26 1 The Muscular System Power Point presentation

26 -1 The Muscular System Power. Point® presentation to accompany: Medical Assisting Third Edition Booth, Whicker, Wyman, Pugh, Thompson © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -2 Learning 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. © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -3 Learning 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. © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -4 Learning 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. © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -5 Introduction o o Bones and joints do not produce movement The human body has more than 600 individual muscles o Muscles cause bones and supported structures to move by alternating between contraction and relaxation You will focus on the differences among three muscle tissue types, the structure of skeletal muscles, muscle actions, and the names of skeletal muscles. © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -6 Functions of Muscle has the ability to contract, permitting muscles to perform various functions o Functions: n n Click for Larger View Movement Stability Control of body openings and passages Heat production © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -8 Functions of Muscle: Movement o Skeletal muscles n n o Smooth muscle n n o Attached to bones by tendons Cross joints so when they contract, bones they attach to move Found on organ walls Contractions produce movement of organ contents Cardiac muscle n n Produces atrial and ventricular contractions This pumps blood from the heart into the blood vessels © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -9 Functions of Muscle: Stability o Hold bones tightly together n o Stabilize joints Small muscles hold vertebrae together n Stabilize the spinal column © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -10 Functions of Muscle: Control of Body Openings and Passages o Sphincters n Valve-like structures formed by muscles n Control movement of substances in and out of passages n Example: o A urethral sphincter prevents or allows urination © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -11 Functions of Muscle: Heat Production o Heat is released with muscle contraction n Helps the body maintain a normal temperature n Moving your body can make you warmer if you are cold © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -12 Apply Your Knowledge True or False: ANSWER: tendons ___ F Skeletal muscles are attached to bones by ligaments. __ T Contractions of smooth muscle produce movement of organ contents. T Cardiac muscle produces atrial and ventricular contractions. ___ in and out F Sphincters control movement of substances out of passages. ___ F Heat is released as muscles relax. ___ contract © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -13 Types of Muscle Tissue o Muscle cells n Myocytes called muscle fibers n Sarcolemma – cell membrane n Sarcoplasm – cytoplasm of cell n Myofibrils – long structures in sarcoplasm o Arrangement of filaments in myofibrils produces striations © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -14 Types of Muscle Tissue (cont. ) Muscle Group Major Location Skeletal Muscle Attached to bones and skin of the face Produces body movements and facial expressions Voluntary Smooth Muscle Walls of hollow organs, blood vessels, and iris Moves contents through organs; vasoconstriction Involuntary Cardiac Muscle Wall of the heart Pumps blood through heart Involuntary Major Function Mode of Control © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -15 Types of Muscle Tissue: Skeletal Muscle o Muscle fibers respond to the neurotransmitter acetylcholine n o Causes skeletal muscle to contract Following contraction, muscles release the enzyme acetylcholinesterase n n Breaks down acetylcholine Allows muscle to relax © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -16 Types of Muscle Tissue: Smooth Muscle o Multiunit smooth muscle n n o In the iris of the eye and walls of blood vessels Responds to neurotransmitters and hormones Visceral smooth muscle n n n In walls of hollow organs Responds to neurotransmitters AND Stimulate each other to contract so that muscle fibers contract and relax together in a rhythmic motion – peristalsis © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -17 Types of Muscle Tissue: Smooth Muscle (cont. ) o Peristalsis – rhythmic contraction that pushes substances through tubes of the body o Neurotransmitters for smooth muscle contraction n Acetylcholine n Norepinephrine n Will cause or inhibit contractions, depending on smooth muscle type © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -18 Types of Muscle Tissue: Cardiac Muscle o Intercalated discs n n Connect groups of cardiac muscle Allow the fibers in the groups to contract and relax together o o Allows heart to work as a pump Self-exciting – does not need nerve stimulation to contract n Nerves speed up or slow down contraction © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -19 Type of Muscle Tissue: Cardiac Muscle (cont. ) o Neurotransmitters n n Acetylcholine – slows heart rate Norepinephrine – speeds up rate © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -20 Apply Your Knowledge Match the following: ANSWER: C Self-exciting ___ A Contract in response to ___ acetylcholine B Stimulate each other to ___ contract B Peristalsis ___ C Slowed by acetylcholine ___ A Voluntary movement A. Skeletal muscle B. Smooth muscle C. Cardiac muscle Very Good! © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -21 Production of Energy for Muscle o ATP (adenosine triphosphate) n n A type of chemical energy Needed for sustained or repeated muscle contractions o Muscle cells must have three ways to store or make ATP n Creatine phosphate o n Aerobic respiration o n Rapid production of energy Uses body’s store of glucose Lactic acid production o Small amounts of ATP © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -22 Production of Energy: Oxygen Debt o Develops when skeletal muscles are used strenuously for several minutes and cells are