Presentation on theme: "The Muscular System Chapter 26 Medical Assisting"— Presentation transcript:
1The Muscular System Chapter 26 Medical Assisting PowerPoint® presentation to accompany:Medical AssistingThird EditionBooth, Whicker, Wyman, Pugh, Thompson
2Learning Outcomes 26.1 List the functions of muscle. 26.2 List the three types of muscle tissue and describe the locations and characteristics of each.26.3 Describe how visceral (smooth) muscle produces peristalsis.26.4 Explain how muscle tissue generates energy.
3Learning Outcomes (cont.) 26.5 Describe the structure of a skeletal muscle.26.6 Define the terms origin and insertion.26.7 List and define the various types of body movements produced by skeletal muscles.26.8 List and identify the major skeletal muscles of the body, and giving the action of each.
4Learning Outcomes (cont.) 26.9 Explain the differences between strain and sprain injuries.26.10 Describe the changes that occur to the muscular system as a person ages.26.11 Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the muscular system.
5Introduction Bones and joints do not produce movement The human body has more than 600 individual musclesMuscles cause bones and supported structures to move by alternating between contraction and relaxationYou will focus on the differences among three muscle tissue types, the structure of skeletal muscles, muscle actions, and the names of skeletal muscles.
6Functions of MuscleMuscle has the ability to contract, permitting muscles to perform various functionsFunctions:MovementStabilityControl of body openings and passagesHeat productionClick for Larger View
8Functions of Muscle: Movement Skeletal musclesAttached to bones by tendonsCross joints so when they contract, bones they attach to moveSmooth muscleFound on organ wallsContractions produce movement of organ contentsCardiac muscleProduces atrial and ventricular contractionsThis pumps blood from the heart into the blood vessels
9Functions of Muscle: Stability Hold bones tightly togetherStabilize jointsSmall muscles hold vertebrae togetherStabilize the spinal column
10Functions of Muscle: Control of Body Openings and Passages SphinctersValve-like structures formed by musclesControl movement of substances in and out of passagesExample:A urethral sphincter prevents or allows urination
11Functions of Muscle: Heat Production Heat is released with muscle contractionHelps the body maintain a normal temperatureMoving your body can make you warmer if you are cold
12Apply Your Knowledge RIGHT! FANSWER:True 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.tendonsTTin and outFFRIGHT!contract
13Types of Muscle Tissue Muscle cells Myocytes called muscle fibers Sarcolemma – cell membraneSarcoplasm – cytoplasm of cellMyofibrils – long structures in sarcoplasmArrangement of filaments in myofibrils produces striations
14Types 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; vasoconstrictionInvoluntaryCardiac MuscleWall of the heartPumps blood through heart
15Types of Muscle Tissue: Skeletal Muscle Muscle fibers respond to the neurotransmitter acetylcholineCauses skeletal muscle to contractFollowing contraction, muscles release the enzyme acetylcholinesteraseBreaks down acetylcholineAllows muscle to relax
16Types of Muscle Tissue: Smooth Muscle Multiunit smooth muscleIn the iris of the eye and walls of blood vesselsResponds to neurotransmitters and hormonesVisceral smooth muscleIn walls of hollow organsResponds to neurotransmitters ANDStimulate each other to contract so that muscle fibers contract and relax together in a rhythmic motion – peristalsis
17Types of Muscle Tissue: Smooth Muscle (cont.) Peristalsis – rhythmic contraction that pushes substances through tubes of the bodyNeurotransmitters for smooth muscle contractionAcetylcholineNorepinephrineWill cause or inhibit contractions, depending on smooth muscle type
18Types of Muscle Tissue: Cardiac Muscle Intercalated discsConnect groups of cardiac muscleAllow the fibers in the groups to contract and relax togetherAllows heart to work as a pumpSelf-exciting – does not need nerve stimulation to contractNerves speed up or slow down contraction
19Type of Muscle Tissue: Cardiac Muscle (cont.) NeurotransmittersAcetylcholine – slows heart rateNorepinephrine – speeds up rate
20Very Good! Apply Your Knowledge Match the following: ___ Self-exciting A. Skeletal muscle___ Contract in response to B. Smooth muscle acetylcholine C. Cardiac muscle ___ Stimulate each other to contract___ Peristalsis___ Slowed by acetylcholine___ Voluntary movementCANSWER:ABVery Good!BCA
21Production of Energy for Muscle ATP (adenosine triphosphate)A type of chemical energyNeeded for sustained or repeated muscle contractionsMuscle cells must have three ways to store or make ATPCreatine phosphateRapid production of energyAerobic respirationUses body’s store of glucoseLactic acid productionSmall amounts of ATPATP = energy
22Production of Energy: Oxygen Debt Develops when skeletal muscles are used strenuously for several minutes and cells are low in oxygenPyruvic acidConverts toLactic acid which builds upMuscle fatigueTo liver for conversion to glucose, requiring more energy and oxygen to make ATPOxygen debt
23Production of Energy: Muscle Fatigue Condition in which a muscle has lost its ability to contractCausesAccumulation of lactic acidInterruption of the blood supply to a muscleA motor neuron loses its ability to release acetylcholine onto muscle fibers
24Yippee! Apply Your Knowledge ANSWER: Match the following: ___ Rapid production energy A. Lactic acid___ Needed for sustained or B. Pyruvic acid repeated muscle contractions C. ATP___ Uses body’s store of glucose D. Aerobic___ Muscle fatigue respiration___ With strenuous exercise, E. Creatine converts to lactic acid phosphateCDABYippee!
