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10 The Muscular System PowerPoint® Lecture Presentations prepared by Alexander G. Cheroske Mesa Community College at Red Mountain © 2011 Pearson Education, Inc. Section 1: Functional Organization of the Muscular System • Learning Outcomes • 10.1 Describe the arrangement of fascicles in the various types of muscles, explain the resulting functional differences, and explain how different classes of levers affect muscle efficiency. • 10.2 Explain how the name of a muscle can help identify its location, appearance, or function. • 10.3 Describe the separation of muscles into axial and appendicular divisions. © 2011 Pearson Education, Inc. Section 1: Functional Organization of the Muscular System • Muscular system • Accounts for almost half body weight • Contains ~700 muscles • Vary widely in size, shape, and function • Performance varies on how fibers are organized and how muscle attaches to skeleton • Divided into two divisions 1. Axial muscles • Support and position axial skeleton 2. Appendicular muscles • Support, move, and brace the limbs © 2011 Pearson Education, Inc. The two divisions of the muscular system: axial muscles and appendicular muscles The proportion of total body weight contributed by the muscular system Urinary system 0.7% Respiratory system 1.7% Nervous system 2% Digestive system 6% Integumentary system 16% Lymphatic system 0.3% Reproductive system 0.15% Endocrine system 0.15% Cardiovascular system 9% Axial muscles Skeletal system 20% Muscular system 44% Tendons conduct the forces of contraction to perform specific tasks. Appendicular muscles Figure 10 Section 1 © 2011 Pearson Education, Inc. Module 10.1: Fascicle organization and range of motion • Fascicle organization • Parallel muscle • Fascicles parallel to muscle long axis • Most skeletal muscles in the body are parallel • Some flat with broad attachments (aponeuroses) • Some plump and cylindrical with tendon attachments • Has central body (belly) • Can contract until shortened by ~30% • Due to muscle fiber shortening • Example: biceps brachii © 2011 Pearson Education, Inc. A parallel muscle: the biceps brachii (1) Fascicle Body (belly) 1 Figure 10.1 © 2011 Pearson Education, Inc. 1 Module 10.1: Fascicle organization and range of motion • Fascicle organization (continued) • Convergent muscle • Fascicles extending over broad area converge on common attachment site • Versatile action • Different portions can contract to produce different actions • Entire muscle can contract • Pulls less on attachment compared to parallel • Example: pectoralis major © 2011 Pearson Education, Inc. A convergent muscle: the pectoralis major (2) Base of muscle Tendon 2 Figure 10.1 © 2011 Pearson Education, Inc. 2 Module 10.1: Fascicle organization and range of motion • Fascicle organization (continued) • Pennate muscle (penna, feather) • Fascicles form common angle with tendon • Pull at an angle on tendon • Shorter movement of tendon versus parallel • Contain more fibers than parallel of same size so produces more tension © 2011 Pearson Education, Inc. Module 10.1: Fascicle organization and range of motion • Fascicle organization (continued) • Pennate muscle (continued) • Three types 1. Unipennate (all fibers on one side of tendon) • Example: extensor digitorum 2. Bipennate (fibers insert on both sides of tendon) • Example: rectus femoris 3. Multipennate (tendon branches within pennate muscle) • © 2011 Pearson Education, Inc. Example: deltoid Three pennate muscles Extensor digitorum muscle Rectus femoris muscle Deltoid muscle (3c) (3a) Tendons 3 Extended tendon If all the muscle fibers are on the same side of the tendon, the pennate muscle is unipennate. If a pennate muscle has fibers on both sides of the tendon, it is called bipennate. (3b) If the tendon branches within a pennate muscle, the muscle is said to be multipennate. Figure 10.1 © 2011 Pearson Education, Inc. 3 A circular muscle, or sphincter (4) 4 Contracted Relaxed Figure 10.1 © 2011 Pearson Education, Inc. 4 Module 10.1: Fascicle organization and range of motion • Levers and Leverage • Skeletal muscle force, speed, and direction depend on how it is attached to a lever • Lever moves when applied force overcomes load • Lever = rigid structure (bone) • Fulcrum = fixed point on which lever pivots (joint) • Applied force = muscle action Animation: Classes of Levers © 2011 Pearson Education, Inc. Module 10.1: Fascicle organization and range of motion • Levers and Leverage (continued) • Lever classes 1. First-class lever • Fulcrum (F) between applied force (AF) and load (L) • Acts like seesaw • • Balance depends on sizes of force and load and distribution on lever Few examples in body but important © 2011 Pearson Education, Inc. A first-class lever Load Fulcrum Applied force Figure 10.1 © 2011 Pearson Education, Inc. 5 Module 10.1: Fascicle organization and range of motion • Levers and Leverage (continued) • Lever classes (continued) 2. Second-class lever • Load is between applied force and fulcrum • • Always farther from fulcrum than load so small force moves large load, but slowly and short distance Acts like wheelbarrow © 2011 Pearson Education, Inc. A second-class lever Load Fulcrum Applied force Figure 10.1 © 2011 Pearson Education, Inc. 6 Module 10.1: Fascicle organization and range of motion • Levers and Leverage (continued) • Lever classes (continued) 3. Third-class lever • Most common lever in body • Force applied between load and fulcrum • Speed and distance traveled increased at expense of effective force © 2011 Pearson Education, Inc. A third-class lever Applied force Load Biceps brachii muscle Fulcrum Figure 10.1 © 2011 Pearson Education, Inc. 7 Module 10.1 Review a. Define a lever, and describe the three classes of levers. b. The joint between the