AP Chapter 9- Mastering

The sliding filament model of contraction states that _

A sarcomere is the distance between two?

What band contains only actin filaments?

What are the thicker filaments called?

Both actin and myosin are found in which band?

Myosin filaments are located in which band

What is the functional role of the T tubules?

Which of the following is the correct sequence of events for muscle contractions?

The mechanism of contraction in smooth muscle is different from skeletal muscle in that __

Part complete An anaerobic metabolic pathway that results in the production of two net ATPs per glucose plus two pyruvic acid molecules is _

Part complete When a muscle is unable to respond to stimuli temporarily, it is in which of the following periods?

Immediately following the arrival of the stimulus at a skeletal muscle cell there is a short period called the ________ period during which the neurotransmitter is released by exocytosis, diffuses across the synaptic cleft, and binds to its receptors.

When muscle tension develops but the load is not moved

Determined by alternating motor units of a muscle organ even when the muscle is at rest.

Continued sustained smooth contraction due to rapid stimulation.

When the muscle tension developed overcomes the load and muscle shortening occurs.

How a smooth increase in muscle force is produced.

Which step precedes all of the other listed steps? Which step precedes all of the other listed steps? The sarcoplasmic reticulum is activated. ACh is released by the motor neuron. Na+ rushes into the cell. An action potential starts on the sarcolemma.

Which of the following is most directly required to initiate the coupling of myosin to actin? Which of the following is most directly required to initiate the coupling of myosin to actin? Ca++ ACh ATP glucose

Identify the correct sequence of the following events. a. Myosin generates a power stroke. b. Ca++ binds to troponin. c. ATP recharges the myosin head. d. Troponin removes tropomyosin from G actin. e. The sarcomere shortens. f. Myosin binds to actin.

the final chemical messenger and "trigger" for muscle contraction. It binds to troponin.

a neurotransmitter released at motor end plates by the axon terminals.

It diffuses across the cell membrane resulting in depolarization.

Activates synaptic vesicles in axon terminals to fuse with plasma membrane of axon terminal.

Where the axon of a motor neuron connects with the muscle fibers.

Breaks down ACh into its building blocks, rendering it inactive.

After nervous stimulation stops, what prevents ACh in the synaptic cleft from continuing to stimulate contraction?

What part of the sarcolemma contains acetylcholine receptors?

Which of the following events triggers the subsequent steps of excitation-contraction coupling? Which of the following events triggers the subsequent steps of excitation-contraction coupling? propagation of an action potential along the sarcolemma and T tubules release of calcium ions from the terminal cisterns of the sarcoplasmic reticulum release of acetylcholine from axon terminals at the neuromuscular junction binding of calcium ions to troponin, which removes the blocking action of tropomyosin