. false

b. false

Immobilization primarily affects:

a. type I fibers

b. type IIa fibers

c. type IIx fibers

d. all fiber types equally

a. type I fibers

Removal of autogenic inhibition most likely plays a key role in "superhuman" feats of strength.

a. true

b. false

a. true

Which of these is NOT a cause of strength loss with DOMS?

a. physical disruption of muscle structure

b. failure of excitation-contraction coupling process

c. loss of contractile proteins

d. long-term accumulation of lactic acid in muscle tissue

d. long-term accumulation of lactic acid in muscle tissue

DOMS is ______________ the development of fiber hypertrophy.

a. essential for

b. counteractive to

c. independent of

d. optional for

a. essential for

Transient hypertrophy is primarily stimulated by:

a. edema

b. lactic acid accumulation

c. glycogen depletion

d. fluid and electrolyte losses

a. edema

Protein synthesis ___________ during exercise and ____________ after exercise.

a. increases, decreases

b. decreases, decreases

c. increases, increases

d. decreases, increases

d. decreases, increases

Absolute strength gains are typically greatest in:

a. women

b. men

c. children

d. the elderly

b. men

The neuromuscular system is:

a. one of the most responsive systems to training

b. very difficult to train

c. fully developed by puberty

d. more responsive as humans age

a. one of the most responsive systems to training

Strength losses after immobilization are greatest during the ___________.

a. first day

b. first week

c. first 2 weeks

d. first month

b. first week

When motor units contract more synchronously,

a. muscles cannot sustain steady forces anymore

b. muscles increase the rate of force development

c. the ability to generate force is impeded

d. a single motor neuron now innervates several motor units

b. muscles increase the rate of force development

Strength gains cannot occur unless there is an increase in muscle size.

a. true

b. false

b. false

The acronym EAMC is short for:

a. exercise-ameliorated muscle cramps

b. exercise-associated myogenic contractions

c. exercise-aggravated muscle coupling

d. exercise-associated muscle cramps

d. exercise-associated muscle cramps

Resistance training is only beneficial for competitive athletes.

a. true

b. false

b. false

Which of the following will likely result in the most severe DOMS?

a. aerobic training around town or in the park

b. sprint interval training on the track

c. downhill-running interval training

d. uphill-running Fartleks

c. downhill-running interval training

Which intracellular change likely contributes the most to increases in fiber size, cross-sectional area, and strength?

a. more sarcoplasm

b. more mitochondria

c. more actin and myosin filaments

d. more connective tissue

c. more actin and myosin filaments

The risk of DOMS after a given training session can be reduced by which training strategy?

a. train at high intensity with both resistance and anaerobic training components

b. train with primarily intense eccentric exercise

c. reduce eccentric component of muscle action

d. employ more downhill exercise in the training program

c. reduce eccentric component of muscle action

________________ is often caused by accumulation of fluid or H+.

a. DOMS

b. Acute muscle soreness

c. Chronic hypertrophy

d. Fiber hyperplasia

b. acute muscle soreness