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CH. 6 MUSCLES
| 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 |