This document provides an overview of the muscular system, including the three types of muscle tissues and the structure and function of skeletal muscle. It discusses the structure of skeletal muscle from the organ level down to the sarcomere. Contraction of skeletal muscle is described, including excitation-contraction coupling, the sliding filament model, and the cross-bridge cycling of actin and myosin. Energy sources and the role of oxygen in muscle contraction are also summarized.

1. Edited by Brenda Holmes MSN/Ed, RN Associate Professor BIOL 2064: Anatomy & Physiology 1 Chapter 9 South Arkansas Community College

2. Chapter 9 Muscular System Hole’s Human Anatomy and Physiology Twelfth Edition Shier  Butler  Lewis Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

10. Animation: Function of the Neuromuscular Junction Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer. Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

13. 9.1 Clinical Application Myasthenia Gravis

17. Animation: The Cross-Bridge Cycle Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

18. Animation: Breakdown of ATP and Cross-Bridge Movement Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer. Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

20. Animation: Action Potentials and Muscle Contraction Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer. Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

22. Animation: Energy Sources for Prolonged Exercise Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer. Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

30. Length-Tension Relationship Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (b) Overly shortened (c) Overly stretched (a) Optimal length Muscle fiber length Force

31. Animation: Length-Tension Relation in Skeletal Muscle Please note that due to differing operating systems, some animations will not appear until the presentation is viewed in Presentation Mode (Slide Show view). You may see blank slides in the “Normal” or “Slide Sorter” views. All animations will appear after viewing in Presentation Mode and playing each animation. Most animations will require the latest version of the Flash Player, which is available at http://get.adobe.com/flashplayer.

37. 9.2 Clinical Application Use and Disuse of Skeletal Muscles

42. Characteristics of Muscle Tissue

45. Levers and Movement Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Radius Resistance Resistance Fulcrum Ulna (a) (b) Fulcrum Force Force Forearm movement Biceps brachii contracting muscle Relaxed muscle Triceps brachii contracting muscle Relaxed muscle Movement Movement

48. 9.8: Major Skeletal Muscles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Brachioradialis Frontalis Deltoid Brachialis Biceps brachii Gracilis Vastus medialis Gastrocnemius Soleus Trapezius Tibialis anterior External oblique Sartorius Rectus femoris Adductor longus Vastus lateralis Fibularis longus Orbicularis oculi Zygomaticus Masseter Orbicularis oris Sternocleido- mastoid Pectoralis major Serratus anterior Rectus abdominis Extensor digitorum longus Tensor fasciae latae

49. Major Skeletal Muscles Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Gracilis Rhomboid Infraspinatus Gluteus medius Vastus lateralis Sartorius Soleus Fibularis longus Brachialis Temporalis Occipitalis Semimembranosus Sternocleidomastoid Trapezius Teres minor Teres major Biceps femoris Semitendinosus Gastrocnemius Calcaneal tendon Deltoid Triceps brachii Latissimus dorsi External oblique Gluteus maximus Adductor magnus

50. Muscles of Facial Expression

51. Muscles of Mastication

52. Muscles of Facial Expression and Mastication Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Epicranial aponeurosis Frontalis Occipitalis Epicranius Masseter Sternocleidomastoid Temporalis Orbicularis oculi Zygomaticus major Zygomaticus minor Buccinator Orbicularis oris Platysma Buccinator Medial pterygoid Lateral pterygoid Temporalis (a) (c) (b)

53. Muscles That Move the Head and Vertebral Column

54. Muscles That Move the Head and Vertebral Column Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Iliocostalis lumborum Quadratus lumborum Spinalis thoracis Iliocostalis thoracis Spinalis cervicis Splenius capitis Spinalis capitis Semispinalis capitis Longissimus capitis Semispinalis capitis (cut) Longissimus cervicis Iliocostalis cervicis Longissimus thoracis Splenius capitis (cut)

55. Muscles That Move the Pectoral Girdle

56. Muscles That Move the Pectoral Girdle Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Trapezius Deltoid Deltoid Latissimus dorsi Levator scapulae Supraspinatus Infraspinatus Teres minor Teres major Rhomboid major Rhomboid minor (a) (d) (c) (b) Rhomboid minor Rhomboid major Latissimus dorsi Trapezius

57. Muscles That Move the Arm

58. Muscles That Move the Arm Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Trapezius Deltoid Pectoralis major External oblique Aponeurosis of external oblique Sternocleidomastoid Pectoralis minor Internal intercostal Serratus anterior Rectus abdominis Internal oblique Transversus abdominis External intercostal Linea alba (band of connective tissue)

59. Muscles That Move the Arm Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Levator scapulae Levator scapulae Supraspinatus Spine of scapula Deltoid Infraspinatus Teres minor Teres major (a) (d) (c) (b) Supraspinatus Infraspinatus Teres minor Teres major Long head of triceps brachii Lateral head of triceps brachii Triceps brachii

60. Muscles That Move the Forearm

61. Muscles That Move the Forearm Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Deltoid Clavicle Subscapularis Coracobrachialis Brachialis Subscapularis Coracobrachialis Brachialis (a) (c) (d) (b) Short head of biceps brachii Long head of biceps brachii Medial border of scapula Biceps brachii (short and long heads) Trapezius

