Bio110 - Ch. 45 Connect: Muscular-Skeletal Systems and Locomotion

Myosin Heads

Each thick filament is made up of many _____ proteins arranged so that the hinges and _____ extend outward, forming cross-bridges.

Fast Short

Fast-glycolytic fibers are used for _____ actions of _____ duration.

ATP

Fast-oxidative and slow-oxidative skeletal muscle fibers are slow to fatigue because they both have the ability to make large amounts of _____.

Rapid

Fast-oxidative fibers are used for prolonged, _____ activity.

Fast-glycolytic

Few mitochondria and little myoglobin; high myosin-ATPase activity.

Few Little

Glycolytic skeletal muscle fibers are characterized by _____ associated blood vessels and _____ myoglobin.

Fast-Oxidative

High myosin ATPase activity

32

If you had a sarcomere that was composed of 16 myosin heads, after two cycles of contraction how may ATP molecules would be consumed?

The sarcomere would not be able to contract therefore the H zone and I band would remain the same in size

If you were running an experiment and interrupted the interaction between thin and thick filaments, what would be the most likely result on sarcomere contraction?

The cross-bridges would remain linked and therefore contraction would stop

In an experiment you, the researcher, removes ATP from the system. What would be a likely consequence of the lack of ATP on muscle contraction?

Muscle contraction would not occur because the tropomyosin filament on the actin molecule would block myosin binding sites preventing the formation of cross bridges

In an experiment you, the researcher, removes calcium ions from the system. What would be a likely consequence of the lack of calcium on muscle contraction?

Oxygen

In muscle fibers, the protein myoglobin acts as an intracellular reservoir of

Myosin Actin

In the cross-bridge of skeletal muscle contraction, a cross-bridge is formed when _____ in the thick filament binds to _____ in the thin filament, pulling the thin filament to the center of the sarcomere in the power stroke.

Slow-Oxidative.

Long-distance flight in a bird

Fast-oxidative

Lots of mitochondria and myoglobin; high myosin-ATPase activity.

Slow-oxidative

Lots of mitochondria and myoglobin; low myosin ATPase activity.

Slow-Oxidative

Low myosin ATPase activity

Slow-oxidative fibers

Low myosin ATPase activity. Occurs in high proportions in long-distance runners. Used in prolonged regular movements. Lowest rate of fatigue. Slow rate of contraction.

Slow-oxidative. Fast-oxidative. Fast-glycolytic.

Major types of skeletal muscle include:

Fast-glycolytic fibers

Make less ATP. Used for short-term actions. Found in high proportions in chicken breast meat. Glycolysis is the primary source of ATP. Fewer mitochondria are present. Fastest rate of fatigue.

2 tails, 2 hinges, 2 heads

Myosin proteins have a structure that includes:

Motor neurons

Neurons in the CNS that transmit signals to control muscles are called:

Smooth muscle

Not striated. Surrounds blood vessels. Surrounds the bladder. Surrounds the airway.

Sarcomere

One complete unit of the repeating pattern of thick and thin filaments within a myofibril is known a(n) _____.

Oxygen

Oxidative fibers are highly vascularized because most of their ATP production requires _____, which is delivered by blood to these muscle.

Numerous High

Oxidative skeletal muscle contains _____ mitochondria and has a _____ capacity for oxidative phosphorylation.

Numerous Fewer

Oxidative skeletal muscle fibers have _____ mitochondria, while glycolytic have far _____.

Pi

Power stroke: Release of _____ causes the cross-bridge to move toward the Z zone. This moves the actin toward the H zone.

High

A fast fiber is a skeletal muscle containing myosin with a _____ rate of ATP hydrolysis.

Few High

A glycolytic muscle fiber contains _____ mitochondria and _____ concentrations of both glycolytic enzymes and glycogen.

Atrophy

A reduction in the size of a muscle due to lack of use is a condition known as

Tropomyosin

A rod-shaped protein arranged end to end along the actin thin filament is:

Fast

A skeletal muscle fiber containing myosin with a high rate of ATP hydrolysis is a _____ fiber.

Slow

A skeletal muscle fiber containing myosin with a low rate of ATP hydrolysis is a _____ fiber.

