Chapter 13: Spinal Control of Movement Flashcards
Smooth muscle
- lines the digestive tract, arteries, and related structures
- is innervated by nerve fibers from the autonomic nervous system
- plays a role in movement of material through intestines
- control of blood pressure and blood flow
Striated Muscle
Cardiac and skeletal
The direction of movement that closes a joint
Flexion
The direction of movement that opens a joint
Extension
Synergist Muscle
A muscle that contracts with other muscles to produce movement in one direction.
Antagonist Muscle
A muscle that acts against another on the same joint.
Axial muscles
- responsible for movement of the trunk
- maintaining posture
Proximal muscles
- responsible for movement of the shoulder, elbow, pelvis, and knee
- also called Girdle muscles
- responsible for locomotion
Distal muscles
- responsible for movement of the hands, feet, and digits.
- responsible for manipulation of objects.
Hypertrophy
exaggerated growth
consequence of increased activity
Atrophy
degeneration of muscle fibers
consequence of prolonged inactivity
isotonic contraction
agonist contracts, antagonist relaxes.
basis of movement
isometric contraction
agonist and antagonist contract across a joint, stabilizing it/freezing it.
basis of posture
fast motor units
- _____ fatiguing ____ fibers
- alpha motor neurons are _____ and _____
- generate ____ -frequency action potentials
- contain rapidly fatiguing white fibers
- alpha motor neurons are bigger and faster
- generate occasional high-frequency bursts of action potentials
slow motor units
- _____ fatiguing ____ fibers
- alpha motor neurons are _____ and _____
- generate ____ -frequency action potentials
- contain slowly fatiguing red fibers
- alpha motor units are smaller and slower
- generate steady, low-frequency activity