occipital bone of the skull and the first cervical vertebra (atlas) is which part of which class of lever system? c. Why does a pennate muscle generate more tension than does a parallel muscle of the same size? © 2011 Pearson Education, Inc. Module 10.2: Muscle names • Individual muscle parts • Origin • Fixed attachment • Most are bones, some are connective tissue sheaths or bands (examples: intermuscular septa or interosseus membranes) • Typically proximal to insertion in anatomical position • Insertion • • Movable attachment Action • Specific movement © 2011 Pearson Education, Inc. The origins, insertion, and action of the biceps brachii muscle Origins of biceps brachii muscle Action Insertion of biceps brachii muscle Figure 10.2 © 2011 Pearson Education, Inc. 1 Module 10.2: Muscle names • Muscles working together • Agonist (prime mover) • Muscle whose contraction chiefly responsible for producing particular movement • Example: biceps brachii is agonist for elbow flexion • Synergist (syn-, together + ergon, work) • Muscle that helps larger agonist work efficiently • May provide additional pull or stabilize origin • Example: brachioradialis for elbow flexion © 2011 Pearson Education, Inc. Module 10.2: Muscle names • Muscles working together (continued) • Antagonist • Muscle whose action opposes particular agonist • Example: triceps brachii for elbow flexion (to biceps brachii) • Agonist for elbow extension © 2011 Pearson Education, Inc. Descriptions of muscles based on their function Agonist, or prime mover Antagonist Synergist Insertion of brachioradialis muscle Origin of brachioradialis muscle Figure 10.2 © 2011 Pearson Education, Inc. 2 Module 10.2: Muscle names • Muscle terminology examples • Terms indicating specific body regions • Abdominis (abdomen) • Anconeus (elbow) • Auricularis (auricle of ear) • Brachialis (brachium) • Terms indicating position, direction of fascicle organization • Anterior (front) • Externus (superficial) • Extrinsic (outside) • Inferioris (inferior) © 2011 Pearson Education, Inc. Module 10.2: Muscle names • Muscle terminology examples (continued) • Terms indicating structural characteristics of muscle • Name of origin • Biceps (two heads) • Triceps (three heads) • Shape • Deltoid (triangle) • Orbucularis (circle) • Other striking features • Alba (white) • Brevis (short) © 2011 Pearson Education, Inc. Module 10.2: Muscle names • Muscle terminology examples (continued) • Terms indicating actions • General • Abductor • Adductor • Depressor • Extensor • Specific • Buccinator (trumpeter) • Risorius (laugher) • Sartorius (like a tailor) © 2011 Pearson Education, Inc. Module 10.2 Review a. Define the term synergist as it relates to muscle action. b. Muscle A abducts the humerus, and muscle B adducts the humerus. What is the relationship between these two muscles? c. What does the name flexor carpi radialis longus tell you about this muscle? © 2011 Pearson Education, Inc. Module 10.3: Axial and appendicular divisions • Axial muscles • Arise on axial skeleton • Encompass ~60% of skeletal muscles in body • Position head and spinal column • Move rib cage, assist breathing • Appendicular muscles • Stabilize or move appendicular skeleton • Remaining 40% of all skeletal muscles © 2011 Pearson Education, Inc. Module 10.3 Review a. What is the function of the axial muscles? b. Identify the division (axial or appendicular) to which each of the following muscles belongs: biceps brachii, external oblique, temporalis, and vastus medialis. c. Which structures labeled in the figures in this module are not muscles? © 2011 Pearson Education, Inc. Section 2: Axial Muscles • Learning Outcomes • 10.4 Identify the principal muscles of facial expressions, along with their origins, insertions, and actions. • 10.5 Identify the principal muscles of the eye and jaw, along with their origins, insertions, and actions. • 10.6 Identify the principal muscles of the tongue, pharynx, and neck, along with their origins, insertions, and actions. © 2011 Pearson Education, Inc. Section 2: Axial Muscles • Learning Outcomes • 10.7 Identify the principal muscles of the vertebral column, along with their origins, insertions, and actions. • 10.8 Identify the principal muscles of the trunk, along with their origins, insertions, and actions. • 10.9 Identify the principal muscles of the pelvic floor, along with their origins, insertions, and actions. © 2011 Pearson Education, Inc. Section 2: Axial Muscles • Axial Muscles • Involved in stabilizing and positioning head, neck, and trunk • Four groups 1. Muscles of head and neck 2. Muscles of vertebral column 3. Muscles of thoracic and abdominal walls 4. Muscles of pelvic floor © 2011 Pearson Education, Inc. The muscles of the head and neck that are not associated with the vertebral column The muscles of the vertebral column The muscles of the pelvic floor The oblique and rectus muscles of the trunk Figure 10 Section 2 © 2011 Pearson Education, Inc. Module 10.4: Facial expression muscles • Muscles of facial expression • Originate on skull surface • Insert into superficial fascia and dermis of skin • Actions move skin A&P Flix: Buccinator Animation: Axial Muscles: Head and Neck © 2011 Pearson Education, Inc. Epicranial aponeurosis Frontal belly of occipitofrontalis Orbicularis oculi An anterior view showing superficial muscles on the right side of the face, and deeper muscles on the left side of the face. Temporalis Corrugator supercilii Procerus Nasalis Zygomaticus minor Zygomaticus major Orbicularis oris Levator labii superioris Levator anguli oris Masseter Buccinator Risorius Depressor anguli oris Platysma Mentalis (cut) Depressor labil inferioris Thyroid cartilage of the larynx Clavicle Figure 10.4 © 2011 Pearson Education, Inc. 1 A lateral view showing the major facial muscles