5.1: Anatomy of the Muscular System Flashcards
Key Terms
What is conscious control?
Ability to move muscles at own will
Define peripheral nerves.
- Nerves outside of the brain and spinal cord
- they send messages to and from the brain
What constitutes the central nervous system?
Brain and spinal cord
What are motor actions?
- Message FROM the central nervous system
- TO a muscle
What are sensory actions?
- Message FROM the external environment
- TO a central nervous system
What is the function of tendons?
Connect skeletal muscle to bone; flexible, can bend at joints, cushion against sudden movement
What do ligaments connect?
Bone to bone; stabilize joints
What is the origin in muscle anatomy?
- the bony site of attachment that is stationary during the movement
- the “fixed” point
Define insertion in muscle contraction.
Place that is MOVED during a muscle contraction
What is the action of a muscle?
The EFFECT produced by the muscle’s contraction
What does innervation refer to?
The peripheral nerve that supplies a muscle with a message from the brain
What is the action of the orbicularis oculi?
Eye closure
Innervation: facial nerve (CN VII)
What action does the orbicularis oris perform?
Mouth closure; closes lips, protrudes lips forward, presses lips against teeth
Innervation: facial nerve (CN VII)
What is the function of the zygomaticus major?
Pull corners of lips upward
Innervation: facial nerve (CN VII)
What is the action of the risorius?
Pulls the corners of the mouth posteriorly (grin or grimace)
Innervation: facial nerve (CN VII)
What does the occipitofrontalis do?
Raises eyebrows
Innervation: facial nerve (CN VII)
What is the action of the buccinator?
Compress cheeks
Innervation: facial nerve (CN VII)