6. What happens to these areas during contraction? Z line (disc) _______________
ID: 3511152 • Letter: 6
Question
6. What happens to these areas during contraction?
Z line (disc) _____________________________________________________
H zone _________________________________________________________
Sarcomere ______________________________________________________
7. Organization of muscle. Put the following components in order, from smallest to largest:
fascicle
myofibril myofilament
muscle muscle fiber (cell)
The Muscular System: Neuromuscular Junction
1. Synaptic vesicles in the axon terminal of a motor neuron contain what
neurotransmitter? _________________________
2. By what means of membrane transport does the neurotransmitter leave the
axon terminal? _________________________
3. How is the neurotransmitter removed from the synaptic cleft?
4. An action potential is propagated along the
_____________________ of the muscle cell and down the ______________________ into the cell.
5. The result of this action potential releases what ion from the sarcoplasmic reticulum? ____________________
The Muscular System: Sliding Filament Theory
1. a. The thick filament is composed of what molecule? _______________________
b. Flexing the head of this molecule provides what is known as the _________________________.
2. The myosin head contains binding sites for what two molecules?
a.
b.
3. Three molecules make up the thin filament.
a. Which molecule has a binding site for myosin heads? _____________________________
b. Which molecule covers this binding site? _________________________________________________
c. Which molecule has a binding site for calcium ions? ______________________________________
4. What molecule must bind to the myosin head in order for it to disconnect with actin? _________________________
5. Hydrolysis of the molecule in question 4 returns the myosin molecule to the _________________________ conformation.
6. Name three roles for ATP in the contraction of muscle.
a.
b.
c.
7. Which of the following shorten during contraction? (may be more than one)
a. Thin filament
b. Sarcomere
c. H zone
d. Thick filament
8. a. What is the name of the condition in which muscles become rigid after death?________________________
b. What is this condition due to?
The Muscular System: Muscle Metabolism
1. List the three processes used to synthesize additional ATP when ATP supplies are low:
1. _______________________________
2. _______________________________
3. _______________________________
2. An immediate source of energy is __________________________ (CP), but the supplies are limited and rapidly depleted. One molecule of CP produces ______ ATP.
3. Glucose is a major source of energy for synthesizing ATP. List the two sources of glucose:
1. ______________________________
2. ______________________________
4. ________________ is the process that breaks down glucose.
Name two products of the breakdown of glucose:
1. _________________
2. _________________
If oxygen is not available, pyruvic acid is converted to _____________ acid, which is the end product of ____________________ respiration.
5. If oxygen is available, the process is known as _________________ respiration.
6. Put the following characteristics under the correct fiber type:
- Krebs cycle and oxidative phosphorylation - uses glycolysis
- fatigue rapidly - high endurance
- few capillaries - many capillaries
- much myoglobin - little myoglobin
- long-distance runner - sprinter
- light in color—large diameter - red in color—small diameter
Red Slow-Twitch Fibers
White Fast-Twitch Fibers
The Muscular System: Contraction of Motor Units
1. Define a motor neuron:_______________________________________________
__________________________________________________________________
2. Define a motor unit: _________________________________________________
__________________________________________________________________
3. The synapse between a motor neuron and the muscle it innervates is called a __________________________.
4. The stimulation of additional motor units will increase the strength of the contraction. This process is called _______________________.
5. The muscles of the eye need to make precise small motor movements. Therefore, you would find (large or small) motor units in the eye.
The muscles of the thigh exhibit gross movements for walking. Therefore, you would find (large or small) motor units in the thigh.
6. How is muscle tone maintained in the muscle? ___________________________
_________________________________________________________________
If the nerve to a muscle is cut, what will happen to the muscle?_______________
________________________________________________________________
The Muscular System: Contraction of Whole Muscle
1. Which of the following contract in an all or none fashion?
a. Whole muscle b. Single muscle fiber
2. The development of tension in a muscle, in response to a stimulus above threshold, is called a _______________________________.
3. Identify the three phases of a muscle twitch from the following definitions:
a. Sarcomeres shorten _______________________________
b. Sarcomeres return to resting length __________________________
c. Sarcomeres at resting length _______________________________
4. a. Temporal summation results from:
b. In temporal summation, you must ______ (or¯) the time interval between
stimuli.
5. Below is a list of the five phases of temporal summation. Put in the correct order and describe each stage.
Order
Stage
Description
Fatigue
Incomplete tetanus
Treppe
Complete tetanus
Red Slow-Twitch Fibers
White Fast-Twitch Fibers
Explanation / Answer
Answer 6 . According to sliding filament theory, during muscle contraction, Z lines comes to closer, H-Zone disappeared, and length of sarcomere decreases.
Answer 7. Organisationt of muscle, from smallest to largest,
Muscle fibers- fascicles- myofibrils- myofilament- muscle
Neuromuscular junction-
Answer 1. Synaptic vesicles at the axon terminal of the motor neuron contains either excitatory type or inhibitory type of neurotransmitter. Excitatory neurotransmitter include Acetylcholine and inhibitory neurotransmitter include GABA and Glycine.
Answer 2. At axon terminal there are presence of Ligand gated ion channels which are involved in transport of ion across membrane. During excitatory neurotransmitter there is influx of positive ion and during release of inhibitory neurotransmitter there is influx of negative ion like Chloride ion to cause the effect. These ligand gated ion channels are activated after the release of neurotransmitter from the axon terminal and effects are accordingly.
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