Occipital belly of the occipitofrontalis muscle Frontal belly of the occipitofrontalis muscle Orbicularis oculi Nasalis Muscles of the Mouth and Cheek Levator labii superioris Zygomaticus minor Zygomaticus major Buccinator Orbicularis oris Risorius Mentalis (cut) Temporalis Masseter Depressor labil inferioris Depressor anguli oris Figure 10.4 © 2011 Pearson Education, Inc. 2 Module 10.4 Review a. Identify the muscles associated with the mouth. b. State whether the following muscles involve the mouth, eye, nose, ear, scalp, or neck: buccinator, corrugator supercilii, mentalis, nasalis, platysma, procerus, and risorius. c. Explain how an individual is able to consciously move the skin on the scalp but is not able to consciously move the skin of the thigh. © 2011 Pearson Education, Inc. Module 10.5: Muscles of external eye and mastication • Extrinsic eye muscles position the eye • • Six muscles insert on surface of eye and originate in orbit Muscles of mastication move the lower jaw • All mastication muscles are seen on the lateral sides of the skull © 2011 Pearson Education, Inc. A lateral view of the right eye (left) showing five extrinsic eye muscles, and a medial view of the right eye (right) showing the sixth extrinsic eye muscle Superior rectus Superior oblique Frontal bone Superior rectus Superior oblique Levator palpebrae superioris Optic nerve Trochlea (ligamentous sling) Inferior oblique Inferior rectus Lateral rectus Maxilla Medial rectus Optic nerve Figure 10.5 © 2011 Pearson Education, Inc. 1 – 2 Module 10.5: Muscles of external eye and mastication A&P Flix: Temporalis A&P Flix: Masseter © 2011 Pearson Education, Inc. Two anterior views of the right eye: the directions of eye movements produced by each extrinsic eye muscle operation independently (left), and the origins of the extrinsic eye muscles in the orbit (right) Superior rectus Trochlea Superior oblique Levator palpebrae superioris Superior rectus Oculomotor nerve (III) Lateral rectus Inferior oblique Medial rectus Lateral rectus Abducens nerve (VI) Inferior rectus Inferior oblique Trochlear nerve (IV) Trochlea Superior oblique Medial rectus Optic nerve (II) Inferior rectus Figure 10.5 © 2011 Pearson Education, Inc. 3 – 4 Figure 10.5 © 2011 Pearson Education, Inc. 5 A superficial lateral view showing the largest muscles of mastication of the right side of the head Superior temporal line Temporalis Capsule of temporomandibular joint Zygomatic arch Masseter Figure 10.5 © 2011 Pearson Education, Inc. 6 A lateral view showing the pterygoid muscles after removal of the superficial muscles and the right mandibular ramus Lateral pterygoid Medial pterygoid Cut edge of mandible Figure 10.5 © 2011 Pearson Education, Inc. 7 Figure 10.5 © 2011 Pearson Education, Inc. 8 Module 10.5 Review a. Name the extrinsic eye muscles. b. Which muscles have their origin on the lateral pterygoid plates and their insertion on the medial surface of the mandibular ramus? c. If you were contracting and relaxing your masseter muscle, what would you probably be doing? © 2011 Pearson Education, Inc. Module 10.6: Muscles of the tongue, pharynx, and neck • Muscles of the tongue are closely associated with pharynx and neck muscles • Actions of these muscles assist in speaking and chewing • Many help support the hyoid bone © 2011 Pearson Education, Inc. A lateral view showing the tongue muscles as dissected after removal of the left half of the mandible Styloid process Palatoglossus Styloglossus Genioglossus Hyoglossus Mandible (cut) Hyoid bone Figure 10.6 © 2011 Pearson Education, Inc. 1 – 2 A lateral view showing the major groups of the muscles of the pharynx Palatal muscles Laryngeal elevators Pharyngeal constrictors Esophagus Figure 10.6 © 2011 Pearson Education, Inc. 3 – 4 The anterior muscles of the neck Mandible Mylohyoid (cut and reflected) Muscles of the Floor of the Mouth Mylohyoid Small Muscles of the Hyoid Bone Digastric Stylohyoid Geniohyoid Hyoid bone Thyrohyoid Sternocleidomastoid (cut) Thyroid cartilage of larynx Muscles Originating at the Sternum Omohyoid: Superior belly Inferior belly Sternothyroid Sternohyoid Sternocleidomastoid (sternal head) Clavicle Cut heads of sternocleidomastoid Sternum Figure 10.6 © 2011 Pearson Education, Inc. 5 Figure 10.6 © 2011 Pearson Education, Inc. 6 A superior view of the isolated mandible Genioglossus (cut) Mylohyoid Geniohyoid Mandible Hyoid bone Figure 10.6 © 2011 Pearson Education, Inc. 7 Module 10.6 Review a. List the muscles of the tongue. b. Which muscles associated with the hyoid form the floor of the mouth? c. Which muscles elevate the soft palate? © 2011 Pearson Education, Inc. Module 10.7: Muscles of the vertebral column • Muscles of the vertebral column • Arranged in several layers • Originate or insert on ribs and processes of vertebrae • The mass of muscles extends from sacrum to skull • Each muscle group composed of numerous separate muscles of various lengths • Example: erector spinae muscles divide into: • Spinalis group • Longissimus group • Iliocostalis group © 2011 Pearson Education, Inc. Module 10.7: Muscles of the vertebral column • Contains many extensors but few flexors • Vertebral column does not need massive series of flexors because: 1. Many large trunk muscles flex vertebral column 2. Most of body weight is anterior and gravity tends to flex spine © 2011 Pearson Education, Inc. The muscles of the vertebral column Spinal Extensors, Superficial Layer Splenius capitus Erector Spinae Muscles Longissimus capitis Spinalis cervicis Spinal Extensors, Deep Layer Longissimus cervicis Semispinalis Group Iliocostalis cervicis Semispinalis capitis Iliocostalis thoracis Semispinalis cervicis Longissimus thoracis Semispinalis thoracis Spinalis thoracis Multifidus Iliocostalis lumborum Spinal Flexors Quadratus lumborum Longus