Question 1

Muscle soreness several days after exercise is an indication that some sarcomeres were permanently damaged.

Accepted Answer

The answer of Muscle soreness several days after exercise is...

Question 2

In the absence of ATP, a contracted muscle can't relax.

Accepted Answer

ATP is necessary for muscle relaxation because it breaks the actin-myosin cross-bridges and pumps calcium ions back into the sarcoplasmic reticulum, allowing the muscle to relax.

Question 3

Match the following.
-contain gap junctions that permit rapid electrical stimulation of muscle cells

Accepted Answer

Intercalated discs contain gap junctions that allow for rapid electrical communication between cardiac muscle cells, facilitating synchronized contraction.

Question 4

Match the following.
-aerobically break down fatty acids and glucose

Accepted Answer

Slow-twitch fibers are muscle fibers that are adapted for endurance and are capable of aerobic metabolism, which includes the breakdown of fatty acids and glucose.

Question 5

Slow-twitch fibers contain many mitochondria and are well supplied with blood vessels, and can make ATP as they need it.

Accepted Answer

Slow-twitch fibers are designed for endurance and continuous activity, relying on aerobic respiration, which requires a good supply of oxygen delivered by blood vessels and many mitochondria for ATP production.

Question 6

Match each disorder or disease of the muscular system with its description.
-a group of muscular diseases that are hereditary; resulting in muscle wasting; no cure

Accepted Answer

Muscular dystrophy is a group of muscular diseases that are hereditary and result in muscle wasting. There is no cure for muscular dystrophy.

Question 7

According to the sliding filament mechanism, during a muscle contraction, myosin pulls actin filaments toward the center of a sarcomere, causing the entire sarcomere to shorten.

Accepted Answer

The sliding filament mechanism describes how myosin heads bind to actin filaments and pull them toward the center of the sarcomere, resulting in the shortening of the sarcomere and muscle contraction.

Question 8

Match the following.
-time between the stimulation of a muscle and the beginning of a muscle contraction

Accepted Answer

The latent period is the time between the stimulation of a muscle and the beginning of a muscle contraction.

Question 9

Unlike skeletal muscle, cardiac and smooth muscle do not respond at all to the nervous system, but contract on their own. Differences in the rate of contraction of smooth and cardiac muscle are due to the action of pacemakers in cardiac muscles.

Accepted Answer

Cardiac and smooth muscles do respond to the nervous system. Cardiac muscle has pacemaker cells that regulate contraction, but both cardiac and smooth muscles can be influenced by autonomic nervous system inputs.

Question 10

Match each disorder or disease of the muscular system with its description.
-uncontrolled contraction of muscle, usually after heavy exercise

Accepted Answer

Muscle cramps are sudden, involuntary contractions of a muscle or group of muscles, often occurring after heavy exercise.

Question 11

Match the following.
-Actin filaments slide over myosin filaments, and the sarcomere shortens.

Accepted Answer

This description matches the process of muscle contraction, where actin filaments slide over myosin filaments, leading to the shortening of the sarcomere.

Question 12

Following running for a long distance, the muscle soreness that occurs the next day is due to chemicals released to repair damaged muscles.

Accepted Answer

Muscle soreness after exercise, known as delayed onset muscle soreness (DOMS), is partly due to the inflammatory response and chemicals released to repair micro-tears in muscle fibers.

Question 13

The "all-or-none principle" states that in a given muscle, all of the cells are contracting simultaneously or none of them is contracting.

Accepted Answer

The "all-or-none principle" applies to individual muscle fibers or neurons, not entire muscles. It means that a single muscle fiber or neuron will fully contract or not at all, depending on whether the stimulus reaches the threshold.

Question 14

Fast-twitch fibers contain large amounts of myoglobin and predominate in "red" muscle.

Accepted Answer

Fast-twitch fibers contain less myoglobin and are associated with "white" muscle, while slow-twitch fibers contain more myoglobin and are found in "red" muscle.

Question 15

Tetanus results from a state of maximum muscle relaxation, which is necessary to allow the muscle to rest before the next contraction.

