Essentials of Human Anatomy & Physiology Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Slides 6.32 – 6.44 Seventh Edition Elaine N. Marieb Chapter 6 The Muscular System Lecture Slides in PowerPoint by Jerry L. Cook

Types of Ordinary Body Movements Slide 6.32 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Flexion  Extension  Rotation  Abduction  Circumduction

Body Movements Slide 6.33 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.13

Special Movements Slide 6.34 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Dorsifelxion  Plantar flexion  Inversion  Eversion  Supination  Pronation  Opposition

Types of Muscles Slide 6.35 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Prime mover – muscle with the major responsibility for a certain movement  Antagonist – muscle that opposes or reverses a prime mover  Synergist – muscle that aids a prime mover in a movement and helps prevent rotation  Fixator – stabilizes the origin of a prime mover

Naming of Skeletal Muscles Slide 6.36a Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Direction of muscle fibers  rectus (straight)  oblique (slanted)  Relative size of the muscle  maximus (largest)  minimus (smallest)  longus (long)

Naming of Skeletal Muscles Slide 6.36b Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Location of the muscle  many muscles are named for bones (e.g., temporalis)  Number of origins  biceps (two heads)  triceps (three heads)  quadriceps (four heads)

Naming of Skeletal Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Location of the muscles origin and insertion  Example: sterno (on the sternum)  Shape of the muscle  Example: deltoid (triangular)  Action of the muscle  Example: flexor and extensor (flexes or extends a bone)

Head and Neck Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Facial Muscles  Frontalis – muscle covering frontal bone; allows for lifting eyebrows and wrinkling forehead  Orbicularis Oculi – circular muscle around eye; allows closing, squinting, blinking, and winking of eye  Orbicularis Oris – circular muscle around lips; closes mouth and protrudes lips

Head and Neck Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Facial Muscles (cont’d)  Buccinator – runs horizontally along cheek and inserts into O. oris; flattens cheek in whistling, blowing, and chewing  Zygomaticus – runs from side of mouth up to cheekbone; raises corner of mouth upward

Head and Neck Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Chewing Muscles  Masseter – covers the angle of the lower jaw, running from zygomatic process to mandible; closes the jaw  Temporalis – covers temporal bone; acts as a synergist/aids the masseter in closing the jaw

Head and Neck Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Neck Muscles  Platysma – covers anterolateral neck, originates from chest and inserts into area around mouth; pulls corners of mouth downward  Sternocleidomastoid – paired muscles with two heads originating from the sternum and clavicle, then inserting into the mastoid process; bend the head down forward and to the sides

Head and Neck Muscles Slide 6.38 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.14

Trunk Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Anterior Trunk Muscles  Pectoralis Major – covers upper part of chest, originates from shoulder girdle and first six ribs, inserts on proximal end of humerus; adducts and flexes arm  Intercostal Muscles – between the ribs; external intercostals raise rib cage to allow air in, internal intercostals depress cage to force air out

Trunk Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Anterior Trunk Muscles (cont’d)  Rectus Abdominals – paired muscles running from pubis to rib cage; flex the vertebral column and compress the abdominal contents  External Oblique – paired muscles of the lateral walls of the abdomen, running from the last eight ribs to the ilium; flex the vertebral column and rotate the trunk and bend laterally

Trunk Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Anterior Trunk Muscles (cont’d)  Internal Oblique – paired muscles deep to external obliques, originate from iliac crest and insert into the last three ribs; same function as external obliques  Transversus abdominals – deepest muscle of abdominal wall with fibers running horizontally, originates from lower ribs and iliac crest and inserts into the pubis; compresses the abdominal contents

Trunk Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Anterior Arm Muscles  Biceps Brachii – originates from the shoulder girdle and inserts into the radial tuberosity; flexes and supinates the forearm  Brachialis – deep to the bicep; flexes the forearm  Brachioradialis – originates from the humerus and inserts into the distal forearm

Trunk Muscles Slide 6.39 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.15

Trunk Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Posterior Trunk Muscles  Trapezius – paired muscles with origin running from base of occipital bone down to the end of the thoracic vertebrae, insert on scapular spine and clavicle; extend the head and move the scapula  Latissimus Dorsi – large paired muscles of lower back, originates from lower back and ilium then inserts into proximal end of humerus; extends and adducts humerus

Trunk Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Posterior Trunk Muscles (cont’d)  Erector Spinae – paired set of three muscle columns that extend the length of the vertebral column; extend the vertebral column  Deltoid – originates from the scapular spine and clavicle and inserts into the deltoid tuberosity of humerus; abduct the arm

Trunk Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Posterior Arm Muscles  Triceps Brachii – originates from shoulder girdle and proximal humerus, inserts into olecranon process of ulna; extends the forearm (antagonist of biceps)

Deep Trunk and Arm Muscles Slide 6.40 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.16

Lower Limb Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Pelvis, Hip and Thigh Muscles  Gluteus Maximus – originates from sacrum and ilium and inserts on gluteal tuberosity of femur, forms the buttocks; extends the thigh, especially when climbing and jumping  Gluteus Medius – originates from ilium and inserts into femur; abducts the thigh with the hip

Lower Limb Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Pelvis, Hip and Thigh Muscles (cont’d)  Iliopsoas – originates from the iliac bone and lower vertebrae and inserts on the lesser trochanter of the femur; flexes the leg at the hip  Adductor Muscles – originate from the pelvis and inserts medially towards the proximal end of the femur; adducts the thigh

Lower Limb Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Pelvis, Hip and Thigh Muscles (cont’d)  Hamstring group – three muscles originating from the ischial tuberosity and inserts onto both sides of the proximal end of the tibia; extend the leg  Sartorius – originates from anterior iliac crest and inserts into medial side of tibia; flexes the thigh

Lower Limb Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Pelvis, Hip and Thigh Muscles (cont’d)  Quadriceps group – four muscles that make the anterior thigh, originating from the femur or pelvis and inserting into the tibial tuberosity; extends the knee and flexes the hip

Muscles of the Pelvis, Hip, and Thigh Slide 6.41 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Anterior View Posterior View

Lower Limb Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lower Leg Muscles  Tibialis Anterior – originates from upper tibia and inserts at the tarsals, running parallel to anterior crest; acts to dorsiflex and invert the foot  Extensor Digitorum Longus – originates from lateral tibial condyle and proximal radius and inserts into toes 2-5, running just lateral to tibialis; extends toes and dorsiflexes foot

Lower Limb Muscles Slide 6.37 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings  Lower Leg Muscles (cont’d)  Gastrocnemius – forms calf muscle, two head originate from each side of distal femur and inserts onto the heel bone; main part of plantar flexion  Soleus – originates from tibia and inserts into the tarsals, just deep to gastrocnemius; aids in plantar flexion of foot

Muscles of the Lower Leg Slide 6.42 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.19

Superficial Muscles: Anterior Slide 6.43 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.20

Superficial Muscles: Posterior Slide 6.44 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings Figure 6.21