capitus The erector spinae muscles, consisting of the spinalis, longissimus, and iliocostalis muscle groups Longus colli Thoracodorsal fascia Muscles of the anterior cervical spine Posterior view © 2011 Pearson Education, Inc. Figure 10.7 1 Module 10.7: Muscles of the vertebral column A&P Flix: Splenius Capitis A&P Flix: Semispinalis Capitis A&P Flix: Iliocostalis A&P Flix: Longissimus A&P Flix: Spinalis © 2011 Pearson Education, Inc. Module 10.7 Review a. List the spinal flexor muscles. b. Which muscles enable you to extend the neck? © 2011 Pearson Education, Inc. Module 10.8: Muscles of the trunk wall • Muscles of the trunk wall • Oblique and rectus muscles form the muscular walls of the trunk • Actions of many trunk wall muscles assist in breathing • Many are layered with fibers running perpendicular to other muscles producing antagonist actions © 2011 Pearson Education, Inc. The scalene muscles Scalenes Anterior view Figure 10.8 © 2011 Pearson Education, Inc. 1 Module 10.8: Muscles of the trunk wall Animation: Muscles of the Trunk Animation: Axial Muscles: Rectus Muscle A&P Flix: External Intercostals A&P Flix: Internal Intercostals A&P Flix: External Obliques © 2011 Pearson Education, Inc. Module 10.8: Muscles of the trunk wall A&P Flix: Internal Obliques A&P Flix: Rectus Abdominis A&P Flix: Transversus Abdominis © 2011 Pearson Education, Inc. Serratus anterior External oblique Tendinous inscription Internal intercostal External intercostal External oblique (cut) Internal oblique Cut edge of rectus sheath Linea alba Rectus abdominis The muscles of the trunk: the superficial muscles on the right side of the body, and deeper muscles of the oblique and rectus groups on the left side of the body © 2011 Pearson Education, Inc. Figure 10.8 2 The muscles of the trunk: In the anterior view, the superficial muscles are shown on the right side of the body, and deeper muscles of the oblique and rectus groups are shown on the left side Rectus Xiphoid Costal External abdominis process cartilages oblique Inferior vena cava External intercostal Internal intercostal Central tendon of diaphragm Esophagus Serratus anterior Diaphragm Thoracic aorta Spinal cord Erector spinae group Superior view through the thoracic cavity looking down at the diaphragm © 2011 Pearson Education, Inc. Figure 10.8 3 The muscles of the trunk: In the anterior view, the superficial muscles are shown on the right side of the body, and deeper muscles of the oblique and rectus groups are shown on the left side Rectus abdominis Rectus sheath Linea alba External oblique Transversus abdominis Internal oblique Thoracolumbar fascia © 2011 Pearson Education, Inc. L3 Quadratus lumborum Horizontal section through the abdominal cavity Figure 10.8 4 An inferior view of the diaphragm Sternum Xiphoid process Central tendon of diaphragm Costal cartilages Inferior vena cava Esophagus in esophageal hiatus Impression for liver Impression for stomach Aorta 12th rib L2 L3 L4 Quadratus lumborum (cut) Figure 10.8 © 2011 Pearson Education, Inc. 6 Figure 10.8 © 2011 Pearson Education, Inc. 7 Module 10.8 Review a. Which muscle connects the ribs and sternum to the pubic bones? b. Which muscle forms the deepest layer of the abdominal wall muscles? c. What is the action of the external oblique muscle? © 2011 Pearson Education, Inc. Module 10.9: Muscles of the pelvic floor • Muscles of the pelvic floor • Form the perineum (muscular sheet that spans pelvic outlet) • Females and males have different superficial muscles • • No differences in deep perineal musculature Urogenital and pelvic diaphragms do not completely close outlet • Urethra, vagina, and anus all pass through • Muscular sphincters surround openings and control urination and defecation • Muscles, nerves, and blood vessels also pass © 2011 Pearson Education, Inc. The muscles of the pelvic floor Deep Dissections Superficial Dissections Urethra Urogenital Diaphragm External urethral sphincter Deep transverse perineal Ischiocavernosus Bulbospongiosus Central tendon of perineum Vagina Superficial transverse perineal Pelvic Diaphragm Pubococcygeus Iliococcygeus Anus Levator ani External anal sphincter Coccygeus Gluteus maximus Sacrotuberous ligament Female The muscles of the pelvic floor in females Figure 10.9 © 2011 Pearson Education, Inc. 1 The muscles of the pelvic floor Superficial Dissections Urethra (connecting segment removed) Testis UROGENITAL TRIANGLE OF PERINEUM Ischiocavernosus Bulbospongiosus Urogenital Diaphragm External urethral sphincter Deep transverse perineal Central tendon of perineum Superficial transverse perineal Pelvic Diaphragm Anus Pubococcygeus Levator Iliococcygeus ani External anal sphincter Gluteus maximus Coccygeus Sacrotuberous ligament The muscles of the pelvic floor in males Male ANAL TRIANGLE Figure 10.9 © 2011 Pearson Education, Inc. 2 Module 10.9 Review a. Which muscles make up the urogenital diaphragm? b. In females, what is the action of the bulbospongiosus muscle? c. The coccygeus muscle extends from the sacrum and coccyx to which structure? © 2011 Pearson Education, Inc. Section 3: Appendicular Muscles • Learning Outcomes • 10.10 Identify the principal appendicular muscles. • 10.11 Identify the principal muscles of the pectoral girdle, along with their origins, insertions, and actions. • 10.12 Identify the principal muscles that move the arm, along with their origins, insertions, and actions. © 2011 Pearson Education, Inc. Section 3: Appendicular Muscles • Learning Outcomes • 10.13 Identify the principal muscles that move the forearm and hand, along with their origins, insertions, and actions. • 10.14 Identify the principal muscles that move the hand and fingers, along with their origins, insertions, and actions. • 10.15 Identify the principal intrinsic hand muscles, along with their