Chapter 11 Physiology of the Muscular System
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nathan_sweat on February 1, 2012
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112 terms
Terms | Definitions |
|---|---|
 What are the general functions of Muscles? | -Movement -Posture -Heat Production |
| What are the characteristics of Muscle tissues? | -Excitablility -Contractility -Extensibility |
| What is the ability of the muscle to be stimulated (respond to nerve impulses)? | Excitability |
| What is the ability of the muscle to contract or shorten? | Contractility |
| What is the ability of the muscle to extend or stretch? | Extensibility |
| What is the plasma membrane of muscle fiber? | Sarcolemma |
| What is the cytoplasm of the muscle fiber? | Sacroplasm |
| What organelle is the "powerhouse of the cell"? | Mitochondria |
| Muscle cells are called fibers because of what? | Their threadlike shape |
| What is the network of tubules and sacs found within muscle fibers that temporarily stores Ca ions? | Sarcoplasmic Reticulum (SR) |
| What part of the muscle cell temporarily stores Ca ions? | Sarcoplasmic Reticulum |
| What extend transversely across the sarcoplasm at right angles to long axis of muscle fiber formed by inward extensions of sarcolemma? | T Tubules |
| What allow electrical signals, or impulses traveling along the sarcolemma to move deeper into the cell? | T Tubules |
| What is a triplet of tubules; a T tubule sandwiched between two sacs of sarcoplasmic reticulum? | Triad |
| What allows the electrical impulse traveling along a T Tubule to stimulate the membranes of adjacent sacs of the Sarcoplasmic Reticulum? | Triad |
| What are the bundles of very fine cytoskeletal filaments that extend lengthwise along skeletal muscle fiber and almost fill the sarcoplasm? | Myofibrils |
| What are the fine fibers that make up Myofibrils? | Myofilaments |
| What are the two types of Myofilaments? | -Thick -Thin |
| What are the protiens that make up the thick Myofilaments? | Myosin |
| What are the protiens that make up the thin Myofilaments? | -Actin -Tropomyosin -Troponin |
| What is the basic contractile unit of the muscle cell? | Sacrocomere |
| What is located in the middle of the thin Myofilament? | Z Line (Z disk) |
| What is a segment of the myofibril between two sucessive Z lines? | Sarcomere |
| What is the segment of sarcomere that runs the entire length of the thick filaments? | A band |
| What is the segment of sacromere that includes the Z line and ends of the thin filaments where they don't overlap the thick filaments? | I band |
| What is another name for muscle? | Straiated Muscle |
| Each myofibril consists of approximately how many sarcomeres? | 15,000 |
| What does myosin make up? | Thick filament |
| What protein is chemically attracted to the Actin? | Myosin |
| What is the area where the Myosin "heads" are attached to actin? | Cross bridges |
| What is the globular protein that forms two fibrous strands that twist around each other to form the bulk of thin filament? | Actin |
| What protein blocks the active sites on the Actin molecules? | Tropomyosin |
| What protein holds the tropomyosin molecules in place? | Troponin |
| What part of the Myosin is atracted (towards) the Actin? | Myosin "heads" |
| What binds with Troponin which causes the troponin to release the tropomyosin? | Calcium |
| When does contraction begin? | When Ca++ binds to Troponin |
| Skeletal muscle fiber remains at rest until stimulated by what? | Motor neuron |
| What is the special type of nerve cell that stimulates skeletal muscle fibers? | Motor Neuron |
| Where do Motor Neuron's connect? | To the Sarcolemma of a muscle fiber at a folded motor endplate |
| What is the area where the motor neurons connect to the carcolemma at the motor endplate? | Neuromuscular junction |
| What is the junction where the motor neuron connects to the sarcolemma of a muscle fiber at a folded motor endplate? | Neuromuscular Junction (NMJ) |
| What is the neurotransmitter that is released into the synaptic cleft that diffuses across gap, stimulates receptros, and initiates impulse in sarcolemma? | Acetylcholine |
| Nerve impulses travels over the Sarcolemma and inward along what? | T Tubules |
| What releases the calcium ions from the SR? | The nerve impulses that traveled along the sacrolemma and inward along the T tubules |
| What binds to Troponin causing Tropomyosin to shift and expose active sites on Actin? | Calcium |
| What happens when the active sites on actin are exposed? | Myosin heads bind to the Actin |
| What is it called when the thick filaments pull on the thin filaments? | Sliding filament model |
| Muscle fibers usually contract how much of their starting length?? | 80% |
| What happens when Ca++ ions are removed from troponin molecules? | Shuts down contraction |
| Where do Ca++ ions go when released from the troponin molecules? | Ca++ ions are pumped back into the sacks of the Sarcoplasmic Reticulum |
| What are the 2 types of energy sources muscle uses for contraction? | -ATP -Creatine Phosphate |
| There is only enough ATP in muscle fiber for how long of maximum contraction? | 2-4 seconds |
| What is the backup energy supply for ATP? | Creatine Phosphate |
| How much additional energy does Creatine Phosphate provide for maximal contraction? | 20 additional seconds |
| Muscle fibers continually resynthesize ATP from the breakdown of what? | Creatine Phosphate |
