Chapter 12 Practice Questions Flashcards
The cells of muscles are called muscle ______.
Fibers
What is the principle purpose of the muscular system?
Create movement
Select all of the following that are muscle tissue types: • Rough • Cardiac • Skeletal • Smooth • Digestive
- Cardiac
- Skeletal
- Smooth
The region where the end of an axon from a neuron comes into close contact with a muscle fiber is called a ______ junction.
Neuromuscular
The main protein that is found in the thin filaments in myofibrils of muscle fibers, is called ______.
actin
What permits rapid passing of a contraction between cardiac muscle fibers?
Intercalated disks
Select all of the following that are components of a muscle fiber: • Sacromere • Sarcoplasmic reticulum • Axon terminal • Myofibril • Sarcolemma
- Sacromere
- Sarcoplasmic reticulum
- Myofibril
- Sarcolemma
Put the molecular events underpinning muscle contraction in order, beginning with the action that provides the required energy:
• ADP and phosphate are bound to myosin
• The myosin head bends as ADP and phosphate are released
• ATP is split by myosin release
• ATP is bound by myosin
- ATP is split by myosin release
- ADP and phosphate are bound to myosin
- The myosin head bends as ADP and phosphate are released
- ATP is bound by myosin
Which of the following describe cramps?
A. Can occur when sleeping after a strenuous workout
B. Can occur in leg and foot after strenuous activity
C. Generally does not occur after or during strenuous activity
D. Strong, painful spasms
A. Can occur when sleeping after a strenuous workout
B. Can occur in leg and foot after strenuous activity
D. Strong, painful spasms
Fascia is a type of connective tissue that surrounds the muscle. What is it called when it extends beyond the muscle?
Tendon
In a myofibril, what is the distance from one Z line to the next?
Sacromere
The main protein that is found in the thick filaments in the myofibrils is called ______.
Myosin
How do the myosin-binding sites become exposed, allowing myosin to bind with actin?
When calcium is released from the sarcoplasmic reticulum, tropomyosin threads shift their position, exposing the myosin-binding sites
What occurs during muscle contraction according to the sliding filament model?
• Myosin blocks binding sites to actin
• When the sarcomere lengthens the actin slide past the myosin
• Myosin filaments break down ATP
• Myosin heads form cross bridges towards the binding sites on sctin
- Myosin filaments break down ATP
* Myosin heads form cross bridges towards the binding sites on actin
What are muscle fibers that fatigue quickly, are light in color, and contain little or no myoglobin?
Fast-twitch fibers
Which of the following are the characteristics of fermentation in muscle contraction? • Produces ATP • Aerobic breakdown of glucose • Does not require oxygen • Results in buildup of lactate
- Produces ATP
- Does not require oxygen
- Results in buildup of lactate
A muscle cell organelle that consist of a linear arrangement of sacromeres and contains both thick and thin filaments is called a ______.
Myofibril
Which of the following is an example of antagonistic muscle action?
A. When the biceps flex the forearm, the triceps extend the forearm
B. When the biceps extend the forearm, the triceps extend the forearm
C. When the biceps flex the forearm, the triceps flex the forearm
D. When the biceps extend the forearm, muscles in the forearm resist the biceps
A. When the biceps flex the forearm, the triceps extend the forearm
The ______ of a muscle is on a stationary bone and the ______ of a muscle is on a bone that moves.
Origin, insertion
Select all of the following ways by which skeletal muscles protect the body.
• Reinforce and cushion joints
• Abdominal muscles protect internal organs
• Pad the skull
• Pad and protect bones
• Form a protective wall around the lungs
- Reinforce and cushion the joints
- Abdominal muscles protect internal organs
- Pad and protect the bones
What is the main source of heat that raises body temperature?
Contraction of skeletal muscles
What does the all-or-none law of muscle contraction state?
Muscle fibers will contract completely or not at all.
Select all of the following relationships between the skeletal and muscle systems that produce body movement:
• Pressure exerted by skeletal muscle contraction helps squeeze tissue fluid into lymphatic capillaries
• Muscle contractions keep bones warm
• Contraction of jaw muscles and tongue allow you to grind food with the teeth
• Skeletal muscles contract and pull on bones
• Bones store calcium needed for muscle contraction
- Contraction of jaw muscles and tongue allow you to grind food with the teeth
- Skeletal muscles contract and pull on bones
- Bones store calcium needed for muscle contraction
______ ______ is a broad term applied to a group of disorders characterized by a progressive degeneration and weakening of muscles.
Muscular dystrophy
The arrangement of ______ within a muscle fiber gives skeletal muscle a striated appearance.
Myofilaments
