during a contraction, muscles are first....

excitable

what are skeletal muscle groups that work together to create the same movement called?

synergistic muscles

stimulation of acetylcholine release cause skeletal muscles to become?

to generate an electric impulse

In order for a muscle contraction to occur, cross bridges must form between...

thin and thick filaments

For a skeletal muscle to contract, what must occur?

it must be activated by a nerve and

have the presence of calcium

when an electrical impulse traveling along a motor neuron arrives at a neuromuscular junction what happens?

acetycholine is released from the nerve terminal

the primary energy source used by muscle cells to generate ATP is?

glucose

isotonic muscle contractions occur when?

a muscle shortens while maintaining a constant force.

During a marathon, runners will use of ATP and glucose early in the race. which energy source is generally used next for producing ATP?

stored glycogen

At the end of the contractile period, energy from the breakdown of ATP is used to?

transport calcium back into the sarcoplasmic reticulium so the relaxation can occur.

T, or transverse, tubes in skeletal muscle function to...

to store ionic calcium

what is a characteristic of an isotonic muscle contraction but not an isometric muscle contraction.

isometric do not cause muscle movement. isotonic does

give me examples of isotonic contractions

lifting light or heavy objects

after intense exercise, your body attempts to overcome oxygen debt by what?

your body takes in excess oxygen.

after electrical stimulation of a muscle cell, calcium functions to...

diffuses into the cell cytoplasm and then comes in contact with the myofibrils where it sets in motion a chain of events that leads to contraction.

a myogram is a recording of what?

of muscle activity

which muscles would one expect to find motor units made up of only a few muscle cells?

where fine control is essential.

fast twitch fibers tend to rely on what for quick bursts of energy?

creatine phosphate and anaerobic metabalism

what increases in the body as a result of aerobic training?

lactid acid

what are the differences between smooth and cardiac muscle?

the cardiac muscles surround the heart. smooth muscle covers other areas like ducts, tubes and cavities of your digestive, urinary, respiratory and genital systems. Smooth muscle is also found in the skin and eyeball.

during aerobic exercise the target heart rate should be maintained for at least how many minutes in order to train the body?

20 minutes

what are the differences between all three muscle types?

cardiac has striated appearance

smooth muscle has no striations

cardiac and smooth muscles are involuntary and are able to contract on their own.

muscle soreness that occurs after jogging down a hill results from what?

release of lactic acid.

intercalated discs contain what?

Intercellular junctions

what do anabolic steroids do to your body?

to increase muscle mass, and muscle strength, it can cause a lot of negative things to happen as well. it increases your risk of heart attack or stroke. and severe liver disease.