| Where does ATP bind to transfer it's energy to perform the work of pullin thin filament during contraction? | Myosin head |
| Muscle fibers ensure an uninterrupted supply of glucose by storing it in the form of what? | Glycogen |
| What is the catabolic process that produces the maximum amount of energy available from each glucose molicule? | Aerobic (oxygen-requiring) |
| Where does the lactic acid return to out of the blood? | the Liver and is converted back into glucose |
| Anaerobic respiration results in the formation of what? | Lactic Acid |
| What gives Myoglobin it's reddish pigmentation? | Iron |
| What muscle fibers have high levels of myoglobin | Red Fibers |
| What muscle fibers have little myoglobin? | White Fibers |
| What are the 3 different types of skeletal muscle fibers that can be classified according to their structural and functional characteristics? | Red fibers- Slow White fibers- Fast Intermediate fibers |
| At rest excess O2 in the sarcoplasm is bound to what? | Myoglobin |
| What type of respiration occurs when low levels of O2 are available and results in the formation of lactic acid? | Anaerobic respiration |
| What type of respiration occurs when adequate O2 is available? | Aerobic respiration |
| What is the functional unit that consists of a Motor neuron plus the muscle fibers to which it attaches? | Motor Unit |
| What type of motor neuron forms that motor unit with a muscle fiber? | Somatic Motor Neuron |
| One single contraction is called what? | A twitch Contraction |
| What are the 3 phases of the twitch contraction? | -Latent Period -Contraction Phase -Relaxation Phase |
| Each twitch contraction usually lasts how long? | Less than 1/10 of a second |
| A series of twitch contractions or "staircase phenomenon" is called what? | Treppe |
| What is the gradual steplike increase in the strength of contractions seen in a series of twitch contractions that occur 1 second apart? | Treppe (staircase phenomenon) |
| What benifits do you get from warming up muscle fibers? | -Calcium ions diffuse through the SR more efficiently -More actin-myosin reactions occur |
| What is a smooth, sustained contraction called? | Tetanus |
| What is caused by any combination of local failure in the steps of muscle contraction? | Physiological Muscle Fatigue |
| What are 3 things that cause Physiological Muscle Fatigue | -Lack of ATP -Depletion of O2 or Glucose -Build up of Lactic Acid |
| What is the continual, partial contraction of a muscle? | Tonic Contraction |
| Muscles with less tone than normal are? | Flaccid |
| Muscles with more tone than normal are? | Spastic |
| What is the principle that skeletal muscles contract with varying degrees of strength at different times? | Graded Strength Principle |
| When is the strongest maximal contraction possible? | Only when the muscle organ has been stretched to it's optimal initial length |
| The maximal strength that a muscle can develope bears a direct relationship to what? | Length of it's fibers |
| What is the response in which the body tries to maintain constancy of muscle length in response to increased load? | Stretch Reflex |
| What are the two different type of muscle contractions? | -Isotonic -Isometric |
| What type of contraction is a contraction in which the tone or tension within a muscle remains the same as the length of the muscle changes? | Isotonic Contraction |
| What does Isotonic mean? | "Same Tension" |
| What type of contraction is a contraction in which muscle lenth remains the same while the muscle tension increases? | Isometric Contraction |
| What are the two types of Isotonic contraction? | -Concentric -Eccentric |
| What type of isotonic contraction is when the muscle shortens as it contracts? | Concentric |
| What type of isotonic contraction is when muscle lengthens while contracting? | Eccentric |
| What are painful muscle spasms? | Cramps |
| What are minor traumas to the body that may cause a muscle bruise? | Contusion |
| What is an injury to skeletal muscles caused by overexertion or trauma called? | Strain |
| What is an injury to a ligament refered as? | Sprain |
| What are the three types of muscle tissue? | -Skeletal -Cardiac -Smooth |
| What type of muscle tissues are voluntary? | Skeletal |
| What type of muscle tissues are involuntary? | -Cardiac -Smooth |
| What type of muscle tissue has Striations? | -Skeletal -Cardiac |
| What type of muscle tissue has NO striations? | Smooth |
| What type of muscle tissues have many nucleus? | Skeletal |
| What type of muscle tissues are characterized by having a single nucleus? | -Cardiac -Smooth |
| What type of muscle tissues have narrow T Tubules that form triads with the SR? | Skeletal |
| What type of muscle tissues have large diameter T Tubules that form diads with the SR and regulate Ca++ entry into the sarcoplasm? | Cardiac |
| What type of muscle tissues have no T Tubules? | Smooth |
| What type of muscle tissue has a very poorly developed sarcoplasmic reticulum? | Smooth |
| What type of muscle tissue has a extensive Sarcoplasmic Reticulum that stores and releases Ca++? | Skeletal |
| What type of muscle tissue has a sarcoplasmic reticulum that is less extensive than in skeletal muscle? | Cardiac |
| What type of muscle tissue has no gap junctions? | Skeletal |
| What type of muscle tissue has cell junctions of intercalated disks? | Cardiac |
| What type of muscle tissue has many gap junctions? | Smooth |
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