Chapter 10 HW

Check all that are a function of skeletal muscle tissue.

- Body Movement - Maintenance of Posture - Heat Production - Regulation Eliminating of materials - Protection and Support

Place the events involved in muscle contraction in the correct order.

1. A nerve impulse causes acetylcholine (ACh) release at a neuromuscular junction. 2. ACh binds receptors on the motor end plate, initiating a muscle impulse. 3. Calcium ions bind to troponin, causing tropomyosin to move and expose active sites. 4. Myosin heads attach to actin and form crossbridges. 5. A cyclic "attach, pivot, detach, return" event occurs. 6. Calcium ions are moved back into the sarcoplasmic reticulum by ATP-driven pumps. 7. Myofilaments passively return to their original state.

Place the organizational level of muscle tissue in order, beginning with the entire muscle and ending with the smallest component.

1. Muscle 2. Fascicle 3. Muscle Fiber 4. Myofibril 5. Myofilament

The area of the muscle fiber where the actin and myosin myofilaments overlap is the

A band

The ability of muscle cells to shorten is called _______, a property that allows muscle cells to cause body movement.

Contractility

In a relaxed muscle, the ends of the actin filaments overlap.

False

In fully contracted muscles, the actin filaments lie side-by-side. Group starts

False

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

Isometric

indicate which type of contraction each figure represents.

Isometric Contraction is the arm bent and close to you Isotonic Contraction is the arm extended

The specialized region of the sarcolemma that has folds and indentations to increase the membrane surface area covered by the synaptic knob is the

Motor end plate

The distance from one Z disk to the next Z disk is called a(n)

Sarcomere

At the ends of muscles, the connective tissues merge to form a __________, which attaches the muscle to other structures.

Tendon

Match each sarcomere region with the filament(s) it contains.

Thick Filaments - H Band and M line Thin Filaments - I band Both - A band

The component of a muscle fiber that quickly transports a muscle impulse from the sarcolemma throughout the entire muscle fiber is called the

Transverse Tubule (T-Tube)

During contraction of a muscle, calcium ions bind to the

Troponin molecule

The sequence of crossbridge formation and myofilament movement will be repeated as long as calcium ions are present.

True

When crossbridges form and the muscle fibers contract, the actin myofilament slides past the myosin myofilament.

True

An individual is better at performing repeated muscle contractions under aerobic conditions if he or she has a greater percentage of _____ fibers in the muscles used in that activity.

Type I

All the muscle fibers under the control of a single motor axon are referred to as

a motor unit

A power stroke involves

a myosin head pulling a thin filament toward the center of the sarcomere.

The action potential of a muscle fiber occurs

along the sarcolemma and down the T-tubules.

the bond between the actin and myosin head is broken when

an ATP molecule binds to the myosin head.

The characteristic of muscle that allows it to be passively stretched is

extensibility.

Energy is released when

ATP is broken down into ADP and phosphate.

During contraction, the actin myofilaments slide toward the

H zone