Question

1. a group of myofilaments make up:

○ myofibril
○ endomysium
○ muscle fiber bundle
○ perimysium

1. stress fractures are also referred to as:

○ double fractures
○ greenstick fractures
○ fatigue fractures
○ compound fractures

Explanation:

Question 3

Myofilaments (actin and myosin filaments) are organized into myofibrils. Endomysium is connective tissue around muscle fibers, muscle fiber bundle is a group of muscle fibers, and perimysium is connective tissue around fascicles. So a group of myofilaments make up a myofibril.

Stress fractures occur due to repeated stress (like in sports), also called fatigue fractures. Double fractures aren't a standard term, greenstick is for incomplete fractures in kids, compound is open fracture. So stress fractures are fatigue fractures.

Answer:

A. myofibril

Question 4