CHAPTER 22 The Muscular System © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-2 Learning Outcomes 22.1 List the functions of muscle 22.2 List the three types of muscle tissue and describe the locations and characteristics of each 22.3 Describe how visceral (smooth) muscle produces peristalsis 22.4 Explain how muscle tissue generates energy © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-3 Learning Outcomes (cont.) 22.5 Describe the structure of a skeletal muscle 22.6 Define the terms origin and insertion 22.7 List and define the various types of body movements produced by skeletal muscles 22.8 List and identify the major skeletal muscles of the body, giving the action of each © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-4 Learning Outcomes (cont.) 22.9 Explain the differences between strain and sprain injuries 22.10 Describe the changes that occur to the muscular system as a person ages 22.11 Describe the causes, signs and symptoms, and treatments of various diseases and disorders of the muscular system © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-5 Introduction • Bones and joints not produce movement • The human body has more than 600 individual muscles • 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 © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-6 Functions of Muscle Muscle has the ability to contract, permitting muscles to perform various functions • Functions: – Movement – Stability – Control of body openings and passages – Heat production Click for Larger View © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-8 Movement • Skeletal muscles – Attached to bones by tendons – Cross joints so when they contract, bones they attach to move • Smooth muscle – Found on organ walls – Contractions produce movement of organ contents • Cardiac muscle – Produces atrial and ventricular contractions – This pumps blood from the heart into the blood vessels © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-9 Stability • Hold bones tightly together – Stabilize joints • Small muscles hold vertebrae together – Stabilize the spinal column © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-10 Control of Body Openings and Passages • Sphincters – Valve-like structures formed by muscles – Control movement of substances in and out of passages – Example: • A urethral sphincter prevents or allows urination © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-11 Heat Production • Heat is released with muscle contraction – Helps the body maintain a normal temperature – Moving your body can make you warmer if you are cold © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-55 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! © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-56 Muscle Strains and Sprains • Strains – injuries due to over-stretched muscles or tendons • Sprains – more serious injuries that result in tears to tendons, ligaments, and/or cartilage of joints • RICE is recommended treatment for either – Rest – Ice – Compression – Elevation © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-57 Muscle Strains and Sprains (cont.) • Prevention – Warm up muscles • A few minutes before an intense activity raises muscle temperature and makes muscle more pliable – Stretching • Improves muscle performance and should always be done after the warm-up or after exercising – Cooling down or slowing down • Before completely stopping prevents pooling of blood in the legs and helps remove lactic acid from muscles © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-58 Aging and the Musculoskeletal System • Contractions become slower and not as strong – Dexterity and gripping ability decrease – Mobility may decrease • Assistive devices helpful • Routine exercise – Swimming – Physical therapy © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d Diseases and Disorders of the Muscular System Disease 22-59 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 dystrophy Inherited disorder characterized by muscle weakness and a loss of muscle tissue Myasthenia gravis Autoimmune condition in which patients experience muscle weakness © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d Diseases and Disorders of the Muscular System (cont.) Disease 22-60 Description Rhabdomyolysis A condition in which the kidneys become damaged after serious muscle injuries Tetanus (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) © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-61 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 © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-62 In Summary 22.1 The functions of muscles include movement, stability, control of body openings and passages, and the production of heat 22.2 The three types of muscle tissue are striated voluntary skeletal muscle, smooth involuntary visceral muscle, and specialized striated and involuntary cardiac muscle 22.3 Peristalsis is the rhythmic contraction produced by smooth muscle to push substances through various tubes in the body © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-63 In Summary (cont.) 22.4 Muscles create energy in three ways Creatine phosphate is a rapid method for muscles to create energy, aerobic respiration uses stored glucose to produce ATP in the Krebs cycle, and lactic acid production occurs when a cell is low in oxygen and coverts pyruvic acid to lactic acid 22.5 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 © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-64 In Summary (cont.) 22.6 The origin of a muscle is the attachment site of the muscle to the less movable bone during muscle contraction The insertion of a muscle is the attachment site for the muscle to the more movable bone during muscle contraction 22.7 The body movements produced by skeletal muscles include flexion, extension, hyperextension, dorsiflexion, plantar flexion, abduction, adduction, rotation, circumduction, pronation, supination, inversion, eversion, retraction, protraction, elevation, and depression © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-65 In Summary (cont.) 22.8 The major muscles of the head are sternocleidomastoid, splenius capitis, frontalis, orbicularis oris and oculi, zygomaticus, platysma, masseter, and temporalis The upper extremity muscles include pectoralis major, latissimus dorsi, deltoid, subscapularis, biceps brachii, brachialis, brachioradialis, triceps brachii, supinator and pronator teres, flexor carpi radialis and ulnaris, plamaris longus, flexor digitorum profundus, extensor carpi radialis longus and brevis, and extensor digitorum The major respiratory muscles are the diaphragm and the external and internal intercostals © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-66 In Summary (cont.) 22.8 (cont.) The abdominal muscles include external and internal obliques, transverse abdominis, and rectus abdominis The pectoral girdle muscles include trapezius and pectoralis minor The muscles of the lower extremity include iliopsoas major; gluteus maximus, medius, and minimus; adductor longus and magnus; biceps femoris; semitendinosus and semimembranosus; rectus femoris; vastus lateralis, medius, and intermedius; sartorius; tibialis anterior; extensor digitorum longus; gastrocnemius; soleus; and flexor digitorum longus © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-67 In Summary (cont.) 22.9 Strain injuries involve injuries to muscles and/or tendons Sprains are more serious injuries that result in tears to tendons, ligaments, and/or the cartilage of joints 22.10 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 © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-68 In Summary (cont.) 22.11 The diseases of the muscular system, as well as their symptoms and treatments, vary widely and are discussed in the Pathophysiology section of this chapter Some of the common diseases discussed include botulism, fibromyalgia, muscular dystrophy, myasthenia gravis, tendonitis, tetanus, and torticollis © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22-69 End of Chapter 22 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 © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d [...]... rights reserv e d 22- 33 Body Movements (cont.) Circumduction – moving a body part in a circle Pronation – turning the palm of the hand down Supination – turning the palm of the hand up © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22- 34 Body Movements (cont.) Inversion – turning the sole of the foot medially Retraction – moving a body part posteriorly Eversion – turning the sole... acetylcholine – Causes skeletal muscle to contract • Following contraction, muscles release the enzyme acetylcholinesterase – Breaks down acetylcholine – Allows muscle to relax © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22- 16 Smooth Muscle • Multiunit smooth muscle – In the iris of the eye and walls of blood vessels – Responds to neurotransmitters and hormones • Visceral smooth muscle – In... – Responds to neurotransmitters AND – Stimulate each other to contract so that muscle fibers contract and relax together in a rhythmic motion – peristalsis © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22- 17 Smooth Muscle (cont.) • Peristalsis – rhythmic contraction that pushes substances through tubes of the body • Neurotransmitters for smooth muscle contraction – Acetylcholine –. .. e d 22- 29 Attachments and Actions of Skeletal Muscles • • Actions depend largely on what the muscles are attached to Attachment sites – Origin – an attachment site for a less movable bone – Insertion – an attachment site for a more movable bone © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22- 30 Attachments and Actions (cont.) • Movement usually produced by a group of muscles – Prime... (agonist) – muscle responsible for most of the movement – Synergists – muscles that help the prime mover by stabilizing joints – Antagonist – muscle that produces movement opposite to prime mover • Relaxes when prime mover contracts © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22- 31 Body Movements Flexion – bending a body part Plantar flexion – pointing the toes down Extension – straightening... -Hill Com panies, Inc A ll rights reserv e d 22- 13 Types of Muscle Tissue • Muscle cells – Myocytes called muscle fibers – Sarcolemma – cell membrane – Sarcoplasm – cytoplasm of cell – Myofibrils – long structures in sarcoplasm • Arrangement of filaments in myofibrils produces striations © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22- 14 Types of Muscle Tissue (cont.) Muscle Group... e d 22- 26 Connective Tissue Coverings • Fascia – Covers entire skeletal muscles – Separates them from each other • Tendon • Aponeurosis – A tough, sheet-like structure made of fibrous connective tissue – Attaches muscles to other muscles – A tough, cord-like structure made of fibrous connective tissue – Connects muscles to bones © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22- 27... Norepinephrine – Will cause or inhibit contractions, depending on smooth muscle type © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22- 18 Cardiac Muscle • Intercalated discs – Connect groups of cardiac muscle – Allow the fibers in the groups to contract and relax together • Allows heart to work as a pump • Self-exciting – does not need nerve stimulation to contract – Nerves speed up... fatigue _ B With strenuous exercise, _ converts to lactic acid A Lactic acid B Pyruvic acid C ATP D Aerobic respiration E Creatine phosphate Yippee! © 2011 The McGraw -Hill Com panies, Inc A ll rights reserv e d 22- 25 Structure of Skeletal Muscles • Skeletal muscles – The major components of the muscular system • Composition – Connective tissue – Skeletal muscle tissue – Blood vessels – Nerves © 2011... -Hill Com panies, Inc A ll rights reserv e d 22- 21 Production of Energy for Muscle • ATP (adenosine triphosphate) – A type of chemical energy – Needed for sustained or repeated muscle contractions • Muscle cells must have three ways to store or make ATP – Creatine phosphate • Rapid production of energy – Aerobic respiration • Uses body’s store of glucose – Lactic acid production • Small amounts of ATP