Low

A slow fiber is a skeletal muscle fiber that contains myosin with a _____ rate of ATP hydrolysis.

Skeletal.

A(n) _____ muscle is composed of muscle fiber cells bound in successive layers of connective tissue:

The release of Ca2+ from the sarcoplasmic reticulum is stimulated by a nerve impulse. Ca2+ ultimately allows contractions to occur by facilitating the binding of actin and myosin.

An accurate characterization of calcium's role in muscle contraction would state that.

Myofibrils

An increase in muscle size is the direct result of a increase in the number of:

Autonomic

As contractions of smooth muscle are involuntary, they are controlled by the ______ nervous system

Fast-oxidative fibers

Associated with rapid actions. Used for production of song in birds. Intermediate rate of fatigue.

Oxidative Glycolytic

Based on the way in which they produce the ATP needed for contraction, muscle fibers are classified as either _____ or _____.

Fast Slow

Based on their rate of shortening, muscle fibers are classified as either _____ or _____.

Ca2+

Binding: When _____ levels are high, cross-bridges can bind to actin.

Movement of contents within tubes and hollow organs

Contraction of smooth muscle control:

Paralysis: Action potentials would be impeded at the neuromuscular junction, and the nerve would be unable to trigger the muscle to act

Curare, a poison from a South American shrub, blocks the binding of Ach by muscle cells. What would happen to muscle function if a toxic dose of curare enter the bloodstream?

ATP.

Despite their low levels of myosin ATPase activity, slow-oxidative skeletal muscle fibers are capable of producing large amounts of _____.

Myosin

Detaching: ATP binds to ______ causing the cross-bridge to detach.

Skeletal muscle

Under voluntary control. Used for locomotion.

Vertebrate skeletal muscle can generate action potentials. Invertebrate skeletal muscle have graded membrane potentials. Vertebrate skeletal muscle is electrically excitable.

Vertebrate skeletal muscle differs from invertebrate muscle in which of the following ways?

Provides the force required for the heart to pump blood

What is the function of cardiac muscle?

To bind with troponin, changing its shape so that binding sites on the acting filament are exposed

What is the role of calcium in muscle contractions?

Fast-glycolytic

What skeletal muscle fibers are used for extremely rapid actions of short duration, fatigue easily, and make ATP using glycolysis?

Surrounding hollow organs and tubes

Where in the vertebrate body is smooth muscle found?

Skeletal

Which muscle type contracts and moves bones?

Skeletal

Which muscle type is directly involved in locomotion?

skeletal.

Which muscle type is directly involved in locomotion?

The H zones contain only myosin, while the I bands contain only actin

Which of the following statements about H zones and I bands is TRUE?

Veins Uterus

Which of the following structures contain smooth muscle?

Fast-glycolytic.

Which skeletal muscle type has the highest rate of fatigue?

Cardiac

_____ muscle provides the force required for the heart to pump blood to the lungs and the rest of the body.

Fast-glycolytic

Produce little ATP with high myosin-ATPase activity.

Fast-oxidative

Produce lots of ATP with high myosin-ATPase activity.

Slow-oxidative

Produce lots of ATP with low myosin-ATPase activity.

Cardiac muscle

Pumps blood. Found only in the heart.

H zone

Resetting: Hydrolysis of ATP provides energy, which causes the cross-bridge to move away from the _____ . ADP and Pi remain bound

Increase Increase

Resistance exercises results in a(n) _____ in the thickness of individual muscle fibers, and thus a(n) _____ in the size of the muscle.

Oxidative Glycolytic

The categories of skeletal muscle based on the type of metabolic pathway used for synthesis of ATP are:

Rate

The classification of muscle fibers as either fast or slow is based upon their _____ of shortening.

ATP

The classification of muscle fibers as either oxidative or glycolytic is based on the way in which they produce the _____ needed for contraction.

Myofibrils.

The cytosol of muscle fibers contains numerous bundles called

Skeletal

The muscle that is found attached to bones throughout the body and is not localized in association with only certain organs is

Myoglobin

The protein _____ increases oxygen availability in skeletal muscle fiber, providing an internal reservoir of oxygen.