origins, insertions, and actions. © 2011 Pearson Education, Inc. Section 3: Appendicular Muscles • Learning Outcomes • 10.16 Identify the principal muscles that move the thigh, along with their origins, insertions, and actions. • 10.17 Identify the principal muscles that move the leg, along with their origins, insertions, and actions. • 10.18 Identify the principal muscles that move the foot and toes, along with their origins, insertions, and actions. © 2011 Pearson Education, Inc. Section 3: Appendicular Muscles • Learning Outcomes • 10.19 Identify the principal intrinsic foot muscles, along with their origins, insertions, and actions. • 10.20 Describe the deep fascia and its relationship to the various limb muscle compartments. © 2011 Pearson Education, Inc. Section 3: Appendicular Muscles • Appendicular Muscles • Upper limb • Muscles That Position the Pectoral Girdle • Originate on axial skeleton and insert on clavicle and scapula • Muscles That Move the Arm • Originate on pectoral girdle and thoracic cage and insert on humerus • Muscles That Move the Forearm and Hand • Primarily originate on pectoral girdle and arm, and insert on radius, ulna, and carpals © 2011 Pearson Education, Inc. Section 3: Appendicular Muscles • Upper limb (continued) • Extrinsic Muscles of the Hand and Fingers • • Primarily originate on humerus and insert on metacarpals and phalanges Intrinsic Muscles of the Hand • Perform fine movements • Primarily originate on carpals and metacarpals and insert on phalanges © 2011 Pearson Education, Inc. Section 3: Appendicular Muscles • Lower Limb • Muscles That Move the Thigh • • Originate in pelvic region and typically insert on femur Muscles That Move the Leg • • Originate on pelvis and femur and insert on tibia and/or fibula Extrinsic Muscles that Move the Foot and Toes • • Originate on tibia and fibula and insert on tarsals, metatarsals, and/or phalanges Intrinsic Muscles of the Foot • Primarily originate on tarsals and metatarsals and insert on phalanges © 2011 Pearson Education, Inc. Module 10.10: Large muscles originating on the trunk • Large muscles originating on the trunk • In general, control gross movements of limbs • Are often large and powerful • Distally, limb muscles get smaller and more numerous • Actions become more precise • Appendicular muscles on posterior of trunk often originate on large girdle bones and proximal limb bones © 2011 Pearson Education, Inc. Module 10.10 Review a. Which axial muscle is often known as the “sixpack” in fit individuals? b. Describe the appearance of the appendicular muscles as you move proximally to distally. c. Identify to which division, axial or appendicular, the following muscles belong: deltoid, external oblique, gluteus maximus, pectoralis major, platysma, and rectus femoris. © 2011 Pearson Education, Inc. Module 10.11: Muscles that position pectoral girdle • Muscles that position the pectoral girdle • Also serve to anchor pectoral girdle to axial skeleton • Smaller range of motion than other appendicular muscles • Help increase upper limb mobility • Trapezius is largest muscle of group © 2011 Pearson Education, Inc. An anterior view of the muscles that position the pectoral girdle Muscles That Position the Pectoral Girdle Trapezius Levator scapulae Muscles That Position the Pectoral Girdle Subclavius Pectoralis minor Pectoralis minor (cut) Serratus anterior Internal intercostals External intercostals T12 Figure 10.11 © 2011 Pearson Education, Inc. 1 A posterior view of the muscles that position the pectoral girdle Superficial Dissection Deep Dissection Muscles That Position the Pectoral Girdle Muscles That Position the Pectoral Girdle Levator scapulae Trapezius Rhomboid minor Rhomboid major Scapula Serratus anterior T12 vertebra Figure 10.11 © 2011 Pearson Education, Inc. 2 Figure 10.11 © 2011 Pearson Education, Inc. 3 Module 10.11: Muscles that position pectoral girdle A&P Flix: Trapezius A&P Flix: Levator Scapula A&P Flix: Serratus Anterior A&P Flix: Rhomboid Minor A&P Flix: Rhomboid Major © 2011 Pearson Education, Inc. Module 10.11: Muscles that position pectoral girdle A&P Flix: Muscles that Act on the Shoulder Joint and Humerus: An Overview Animation: Muscles of the Pectoral Girdle A&P Flix: Movement of the Pectoral Girdle © 2011 Pearson Education, Inc. Module 10.11 Review a. Identify the largest of the superficial muscles that position the pectoral girdle. b. Which muscles enable you to shrug your shoulders? c. Which muscle originates on the first rib and inserts on the inferior border of the clavicle? © 2011 Pearson Education, Inc. Module 10.12: Muscles that move the arm • Action of muscles positioning the arm are best understood by considering pull or line of force (action line) relative to glenoid cavity • Rotator cuff • Muscles often injured in sports involving ball throwing • Consists of four muscles (SITS) 1. Supraspinatus 2. Infraspinatus 3. Teres minor 4. Subscapularis Animation: Appendicular Muscles: Arm © 2011 Pearson Education, Inc. Deep Dissection Superficial Dissection Sternum Clavicle Muscles That Move the Arm Deltoid Pectoralis major Ribs (cut) Muscles That Move the Arm Subscapularis Coracobrachialis Teres major An anterior view of the muscles that move the arm Vertebra T12 Figure 10.12 © 2011 Pearson Education, Inc. 1 Module 10.12: Muscles that move the arm A&P Flix: Rotator Cuff Muscles: An Overview A&P Flix: Rotator Cuff Muscles A&P Flix: Movement from the Rotator Cuff Muscles A&P Flix: Muscles that Cross Glenohumeral Joint © 2011 Pearson Education, Inc. Module 10.12: Muscles that move the arm A&P Flix: Latissimus Dorsi A&P Flix: Supraspinatus A&P Flix: Infraspinatus A&P Flix: Teres Major A&P Flix: Teres Minor © 2011 Pearson Education, Inc. Module 10.12: Muscles that move the arm A&P Flix: Subscapularis A&P Flix: Pectoralis