Y khoa - Dược - Chapter 25: The muscular system

25The Muscular SystemLearning Outcomes (cont.)25.1 Describe the functions of muscle. 25.2 Compare the three types of muscle tissue including their locations and characteristics.25.3 Explain how muscle tissue generates energy. 25.4 Describe the structure of a skeletal muscle. Learning Outcomes (cont.)25.5 Recognize the terms origin and insertion. 25.6 Identify the major skeletal muscles of the body, giving the action of each. 25.7 Summarize the changes that occur to the muscular system as a person ages. 25.8 Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the muscular system.Introduction Muscles contract and relax to cause movement600 individual muscles in the bodyYou will focus on the differences among three muscle tissue types, the structure of skeletal muscles, muscle actions, and the names of skeletal muscles. Functions of MuscleThe ability to contract enables muscles to Allow movementProvide stabilityControl body openings and passages Warm the bodyFunctions of Muscle (cont.)Skeletal muscles Attach to bones by tendonsContractions result in movementSmooth muscle – contractions move organ contentsCardiac muscle – contractions pump blood from the heartFunctions of Muscle (cont.)StabilityHold bones tightly together Small muscles hold vertebrae together Heat ProductionHeat is released when muscles contract Helps maintain a normal temperatureControl of Body Openings and PassagesSphincters Valve-like structuresControl movement in and out of passagesApply Your KnowledgeTrue or False:___ Skeletal muscles are attached to bones by ligaments.___ Contractions of smooth muscle produce movement of organ contents.___ Cardiac muscle produces atrial and ventricular contractions.___ Sphincters control movement of substances out of passages.___ Heat is released as muscles relax.tendonsin and outcontractTTFFFANSWER:RIGHT!Types of Muscle Tissue Muscle cells or myocytes – muscle fibersSarcolemmaSarcoplasm Sarcoplasmic reticulum Myofibrils Long structures in sarcoplasmStriations – arrangement of filamentsMuscle structureBackTypes of Muscle Tissue (cont.)Muscle GroupMajor LocationMajor FunctionMode of ControlSkeletal MuscleAttached to bones and skin of the faceProduces body movements and facial expressionsVoluntarySmooth MuscleWalls of hollow organs, blood vessels, and irisMoves contents through organs; vasoconstrictionInvoluntary Cardiac MuscleWall of the heartPumps blood through heartInvoluntarySkeletal MuscleSkeletal muscle fibers Contract in response to the neurotransmitter acetylcholineAfter contraction, muscles release the enzyme acetylcholinesteraseBreaks down acetylcholineAllows muscle to relaxSmooth MuscleMultiunit smooth muscles – respond to neurotransmitters and hormonesVisceral smooth musclesResponds to neurotransmitters ~ acetylcholine and norepinephrine Stimulate each other to contract ~ peristalsisCardiac MuscleIntercalated discsConnect groups of cardiac muscleAllow the heart to work as a pumpSelf-excitingResponds to neurotransmittersAcetylcholineNorepinephrineApply Your KnowledgeMatch the following:___ Self-exciting ___ Contract in response to acetylcholine ___ Stimulate each other to contract___ Peristalsis___ Slowed by acetylcholine___ Voluntary movementCAABBVery Good!CANSWER:Skeletal MuscleSmooth muscleCardiac muscleProduction of Energy for Muscle ATPMuscle cells make ATP byCreatine phosphate ~ rapid production of energyAerobic respiration ~ uses body’s store of glucose Lactic acid production from pyruvic acidMuscle fatigueOxygen DebtStrenuous use of skeletal muscles depletes cells of oxygenTo liver for conversion to glucose, requiring more energy and oxygen to make ATPPyruvic AcidLactic acidOxygen debtMuscle FatigueLoses ability to contractCausesAccumulation of lactic acid Interruption of the blood supplyAcetylcholine not released by motor neuronMatch the following:___ Rapid