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Muscle Q's/Notes
Question | Answer |
---|---|
Four Major Functional Characteristics | Contractility, Excitability, Extensibility, & Elasticity |
the ability to be stretched. | Extensibility |
the ability of skeletal muscle to shorten with force. | Contractility |
the ability to recoil to their original resting length after they have been stretched. | Elasticity |
the capacity of skeletal muscle to respond to a stimulus. | Excitability |
a threadlike structure that extends from one end of the fiber to the other. | Myofibrils |
Of each fiber the cytoplasm is filled with... | Myofibrils |
A muscle that is composed with numerous visible bundles called... | Fasciculi or (fascicle) |
The numerous visible bundles are surrounded by a loose connective tissue called... | Perimysium |
Is another connective tissue located outside the epimysium... | Fascia |
Each skeletal muscle is surrounded by a connective tissue sheath called... | Epimysium |
Each fiber is surrounded by a connective tissue sheath called... | Endomysium |
The fasciculi are composed of single muscle cells called... | Fibers |
2 major kinds of protein fibers | Actin & Myosin |
Thin myofilaments... | Actin Myofilament |
Thick myofilaments... | Myosin Myofilament |
Actin and myosin myofilaments for highly ordered units called... | Sarcomeres |
What is joined end to end to form myofibrils? | Sarcomere |
Is the basic structural and functional unit of the muscle... | Sarcomere |
Each sarcomere extends from one __ (disc) to another __ line (disc)... | Z line |
The arrangement of ___ and ___ give a banded appearance... | Actin & Myosin |
On each side of the Z line is a light area called... | I bands |
I bands consist of ___ | Actin |
The ____ band extends the length of the myosin | A band |
The ___ band is the darker central region in each ___ | A band ; sarcomere |
In the center of each sarcomere is another light area called... | H band |
The H band consists of only____ | Myosin |
Myosin myofilaments are anchored in the center of the sarcomere at a dark staining band called... | The M line. |
What are the two membrane potentials... | Resting membrane potentials & Action potential |
When a muscle cell is stimulated the membrane characteristics change briefly. The brief reversal back of the charge is called... | Action potential |
The outside of most cell membranes is positively charged compared to the inside of the cell membrane, which is negatively charged. The charge difference across the membrane is called... | Resting potential |
What kind of supply is in the muscles? | Nerve supply |
Nerve cells that carry action potentials to skeletal muscle fibers are called... | Motor neurons |
A single motor neuron and all the skeletal muscle fibers it innervates are called... | Motor units |
Many motor units for a ___ muscle... | Single muscle |
Axons enter the ______ and ______. | Muscles and branch |
Each branch that connects to the muscle forms a... | Neuromuscular junction or synapse |
The neuromuscular junction or synapse is located near the _____ of the cell... | Center |
A neuromuscular junction is formed by an ___ ____ _____ resting in an indentation of the muscle cell membrane... | Enlarged nerve terminal |
The enlarged nerve terminal is the ____ ____... | Presynaptic terminal |
The space between the presynaptic terminal and the muscle cell is the ____ ____ and the muscle fiber is the _____ _____... | Synaptic cleft ; postsynaptic terminal |
Each presynaptic terminal contains ___ ___... | Synaptic vesicles |
Synaptic vesicles secrete a neurotransmitter called... | Acetylcholine |
It diffuses across the synaptic cleft and binds to the postsynaptic terminal causing a change in the _____ cell... | Postsynaptic |
When ____ potential reaches the nerve terminal, it causes the synaptic vesicles to release acetylcholine into the synaptic cleft... | Action potential |
When synaptic vesicles release acetylcholine into the synaptic cleft it is caused by _____... | Exocytosis |
____ rapidly breakdowns and is an enzyme called... | Acetylcholinesterase |
The acetylcholinesterase enzymatic breakdown ensures that one action potential in the ____ yields only one action potential... | Neuron |
What kind of contraction is in the skeletal muscle? | Muscle contraction |
Muscle contractions occurs as ___ and ___ myofilaments slide past one another... | Actin and myosin |
When the actin and myosin myofilaments slide past each other it causes the ____ to shorten... | Sarcomeres |
When the sarcomeres shorten it causes the ____ to shorten... | Muscle |
During contraction the sliding of the actin myofilaments pass myosin filaments when this happens this is called the ____ of muscle contraction | Sliding filament mechanism |
The H and I bands shorten, but the ___ bands do not change in length. | A band |
A contraction of an entire muscle in response to a stimulus that causes the action potential in one or more muscle fibers is called... | Muscle twitch |
A muscle fiber will not respond to stimulus until that stimulus reaches a level called... | Threshold |
At the point of threshold the muscle fiber will contract maximally, this phenomenon is called the... | All-or-none response |
Time between application of a stimulus to a motor neuron and the beginning of a contraction is the... | Lag phase |
Time of contraction is the... | Contraction phase |
Time during which the muscle relaxes... | Relaxation phase |
If successive stimuli are given you get successive ___ that occur so frequently the muscle doesn't have time to fully relax... | Twitches |
Where the muscle remains contracted without relaxing is called... | Tetany |
The increase in number of motor units being activated is called... | Recruitment |
What kind of requirement does the skeletal muscle need? | Energy requirements |
What is ATP? | Adenosine triphosphate |
What is needed for energy for muscle contraction? | ATP |
ATP is produced in the ___ | Mitochondria |
ATP is ____ and unstable. It degenerates to the more stable ADP plus phosphate. | Short-lived |
What is ADP? | Adenosine diphosphate |
It is necessary for _____ cells to constantly produce ATP... | Muscle cells |
When muscle cells are at rest they can't stockpile ____... | ATP |
When muscle cells are unable to stockpile ATP they can store another high-energy molecule called... | Creatine phosphate |
With oxygen (more efficient) is called... | Aerobic respiration |
Without oxygen is called... | Anaerobic respiration |
When doing intense exercise, the ______ rate remains remains elevated for a period of time. | Respiration rate |