Bài giảng Medical Assisting - Chapter 26: The Muscular System

ChapterPowerPoint® to accompany Second EditionRamutkowski  Booth  Pugh  Thompson  WhickerCopyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.Medical AssistingChapter 261Objectives26-1 List the functions of muscle. 26-2 Explain how muscle tissue generates energy.26-3 List the three types of muscle tissue and describe the locations and characteristics of each.26-4 Describe how smooth muscle produces peristalsis.26-5 Describe the structure of a skeletal muscle.The Muscular System 2Objectives (cont.)26-7 List and define the various types of body movements produced by skeletal muscles.26-8 Define the terms origin and insertion.26-9 List the major skeletal muscles of the body and give the action of each.26-10 Describe various disorders and diseases of the muscular system. The Muscular System3Introduction Bones and joints do not themselves produce movement. The human body has more than 600 individual musclesBy alternating between contraction and relaxation, muscles cause bones and supported structures to move.You will focus on the differences among three muscle tissue types, the structure of skeletal muscles, muscle actions, and the names of skeletal muscles. 4Functions of Muscle Muscle has the ability to contract, and this contraction allows muscles to perform various functions.Functions:MovementStabilityControl of body openings and passages Heat productionClick for Larger View5Skeletal Muscle6Functions of MuscleMovement:Skeletal muscles are attached to bones which allow you to walk or wave your hand.Smooth muscle is found on organ walls such as the intestine. Contractions produces movement of food through the intestine.Cardiac muscle produces the pumping of the blood in the heart.7Functions of MuscleStability:Muscles hold your bones together to stabilize joints.Small muscles hold your vertebrae together to stabilize your spinal column.8Functions of MuscleControlling of openings and passages:Muscles form valve like structures called sphinctersSphincters control movement of substances in and out of passages.A urethral sphincter prevents or allows urination9Functions of MuscleHeat production:When muscles contract heat is releasedThis helps the body maintain a normal temperatureMoving your body can make you warmer if you are cold.103 Types of Muscle TissueMuscle 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; vasoconstriction Involuntary Cardiac MuscleWall of the heartPumps blood through heartInvoluntary11PeristalsisRhythmic contraction that pushes substances through tubes of the body. Muscle fibers in visceral smooth muscle respond to neurotransmitters but they also stimulate each other to contract.The muscle fibers tend to contract and relax together.This type of muscle produces an action called peristalsis. 12Production of Energy for Muscle Muscle cells must have three ways to store or make this substance: Creatine phosphate Aerobic respiration of glucose Lactic acid production ATP (adenosine triphosphate), a type of chemical energy, is needed for sustained or repeated muscle contractions. 13Oxygen DebtOxygen debt develops when skeletal muscles are used strenuously for a minute or two and:supplies in the muscle are low the aerobic respiration of glucose can no longer be used to produce ATP. This process accounts for why you still burn energy after you exercise. 14Muscle FatigueCondition in which a muscle has lost its ability to contract Develops due to an accumulation of lactic acid Occurs when the blood supply to a muscle is interrupted A motor neuron loses its ability to release acetylcholine onto muscle fibers Cramps or painful involuntary contractions of muscles, can accompany muscle fatigue15Apply Your KnowledgeWhat causes bones to move?16Apply Your Knowledge -AnswerBones move by alternating between contraction and relaxation; muscles cause bones and supported structures to move. What causes bones to move?17Structure of Skeletal MusclesSkeletal muscles are the major organs that make up the muscular system Consists of connective tissues, skeletal muscle tissue, blood vessels, and nervesWhen body movements are produced, not just one muscle is involved, but a group of muscles contract 18Connective Tissue CoveringsFascia - covers entire skeletal muscles and separates them from each other. Tendon - a tough, cord-like structure made of fibrous connective tissue that connects muscles to bones. Aponeurosis - a tough, sheet-like structure made of fibrous connective tissue that attaches muscles to other muscles. Epimysium - a thin covering that is just deep (underneath) to the fascia of a muscle that surrounds the entire muscle.Perimysium - connective tissue divides a muscle into sections called fascicles.Endomysium - covering of connective tissue surrounds individual muscle cells.19Attachments and Actions of Skeletal Muscles Actions of skeletal muscles depend largely on what the skeletal muscles are attached Insertion - an attachment site that moves when a muscle contracts. Origin - an attachment site that does not move when a muscle contracts20Body Movements Flexion – Bending a body part Extension – Straightening a body part Hyperextension – Extending a body part past the normal anatomical position Dorsiflexion – Pointing the toes up Plantar flexion – Pointing the toes down Abduction – Moving a body part away from its position in the anatomical position Adduction – Moving a body part toward its position in the anatomical position 21Body Movements (cont.)Circumduction- Moving a body part in a circle; for example, moving your arm in a circular motion Pronation – Turning the palm of the hand down Supination – Turning the palm of the hand up Inversion – Turning the sole of the foot mediallyEversion – Turning the sole of the foot laterally Retraction – Moving a body part posteriorlyProtraction – Moving a body part anteriorly22Body 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 shoulders23Apply Your KnowledgeThe 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?24Apply Your