A&P10

Muscle tissue, one of the four basic tissue groups, consists chiefly of cells that are highly specialized for

The dense layer of connective tissue that surrounds an entire skeletal muscle is the

A fascicle is

The bundle of collagen fibers at the end of a skeletal muscle that attaches the muscle to bone is called a

In a sarcomere, thick filaments are linked laterally by proteins of the

The repeating unit of a skeletal muscle fiber is the

Muscle fibers differ from "typical cells" in that muscle fibers

The region of the sarcomere containing the thick filaments is the

Each skeletal muscle fiber contains ________ myofibrils

The thin filaments of striated muscle are made primarily of which proteins?

Action potential propagation in a skeletal muscle fiber ceases when acetylcholine is removed from the synaptic cleft. What mechanism ensures a rapid and efficient removal of acetylcholine?

The neuromuscular junction is a well-studied example of a chemical synapse. Describe a critical event that occurs at the neuromuscular junction

Action potentials travel the length of the axons of motor neurons to the axon terminals. These motor neurons

Calcium entry into the axon terminal triggers which of the following events?

Acetylcholine binds to its receptor in the sarcolemma and triggers __________.

Sodium and potassium ions do not diffuse in equal numbers through ligand-gated cation channels. Why?

Excitation-contraction coupling is a series of events that occur after the events of the neuromuscular junction have transpired. The term excitation refers to which step in the process?

Excitation of the sarcolemma is coupled or linked to the contraction of a skeletal muscle fiber. What specific event initiates the contraction?

A triad is composed of a T-tubule and two adjacent terminal cisternae of the sarcoplasmic reticulum. How are these components connected?

What is name given to the regularly spaced infoldings of the sarcolemma?

Which of the following is most directly responsible for the coupling of excitation to contraction of skeletal muscle fibers?

What is the relationship between the number of motor neurons recruited and the number of skeletal muscle fibers innervated?

The cross bridge cycle is a series of molecular events that occur after excitation of the sarcolemma. What is a cross bridge?

What structure is the functional unit of contraction in a skeletal muscle fiber?

Calcium ions couple excitation of a skeletal muscle fiber to contraction of the fiber. Where are calcium ions stored within the fiber?

After a power stroke, the myosin head must detach from actin before another power stroke can occur. What causes cross bridge detachment?

How does the myosin head obtain the energy required for activation?

What specific event triggers the uncovering of the myosin binding site on actin?

When does cross bridge cycling end?

In a neuromuscular junction, synaptic vesicles in the motor neuron contain which neurotransmitter?

When an action potential arrives at the axon terminal of a motor neuron, which ion channels open?

What means of membrane transport is used to release the neurotransmitter into the synaptic cleft?

The binding of the neurotransmitter to receptors on the motor end plate causes which of the following to occur?

How is acetylcholine (ACh) removed from the synaptic cleft?

The action potential on the muscle cell leads to contraction due to the release of calcium ions. Where are calcium ions stored in the muscle cell?

Inside a muscle, bundles of single muscle fibers form __________.

The muscle action potentials that initiate contraction are transmitted from the sarcolemma into the interior of the muscle fiber by __________.

T tubules and the terminal cisternae are clustered into structures called __________

The sarcoplasmic reticulum contains __________

Which organelle completely surrounds each myofibril inside a muscle fiber?

To what regulatory protein does calcium bind during the initiation of the contraction cycle in skeletal muscle fibers?

What causes the active site on actin to be exposed or uncovered?

Describe excitation in the context of excitation-contraction coupling in skeletal muscle?

Describe how excitation is coupled to contraction in skeletal muscle fibers?

Malignant hyperthermia (MH) is a rare genetic disease in which the sarcoplasmic reticulum leaks calcium when the patient is put under general anesthesia. How would anesthesia affect the skeletal muscles of a patient with MH?

The most important factor in decreasing the intracellular concentration of calcium ion after contraction is

How would the loss of acetylcholinesterase from the motor end plate affect skeletal muscle?

What causes the release of calcium from the terminal cisternae of the sarcoplasmic reticulum within a muscle cell?

The binding of calcium to which molecule causes the myosin binding sites to be exposed?

A myosin head binds to which molecule to form a cross bridge?

What causes the myosin head to disconnect from actin?

What energizes the power stroke?

When a muscle is stimulated repeatedly at a high rate, the amount of tension gradually increases to a steady maximum tension. This is called

The increase in muscle tension that is produced by increasing the number of active motor units is called

A resting muscle generates most of its ATP by

After heavy exercise, if energy reserves in a muscle are depleted, ________ occurs.

At peak levels of muscle exertion the mitochondria can supply

The type of muscle fiber that is most resistant to fatigue is the ________ fiber.

Muscles that move the eyeball have

Fast muscle fibers can adapt to aerobic metabolism by generating more mitochondria in response to

Which type of muscle fibers are best adapted for prolonged contraction such as standing all day?