________ is the activation of more and more motor muscle units, ...

[D2AR0N]

________ is the activation of more and more motor muscle units, resulting in a smooth, steady increase in muscular tension.
 
  A) Isotonic contraction B) Recruitment
  C) Muscle tone D) Atrophy

Question 2

The smallest functional unit of the muscle fiber is the what? Interactions between its thick and thin filaments are responsible for muscle contractions.
 
  A) Myofibril B) Sarcolemma C) Sarcomere D) Myofilament

[kristenb95]

Answer to Question 1

B

Answer to Question 2

C