Knowledge - AnswerMoving the patient’s leg away from its position in the anatomical position. The doctor has asked you to abduct the patient’s leg, so he can see the patients wound. In order to position the patient correctly what will you have to do?25Major Skeletal Muscles The muscle name indicates the location, size, action, shape, or number of attachments of the muscle. As you study muscles, you will find it easier to remember them if you think about what the name describes.26Muscles of the HeadSternocleidomastoid - pulls the head to one side and also pulls the head to the chestSplenius capitis - rotates the head and allows it to bend to the sideFrontalis - raises the eyebrowsOrbicularis oris - allows the lips to pucker Orbicularis oculi - allows the eyes to close Zygomaticus - pulls the corners of the mouth upPlatysma - pulls the corners of the mouth downMasseter and temporalis - close the jaw27Arm Muscles Pectoralis major - pulls the arm across the chest; it also rotates and adducts the arms Latissimus dorsi - acts to extend, adduct, and rotate the arm inwardlyDeltoid - acts to abduct and extend the arm at the shoulder Subscapularis - rotates the arm mediallyInfraspinatus - rotates the arm laterally28Forearm Muscles Biceps brachii - flexes the arm at the elbow and rotates the hand laterallyBrachialis - flexes the arm at the elbowBrachioradialis - flexes the forearm at the elbowTriceps brachii - extends the arm at the elbowSupinator - rotates the forearm laterally (supination)Pronator teres - rotates the forearm medially (pronation)29Muscles of the Wrist, Hand and FingersFlexor carpi radialis and flexor carpi ulnaris - act to flex and abduct the wrist.Palmaris longus - acts to flex the wrist.Flexor digitorum profundus - acts to flex the distal joints of the fingers but not the thumb.Extensor carpi radialis longus and brevis - act to extend the wrist and abduct the hand.Extensor carpi ulnaris - acts to extend the wrist.Extensor digitorum - acts to extend the fingers but not the thumb.30Respiratory MusclesDiaphragm - separates the thoracic cavity from the abdominal cavity; its contraction causes inspiration.External and internal intercostals - muscles expand and lower the ribs during breathing. 31Apply Your KnowledgeA patient has arrived in the office complaining of pain when she raises her arm. What muscle would be involved in this action?32Apply Your Knowledge -AnswerThe deltoid muscle acts to abduct and extend the arm at the shoulder. A patient has arrived in the office complaining of pain when she raises her arm. What muscle would be involved in this action?33Abdominal MusclesExternal and internal obliques - compress the abdominal wall.Transverse abdominis - also compresses the abdominal wall.Rectus abdominis - acts to flex the vertebral column and compress the abdominal wall.Click for Larger View34Abdominal Muscles (cont.)35Muscles of the Pectoral Girdle Trapezius - muscle raises the arms and pulls the shoulders downward.Pectoralis minor - muscle pulls the scapula downward and raises the ribs.36Leg MusclesPsoas major & iliacus - flexes the thigh.Gluteus maximus - extends the thigh.Gluteus medius and minimus - abduct the thighs and rotate them medially.Adductor longus and magnus - muscles adduct the thighs and rotate them laterally.Biceps femoris, semitendinosus, and semimembranosus - three muscles are known as the hamstring group. They act to flex the leg at the knee and extend the leg at the thigh.37Leg Muscles (cont.)Rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius - act to extend the leg at the knee.Sartorius - flexes the leg at the knee and thigh and abducts the thigh, rotating the thigh laterally but rotating the lower leg medially.38Muscles of the Ankle, Foot, and ToesTibialis anterior - acts to invert the foot and point the foot up (dorsiflexion).Extensor digitorum longus - acts to extend the toes and point the foot up. Gastrocnemius - acts to flex the foot and flex the leg at the knee.Soleus - also acts to flex the foot.Flexor digitorum longus - acts to flex the foot and toes.39Apply Your KnowledgeYour patient complains of hurting his hamstring when running today. You would look at what part of the leg, and what muscles would be involved?40Apply Your Knowledge -AnswerYou 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. 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?41Muscle Strains and SprainsWarm Up – Warming up muscles for just a few minutes before an intense activity raises muscle temperature. Stretch – Stretching improves muscle performance and should always be done after the warm up or after exercising. Cool Down – Slowing down the exercise before completely stopping prevents dizziness and fainting. 42Diseases and Disorders of the Muscular SystemBotulism - affects the gastrointestinal tract and various muscle groups Fibromyalgia - fairly common condition that causes chronic pain primarily in joints, muscles, and tendons Muscular Dystrophy -inherited disorder characterized by muscle weakness and a loss of muscle tissue Myasthenia gravis - patients experience muscle weakness 43Diseases and Disorders of the Muscular SystemRhabdomyolysis - a condition in which the kidneys have been damaged related to serious muscle injuriesTetanus - commonly called lockjaw Trichinosis - an infection caused by parasites (worms)44Apply Your KnowledgeThe doctor has told your patient that his son has muscular dystrophy disorder. What is muscular dystrophy?45Apply Your Knowledge -AnswerMuscular dystrophy is an inherited disorder characterized by muscle weakness and a loss of muscle tissue. The doctor has told your patient that his son has muscular dystrophy disorder. What is Muscular dystrophy?46Summary Medical Assistant Skeletal muscle works in conjunction with the skeletal system to produce movement. You must understand the muscular system in order to give muscular injections, prepare patients for massage therapy, demonstrate ambulatory techniques, and assist in the care of sprains and strains.47End of ChapterEnd of Chapter48