Question

question 1
a motor unit within the powerful quadriceps muscle would
contain several motor neurons.
be much like those in the eye muscles.
generally contain less than ten fibers.
generally contain several hundred fibers.
question 2
which protein makes up the thick filaments?
myosin
actin
tropomyosin
troponin
myopathy

Explanation:

• Question 1: A motor unit consists of a single motor neuron and the muscle fibers it innervates. The quadriceps is a large, powerful muscle. Motor units in large, powerful muscles (like the quadriceps) generally contain several hundred fibers. Motor units in precise - control muscles (like eye muscles) have few fibers. A motor unit has one motor neuron, not several.
• Question 2: Myosin makes up the thick filaments in muscle fibers. Actin makes up the thin filaments. Tropomyosin and troponin are regulatory proteins associated with the thin filaments. Myopathy is a general term for muscle disease, not a protein.

Answer:

• Question 1: generally contain several hundred fibers.
• Question 2: Myosin.