low in oxygen Pyruvic acid Converts to To liver for conversion to glucose, requiring more energy and oxygen to make ATP Lactic acid which builds up Muscle fatigue Oxygen debt © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -23 Production of Energy: Muscle Fatigue Condition in which a muscle has lost its ability to contract o Causes o n n n Accumulation of lactic acid Interruption of the blood supply to a muscle A motor neuron loses its ability to release acetylcholine onto muscle fibers © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -24 Apply Your Knowledge Match the following: ANSWER: ___ E Rapid production energy ___ C Needed for sustained or repeated muscle contractions D Uses body’s store of glucose ___ A Muscle fatigue ___ B respiration ___ With strenuous exercise, converts to lactic acid A. Lactic acid B. Pyruvic acid C. ATP D. Aerobic E. Creatine phosphate Yippee! © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -25 Structure of Skeletal Muscles o Skeletal muscles n o The major components of the muscular system Composition n n Connective tissue Skeletal muscle tissue Blood vessels Nerves © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -26 Structure: Connective Tissue Coverings o Fascia n n Covers entire skeletal muscles Separates them from each other o Aponeurosis n n o A tough, sheet-like structure made of fibrous connective tissue Attaches muscles to other muscles Tendon n n A tough, cord-like structure made of fibrous connective tissue Connects muscles to bones © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -27 Structure: Connective Tissue Coverings (cont. ) o Epimysium n o Perimysium n o A thin covering that is just below the fascia of a muscle and surrounds the entire muscle Connective tissue that divides a muscle into sections called fascicles Endomysium n Covering of connective tissue that surrounds individual muscle cells © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -28 Apply Your Knowledge Match the following: D __ Thin covering under the fascia that surrounds the muscle A. Tendon B. Perimysium E __ Separates muscles from each other C. Aponeurosis A __ Connects muscles to bones D. Epimysium B __ Divides a muscle into sections E. Fascia called fascicles F __ Surrounds individual muscle cells F. Endomysium C __ Attaches muscles to other muscles ANSWER: © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -29 Attachments and Actions of Skeletal Muscles o o Actions depend largely on what the muscles are attached to Attachment sites n n Origin – an attachment site for a less movable bone Insertion – an attachment site for a more moveable bone © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -30 Attachments and Actions (cont. ) o Movement usually produced by a group of muscles n n n Prime mover – muscle responsible for most of the movement Synergists – muscles that help the prime mover by stabilizing joints Antagonist (agonist) – produces movement opposite to prime mover o Relaxes when prime mover contracts © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -31 Attachments and Actions: Body Movements Flexion – bending a body part Plantar flexion – pointing the toes down Extension – straightening a body part Abduction – moving a body part away from the anatomical position Hyperextension – extending a body part past the normal anatomical position Dorsiflexion – pointing the toes up Adduction – moving a body part toward the anatomical position © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -32 Attachments and Actions: Body Movements (cont. ) Circumduction – moving a body part in a circle Inversion – turning the sole of the foot medially Pronation – turning the palm of the hand down Eversion – turning the sole of the foot laterally Supination – turning the palm of the hand up Retraction – moving a body part posteriorly Protraction – moving a body part anteriorly © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -33 Attachments and Actions: Body Movements (cont. ) Elevation – lifting a body part; for example, elevating the shoulders as in a shrugging expression Depression – lowering a body part; for example, lowering the shoulders © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -34 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! © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -35 Major Skeletal Muscles o The muscle name indicates n n n Location Size Action Shape OR Number of attachments of the muscle o As you study muscles, you will find it easier to remember them if you think about what the name describes. © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -36 Major Skeletal Muscles: The Head o Sternocleidomastoid n n o Pulls the head to one side Pulls the head to the chest Frontalis n o Splenius capitis n n o Rotates the head Allows it to bend to the side Orbicularis oris n Allows the lips to pucker Raises the eyebrows © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -37 Major Skeletal Muscles: The Head (cont. ) o Orbicularis oculi n o Allows the eyes to close Zygomaticus n o Pulls the corners of the mouth up Platysma n o Pulls the corners of the mouth down Masseter and temporalis n Close the jaw © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -38 Major Skeletal Muscles: o Pectoralis major n n o Upper Arm Pulls the arm across the chest Rotates and adducts the arms Latissimus dorsi n Extends and adducts the arm and rotates the arm inwardly © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -39 Major Skeletal Muscles: o Deltoid n o Abducts and extends the arm at the shoulder Subscapularis n o Upper Arm (cont. ) Rotates the arm medially Infraspinatus n Rotates the arm laterally © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -40 Major Skeletal Muscles: o Biceps brachii n n o Flexes the arm at the elbow Rotates the hand laterally Brachialis n o Forearm Flexes the arm at the elbow Brachioradialis n Flexes the forearm at the elbow © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -41 Major Skeletal Muscles: o Triceps brachii n o Extends the arm at the elbow Supinator n o Forearm (cont. ) Rotates the forearm laterally (supination) Pronator