Accepted Answer

Tetanus is a condition characterized by sustained muscle contraction, not relaxation, due to rapid and repeated stimulation of the muscle fibers.

Question 16

Muscles of the hand contain a high percentage of fast-twitch fibers, which allows for actions that are strong and quick.

Accepted Answer

Fast-twitch fibers are known for their ability to generate quick and powerful contractions, making them ideal for actions that require strength and speed.

Question 17

Match each disorder or disease of the muscular system with its description.
-disease caused by a bacterial infection; bacterial toxin affects primarily the muscles of the jaw and neck; also known as "lockjaw"

Accepted Answer

Tetanus is a disease caused by a bacterial infection, specifically by the bacterium Clostridium tetani, which produces a toxin that affects the muscles, particularly those of the jaw and neck, leading to the condition commonly known as "lockjaw."

Question 18

Match each disorder or disease of the muscular system with its description.
-inflammation of the connective tissue layers surrounding a muscle; common in the sole of the foot

Accepted Answer

Fasciitis is the inflammation of the connective tissue layers surrounding a muscle, commonly occurring in the sole of the foot.

Question 19

Isometric contractions usually result in no movement of the skeleton or objects.

Accepted Answer

Isometric contractions involve muscle tension without changing the muscle's length, resulting in no movement of the skeleton or objects.

Question 20

Match the following.
-Sarcomere lengthens as calcium is returned to sarcoplasmic reticulum, and the troponin-tropomyosin complex attaches to myosin binding sites on actin.

Accepted Answer

During relaxation, calcium is returned to the sarcoplasmic reticulum, and the troponin-tropomyosin complex covers the myosin binding sites on actin, leading to the lengthening of the sarcomere.

Quiz 6: The Muscular System

Muscle soreness several days after exercise is an indication that some sarcomeres were permanently damaged.

In the absence of ATP, a contracted muscle can't relax.

Match the following. -contain gap junctions that permit rapid electrical stimulation of muscle cells

Match the following. -aerobically break down fatty acids and glucose

Slow-twitch fibers contain many mitochondria and are well supplied with blood vessels, and can make ATP as they need it.

Match each disorder or disease of the muscular system with its description. -a group of muscular diseases that are hereditary; resulting in muscle wasting; no cure

According to the sliding filament mechanism, during a muscle contraction, myosin pulls actin filaments toward the center of a sarcomere, causing the entire sarcomere to shorten.

Match the following. -time between the stimulation of a muscle and the beginning of a muscle contraction

Unlike skeletal muscle, cardiac and smooth muscle do not respond at all to the nervous system, but contract on their own. Differences in the rate of contraction of smooth and cardiac muscle are due to the action of pacemakers in cardiac muscles.

Match each disorder or disease of the muscular system with its description. -uncontrolled contraction of muscle, usually after heavy exercise

Match the following. -Actin filaments slide over myosin filaments, and the sarcomere shortens.

Following running for a long distance, the muscle soreness that occurs the next day is due to chemicals released to repair damaged muscles.

The "all-or-none principle" states that in a given muscle, all of the cells are contracting simultaneously or none of them is contracting.

Fast-twitch fibers contain large amounts of myoglobin and predominate in "red" muscle.

Tetanus results from a state of maximum muscle relaxation, which is necessary to allow the muscle to rest before the next contraction.

Muscles of the hand contain a high percentage of fast-twitch fibers, which allows for actions that are strong and quick.

Match each disorder or disease of the muscular system with its description. -disease caused by a bacterial infection; bacterial toxin affects primarily the muscles of the jaw and neck; also known as "lockjaw"

Match each disorder or disease of the muscular system with its description. -inflammation of the connective tissue layers surrounding a muscle; common in the sole of the foot

Isometric contractions usually result in no movement of the skeleton or objects.

Match the following. -Sarcomere lengthens as calcium is returned to sarcoplasmic reticulum, and the troponin-tropomyosin complex attaches to myosin binding sites on actin.