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Definition
| Membrane of muscle fiber. Consists of a plasma membrane and an outer coat. |
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Definition
| Bundle of muscle fibers. Surrounded by the perimysium. |
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Definition
| Surrounded by the endomysium. Contain thousands of myofibrils along with nuclei and mitochondria. |
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Definition
| Intracellular fluid inbetween myofibrils. |
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Term
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Definition
| Outer layer surrounding muscle fascicles. |
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Definition
| Outer layer surrounding a muscle. |
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Definition
| Outer layer surrounding muscle fibers. |
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Definition
| Make up muscle fibers. Contains ~3000 thin and ~1500 thick filaments. |
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Definition
| Basic unit of myofibrils. Divided into different bands running from Z disk to Z disk. |
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Term
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Definition
| Calcium reservoir. Composed of longitudinal tubules that run parallel to myofibrils. Terminates in the terminal cisternae up against the transverse tubules. |
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Term
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Definition
| Found in Sarcoplasmic Reticula. Each molecule binds to 43 Calcium ions. |
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Term
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Definition
| Disease of the neuromusucular junction, where circulating antibodies block ACh receptors at the neuromuscular junction. |
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Term
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Definition
| Thick filaments in myofibrils. Formation of six polypeptide chains, two heavy, four light. The heavy chains wrap to form a helix called the tail, while the head is composed of both heavy and light. Head contains actin/ATP binding sites. |
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Term
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Definition
| Thin filaments in myofibrils. Composed of three protein components - actin, tropomyosin and troponin. Tropomyosin wraps around F-actin helix. Troponin attached to tropomosin. Contains binding sites for myosin heads. |
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Term
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Definition
| Wraps around actin helix. When resting, covers active sites on actin to prevent contraction. |
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Term
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Definition
| Divided into three subunits: I, T, and C. I have affinity for actin, T for tropomyosin, and C for calcium. When calcium binds to C the tropomyosin shifts uncovering the active sites on the actin. |
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Term
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Definition
| Structure that holds myofibrils together. Contains alpha-actinin, titin, nebulin, and dystrophin-glycoprotein complex. |
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Term
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Definition
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Term
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Definition
| Anchors thick filaments Z disks. Springy as to allow for expansion/contraction. |
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Term
| Dystrophin-Glycoprotein Complex |
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Definition
| Anchors thin filaments to cytoskeleton. |
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Term
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Definition
| Absence of dystrophin-glycoprotein complex. Severe muscle weakness. |
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Term
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Definition
| Meeting of a nerve ending with a muscle fiber. |
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Term
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Definition
| Area between nerve and sarcolemma of muscle fiber. |
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Term
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Definition
| Invaginations in the muscle fiber. Part of the synaptic cleft? |
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Term
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Definition
| Folds of muscle fiber membrane |
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Term
| Dihydropyridine Receptor (DHPR) |
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Definition
| Calcium channel in the transverse tubule. Links to Ryanodine Receptor. |
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Term
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Definition
| Voltage sensitive receptor that monitors the DHPR receptor. Causes sarcoplasmic reticulum to dump calcium upon excitation. |
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Term
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Definition
| Mutation in Ryanodine Receptor. |
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Term
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Definition
| Slow oxidative. Slow rate of ATP Hydrolysis. Primarily dependent on oxidative phosphorylation for ATP needs. Blood glucose and free fatty acids are major energy source. Muscle glycogen is slowly depleted. |
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Term
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Definition
| Fast glycolitic. Fast ATP hydrolysis, mostly dependent on glycolysis for ATP needs. Major energy source is glucose from muscle glycogen through anaerobic glycolysis. Rapidly depleted. |
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Term
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Definition
| Infrequent in humans. Fast Oxidative - fast ATP hydrolysis. Primarily dependent on oxidative phosphorylation. |
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Term
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Definition
| Enlargement of muscle mass from increased amounts of actin and myosin filaments in muscle fibers as well as enzymes linked to energy production. Response from contraction at maximal or near maximal force. |
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Term
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Definition
| Formation of new muscle cells by adding new sarcomeres to the end of muscle cells. Occurs during growth/development. Most post development occurs from hypertrophy. |
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Term
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Definition
| Reduction in muscle mass due to lack of use. Decay of muscle proteins. Also occurs in response to muscle denervation or to diseases of the nervous system / neuromuscular junction. (Polio, myasthemia gravis...) |
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Term
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Definition
| Cell membranes that separate individual cardiac muscle cells. Form specific junctional complexes. |
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Term
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Definition
| Cell structure specialized for cell-to-cell adhesion. Holds adjacent cardiac cells together in the transverse section. |
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Term
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Definition
| Connects thin filaments from adjacen cells and holds them in register with myosin filaments. In transverse section of cardiac muscle. |
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Term
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Definition
| Allows for exchange of cytoplasmic solutes. Permits electrical coupling of cardiac muscle cells in longitudinal section. |
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Term
| Diphenylalkylamine (verapamil) |
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Definition
| Calcium channel blocker. Affects cardiac and smooth muscle evenly. |
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Term
| Benzothiazepines (diltiazem) |
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Definition
| Calcium channel blocker. Affects smooth muscle more than cardiac. |
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Term
| Dihydtropyridines (nifedipin) |
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Definition
| Calcium channel block. Affects smooth muscle more than cardiac. |
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Term
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Definition
| Enhance cardiac muscle contractility to increase cardiac output by increasing cytosolic calcium. |
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Term
| Cardiac Glycosides (digitalis) |
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Definition
| Ionotrophic Agent that binds to sodium channels increasing intracellular sodium causing sodium/calcium pump to pump sodium out and calcium in. Leads t high intracellular calcium concentration. |
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Term
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Definition
| Increase intracellular cAMP to phosphorlate and activate calcium channels. Ionotrophic Agent. |
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Term
| Phosphodiesterase Inhibitors |
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Definition
| Increase intracellular cAMPM by preventing its breakdown to AMP. Ionotrophic agent. |
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Term
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Definition
| Smooth Muscle with no Gap Junctions. Fibers are structurally independent. Innervated by a single nerve fiber with many nerve endings. Allows for finer control. Found in airways, ciliar muscle, piloerector muscle. |
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Term
| Single-unit Smooth Muscle |
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Definition
| Smooth muscle than contracts as a unit or in a coordinated fashion. Aggregated into sheets or bundles with adjacent membranes by gap junctions. Allows for coordinated control. |
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Term
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Definition
| Small saclike pockets in smooth muscle that increase surface area. |
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