production of energy___ Needed for sustained or repeated muscle contractions___ Uses body’s store of glucose ___ Muscle fatigue ___ With strenuous exercise, converts to lactic acid Apply Your KnowledgeLactic acidPyruvic acidATPAerobic respirationCreatine phosphateCADBEANSWER:Yippee!Structure of Skeletal MusclesSkeletal muscles – the major organs of the muscular systemComposition Connective tissueSkeletal muscle tissue Blood vessels NervesStructure of Skeletal Muscles (cont.)Connective tissue coveringsFasciaTendon AponeruosisEpimysium Perimysium EndomysiumMuscle structureApply Your KnowledgeMatch the following:__ Thin covering under the fascia that surrounds the muscle __ Separates muscles from each other__ Connects muscles to bones__ Divides a muscle into sections called fascicles __ Surrounds individual muscle cells__ Attaches muscles to other musclesTendonPerimysium AponeurosisEpimysiumFasciaEndomysiumEABFCDANSWER:Excellent!Attachments and Actions of Skeletal Muscles Attachment typesOrigin ~ for a less movable boneInsertion ~ for a more movable boneAttachments and Actions of Skeletal Muscles (cont.)Movement Prime mover (agonist) ~ responsible for most of the movementSynergists ~ help the prime mover by stabilizing jointsAntagonist ~ produces movement opposite to prime moverAttachments and Actions of Skeletal Muscles (cont.)FlexionExtension Hyperextension Dorsiflexion Plantar flexionAbductionAdductionFigure of Body MovementsBackDorsiflexionPlantar flexionAdduction ExtensionHyperextensionFlexionExtensionFlexion Abduction Attachments and Actions of Skeletal Muscles (cont.)RotationCircumductionPronationSupinationRotation CircumductionSupination PronationAttachments and Actions of Skeletal Muscles (cont.)Inversion EversionRetraction ProtractionElevationDepressionFigure of movementsAttachments and Actions of Skeletal Muscles (cont.)InversionEversionProtraction RetractionElevation DepressionBackApply Your KnowledgeANSWER: True or false? An agonist is the muscle that produces a movement  opposite to a prime mover. Synergists stabilize joints. Origin is an attachment site for the less moveable  bone during muscle contraction. Insertion is an attachment site for the more moveable  bone during muscle contraction.TFTTantagonistMajor Skeletal Muscles Name often describes muscle byLocationSizeActionShapeNumber of attachmentsBackMuscles of the HeadSternocleidomastoidSplenius capitisMuscles of the jawMasseter Temporalis Muscles of facial expressionFrontalisOrbicularis orisOrbiuclaris oculiZygomaticus Platysma Skeletal musclesArm MusclesPectoralis majorLatissimus dorsi DeltoidSubscapularis Infraspinatus Skeletal musclesArm Muscles (cont.)Biceps brachiiBrachialisBrachioradialisTriceps brachiiSupinatorPronator teres Skeletal musclesMuscles of the Wrist, Hand, and FingersFlexor carpi radilasFelxor carpi ulnarisPalmaris longusFlexor digitorum profundusExtensor carpi radialis longus and brevisExtensor carpi ulnairsExtensor digitorumDiagram of handBackRespiratory MusclesDiaphragm Separates thoracic and abdominal cavitiesContracts for inspirationExternal and internal intercostals – expand and lower the ribsFor diagramSkeletal Muscles (cont.)Abdominal musclesExternal and internal obliques Transverse abdominis Rectus abdominisMuscles of the Pectoral GirdleTrapeziusPectoralis minorFor diagramSkeletal Muscles (cont.)BackLeg MusclesIliopsoas majorGluteus maximus Gluteus medius and minimus Adductor longus and magnusSkeletal musclesLeg Muscles (cont.)Biceps femoris, semitendinosus, and semimembranosusRectus femoris, vastus lateralis, vastus medialis, and vastus intermediusSartoris Skeletal musclesAnkle, Foot, and Toe MusclesTibialis anterior Extensor digitorum longus GastrocnemiusSoleusFlexor digitorum longusSkeletal musclesApply Your KnowledgeMatching: raises the eyebrows chewing expand and lower ribs compress the abdominal wall extends the thigh extends the