Chapter 10 Pt. 2 A&P Flashcards
What is muscle fatigue?
Inability to maintain force of contraction after prolonged activity
What happens in central fatigue?
When CNS no longer adequately activates motor neurons
Single motor unit with few muscle fibers=
Fine movement
Single motor unit with many muscle fibers=
no fine movement
Even when at rest, a skeletal muscle exhibits a small amount of tension, called. . .
Tone
What is a twitch contraction?
Brief contractions of all muscle fibers in a motor unit in response to a single action potential
A smooth, sustained contraction of maximal strength:
Tetanus
3 types of skeletal muscle fibers:
- Slow oxidative
- Fast-oxidative
- Fast-glycolytic
Fast fibers have higher. . .
Myosin ATPase
Between oxidative and glycolytic fibers, which are slow to fatigue?
Oxidative
What kind of muscle has dense bodies?
Smooth muscle
What kind of smooth muscle is found in small airway of lungs, iris of eye, and your arrector pili muscles?
Multiunit smooth muscle
Where is single-unit smooth muscle/visceral smooth muscle found?
Hollow organs or viscera - functional syncytium
How long does smooth muscle contraction last?
3 seconds
Which muscle is highly organized, striated, slender, and has short fibers?
Cardiac muscle
What is the purpose of intercalated discs?
To join cells together
What is innervated by the autonomic nervous system?
The heart
What is muscular hypertrophy?
Increased production of:
- Myofibrils
- Mitochondria
- Sarcoplasmic Reticulum
This causes an increase in muscle cells.
What is muscular atrophy?
Decrease in size of muscle fibers due to disuse and denervation.