62. Muscles That Move the Forearm Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Biceps brachii Brachialis Supinator Pronator teres Brachioradialis Flexor carpi radialis Palmaris longus Flexor carpi ulnaris Flexor carpi ulnaris Pronator quadratus Flexor retinaculum Brachioradialis Flexor carpi radialis Pronator teres Pronator quadratus (a) (b) (c) (d) (e) Flexor digitorum superficialis Extensor carpi radialis longus Flexor digitorum superficialis

63. Cross Section of the Forearm Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Abductor pollicis longus m. Flexor pollicis longus m. Radius Pronator teres m. Brachioradialis m. Radial n. Radial a. Flexor carpi radialis m. Extensor digitorum m. Ulna Ulnar n. Ulnar a. Flexor carpi ulnaris m. Median n. Palmaris longus m. Anterior Plane of section Extensor carpi radialis brevis m. Extensor carpi radialis longus m. Extensor carpi ulnaris m. Extensor pollicis longus m. Flexor digitorum profundus m. Flexor digitorum superficialis m.

65. Muscles That Move the Hand Triceps brachii Flexor carpi ulnaris Extensor carpi ulnaris Extensor digitorum Extensor retinaculum Brachioradialis Extensor carpi radialis longusand brevis (a) (b) (c) Extensor carpi radialis longus Extensor carpi radialis brevis Extensor carpi ulnaris Extensor digitorum Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

66. Muscles of the Abdominal Wall

67. Muscles of the Abdominal Wall Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. (a) (b) (c) (d) External oblique Rectus abdominis Internal oblique Transversus abdominis External oblique Internal oblique Transversus abdominis (e) Internal oblique Transversus abdominis External oblique Linea alba Rectus abdominis Peritoneum Skin Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

68. Muscles of the Pelvic Outlet

69. Muscles of Pelvic Outlet Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Scrotum Ischiocavernosus Clitoris Urethral orifice Anus Bulbospongiosus Levator ani Gluteus maximus Penis Anus Coccyx Rectum Urethra Symphysis pubis Coccygeus Urogenital diaphragm Levator ani (b) (a) (c) Vagina External anal sphincter Superficial transversus perinei Vaginal orifice

70. Muscles That Move the Thigh

71. Muscles That Move the Thigh Psoas major Psoas minor Iliacus Rectus femoris Sartorius Sartorius Vastus lateralis Vastus intermedius Patella Adductor longus Pectineus Adductor magnus Gracilis Vastus medialis Gracilis Adductor brevis Adductor longus Adductor magnus Iliacus Psoas major Psoas minor (a) (b) (c) (d) (e) (f) (g) Tensor fasciae latae Quadriceps femoris tendon (patellar tendon) Patellar ligament Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

72. Muscles That Move the Thigh Gluteus medius Gluteus medius Gluteus maximus Gluteus maximus Biceps femoris Iliotibial tract (band) Vastus lateralis Rectus femoris Sartorius Tensor fasciae latae Gluteus minimus Piriformis (a) (b) (c) (d) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

73. Muscles That Move the Leg

74. Muscles That Move the Leg Adductor magnus Gracilis Semitendinosus Semimembranosus Semimembranosus Sartorius Gastrocnemius Gluteus medius Gluteus maximus Biceps femoris Semitendinosus (a) (b) (c) Vastus lateralis covered by fascia Biceps femoris (short head) Biceps femoris (long head) Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

75. Muscles That Move the Leg Gracilis m. Semimembranosus m. Semitendinosus m. Sartorius m. Vastus medialis m. Rectus femoris m. Adipose tissue Skin Adductor magnus m. Adductor longus m. Great saphenousv. Femoralv . and a. Vastus intermedius m. Shaft of femur Sciatic n. Vastus lateralis m. Lateral Medial Anterior Long head of biceps femoris m. Short head of biceps femoris m. Plane of section Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

76. Muscles That Move the Leg Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Semitendinosus Semimembranosus Gracilis Sartorius Gastrocnemius: Medial head Lateral head Soleus Calcaneal tendon Flexor retinaculum Calcaneus Biceps femoris Plantaris Soleus Gastrocnemius (a) (b) (c) (d) (e) Flexor digitorum longus Fibular retinacula Fibularis brevis Fibularis longus Iliotibial tract (band) Flexor digitorum longus Tibialis posterior

77. Muscles That Move the Foot

78. Muscles That Move the Foot Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Fibularis longus Fibularis brevis Fibularis tertius Patella Patellar ligament Gastrocnemius Soleus Extensor retinacula (a) (b) (c) (d) Tibia Tibialis anterior Extensor digitorum longus Extensor digitorum longus Tibialis anterior Extensor hallucis longus

79. Muscles That Move the Foot Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Biceps femoris Gastrocnemius Soleus Fibularis longus Fibularis longus Calcaneal tendon Head of fibula Fibularis tertius Fibularis brevis Extensor retinacula Fibularis brevis (a) (b) (c) Vastus lateralis Tibialis anterior Extensor digitorum longus Fibular retinacula

80. 9.3 Clinical Application TMJ Syndrome

86. Quiz 9 Complete Quiz 9 now! Read Chapter 10.