Question

muscles are made of bundles upon bundles of fibers. which is the correct order from smallest to largest in this organizational structure of a muscle?
○ fascicle, muscle fiber, myofibril, muscle
○ muscle fiber, myofibril, fascicle, muscle
○ myofibril, fascicle, muscle fiber, muscle
○ myofibril, muscle fiber, fascicle, muscle

which of the following membranes surrounds an entire muscle (organ)? *
○ epimysium
○ perimysium
○ endomysium
○ actin

Explanation:

First Sub - Question (Muscle Organizational Structure)

To determine the correct order from smallest to largest in muscle organizational structure, we recall the hierarchy: Myofibrils are within muscle fibers (cells), muscle fibers are grouped into fascicles, and fascicles make up the whole muscle. So the order is myofibril, muscle fiber, fascicle, muscle.

Epimysium is the connective tissue membrane that surrounds an entire muscle (organ). Perimysium surrounds fascicles, endomysium surrounds individual muscle fibers, and actin is a protein, not a membrane.

Answer:

D. myofibril, muscle fiber, fascicle, muscle

Second Sub - Question (Membrane Surrounding Entire Muscle)