Major A&P Flix: Pectoralis Minor A&P Flix: Deltoid © 2011 Pearson Education, Inc. Module 10.12: Muscles that move the arm A&P Flix: Scapular Muscles of the Glenohumeral Joint A&P Flix: Axial Muscles of the Glenohumeral Joint A&P Flix: Movement at the Glenohumeral Joint: An Overview A&P Flix: Movement at the Glenohumeral Joint © 2011 Pearson Education, Inc. Superficial Dissection Muscles That Move the Arm Vertebra T1 Supraspinatus Deltoid Latissimus dorsi Deep Dissection Muscles That Move the Arm Supraspinatus Infraspinatus Teres minor Teres major Thoracolumbar fascia A posterior view of the muscles that move the arm Figure 10.12 © 2011 Pearson Education, Inc. 2 The actions of muscles that position the arm Abduction Extension Flexion Deltoid POSTERIOR GLENOID CAVITY Tendons of biceps brachii ANTERIOR Teres minor Subscapularis Triceps brachii Lateral rotation Teres major Adduction © 2011 Pearson Education, Inc. Medial rotation Figure 10.12 4 Figure 10.12 © 2011 Pearson Education, Inc. 3 Module 10.12 Review a. Define action line. b. Name the muscle that abducts the upper arm. c. Which muscle originates on the anterior surface of the scapula and inserts on the lesser tubercle of the humerus? © 2011 Pearson Education, Inc. Module 10.13: Muscles that move the forearm and hand • Muscles that move the forearm and hand • Special connective tissues • Extensor retinaculum • Wide band of connective tissue holding extensor muscles in place • Flexor retinaculum • Wide band of connective tissue holding flexor muscles in place • Carpal tunnel syndrome (inflammation of medial nerve passing through) • Synovial tendon sheaths • Tubular bursae surrounding tendons where they cross bones Animation: Appendicular Muscles: Forearm and Hand © 2011 Pearson Education, Inc. A posterior view showing the superficial layer of muscles involved in extension at the elbow and wrist Elbow Extensors Triceps brachii Anconeus Wrist Extensors Extensor carpi ulnaris Olecranon of ulna Flexor carpi ulnaris Extensor carpi radialis longus Extensor carpi radialis brevis Radius Ulna Extensor retinaculum Figure 10.13 © 2011 Pearson Education, Inc. 1 Module 10.13: Muscles that move the forearm and hand A&P Flix: The Elbow Joint and Forearm: An Overview A&P Flix: Muscles of the Elbow Joint A&P Flix: Movement at the Elbow Joint A&P Flix: Muscles of the Forearm © 2011 Pearson Education, Inc. Module 10.13: Muscles that move the forearm and hand A&P Flix: Biceps Brachii A&P Flix: Brachialis A&P Flix: Triceps Brachii A&P Flix: Pronator Teres A&P Flix: Brachioradialis © 2011 Pearson Education, Inc. Module 10.13: Muscles that move the forearm and hand A&P Flix: Supinator A&P Flix: Flexor Digitorum Superficialis A&P Flix: Flexor Carpi Radialis A&P Flix: Flexor Carpi Ulnaris © 2011 Pearson Education, Inc. Module 10.13: Muscles that move the forearm and hand A&P Flix: Extensor Digitorum A&P Flix: Extensor Carpi Radialis Longus A&P Flix: Extensor Carpi Radialis Brevis A&P Flix: Extensor Carpi Ulnaris © 2011 Pearson Education, Inc. An anterior view showing the superficial muscles involved in flexion at the elbow and wrist Coracoid process of scapula Humerus Elbow Flexors Biceps brachii Elbow Extensors Triceps brachii Brachialis Brachioradialis Medial epicondyle of humerus Wrist Flexors Flexor carpi radialis Palmaris longus Flexor carpi ulnaris Pronators and Supinators Pronator teres Supinator Pronator quadratus Flexor retinaculum Figure 10.13 © 2011 Pearson Education, Inc. 2 A cross section of the right wrist (palm up) showing the synovial tendon sheaths and nearby structure Median nerve Flexor retinaculum Synovial tendon sheaths Carpal tunnel Pisiform Triquetrum Lunate Carpal bones Scaphold Figure 10.13 © 2011 Pearson Education, Inc. 4 Module 10.13 Review a. Define retinaculum. b. On which surface, anterior or posterior, are the wrist extensors located? c. Which muscles are involved in turning a doorknob? © 2011 Pearson Education, Inc. Module 10.14: Muscles that move the hand and fingers • Muscles that move the hand and fingers • Extensors usually lie along the posterior and lateral surfaces of the forearm • Muscles that extend fingers can only be seen after removal of those that extend the wrist • Flexors usually lie along the anterior and medial surfaces © 2011 Pearson Education, Inc. Two anterior views of the muscles that move the hand and fingers Median nerve Tendon of biceps brachii Brachial artery Radius Flexor carpi ulnaris (retracted) Brachioradialis (retracted) Supinator Cut tendons of flexor digitorum superficialis Muscles That Flex the Fingers and Thumb Flexor digitorum superficialis Flexor digitorum profundus Flexor pollicis longus LATERAL MEDIAL Anterior View, Middle Layer Anterior View, Deepest Layer Figure 10.14 © 2011 Pearson Education, Inc. 1 – 2 Module 10.14: Muscles that move the hand and fingers A&P Flix: Muscles that Act on the Wrist and Fingers: An Overview A&P Flix: Anterior Muscles of the Wrist and Fingers A&P Flix: Posterior Muscles of the Wrist and Fingers A&P Flix: Carpal Tunnel A&P Flix: Movements of the Wrist and Fingers © 2011 Pearson Education, Inc. Two posterior views of the muscles that move the hand and fingers Anconeus Anconeus Muscles That Extend the Fingers Supinator Extensor digitorum Muscles That Move the Thumb Extensor digiti minimi Abductor pollicis longus Extensor pollicis longus Abductor pollicis longus Extensor pollicis brevis Tendon of extensor pollicis longus Extensor indicis Ulna Tendon of extensor digiti minimi (cut) MEDIAL Posterior View, Middle Layer LATERAL Extensor pollicis brevis Radius Tendon of extensor digitorum (cut) Posterior View, Deepest Layer Figure 10.14 © 2011 Pearson Education, Inc. 3 – 4 Module 10.14 Review a. List the muscles that extend the fingers. b. Name the muscles that abduct the wrist. c. The names