The size of a motor unit (i.e., the # of muscle fibers innervated) can directly influence which of the following? a.) Ability to finely increase or decrease force produced during a movement b.) Ability to produce force for long duration c.) Speed (velocity) of a movement d.) The arrangement of actin and myosin within the sarcomere

The three key ions in muscular contractions are .... A) sodium, calcium, chloride B) calcium, sodium, phosphate C) calcium, chloride, potassium D) sodium, potassium, calcium

Isometric exercise is best described as applying a force O a) with movement through a full and complete range of motion O b) while a muscle is lengthening and returning to a resting position c) without any change in length of the muscle O d) at a constant speed

Smooth muscles relax when: a) myosin kinase phosphorylates the myosin head b) myosin phosphatase removes a phosphate group from myosin c) Ca2 + binds to calmodulin d) Ca2 + flows out of the sarcoplasmic reticulum

Which of the following causes ( the state of ) rigor in skeletal muscle ?a) lack of atp b) decrease of intracellular ca2plus c) increase in intracellular ca2+ d) lack of action potential in motor neurons

Which of the following statements relating to the developmental aspects of muscles is false? a. All muscle tissue types arise from myoblasts b. Skeletal muscles become amitotic while smooth muscles regenerate throughout life c. Sarcopenia begins by age 30 and is irreversible d. Body strength per unit muscle mass is the same in both sexes  e. none of the above   Which of the following structures is located in the head region of the thick filament myosin? a. actin binding site b. ATP binding site c. ATPase enzyme d. all of the above e. none of the above

According to the size principle, which type of muscle fibers are recruited last during a muscle contraction? Group of answer choices:   1.) Type I 2.) type IIB 3.) Type IIA

20) which of following is true regarding skeletal muscle cells? a) All of these are properties of skeletal muscle cells b) they are striated  c) they have many mitochondria  d) they contain multiple nuclei