The number of muscle fibers innervated by a motor axon is smallest in:: (A) Gastrocnemius, (B) Orbicularis oculi, (C) Single-unit smooth muscle, (D) Soleus
Answer is B. The extraocular and hand muscle has a ratio of 3-6 (total 3000 motor units) whereas gastrocnemius and back muscle (concern with posture) has a innervation ratio of 2000 (total 600 units).