of muscles associated with the thumb frequently include what term? © 2011 Pearson Education, Inc. Module 10.15: Intrinsic muscles of the hand • Intrinsic muscles of the hand • Provide fine movement of hand • • No muscles originate on phalanges • • More powerful movements are controlled by forearm muscles Tendons extend across distal finger joints Responsible for: 1. Flexion/extension of fingers at metacarpophalangeal joints 2. Abduction/adduction of fingers at metacarpophalangeal joints 3. Opposition/reposition of thumb © 2011 Pearson Education, Inc. The intrinsic muscles of the hand Intrinsic Muscles of the Hand Tendons of flexor digitorum Lumbricals Palmar interosseus First dorsal interosseus Abductor digiti minimi Flexor digiti minimi brevis Opponens digiti minimi Palmaris brevis (cut) Intrinsic Muscles of the Thumb Adductor pollicis Flexor pollicis brevis Opponens pollicis Abductor pollicis brevis Anterior view Figure 10.15 © 2011 Pearson Education, Inc. 1 The intrinsic muscles of the hand Tendons of extensor digitorum Intrinsic Muscles of the Hand First dorsal interosseus muscle Abductor digiti minimi Extensor retinaculum Posterior view Figure 10.15 © 2011 Pearson Education, Inc. 2 Module 10.15 Review a. Name the intrinsic muscles of the thumb. b. Which muscles originate on the phalanges? c. If there are no muscles in the fingers, how are we able to move them? © 2011 Pearson Education, Inc. Module 10.16: Muscles that move the thigh • Muscles that move the thigh • Understanding diverse actions of thigh/hip muscles from orientation to hip joint • Muscles originating on surface of pelvis and inserting on femur • Produce characteristic movements by position relative to acetabulum • Many muscles are broad and have more than one action line (more than one action at hip) • Example: Adductor magnus • Produces flexion, extension, and adduction at hip © 2011 Pearson Education, Inc. The muscles that move the thigh Iliac crest Sacrum Gluteal Group Gluteus medius (cut) Gluteus medius Gluteus maximus (cut) Gluteus maximus Gluteus minimus Tensor fasciae latae Iliotibial tract Gluteal muscles, posterior view Lateral view of the gluteal region Figure 10.16 © 2011 Pearson Education, Inc. 1 – 2 Module 10.16: Muscles that move the thigh A&P Flix: Muscles that Act on the Hip Joint and Femur: An Overview A&P Flix: Anterior Muscles that Cross the Hip Joint A&P Flix: Medial Muscles that Cross the Hip Joint A&P Flix: Posterior Muscles that Cross the Hip Joint A&P Flix: Movement at the Hip Joint: An Overview A&P Flix: Movement at the Hip Joint © 2011 Pearson Education, Inc. Module 10.16: Muscles that move the thigh A&P Flix: Sartorius A&P Flix: Tensor Fasciae Latae A&P Flix: Iliiopsoas A&P Flix: Pectineus © 2011 Pearson Education, Inc. Module 10.16: Muscles that move the thigh A&P Flix: Rectus Femoris A&P Flix: Vastus Medialis A&P Flix: Vastus Intermedius A&P Flix: Vastus Lateralis © 2011 Pearson Education, Inc. Module 10.16: Muscles that move the thigh A&P Flix: Gluteus Maximus A&P Flix: Gluteus Medius A&P Flix: Semimembranosus A&P Flix: Semitendinosus A&P Flix: Biceps Femoris © 2011 Pearson Education, Inc. The muscles that move the thigh Iliopsoas Group Gluteal Group Gluteus maximus (cut) Gluteus Gluteus medius minimus (cut) Tensor fasciae latae An anterior view showing the isolated iliopsoas muscle group and the adductor group Psoas major Iliacus L5 Lateral Rotator Group Inguinal ligament Piriformis Superior gemellus Adductor Group Obturator internus Pectineus Obturator externus Adductor brevis Inferior gemellus Adductor longus Quadratus femoris Adductor magnus Gracilis Ischial tuberosity Iliotibial tract A lateral view of a dissection of the gluteal region Figure 10.16 © 2011 Pearson Education, Inc. 3 – 4 Module 10.16 Review a. Name the muscles that compose the gluteal group. b. Identify the muscle whose origin is the lateral border of the ischial tuberosity and whose insertion is the intertrochanteric crest of the femur. c. Which leg movement would be impaired by injury to the obturator muscles? © 2011 Pearson Education, Inc. Module 10.17: Muscles that move the leg • Muscles that move the leg • Flexors of the knee • Originate on pelvic girdle and extend along posterior and medial surfaces of thigh • Extensors of the knee • Originate on femoral surface and extend along anterior and lateral surfaces of thigh • Collectively called quadriceps muscles or quadriceps femoris Animation: Appendicular Muscles: Lower Limb Animation: Appendicular Muscles: Thigh © 2011 Pearson Education, Inc. The muscles that move the leg Iliac crest Anterior superior iliac spine Inguinal ligament Gluteus medius Tensor fasciae latae Iliacus Psoas major Iliopsoas Pubic tubercle Gluteus maximus Tensor fasciae latae Pectineus Adductor longus Gracilis Adductor magnus Gracilis Iliotibial tract Flexors of the Knee Biceps femoris Semitendinosus Sartorius Extensors of the Knee (Quadriceps muscles) Rectus femoris Vastus intermedius (lies deep to the rectus femoris and vastus lateralis) Vastus lateralis Vastus medialis Quadriceps tendon Semimembranosus Sartorius Patella Popliteus Patellar ligament The flexors of the knee © 2011 Pearson Education, Inc. The extensors of the knee, collectively called the quadriceps muscles or the quadriceps femoris Figure 10.17 1 – 2 Module 10.17: Muscles that move the leg A&P Flix: Muscles that Cross the Knee Joint: An Overview A&P Flix: Anterior Extensors that Act on the Knee A&P Flix: Posterior Flexors that Act on the Knee A&P Flix: Movement at the Knee Joint © 2011 Pearson Education, Inc. Module 10.17: Muscles that move the leg A&P Flix: Tibialis Anterior A&P Flix: Extensor Digitorum Longus A&P Flix: Extensor Hallucis Longus A&P Flix: Fibularis Longus A&P Flix: Gastrocnemius © 2011 Pearson Education, Inc. Module 10.17: Muscles that move