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Ch.6 Muscles
Term | Definition |
---|---|
Ability of a muscle to shorten with force | Contractility |
Ability of a muscle to be stretched | Extensibility |
Muscle cells | Muscle fibers |
Actin and Myosin form units called | Sarcomeres |
Loose connective tissue that surrounds muscle fasciculi | Perimysium |
Connective tissue that separates muscles | Fascia |
Myofilaments that resemble minute strands of pearls | Actin |
Myofilaments that resemble minute bundles of golf clubs | Myosin |
Time of contraction | Contraction phase |
When the muscle remains contracted | Tetany |
Time when the muscle relaxes | Relaxation phase |
Required energy for muscle contraction | ATP |
Without oxygen | Anaerobic Respiration |
With oxygen | Aerobic Respiration |
When ATP is used during muscle contraction faster than it can be produced | Muscle Fatigue |
Chewing process | Masfication |
Moves the tongue | Extrinsic tongue muscle |
Changes shape of tongue | Intrinsic |
Characteristics of cardiac muscle | Not striated, involuntary |
Characteristics of smooth muscle | Not striated, No nucleus |
Anterior muscle that extends the leg | Sartorius |
Two types of muscle fibers | Slow twitch, fast twitch |
Extends from Z line to the next | Sarcomere |
Where is the Flexor carpi | forearm |
Muscles fibers are surrounded by the | Endomysium |
Anterior upper arm muscle | Bicep |
Posterior upper arm muscle | Tricep |
The end of a muscle that doesn't move | Origin |
The end of a muscle that moves the most | Insertion |
The circular movement of an appendage | Circumduction |
4 major functional characteristics of muscles | Contractility Elasticity Extensibility Excitability |
Capacity of a muscle to respond to a stimulus | Excitability |
Ability to be stretched | Extensibility |
Ability to return to original length after being stretched | Elasticity |
Superficial to the epimysium | Fascia |
Fascicle | Composes a muscle |
Myofibrils | 2 major kinds of protein fibers |
Sarcomere | Structural unit of a muscle |
I band | Light area made up of actin |
A band | Dark area composed of myosin |
M line | Line in between A bands |
H zone | Space between A bands and M line composed of myosin |
Outside cell membranes | Positively charged |
Inside cell membranes | Negatively charged |
Charge difference across membrane | Resting membrane potential |
Nerve cells that carry action potentials to muscle fibers | Motor neurons |
Branch that connects to a muscle forms a _______ | Neuromuscular junction; synapse |
Single motor neuron and the muscle fibers it innervates | Motor unit |
Space between the presynaptic terminal and the muscle fibers | Synaptic cleft |
Acetylcholine | Diffuses across the synaptic cleft and binds to the postsynaptic terminal causing changes in the postsynaptic cell |
Sliding filament mechanism | Sliding of actin and myosin against each other during contraction |
During contraction H and I bands... | Shorten |
During contraction A bands..... | Stay the same |
Muscle twitch | Contraction of entire muscle in response to a stimulus |
Muscle fibers no longer respond to stimuli when it reached a level called | Thresh hold |
Lag phase | Time between application of stimulus at the beginning of contraction |
Increase in number of motor units being activated | Recruitment |
Type of muscle that makes up the heart | Cardiac muscle |
ATP | Adenosine triphosphate |
ATP is produced by | Mitochondria |
ADP | Adenosine diphosphate |
Creatine phosphate | Stored in place of ATP and is used for energy |
Amount of oxygen needed to replenish amounts of creatine phosphate stored in muscle fibers | Oxygen debt |
2 types of muscle contractions | Isotonic Isometric |
Isotonic | Tension is constant, length changes |
Isometric | Tension changes, length stays the same |
Muscle tone | Constant tension of certain muscles for long periods of time (Keeps head up) |
Fast twitch fibers | Contract quicky, fatigue quickly |
Slow twitch fibers | Contract slowly, fatigue slowly |
Zygomaticus | Smiling muscles |
Orbicularis Oris | Puckers the lips |
Levator Labii Superius | Sneering muscles |
Depressor Anguli Oris | Frowning muscles |
Antagonists | Muscles that work opposite to each other |
Synergists | Muscles that work together to perform specific movementsl.. |