leg at the kneeGluteus maximusIntercostalsFrontalisQuadriceps groupObliques Masseter ANSWER:Bravo!ABCDEFAging and the Musculoskeletal SystemSpeed and strength of muscle contractions decreaseAging Decreased dexterity and gripping abilityDecreased mobilityAssistive devices helpfulRoutine exerciseDiseases and Disorders of the Muscular SystemDiseaseDescriptionBotulismAffects the gastrointestinal tract and various muscle groups FibromyalgiaFairly common condition that causes chronic pain primarily in joints, muscles, and tendonsMuscular dystrophyInherited disorder characterized by muscle weakness and a loss of muscle tissueMyasthenia gravisAutoimmune condition in which patients experience muscle weakness and loss of muscle tissueDiseases and Disorders of the Muscular System (cont.)DiseaseDescriptionRhabdomyolysisKidneys become damaged because of toxins released from muscle cells after serious muscle injuriesTendonitis Painful inflammation of a tendon and the tendon-muscle attachment to a boneTetanus (lockjaw)Muscle spasms in the jaw, keck and facial muscles; high mortality rateDiseases and Disorders of the Muscular System (cont.)DiseaseDescriptionTorticollis (wryneck)A cervical deformity in which the head bends toward the affected side while the chin rotates to the opposite sideTrichinosisAn infection caused by parasites ingested by eating undercooked meatApply Your KnowledgeANSWER: Speed and strength of muscle contractions decrease with aging.The aging process results in: Decreased dexterity and gripping abilityDecreased mobilityWhat changes occur to the muscular system as a result of aging?Good Job!Apply Your KnowledgeTrue or False: Botulism is a condition resulting in chronic pain in joints,  muscles and tendons. Kidney damage due to toxins released by serious  muscle injuries is the condition called rhabdomyolysis. Tetanus is caused by a toxin and causes muscle  spasms in the jaw, neck, and facial muscles. Lockjaw is caused by spasm or shortening of the  sternocleidomastoid muscle.ANSWER:Good Job!TTFFFibromyalgiaTorticollisIn Summary25.1 The functions of muscles include movement, stability, control of body openings and passages, and the production of heat. Valve- like muscular structures called sphincters control passage of substances into and out of organs like the stomach and bladder..25.2 The three types of muscle tissue are striated, voluntary skeletal muscle; smooth, involuntary visceral muscle; and specialized striated and involuntary cardiac muscle. In Summary (cont.)25.3 There are three ways muscles create energy. Creatine phosphate, aerobic respiration, and lactic acid production.25.4 Skeletal muscle is composed of connective tissues, skeletal muscle tissue, blood vessels, and nerves. The coverings of skeletal muscles include fascia, tendon, aponeurosis, epimysium, perimysium, and endomysium. In Summary (cont.)25.5 The origin of a muscle is the attachment site of the muscle to the less moveable bone during muscle contraction. The insertion of a muscle is the attachment site for the muscle to the more moveable bone during muscle contraction. 25.6 The major muscles of the head and the upper extremity, major respiratory muscles, abdominal muscles, pectoral girdle muscles and those of the lower extremity are covered in this learning outcome.In Summary (cont.)22.7 The common diseases of aging include arthritis, fractures, osteoporosis, and muscular decline. Aging causes a decline in strength and speed of muscle contractions. Dexterity and gripping abilities lessen and mobility often decreases related to skeletal and muscular decline.22.8 There are many common diseases and disorders of the muscular system with varied signs, symptoms, and treatments. Everyone has a ‘risk muscle.’ You keep it in shape by trying new things. If you don’t, it atrophies. Make a point of using it at least once a day.~Roger von OechEnd of Chapter 25