A&P I Lecture exam #3 review Part 2

Thick filaments are composed of ______ protein, which has movable heads. Thin filaments are composed of ______ protein which is connected to regulatory proteins.

Myosin G actin

You can increase the amount of tension being generated by muscle by increasing:

The intensity of stimulation. The frequency of stimulation

Sliding filament theory states that the sarcomere, not the myofilaments, shorten during contraction. Which filaments remain stationary, using their heads to manipulate the filaments listed below? Which filaments move, sliding towards the center of the sarcomere?

Thick Thin

Triad consist of two types of structures. ______ Are invaginations of the sarcolemma which carry electrical signals into the sarcoplasm. ______ Are expanded regions belong into the sarcoplasmic reticulum, which surround the above structure

Transverse tubules or T tubules Terminal cisterns or terminal cisternae

A contraction can only begin when calcium binds to which protein ?

Troponin

Why does oxygen consumption rise during long workout? Why does oxygen consumption remain high after ending exercise?

During periods of long exercise, oxygen consumption rises in order to supply the body with enough oxygen to sustain aerobic respiration. Oxygen consumption remains high following exercise in order to restore the muscle to pre-exercise conditions.

In an ________ contraction more resistance is present than tension is generated, so the contracting muscle lengthens. In a ______ contraction, more tension is generated than needed to move the resistance, so the contracting muscle shortens.

Eccentric isotonic Concentric isotonic

What exercise improves the fatigue resistance of the muscle? What exercise improves the strength of the muscle?

Endurance Resistance

Match the connective tissue to the correct description

Epimysium - most superficial layer, surrounds all muscles. Endomysium-deepest layer, surrounds muscle fibers. Perimysium-intermediate layer, surrounds fascicles. Fascia - separate individual muscles and muscle groups, connects to tendons.

List the four events of muscle contraction in chronological order

Excitation Excitation-contracting coupling Contraction Relaxation

Match the characteristics of muscle tissue to the correct definition

Extensibility - capable of stretching beyond resting length. Conductivity - capable of allowing electrical signals to spread along length of cell. Excitability - capable of producing electrical signals when stimulated by stimuli. Elasticity -capable of recoiling after stretch. Contractility - capable of contracting and producing tension.

Pick which of the following would be stronger (produce more tension).

Fascicle arrangement: Pennate Size-Larger Fatigue -Muscle that has not exercised today Size of active motor units- Larger motor unit Sarcomere length- Normal resting length

What type of fibers have fast, powerful contractions but fatigue easily? What type of fibers are slower and weaker, but fatigue-resistant?

Fast-twitch Slow- twitch

What is defined as progressive weakness and loss of contractility in muscles, caused by continuous usage True or false: running out of ATP is the primary cause of the above phenomenon.

Fatigue False

A single skeletal muscle cell is known as a muscle ______ Groups of the above cells are arranged into bundles called _____

Fiber Fascicles

You can alter the strength of a contraction by altering the _____ of stimulation, which results in temporal (wave) summation. You can alter the strength of a contraction by altering the ______ of stimulation (recruitment)

Frequency Intensity

List any two functions of muscle tissue. Explain how two functions you chose benefits the organism.

Glycogen control - it regulates the concentration of blood glucose in the body, absorbs and stores glucose as glycogen. Stability - muscles maintain posture by preventing unwanted movements. Many muscles also stabilize the joints by maintaining tension on tendons and bones.

Thin filaments have a complex anatomy with many named proteins, including these two regulatory proteins. The protein _____ houses a binding site for calcium, and is connected to the below. When calcium binds to the above, it causes the protein ______ to slide off of the active sites

Troponin Tropomyosin

What regulatory protein does calcium binds to, once released into the sarcoplasm from storage? The binding causes which protein to slide off of the active sites, exposing them and permitting binding of the myosin heads?

Troponin Tropomyosin

When a muscle is affected by a single stimulus, they produce a single _______ What is a brief phase in which only internal tension is generated, and corresponds to the events of excitation and excitation-contraction coupling

Twitch Latent period

Are the following statements is true or false?

• During a contraction, only the thin fibers slide towards the center. True • Skeletal striated muscle tissue is the only voluntary muscle tissue. True • Calcium is required to bind to troponins for a contraction to begin. True • A single muscle fiber can be innervated by multiple motor neurons. False • Sarcomeres lengthen during a contraction. False

Define maximum oxygen intake. Define excessive post exercise oxygen consumption.

• The maximum oxygen intake is the maximum rate of oxygen consumption during exercise. • Excess post exercise oxygen consumption is the elevated consumption of oxygen following exercise, used to restore the muscle to pre-exercise conditions.

Match the region of the sarcomere to the best description

• Z discs - mark the boundaries of sarcomeres, anchors protein filaments, move closer together during contraction. • A band - contains thick and thin filaments at rest, darker in color. • H band - contains only thick filaments at rest, shrinks during contraction. • I bands - contain only Thin filaments at rest, lighter in color. • M line-center of the sarcomere, stabilizes thick filaments.

Define the term motor unit. How does motor unit size affect its properties?

A motor unit is one motor neuron and all of the muscle fibers that it innervates. Smaller motor units are weaker, but more precise. Larger motor units are a stronger, but less precise. Smaller units are also more sensitive to stimulation.

