The Muscular System Questions and Answers (36-56)

36) A muscle group that works with and assists the action of a prime mover is a(n): A) antagonist only B) fixator only C) synergist only D) antagonist and synergist E) antagonist and fixator Answer : C Diff: 1 Page Ref: 202 37) Which of the following muscles is not involved in dorsiflexion and/or plantar flexion of the foot: A) gastrocnemius B) tibialis anterior C) extensor digitorum longus D) soleus E) iliopsoas Answer : 30 E Diff: 3 Page Ref: 212; 214 38) Which one of the following is the action of the orbicularis oris: A) closes, purses, and protrudes the lips B) pulls the lower lip down and back C) draws the eyebrows together D) allows blinking, squinting, and various other protective mechanisms for the eye E) closes the jaw Answer : A Diff: 1 Page Ref: 207 39) Paralysis of which of the following would make an individual unable to flex the thigh: A) biceps femoris B) vastus medialis C) vastus lateralis D) vastus intermedius E) 31 iliopsoas and rectus femoris Answer : E Diff: 2 Page Ref: 212; 214 40) Which one of the following muscles is involved in abduction of the arm at the shoulder joint: A) deltoid B) biceps brachii C) triceps brachii D) latissimus dorsi E) pectoralis major Answer : A Diff: 2 Page Ref: 210 32 41) Which of the following muscles adducts the thigh: A) peroneus muscles B) gluteus maximus C) sartorius D) quadriceps group E) adductor muscles Answer : E Diff: 1 Page Ref: 214 42) While doing "jumping jacks" during an exercise class, your arms and legs move laterally away from the midline of your body. This motion is called: A) extension B) flexion C) abduction D) adduction E) circumduction Answer : 33 C Diff: 1 Page Ref: 199 43) Which of the following muscles are antagonists: A) biceps brachii and triceps brachii B) bicpes femoris and biceps brachii C) vastus medialis and vastus lateralis D) masseter and temporalis E) gastrocnemius and soleus Answer : A Diff: 3 Page Ref: 211 44) Paralysis of which of the following would make an individual unable to flex the knee: A) hamstring muscle group B) gluteal muscle group C) gastrocnemius D) sartorius E) 34 iliopsoas Answer : A Diff: 3 Page Ref: 214 45) Which one of the following is NOT a criteria generally used in naming muscles: A) relative size of the muscle B) number of origins of the muscle C) shape of the muscle D) method of attachment of the muscle to bone E) action of the muscle Answer : D Diff: 2 Page Ref: 204 35 True/False 1) Skeletal muscle is considered involuntary because it is the only type of muscle usually subject to conscious control. Answer : FALSE Diff: 1 Page Ref: 183; 185 2) The epimysium covers individual muscle fibers. Answer : FALSE Diff: 1 Page Ref: 185 3) Skeletal muscles need nerve stimulation for contraction to occur. Answer : TRUE Diff: 1 Page Ref: 189 4) A nerve cell and all the muscle cells that it stimulates are referred to as a motor unit. Answer : TRUE Diff: 1 Page Ref: 189 5) A contraction in which a skeletal muscle does not shorten but its tension increases is called isometric. Answer : TRUE Diff: 1 Page Ref: 197 36 6) Cardiac muscle fibers are relatively short, tapering cells within a single centrally located nucleus. Answer : FALSE Diff: 1 Page Ref: 186 7) The neurotransmitter used by the nervous system to activate skeletal muscle cells is acetylcholine. Answer : TRUE Diff: 1 Page Ref: 189 8) Thick filaments are made of a protein called actin. Answer : FALSE Diff: 1 Page Ref: 189 9) One of the important functions of skeletal muscle is to generate heat. Answer : TRUE Diff: 1 Page Ref: 187 10) Lactic acid results from aerobic respiration. Answer : FALSE Diff: 2 Page Ref: 195 11) A sustained partial contraction of skeletal muscle is called muscle tone. 37 Answer : TRUE Diff: 1 Page Ref: 197 38