Muscular System Flashcards
What are muscles structured from (general)?
Fibers that can contract and relax.
What does the muscular system allow for?
Mechanical action in the form of mobility in the skeleton, movement of material along tubular organs, and pumping blood through the circulatory system.
*Where much of the energy in the body is used.
What are the three muscle types found in the body?
- Involuntary/smooth.
- Cardiac.
- Voluntary/striated.
Where is involuntary muscle found?
- Blood vessels.
- Air passages.
- Alimentary canal.
- Other tubular structures.
What are the physical characteristics of involuntary muscles?
- Beyond conscious control.
- Non-striated.
What are the physical characteristics of cardiac muscle?
- Beyond conscious control.
- Nucleated.
- Many Purkinje Fibers.
- Forms a syncytium.
Where is cardiac muscle found?
In the heart.
What are the characteristics of voluntary muscle?
- Consists of very minute thread-like muscle fibers in bundles.
- Striated.
Where is striated muscle found?
On the appendages.
What are the long strands in skeletal muscle called?
Myofibrils.
What are myofibrils made of?
Myofilaments.
What are myofilaments made of?
Myosin fibers surrounded by actin filaments in a manner that forms a cap-like structure at each end.
What attaches skeletal muscle to bone?
Tendons.
What causes muscle contraction to occur?
Stimulus/i from the nervous system (voluntary or involuntary).
What happens when a muscle contracts?
The myofibril segment shortens due to the actin filament caps sliding along the myosin filaments.
What are the two types of skeletal muscle fibers?
- Red.
- White.
*All skeletal muscle possess some of both.
What are the characteristics of white skeletal muscle?
- Lacks myoglobin.
- Stores more glycogen.
- Can manage fast contractions for short durations. Little staying power.
*Fast twitch.
What is myoglobin?
A compound that helps oxygenate muscle tissue.
Where is predominately white muscle found in chickens?
The breast muscles.
What are the characteristics of red skeletal muscle?
- Contains myoglobin.
- Contains other cellular structures for continuous production of energy.
- Slow contractions for long durations.
*Slow twitch.
What is rigor mortis?
The stiffness that comes over a body shortly after death due to the muscles being unable to relax.
What two factors quicken the onset of rigor mortis?
- Warmer temperatures.
- Fatigue.
Is the state of rigor mortis permanent?
No. the muscles will relax after 10-12 hours due to subsequent changes in the body.
