Muscular System

Question 1

What are muscles structured from (general)?

Answer 1

Fibers that can contract and relax.

Question 2

What does the muscular system allow for?

Answer 2

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.

Question 3

What are the three muscle types found in the body?

Answer 3

1. Involuntary/smooth.
2. Cardiac.
3. Voluntary/striated.

Question 4

Where is involuntary muscle found?

Answer 4

1. Blood vessels.
2. Air passages.
3. Alimentary canal.
4. Other tubular structures.

Question 5

What are the physical characteristics of involuntary muscles?

Answer 5

1. Beyond conscious control.
2. Non-striated.

Question 6

What are the physical characteristics of cardiac muscle?

Answer 6

1. Beyond conscious control.
2. Nucleated.
3. Many Purkinje Fibers.
4. Forms a syncytium.

Question 7

Where is cardiac muscle found?

Answer 7

In the heart.

Question 8

What are the characteristics of voluntary muscle?

Answer 8

1. Consists of very minute thread-like muscle fibers in bundles.
2. Striated.

Question 9

Where is striated muscle found?

Answer 9

On the appendages.

Question 10

What are the long strands in skeletal muscle called?

Answer 10

Myofibrils.

Question 11

What are myofibrils made of?

Answer 11

Myofilaments.

Question 12

What are myofilaments made of?

Answer 12

Myosin fibers surrounded by actin filaments in a manner that forms a cap-like structure at each end.

Question 13

What attaches skeletal muscle to bone?

Answer 13

Tendons.

Question 14

What causes muscle contraction to occur?

Answer 14

Stimulus/i from the nervous system (voluntary or involuntary).

Question 15

What happens when a muscle contracts?

Answer 15

The myofibril segment shortens due to the actin filament caps sliding along the myosin filaments.

Question 16

What are the two types of skeletal muscle fibers?

Answer 16

1. Red.
2. White.
   *All skeletal muscle possess some of both.

Question 17

What are the characteristics of white skeletal muscle?

Answer 17

1. Lacks myoglobin.
2. Stores more glycogen.
3. Can manage fast contractions for short durations. Little staying power.
   *Fast twitch.

Question 18

What is myoglobin?

Answer 18

A compound that helps oxygenate muscle tissue.

Question 19

Where is predominately white muscle found in chickens?

Answer 19

The breast muscles.

Question 20

What are the characteristics of red skeletal muscle?

Answer 20

1. Contains myoglobin.
2. Contains other cellular structures for continuous production of energy.
3. Slow contractions for long durations.
   *Slow twitch.

Question 21

What is rigor mortis?

Answer 21

The stiffness that comes over a body shortly after death due to the muscles being unable to relax.

Question 22

What two factors quicken the onset of rigor mortis?

Answer 22

1. Warmer temperatures.
2. Fatigue.

Question 23

Is the state of rigor mortis permanent?

Answer 23

No. the muscles will relax after 10-12 hours due to subsequent changes in the body.