Muscular System

Check all that are a function of skeletal muscle tissue

-Body movement -Maintenance of posture -Heat production -Regulating elimination of materials -Protection and support

Check all the characteristic of cardiac muscle.

-Cells are short and branching -Cells have one or two nuclei in the center of the cell -They are composed of thick and thin filaments -Cells have one or two nuclei in the outer of the cell -The functional contractile unit is the sarcomere

The typical skeletal muscle fiber contains several components that facilitate the production of ATP. Check all that apply.

-Mitochondria -Glycogen -Myoglobin

Place a single word into each sentence to make it correct, and then place each sentence into a logical paragraph order. Not all terms will be used.

A quick cycle of contraction and relaxation of the muscle is called a twitch. With moderately frequent stimulation, muscle relaxes fully between contractions, but successive twitches are stronger, a phenomenon known as treppe. When the frequency is progressively higher, the muscle does not have time to relax. At an even higher frequency, the muscle exhibits a state of continual contraction, called tetanus . The muscle will eventually fatigue and the muscle tension will then decline.

A decrease in muscular activity or damage to neurons that attach to skeletal muscle can lead to a reduction in the size of muscle called

Atrophy

Place a single word into each sentence, and then arrange the sentences into a logical paragraph order to describe the process of excitation.

Excitation is the process in which action potentials in the nerve fiber lead to action potentials in the muscle fiber. The process begins with a nerve signal stimulating a voltage-gated calcium ion channel to open and the ions entering the synaptic knob The ions stimulate the release of acetylcholine into the synaptic cleft. There is then a rapid fluctuation in membrane voltage at the motor end plate called the end-plate potential. Areas of sarcolemma near the motor plate have gates that open moving ions causing a(n) action potential that excites the muscle fiber.

T or F Smooth muscle is not located in the respiratory system

False

Place a single word into each sentence to make it correct, and then place each sentence into a logical paragraph order that describes the length-tension relationship. Not all terms will be used.

In resting muscle fiber, a sarcomere is normally 2.0 to 2.5 micrometers long. This is the optimum length for producing maximum tension when the muscle contracts. If a muscle fiber is overly contracted, the thick filaments butt against the Z discs. Conversely, if the muscle fiber is overly stretched, there is not enough overlap between the thick and thin myofilaments. Therefore, if the thick and thin filaments do not overlap, very few crossbridges are formed.

Match each sarcomere region with the filaments it contains

Thick -H band -M line Thin -I band Both -A band

If you were studying the neurotransmitter released from axon terminals at a neuromuscular junction, you would be studying

acetylcholine

Place a single word into each sentence to make it correct, and then place each sentence into a logical paragraph order.

during exercise, different mechanisms of ATP production are used depending on the duration of exercise. for immediate energy, the MYOGLOBIN in muscle fiber can supply oxygen for limited cellular respiration. glucose can be released from storages of GLYCOGEN chains for short-term energy needs. long-term exercise requires the completion of the steps of aerobic RESPIRATION to make the maximum amount of atp.

Your school wins the homecoming football game against its biggest rival. You watch as the smallest player tries to lift up the heaviest. As he strains against the 300-pound load and does not move him, what type of muscle contraction are his muscles experiencing?

isometric

Which of the following will increase during strenuous muscular activity?

lactate

Based on your understanding of the process of skeletal muscle contraction, indicate whether each figure represents a relaxed, partially contracted, or fully contracted skeletal muscle.

left -partially contracted right -fully contracted middle -relaxed

A motor neuron transmits the effect of a nerve impulse to the muscle fiber at a _________________.

neuromuscular junction

Which of the following connects muscle to bone?

tendons

Which of the following refers to a sustained muscle contraction?

tetanus

A ________ is defined as a single, brief contraction period and then relaxation period of a skeletal muscle in response to a single stimulation.

twitch