25Structure of Skeletal Muscles The major components of the muscular systemCompositionConnective tissueSkeletal muscle tissueBlood vesselsNerves
26Structure: Connective Tissue Coverings AponeurosisA tough, sheet-like structure made of fibrous connective tissueAttaches muscles to other musclesFasciaCovers entire skeletal musclesSeparates them from each otherTendonA tough, cord-like structure made of fibrous connective tissueConnects muscles to bones
27Structure: Connective Tissue Coverings (cont.) EpimysiumA thin covering that is just below the fascia of a muscle and surrounds the entire musclePerimysiumConnective tissue that divides a muscle into sections called fasciclesEndomysiumCovering of connective tissue that surrounds individual muscle cells
28Apply Your Knowledge Excellent! D E A B F C Match 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 musclesTendonPerimysiumAponeurosisEpimysiumFasciaEndomysiumDANSWER:EABFExcellent!C
29Attachments and Actions of Skeletal Muscles Actions depend largely on what the muscles are attached toAttachment sitesOrigin – an attachment site for a less movable boneInsertion – an attachment site for a more moveable bone
30Attachments and Actions (cont.) Movement usually produced by a group of musclesPrime mover – muscle responsible for most of the movementSynergists – muscles that help the prime mover by stabilizing jointsAntagonist (agonist) – produces movement opposite to prime moverRelaxes when prime mover contracts
31Attachments and Actions: Body Movements Flexion – bending a body partExtension – straightening a body partHyperextension – extending a body part past the normal anatomical positionDorsiflexion – pointing the toes upPlantar flexion – pointing the toes downAbduction – moving a body part away from the anatomical positionAdduction – moving a body part toward the anatomical position
32Attachments and Actions: Body Movements (cont.) Circumduction – moving a body part in a circlePronation – turning the palm of the hand downSupination – turning the palm of the hand upInversion – turning the sole of the foot mediallyEversion – turning the sole of the foot laterallyRetraction – moving a body part posteriorlyProtraction – moving a body part anteriorly
33Attachments and Actions: Body Movements (cont.) Elevation – lifting a body part; for example, elevating the shoulders as in a shrugging expressionDepression – lowering a body part; for example, lowering the shoulders
34Correct! Apply Your Knowledge The doctor has asked you to abduct the patient’s leg so he can see the patient’s wound. In order to position the patient correctly, what will you have to do?ANSWER: Move the patient’s leg away from its position in the anatomical position.Correct!
35Major Skeletal Muscles The muscle name indicatesLocationSizeActionShapeORNumber of attachments of the muscleAs you study muscles, you will find it easier to remember them if you think about what the name describes.
