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Chapter 22 - The muscular system. This chapter focuses on the differences among three muscle tissue types, the structure of skeletal muscles, muscle actions, and the names of skeletal muscles.
CHAPTER 22 The Muscular System © 2011 The McGraw-Hill Companies, Inc All rights reserved 222 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 Companies, Inc All rights reserved 223 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 Companies, Inc All rights reserved 224 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 Companies, Inc All rights reserved 225 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 Companies, Inc All rights reserved 226 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 Companies, Inc All rights reserved 227 Skeletal Muscle © 2011 The McGraw-Hill Companies, Inc All rights reserved 228 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 Companies, Inc All rights reserved 229 Stability • Hold bones tightly together – Stabilize joints • Small muscles hold vertebrae together – Stabilize the spinal column © 2011 The McGraw-Hill Companies, Inc All rights reserved 2210 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 Companies, Inc All rights reserved 2255 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 Companies, Inc All rights reserved 2256 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 Companies, Inc All rights reserved 2257 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 Companies, Inc All rights reserved 2258 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 Companies, Inc All rights reserved Diseases and Disorders of the Muscular System Disease 2259 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 Companies, Inc All rights reserved Diseases and Disorders of the Muscular System (cont.) Disease 2260 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 Companies, Inc All rights reserved 2261 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 Companies, Inc All rights reserved 2262 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 Companies, Inc All rights reserved 2263 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 Companies, Inc All rights reserved 2264 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 Companies, Inc All rights reserved 2265 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 Companies, Inc All rights reserved 2266 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 Companies, Inc All rights reserved 2267 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 Companies, Inc All rights reserved 2268 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 Companies, Inc All rights reserved 2269 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 Companies, Inc All rights reserved ... All rights reserved 22 13 Types of Muscle Tissue • Muscle cells – Myocytes called muscle fibers – Sarcolemma – cell membrane – Sarcoplasm – cytoplasm of cell – Myofibrils – long structures in... functions • Functions: – Movement – Stability – Control of body openings and passages – Heat production Click for Larger View © 2011 The McGraw-Hill Companies, Inc All rights reserved 22 7 Skeletal.. .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