the leg A&P Flix: Soleus A&P Flix: Tibialis Posterior A&P Flix: Flexor Digitorum Longus A&P Flix: Flexor Hallucis Longus © 2011 Pearson Education, Inc. A cross sectional view showing the positions of the major thigh muscles relative to the femur POSTERIOR Semitendinosus Semimembranosus Sciatic nerve Adductor magnus Biceps femoris Gracilis Adductor longus Vastus lateralis Great saphenous vein Vastus intermedius Sartorius Femur Vastus medialis Rectus femoris ANTERIOR Figure 10.17 © 2011 Pearson Education, Inc. 4 Module 10.17 Review a. Name the quadriceps muscles. b. Which muscles flex the knee? c. Identify the muscle whose origin is on the lateral condyle of the femur. © 2011 Pearson Education, Inc. Module 10.18: Extrinsic muscles that move the foot and toes • Extrinsic muscles that move the foot and toes • Gastrocnemius and Soleus • Largest muscles associated with ankle movement • Produce ankle extension (plantar flexion) • Muscles that move toes are much smaller and originate on tibia and/or fibula • Tendons stabilized by superior and inferior retinacula Animation: Appendicular Muscles: Leg and Foot © 2011 Pearson Education, Inc. The multiple muscle layers in the posterior leg Deep Dissection Superficial Dissection Ankle Extensors Plantaris Head of fibula Gastrocnemius Popliteus Soleus Ankle Extensors (Deep) Tibialis posterior Fibularis longus Fibularis brevis Digital Flexors Gastrocnemius (cut and removed) Flexor digitorum longus Flexor hallucis longus Calcaneal tendon Calcaneus Tendon of flexor digitorum longus Tendon of fibularis brevis Tendon of fibularis longus Figure 10.18 © 2011 Pearson Education, Inc. 1 Module 10.18: Extrinsic muscles that move the foot and toes A&P Flix: Muscles that the Act on Ankle and Foot: An Overview A&P Flix: Anterior Muscles that Act on the Ankle and Foot A&P Flix: Lateral Muscles that Act on the Ankle and Foot A&P Flix: Posterior Muscles that Act on the Ankle and Foot A&P Flix: Movements of the Ankle and Foot © 2011 Pearson Education, Inc. The arrangement of the major superficial muscles that move the foot and toes Lateral View Medial View Patella Iliotibial tract Head of fibula Ankle Extensors Gastrocnemius Fibularis longus Patellar ligament Ankle Flexors Tibialis anterior Soleus Digital Extensors Calcaneal tendon Inferior extensor retinaculum Ankle Extensors Gastrocnemius Soleus Fibularis brevis Superior extensor retinaculum Medial surface of tibial shaft Extensor digitorum longus Tendon of extensor hallucis longus Tendon of tibialis anterior Tibialis posterior Superior extensor retinaculum Calcaneal tendon Inferior extensor retinaculum Figure 10.18 © 2011 Pearson Education, Inc. 2 – 3 Module 10.18 Review a. Name the muscles involved in flexing the toes. b. Name the muscles involved in extending the ankle. c. How would a torn calcaneal tendon affect movement of the foot? © 2011 Pearson Education, Inc. Module 10.19: Intrinsic muscles of the foot • Intrinsic muscles of the foot • Retinacula stabilize tendons descending from leg • More numerous on inferior surface of foot • Many are flexors that tense during ankle extension and help “push off” when walking • Provide padding • Assist in maintaining arches of foot © 2011 Pearson Education, Inc. A superior view of the foot showing the intrinsic muscles of the foot and toes Superior extensor retinaculum Medial malleolus of tibia Lateral malleolus of fibula Inferior extensor retinaculum Tendons of extensor digitorum longus Intrinsic Muscles of the Foot, Toes 2–5 Tendon of tibialis anterior Intrinsic Muscles of the Foot, Great Toe Extensor hallucis brevis Abductor hallucis Dorsal interossei Tendons of extensor digitorum brevis Tendon of extensor hallucis longus Figure 10.19 © 2011 Pearson Education, Inc. 1 The intrinsic muscles on the inferior surface of the foot Superficial Muscles of the Sole of the Foot Fibrous tendon sheaths Tendons of flexor digitorum brevis Instrinsic Muscles of the Foot Deep Muscles of the Sole of the Foot Tendon of flexor hallucis longus Lumbricals Flexor hallucis brevis Flexor digiti minimi brevis Adductor hallucis Quadratus plantae Flexor digitorum brevis Abductor digiti minimi Plantar aponeurosis (cut) Tendon of flexor digitorum longus Tendon of tibialis posterior Tendon of fibularis longus Calcaneus Figure 10.19 © 2011 Pearson Education, Inc. 2 A cross section showing the intrinsic muscles of the foot Instrinsic Muscles of the Foot Metatarsal bones Tendons of extensor digitorum longus Instrinsic Muscles of the Foot Tendons of extensor digitorum brevis Tendon of extensor hallucis brevis Flexor digiti minimi brevis Dorsal interossei Adductor hallucis Abductor digiti minimi Adductor hallucis Plantar interossei Flexor hallucis brevis Tendons of flexor digitorum brevis Lumbricals Tendons of flexor digitorum longus Plantar aponeurosis Figure 10.19 © 2011 Pearson Education, Inc. 4 Module 10.19 Review a. Identify the intrinsic muscle that flexes the great toe. b. What are the functions of the superior and inferior retinacula of the foot? c. Describe the origin, insertion, and action of the lumbrical muscles. © 2011 Pearson Education, Inc. Module 10.20: Deep fascia • Deep fascia organizes limb muscles into compartments • Muscles within a compartment have compatible functions • Each compartment has characteristic blood supply and innervation • Clinically important because trauma can cause bleeding within compartment • Elevates pressure and compresses blood vessels and nerves • = Compartment syndrome • Can lead to paralysis or death of muscles if not relieved in 2– 4 hours © 2011 Pearson Education, Inc. Module 10.20 Review a. Name the six possible compartments of the muscles of the limbs. b. Define compartment syndrome. c. Propose a reason why compartment syndrome can be life threatening. © 2011 Pearson Education, Inc.