Question | Answer |
Ability of skeletal muscle to shorten with force. | Contractility |
Capacity of skeletal muscle to respond to a stimulus. | Excitability |
Ability to be stretched. | Extensibility |
Ability to recoil to their original resting length after being stretched. | Elasticity |
What helps to produce heat essential for maintenance of normal body temperature? | Muscles |
What connective tissue sheath surrounds the skeletal muscle? | Epimysium |
What connective tissue is located and surrounds the outside of the Epimysium? | Fascia |
What loose connective tissue surrounds the muscle fascicle? | Perimysium |
Fasciculi are composed of single muscle cells. | Fibers |
What connective tissue sheath is surrounds each fiber? | Endomysium |
Each muscle fiber is a ______ cylindrical cell containing several nuclei. | Single |
A threadlike structure that extends from one end of the fiber to the other. | Myofibrils |
Myofibrils consist of 2 major kinds of protein fibers: | Actin and Myosin Myofilaments |
Thin; resemble 2 minute strands of pearls twisted together. | Actin Myofilaments |
Thick; resemble bundles of minute golf clubs. | Myosin Myofilaments |
Both myofilaments form highly ordered units called | Sarcomeres |
Sarcomeres are joined end to end to form what? | Myofibril |
Each Z line extends from where? | One Z line to another Z line. |
On each side of the Z line is a light area called | An I Band |
What consists of Actin? | An I Band |
What extends the length of the myosin? | A Band |
What is the darker area of each sarcaromere? | A Band |
What is another light area in the sarcomere? | H Zone |
What consists of only myosin? | H Zone |
What is in the center of the sarcormere at a dark staining band? | M Line |
The outside of most cell membranes is ______ ______. | Positively Charged |
The inside of most cell membranes is ______ ______. | Negatively Charged |
What is the charge difference across the membrane called? | Rest Membrane Potential |
The brief reversal back of charge is called______ _____. | Action Potential |
What are nerve cells that carry action potentials to skeletal muscle fibers? | Motor Neurons |
Axons enter the ______ and branch. | Muscles |
Each branch that connects to the muscle forms a what? | Neuromusclular Junction |
What is another word for Neuromusclular Junction? | Synapse |
A single motor neuron and all the skeletal muscle fibers it innervates are called ______ ______. | Motor Unit |
Many motor units form a ______ muscle. | Single |
An enlarged nerve terminal resting in in an indentation of the muscle cell membrane forms what? | Neuronmusclular Junction |
What is the enlarged terminal? | Presynaptic Terminal |
What is the space between the Presynaptic Terminal and the muscle cell? | Synaptic Cleft |
What is the muscle fiber inside of the Syaptic Cleft? | Postsynaptic Terminal |
What does each presynaptic terminal contain? | Synaptic Vesicles |
What is a secreted neurotransmitter? | Acetylcholine |
What is an enzymatic breakdown? | Acetylcholinesterase |
When does muscle contraction occur? | When actin and myosin myofilaments slide past one another. |
What happens when sarcomeres shorten? | It causes the muscle to shorten. |
The sliding of actin myofilaments past myosin myofilaments during contraction is called the _____ _____ _____. | Sliding Filament Mechanism |
Which band doesn't shorten: A, H, or I? | A Bands |
What is a contraction of an entire muscle in response to a stimulus? | Muscle Twitch |
A muscle fiber will not respond to stimulus until that stimulus reaches a level called _______. | Threshold |
The muscle fiber will contract maximally; the phenomenon is called ______ ______. | All-or-None Response |
The tine between application of a stimulus to a motor neuron and the beginning of a contraction is the_____ _____. | Lag Phase |
What is the time of contraction called? | Contraction Phase |
What is the time during which the muscle relaxes called? | Relaxation Phase |
Where the muscle remains contracted without relaxing is called? | Tetany |
What is the increase in number of motor units being activated called? | Recruitment |
What does ATP stand for? | Adenosine Triphosphate |
What is ATP needed for? | Energy for muscle contraction |
Where is ATP produced? | Mitochondria |
ATP is ________ and __________. | Short-lived and Unstable |
ATP degenerates to the more stable ___ plus phosphate. | ADP |
What does ADP stand for? | Adenosine Diphosphate |
What is another high-energy molecule called? | Creatine Phosphate |
Without oxygen... | Anaerobic Respiration |
With oxygen... | Aerobic Respiration |
The amount of oxygen needed in chemical reactions to convert lactic acid to glucose. | Oxygen Debt |
What results when ATP is used during muscle contraction faster than it can be produced in the muscle cells? | Muscle Fatigue |
The length of the muscle does not change, but the tension increases during the contraction process. | Isometric |
The amount of tension produced by the muscle is constant during contraction, but the length of the muscle changes. | Isotonic |
Refers to constant tension produced by muscles of the body for long periods of time; Keeps head up and back straight. | Muscle Tone |
Contract and fatigue quickly; white meat of a chicken's breast. | Fast-Twitch Fibers |
Contract more slowly and are more resistant to fatigue; dark meat of a duck's breast or the legs of a chicken. | Slow-Twitch Fibers |
The most stationary end of the muscle; head. | Origin |
The end of the muscle undergoing the greatest movement. | Insertion |
The portion of the muscle between the origin and the insertion. | Belly |
Muscles that work together to accomplish specific movements. | Synergists |
Muscles that work in opposition to one another. | Antagonists |
If one muscle plays the major role in accomplishing the desired movement then it is... | The Prime Mover |