True

The sequence of cross-bridge formation and myofilament movement will be repeated as long as calcium ions are present

Excitation - Contraction

The sequence of events by which an action potential in the plasma membrane of a muscle fiber leads to cross-bridge activity is known as _____ - _____ coupling.

Cycle

The sequence of events from the time that a cross-bridge binds to a thin filament, through the movement, to the time that it is ready to bind again is known as the cross-bridge _____.

Myosin

The thick filaments within myofibrils are composed of the protein _____.

Skeletal Cardiac Smooth

The three types of muscle found in vertebrates are _____ muscle, _____ muscle, and _____ muscle.

Myoglobin

The white coloration of glycolytic muscle fibers is due to the low concentration of _____.

In the middle of each sarcomere

Thick filaments are located:

One-half

Thin filaments are _____ the diameter of thick filaments.

Actin

Thin filaments within myofibrils are composed of the cytoskeletal protein.

Oxidative

ATP production in _____ skeletal muscle is reliant upon the oxygen and nutrients delivered via the circulatory system?

Glycolytic

ATP production in fast-glycolytic skeletal muscle fibers is low because ATP in these fibers is produced via _____.

Heart

Cardiac muscle is found only in the _____.

They transmit signals away from the CNS. They activate muscle contractions. Their bodies are located in the CNS

Choose the statements that describe motor neurons:

They transmit signals away from the CNS. They activate muscle contractions. Their cell bodies are located in the CNS.

Choose the statements that describe motor neurons:

Striated

Due to its regular banding pattern, skeletal muscle is also known as _____ muscle.

The troponin molecule

During contraction of muscle, calcium ions binds to...

1, 2, 5, 6

During contraction specific regions and subunits of the sarcomere remain unchanged while others do not. From the list below identify the structures and regions that remain constant 1. A band 2. Actin 3. H zone 4. I band 5. Myosin 6. Z line

3, 4

During contraction specific regions and subunits of the sarcomere remain unchanged while others do not. From the list below identify the structures and regions that shorten during muscle contraction 1. A band 2. Actin 3. H zone 4. I band 5. Myosin 6. Z line

Low Higher

Slow skeletal muscle fibers have a _____ rate of ATPase activity, whereas fast muscle fibers have a _____ rate.

Sustained Long

Slow-oxidative fiber can maintain _____ activity over _____ periods of time without tiring.

Actin filaments sliding past myosin filaments

Muscle contraction is caused by

The maximal rate of ATP hydrolysis

Muscle contraction rate is ultimately determined by:

Myofibrils

Muscle fibers are composed of bundles of _____.

Slow-oxidative.

Muscle fibers used for prolonged, regular types of movement are:

Sarcomeres

Myofibrils are composed of units of thin and thick filaments called:

ATP ATPase

Slow-oxidative skeletal muscle fibers can make large amounts of _____ despite their low rates of _____ activity.

Fast-Oxidative.

Shaking of a rattlesnake's tail

Myosin ATP

Skeletal muscle can be classified into three major types based on two characteristics: ATPase activity of the protein _____, and the metabolic pathways used for the synthesis of ______.

Glycolytic.

Skeletal muscle fibers can be classified based on the type of metabolic pathways used to make ATP _____ fibers possess large stores of glycogen (a glucose polymer) and little myoglobin (corresponding to their limited use of oxygen).

Oxidative

Skeletal muscle fibers can be classified based on the type of metabolic pathways used to make ATP. Fibers that contain numerous mitochondria and have a high capacity for oxidative phosphorylation are called _____ fibers.

Throughout the body

Skeletal muscle is found:

Muscle

Skeletal, cardiac, and smooth are the three types of _____ found in the vertebrate body.

Skeletals

Striated muscle is a synonym for what type of muscle?

Cardiac

The heart is composed only of _____ muscle.

Connects the heads to the tails. Is flexible.

The hinge of the myosin protein:

Excitation-contraction coupling

The linkage of the action potential in the plasma membrane of a muscle fiber to the action of the muscle is called

Actin.

Tropomyosin is composed of two intertwining rod-shaped proteins that are arranged along the _____ filament.