Question

1. What is the name of the connective tissue that surrounds each individual muscle fiber?

Select one:

a. Perimysium

b. Endomysium

c. Sarcolemma

d. Epimysium

2. Which of the following statements is TRUE?

Select one:

a. Large motor units are recruited for fine/precise movements and innervate ~1000-2000 muscle fibers

b. Large motor units are recruited for coarse movements and innervate ~1000-2000 muscle fibers

c. Small motor units are recruited for coarse movements and innervate as few as 10 muscle fibers

d. Small motor units are recruited for coarse movements and innervate ~1000-2000 muscle fibers

3. What is the definition of a motor unit?

Select one:

a. A motor neuron and all the muscle fibers it innervates

b. A motor neuron and all the motor units it innervates

c. A motor fiber and all the muscle neurons it innervates

d. A muscle unit and all the motor fibers it innervates

4.What is the name of the specific neurotransmitter secreted at the axon terminal of a motor neuron into the synapse of the neuromuscular junction?

Select one:

a. Acetylcholine

b. Adenosine Triphosphate

c. Testosterone

d. Acetyl CoA

5. _____________ is the thin contractile protein that contains the regulatory protein ______________ which calcium ions bind to, initiating muscular contraction.

Select one:

a. myosin, troponin

b. actin, troponin

c. actin, tropomyosin

d. myosin, tropomyosin

6. Which of the following is one of the training adaptions specific to strength "resistance" training?

Select one:

a. Increased oxygen extraction from the blood by active muscles

b. Increased glycolytic enzyme activity

c. Increased number and size of mitochondria

d. Increased motor units recruited

7. Strength training results in increased size of myofibrilar proteins

Select one:

True

False

8. Water composition in skeletal muscles account for nearly _____ percent of muscle weight

Select one:

a. 75

b. 55

c. 65

d. 85

9. Which of the following has been scientifically proven to reduce muscle cramps?

Select one:

a. Injecting calcium gluconate or magnesium sulfate into the localized area

b. Taking a spoonful of mustard

c. Drinking pickle juice

d. Eating bananas

10. Which of the following is currently the accepted theory as to why muscles feel tight when stretched?

Select one:

a. Weak tendons stimulate a contraction response

b. Titin molecules being stretched

c. Actin and myosin filaments become overlapped

d. Increased tension in the connective tissues surrounding the muscles

11. Two individuals starting at the same strength and fitness characteristics begin a training program. These individuals are also both highly motivated. They will end up with the same training adaptations as long as they both make sure they are fully rested, hydrated, maintain a healthy diet, and have nothing wrong with their nervous, endocrine or immune systems.

Select one:

True

False

12. What is one of the main reasons why fit people who detrain get back into shape faster compared to inexperienced exercisers?

Select one:

a. Increased content of contractile proteins in muscle cells

b. Proliferation of satellite cells causes increase mitochondrial content in the muscles

c. Increased plasma volume initially in the first 2 weeks of a training program

d. Increased number of nuclei remain after training

13. Which of the following is a reason why Type II fibers are better suited for fast, powerful movements?

Select one:

a. Sarcoplasmic reticulum is better at cycling calcium

b. More mitochondrial content

c. Slower myosin ATPase activity

d. Increased blood vessel quantity around the area

14. Research has shown that up to _____ percent of aerobic performance may be determined by genetics

Select one:

a. 50

b. 17

c. 10

d. 6

15. In general, muscles need to be damaged in order for them to get bigger (hypertrophy)

Select one:

True

False

Answer 1

1) b. Endomysium

Each bundle of muscle fiber is called a fasciculus and is surrounded by a layer of connective tissue called the perimysium. Within the fasciculus, each individual muscle cell, called a muscle fiber, is surrounded by connective tissue called the endomysium.

2)c. Small motor units are recruited for coarse movements and innervate as few as 10 muscle fibers

A typical muscle consists of many thousands of muscle fibers working in parallel and organized into a smaller number of motor units.

3)a.  A motor neuron and all the muscle fibers it innervates

A motor unit, the functional unit of muscle contraction, is a single motor nerve and the associated muscle fibers that are innervated upon stimulation from the nerve.

4) a. Acetylcholine

Acetylcholine is released by motor neurons at synapses with muscle cells, often called neuromuscular junctions. Like other neurotransmitters, acetylcholine is synthesized in the cytosol of the presynaptic axon terminal and stored in synaptic vesicles.

5)b. actin, troponin

Troponin binds to tropomyosin and helps to position it on the actin molecule; it also binds calcium ions.

6)d.  Increased motor units recruited

Changes in nervous system input resulting from resistance training include recruitment of an increased number and firing rate of motor units.

7) true

during sarcoplasmic hypertrophy, the volume of sarcoplasmic fluid in the muscle cell increases with no accompanying increase in muscular strength, whereas during myofibrillar hypertrophy, actin and myosin contractile proteins increase in number and add to muscular strength

8)a. 75

Muscle Biochemical Composition. Skeletal muscles contain approximately 75% water, 20% protein, 1–10% fat, and 1% glycogen.