teres n Rotates the forearm medially (pronation) © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -42 Major Skeletal Muscles: Wrist, Hand, and Fingers o Flexor carpi radialis and flexor carpi ulnaris n o Palmaris longus n o Flex and abduct the wrist Flexes the wrist Flexor digitorum profundus n Flexes the distal joints of the fingers, but not the thumb © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -43 Major Skeletal Muscles: Wrist, Hand, and Fingers (cont. ) o Extensor carpi radialis longus and brevis n o Extensor carpi ulnaris n o Extend the wrist and abduct the hand Extends the wrist Extensor digitorum n Extends the fingers, but not the thumb © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -44 Major Skeletal Muscles: o Diaphragm n n o Respiratory Separates the thoracic cavity from the abdominal cavity Its contraction causes inspiration External and internal intercostals n Expand lower the ribs during breathing © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -45 Major Skeletal Muscles: Abdominal o External and internal obliques n o Transverse abdominis n o Compress the abdominal wall Also compresses the abdominal wall Rectus abdominis n n Flexes the vertebral column Compresses the abdominal wall Click for View of Abdominal Muscles © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -47 Major Skeletal Muscles: Pectoral Girdle o Trapezius n n o Raises the arms Pulls the shoulders downward Pectoralis minor n n Pulls the scapula downward Raises the ribs Click for View of Pectoral Girdle Muscles © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -48 Major Skeletal Muscles: o Psoas major and iliacus n o Flexes the thigh Gluteus maximus n o Leg Extends the thigh Gluteus medius and minimus n n Abduct the thighs Rotate them medially © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -49 Major Skeletal Muscles: o Adductor longus and magnus n n o Leg (cont. ) Adduct the thighs Rotate them laterally Biceps femoris, semitendinosus, and semimembranosus n n n Known as the hamstring group Flex the leg at the knee Extend the leg at the thigh © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -50 Major Skeletal Muscles: Leg (cont. ) o Rectus femoris, vastus lateralis, vastus medialis, and vastus intermedius n o Extend the leg at the knee Sartorius n n Flexes the leg at the knee and thigh Abducts the thigh, rotating the thigh laterally but rotating the lower leg medially © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -51 Major Skeletal Muscles: Ankle, Foot, and Toes o Tibialis anterior n o Extensor digitorum longus n o Inverts the foot and point the foot up (dorsiflexion) Extends the toes and point the foot up Gastrocnemius n Flexes the foot and flexes the leg at the knee © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -52 Major Skeletal Muscles: Ankle, Foot, and Toes (cont. ) o Soleus n Flexes the foot o Flexor digitorum longus n Flexes the foot and toes © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -53 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! © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -54 Muscle Strains and Sprains o Strains – injuries due to over-stretched muscles or tendons o Sprains – more serious injuries that result in tears to tendons, ligaments, and/or cartilage of joints o RICE is recommended treatment for either n n Rest Ice Compression Elevation © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -55 Muscle Strains and Sprains (cont. ) o Prevention n Warm up muscles o n Stretching o n A few minutes before an intense activity raises muscle temperature and makes muscle more pliable Improves muscle performance and should always be done after the warm-up or after exercising Cooling down or slowing down o Before completely stopping prevents pooling of blood in the legs and helps remove lactic acid from muscles © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -56 Aging and the Musculoskeletal System o Contractions become slower and not as strong n n o o Dexterity and gripping ability decrease Mobility may decrease Assistive devices helpful Routine exercise n n Swimming Physical therapy © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -57 Diseases and Disorders of the Muscular System Disease Description Botulism Affects the gastrointestinal tract and various muscle groups Fibromyalgia Fairly common condition that causes chronic pain primarily in joints, muscles, and tendons Muscular Inherited disorder characterized by muscle Dystrophy weakness and a loss of muscle tissue Myasthenia gravis Autoimmune condition in which patients experience muscle weakness © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -58 Diseases and Disorders of the Muscular System (cont. ) Disease Description Rhabdomyolysis A condition in which the kidneys become damaged after serious muscle injuries Tendonitis (lockjaw) Painful inflammation of a tendon and the tendon-muscle attachment to a bone Torticollis (wryneck) Acquired or congenital; spasm or shortening of the sternocleidomastoid muscle; head bends to affected side and chin rotates to opposite side Trichinosis An infection caused by parasites (worms) © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -59 Apply Your Knowledge 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. © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -60 In Summary o Skeletal muscles n n Voluntary control Produce movement in conjunction with skeletal system Help stabilize joints Participate in heat production o Smooth muscles n n o Involuntary control Control body openings and passages Cardiac muscles n n Involuntary control Responsible for pumping action of the heart © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -61 In Summary (cont. ) o Medical assistants must understand the muscular system to n n Give IM injections Prepare patients for massage therapy Demonstrate ambulatory techniques Assist in care and prevention of muscular disorders © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved

26 -62 End of Chapter 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 Oech © 2009 The Mc. Graw-Hill Companies, Inc. All rights reserved