chapter 7 hw

The term used to describe muscular growth in response to usage is

hypertrophy.

Which of the following occurs when tension production rises to a peak and very brief periods of relaxation occur?

incomplete tetanus

The specialized sarcolemma that contains acetylcholine receptors is the

motor end plate

Botulism

results from a bacterial toxin that prevents the release of acetylcholine at the axon terminals.

The skeletal muscles store calcium ions in the terminal cisternae of the

sarcoplasmic reticulum.

A person whose genetic makeup makes him or her a better marathon runner than a sprinter probably has more ________ in his or her leg muscles.

slow fibers

Creatine phosphate serves to

supply energy to synthesize ATP.

Acetylcholinesterase is found within the

synaptic cleft

Tropomyosin strands are held in position by which of the following?

troponin molecules

A single stimulus-contraction-relaxation sequence in a muscle fiber is known as a(n)

twitch.

Upon the nerve impulse arriving at the axon terminal,

acetylcholine is released.

Myofibrils are made primarily of

actin and myosin

Which of the following terms is a descriptive word for a muscle's action?

adductor

A resting muscle generates most of its ATP by

aerobic respiration.

Why do individual muscle twitches have to be added together, as in summation or tetanus?

Multiple twitches add up to an increase in muscle fiber tension, which increases the strength of the muscle.

Place these steps of muscle contraction in the correct order.1. Action potential is generated along the sarcolemma2. Nerve impulse arrives at synapse3. Calcium is released into muscle cell cytoplasm4. Acetylcholine is produced5. Actin and myosin molecules continuously cross-link, with actin molecules being pulled inward

2, 4, 1, 3, 5

The stiffness that occurs at death, when actin and myosin molecules stay linked to each other in a contracted state, is due to a lack of

ATP

Which of the following is one of the steps that ends a contraction?

Acetylcholine is broken down by acetylcholinesterase.

During moderate activity, which of the following is true regarding muscle metabolism?

Glucose and fatty acids are catabolized.

The area of the sarcomere that is the light region between two successive A-bands is the

I band.

Which of the following occurs when glycolysis produces pyruvate faster than it can be used by the mitochondria?

Lactic acid is produced.

Which of the following statements describes how muscles help maintain homeostasis?

Skeletal muscle contractions help maintain body temperature.

Which of the following is an effect of aging on the muscular system?

Skeletal muscle fibers become smaller in diameter.

Which statement regarding skeletal muscle is true?

Skeletal muscles contain blood vessels.

In response to action potentials arriving from the transverse tubules, the sarcoplasmic reticulum releases

calcium ions.

Muscle cells

can only contract.

Active muscles generate

carbon dioxide and heat

"Anaerobic endurance"

is exemplified by contractions of fast muscle fibers.

Calcium ions are released from the sarcoplasmic reticulum during the ________ phase of contraction.

latent

Regarding lactic acid regulation, which cells in the body consume extra oxygen and produce ATP for the conversion of excess lactate absorbed from the blood back to glucose?

liver cells

During activities requiring aerobic endurance,

most of the muscle's energy is produced in mitochondria.

The difference in the action when comparing the biceps brachii to the flexor carpi radialis, is

one muscle flexes the hand at the wrist and the other flexes the entire forearm.

The additional oxygen required during the recovery period to restore the normal pre-exertion levels is called the

oxygen debt.

The heart has to be able to regulate its contractions. Heart muscle, unlike skeletal muscle, cannot go into a tetanus. This is because

the heart muscle has to be able to consistently contract and pump blood in a controlled fashion.

Tom is having difficulty dorsiflexing and inverting his right foot. Which muscle is most likely involved in this problem?

tibialis anterior

What is the function of the transverse tubule?

to transmit electrical impulses to the cell's interior

Which statement regarding isometric contractions is true?

The tension produced never exceeds the load.

Which statement regarding "heat loss" is true?

Muscle contractions play an important role in the maintenance of normal body temperature.

Neurotransmitters that cause skeletal muscle contraction are normally stored in

motor neuron axon terminals.

Exhaustion of energy reserves or decline in pH due to production and dissociation of lactic acid causes

muscle fatigue.