36Major Skeletal Muscles: The Head SternocleidomastoidPulls the head to one sidePulls the head to the chestFrontalisRaises the eyebrowsSplenius capitisRotates the headAllows it to bend to the sideOrbicularis orisAllows the lips to pucker
37Major Skeletal Muscles: The Head (cont.) Orbicularis oculiAllows the eyes to closeZygomaticusPulls the corners of the mouth upPlatysmaPulls the corners of the mouth downMasseter and temporalisClose the jaw
38Major Skeletal Muscles: Upper Arm Pectoralis majorPulls the arm across the chestRotates and adducts the armsLatissimus dorsiExtends and adducts the arm and rotates the arm inwardly
39Major Skeletal Muscles: Upper Arm (cont.) DeltoidAbducts and extends the arm at the shoulderSubscapularisRotates the arm mediallyInfraspinatusRotates the arm laterally
40Major Skeletal Muscles: Forearm Biceps brachiiFlexes the arm at the elbowRotates the hand laterallyBrachialisBrachioradialisFlexes the forearm at the elbow
41Major Skeletal Muscles: Forearm (cont.) Triceps brachiiExtends the arm at the elbowSupinatorRotates the forearm laterally (supination)Pronator teresRotates the forearm medially (pronation)
42Major Skeletal Muscles: Wrist, Hand, and Fingers Flexor carpi radialis and flexor carpi ulnarisFlex and abduct the wristPalmaris longusFlexes the wristFlexor digitorum profundusFlexes the distal joints of the fingers, but not the thumb
43Major Skeletal Muscles: Wrist, Hand, and Fingers (cont.) Extensor carpi radialis longus and brevisExtend the wrist and abduct the handExtensor carpi ulnarisExtends the wristExtensor digitorumExtends the fingers, but not the thumb
44Major Skeletal Muscles: Respiratory DiaphragmSeparates the thoracic cavity from the abdominal cavityIts contraction causes inspirationExternal and internal intercostalsExpand and lower the ribs during breathing
45Major Skeletal Muscles: Abdominal External and internal obliquesCompress the abdominal wallTransverse abdominisAlso compresses the abdominal wallRectus abdominisFlexes the vertebral columnCompresses the abdominal wallClick for View of Abdominal Muscles
47Major Skeletal Muscles: Pectoral Girdle TrapeziusRaises the armsPulls the shoulders downwardPectoralis minorPulls the scapula downwardRaises the ribsClick for View of Pectoral Girdle Muscles
48Major Skeletal Muscles: Leg Psoas major and iliacusFlexes the thighGluteus maximusExtends the thighGluteus medius and minimusAbduct the thighsRotate them medially
49Major Skeletal Muscles: Leg (cont.) Adductor longus and magnusAdduct the thighsRotate them laterallyBiceps femoris, semitendinosus, and semimembranosusKnown as the hamstring groupFlex the leg at the kneeExtend the leg at the thigh
50Major Skeletal Muscles: Leg (cont.) Rectus femoris, vastus lateralis, vastus medialis, and vastus intermediusExtend the leg at the kneeSartoriusFlexes the leg at the knee and thighAbducts the thigh, rotating the thigh laterally but rotating the lower leg medially
51Major Skeletal Muscles: Ankle, Foot, and Toes Tibialis anteriorInverts the foot and point the foot up (dorsiflexion)Extensor digitorum longusExtends the toes and point the foot upGastrocnemiusFlexes the foot and flexes the leg at the knee
52Major Skeletal Muscles: Ankle, Foot, and Toes (cont.) SoleusFlexes the footFlexor digitorum longusFlexes the foot and toes
53Bravo! Apply Your Knowledge Your patient complains of hurting his hamstring when running today. You would look at what part of the leg, and what muscles would be involved?ANSWER: You would look at the back of his leg, and the muscles involved would be the biceps femoris, semitendinosus, and semimembranosus. These three muscles are known as the hamstring group.Bravo!
54Muscle Strains and Sprains Strains – injuries due to over-stretched muscles or tendonsSprains – more serious injuries that result in tears to tendons, ligaments, and/or cartilage of jointsRICE is recommended treatment for eitherRestIceCompressionElevation
55Muscle Strains and Sprains (cont.) PreventionWarm up musclesA few minutes before an intense activity raises muscle temperature and makes muscle more pliableStretchingImproves muscle performance and should always be done after the warm-up or after exercisingCooling down or slowing downBefore completely stopping prevents pooling of blood in the legs and helps remove lactic acid from muscles
56Aging and the Musculoskeletal System Contractions become slower and not as strongDexterity and gripping ability decreaseMobility may decreaseAssistive devices helpfulRoutine exerciseSwimmingPhysical therapy
57Diseases and Disorders of the Muscular System DescriptionBotulismAffects the gastrointestinal tract and various muscle groupsFibromyalgiaFairly 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
58Diseases and Disorders of the Muscular System (cont.) DescriptionRhabdomyolysisA condition in which the kidneys become damaged after serious muscle injuriesTendonitis (lockjaw)Painful inflammation of a tendon and the tendon-muscle attachment to a boneTorticollis (wryneck)Acquired or congenital; spasm or shortening of the sternocleidomastoid muscle; head bends to affected side and chin rotates to opposite sideTrichinosisAn infection caused by parasites (worms)
59Apply Your Knowledge Good Job! The doctor has told your patient that his son has muscular dystrophy disorder. What is muscular dystrophy?ANSWER: Muscular dystrophy is an inherited disorder characterized by muscle weakness and a loss of muscle tissue.Good Job!
60In Summary Skeletal muscles Smooth muscles Cardiac muscles Voluntary controlProduce movement in conjunction with skeletal systemHelp stabilize jointsParticipate in heat productionSmooth musclesInvoluntary controlControl body openings and passagesCardiac musclesResponsible for pumping action of the heart
61In Summary (cont.)Medical assistants must understand the muscular system toGive IM injectionsPrepare patients for massage therapyDemonstrate ambulatory techniquesAssist in care and prevention of muscular disorders
62End of ChapterEnd of Chapter 26Everyone 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 Oech