• According to the length tension relationship, you will generate the most tension when the sarcomere begins contracting at ________ Contractions cannot occur without the use of the element ______, as it is needed to release neurotransmitters and bind to regulatory proteins

A normal resting length Calcium

Contractions require hydrolyzing (breaking apart) ______ in order to provide energy This energy is used to energize the ______of the tick filament, allowing them to move to the "high energy" position and form cross bridges

ATP Myosin heads

The only neurotransmitter used at the neuromuscular junction is ______ When the above neurotransmitter binds to receptors, chemically-gated channels open which produce an ______

Acetylcholine End - plate potential

List one advantage and one disadvantage of anaerobic fermentation List one advantage and one disadvantage of aerobic respiration

Advantage of anaerobic fermentation it does not require oxygen and it is fast. Disadvantage of it being short term and an inefficient. Advantage of aerobic respiration is it generates more ATP but disadvantage is it requires oxygen

Match the ideal method of energy production to the duration of activity

Aerobic respiration - long duration, typically low intensity activity. Phosphagen system - immediate usage, short duration, typically high intensity activity. Anaerobic fermentation - short duration, typically high intensity activity.

Once ATP is depleted, more can be produced via: _______ Which does not require oxygen and involves fewer steps. ________ Which does not require oxygen but involves more steps.

Anaerobic fermentation Aerobic respiration

During sprinting, the majority of the ATP needed to maintain activity would come from

Anaerobic fermentation and glycolysis

Which protein binds and stores oxygen, and is exclusive to muscle tissue? What is the storage form of glucose and muscle have abundant stores of?

Myoglobin Glycogen

Why is calcium necessary for a contraction to occur? Why is calcium moved out of the sarcoplasm and stored when a muscle fiber is at rest?

Calcium is required in order to generate a contraction as it binds to troponin, a regulatory protein • To allow muscle to relax, calcium must be moved into storage so that the active site can be recovered. Calcium can also harm the cell if it remains in the sarcoplasm, as it may form crystals with phosphate.

Match the cause of fatigue to the type of activity

Central fatigue - low-intensity, long-duration ADP/phosphate accumulation - high intensity, short duration. Fuel depletion - low intensity, long duration. Potassium accumulation - high intensity, short duration. Electrolyte loss - low intensity, long duration.

What is the formal definition of the generation of internal tension that does not have to involve a change in length? What term refers to the amount of weight that muscle must move or lift?

Contraction Resistance

Where in the motor neuron and/or muscle fiber to the event of contraction occur?

Contraction - Sarcomere Excitation-contraction coupling -Sarcolemma Relaxation - All of the above structures Excitation -Neuromuscular junction

Muscle tissue can store phosphate groups by binding them to a unique storage molecules called ______. The combination of all muscle fibers ATP along with the above storage molecule is referred as the ________ system

Creatine phosphate Phosphagen

When an energized myosin head binds to a binding site on a G actin, this connection is called a _______ In order to energize the head, you must hydrolyze or break apart, a molecule of _______

Cross - bridge ATP

Increasing the frequency of stimulation results in ________, as state of sustained contraction in which the next contraction begins before the relaxation period ends Increasing stimulation frequency still further results in _____, as single prolonged contraction with no relaxation

Incomplete tetanus Complete tetanus

Which contraction results in the muscle to visibly change in length? Which contraction result in the muscle not visibly change length even though tension is still generated?

Isotonic Isometric

Are they following statements true or off fast twitch or slow twitch muscle fibers?

Lots of myoglobin - Slow twitch Lots of glycogen - Fast which Smaller diameter - Slow twitch Fewer mitochondria - Fast which Better capillary supply - Slow twitch

What is refers to the tendency of muscle to maintain a partial state of contraction? They do this by alternating the activation and relaxation of different_______

Muscle tone Motor units

Skeletal muscle fibers are formed by the merger of multiple _____ cells in the embryo. Some of the above do not merge and become _______ cells, which participate in repair of damaged muscle.

Myoblast Satellite

Sarcomeres are a repeating pattern of protein filaments that are found within:

Myofibrils

Muscle fibers contain many long cords of protein called _______, which are the contractile units of cell. These in turn are composed of long proteins strands called ________, which contain motor (contracttile) proteins.

Myofibrils Myofilaments

To support their activity, muscles can store both oxygen and glucose. Muscle fibers store oxygen by attaching it to _____, a reddish proteins found only in muscle Muscle fibers store glucose in a polymer storage form known as _____, or "animal starch".

Myoglobin Glycogen

What is the term of synapse between a motor neuron and the muscle fibers known as? Which neurotransmitter only used at this type of synapse?

Neuromuscular junction or motor end plate Acetylcholine

• During the _______, the myosin head snaps from the high energy to the low energy position, which moves the attached thin filament. • Following this, another molecule of ATP must be spent doing the ______ in order to reset the head and return it to the high energy position.

Power stroke Recovery stroke

When sufficient oxygen is present, glucose is first converted into ______, which will later be used to produce more ATP. When sufficient oxygen is not present, the above molecule instead becomes _______, which is removed from the muscle and can serve as fuel elsewhere.

Pyruvate Lactate

Muscle cells use unique sets of terms. The plasma membrane is known as the _____ Cytoplasm is known as ______

Sarcolemma Sarcoplasm

What is modified form of smooth ER that wraps round myofibrils? What kind of ion does above structure stores?

Sarcoplasmic reticulum Calcium

Motor units obey the _______, which states that smaller, weaker units are stimulated before larger, stronger units True or false: all twitches within a muscle are always of the same strength regardless of conditions

Size principle False

Which forms of muscle tissue are voluntary

Skeletal striated only

Which division of the nervous system controls all skeletal muscle? Which neurons are the only type of neurons that innervate skeletal muscle?

Somatic motor Motor or multi polar

Skeletal and cardiac muscle cells are______ , or striped in appearance. The above is due to the fact that myofibrils are divided into functional units called _____

Striated Sarcomeres

Waves of action potentials are conducted along the muscle cell, which pass into invagination in the sarcolemma called ______ The action potential's trigger the opening of voltage-gated channels on the ______ which lie directly next to the above structure, forming a triad

T tubules Terminal cisterns