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22-52 Structure of Skeletal Muscles • Skeletal muscles – The major components of the muscular system • Composition – Connective tissue – Skeletal muscle tissue – Blood vessels – Nerves © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

22-53 Connective Tissue Coverings • Fascia • Aponeurosis – Covers entire skeletal – A tough, sheet-like muscles structure made of fibrous connective – Separates them from tissue each other – Attaches muscles to • Tendon other muscles – A tough, cord-like structure made of fibrous connective tissue – Connects muscles to bones © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

22-54 Connective Tissue Coverings (cont.) • Epimysium – A thin covering that is just below the fascia of a muscle and surrounds the entire muscle • Perimysium – Connective tissue that divides a muscle into sections called fascicles • Endomysium – Covering of connective tissue that surrounds individual muscle cells © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

22-55 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 Companies, Inc. All rights reserved.

22-56 Attachments and Actions (cont.) • Movement usually produced by a group of muscles – Prime mover (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 Companies, Inc. All rights reserved.

Body Movements 22-57 Flexion – bending a body Plantar flexion – pointing part the toes down Extension – straightening a Abduction – moving a body part body part away from the anatomical position Hyperextension – extending a body part Adduction – moving a past the normal body part toward the anatomical position anatomical position Dorsiflexion – pointing the Figure of Body toes up Movements © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

22-58 Body Movements (cont.) Back © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

22-59 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 Companies, Inc. All rights reserved.

22-60 Body Movements (cont.) Inversion – turning the sole Retraction – moving a body of the foot medially part posteriorly Eversion – turning the sole Protraction – moving a of the foot laterally body part anteriorly © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Body Movements (cont.) 22-61 Elevation – lifting a body © 2011 The McGraw-Hill Companies, Inc. All rights reserved. part; for example, elevating the shoulders as in a shrugging expression Depression – lowering a body part; for example, lowering the shoulders

Axial and Appendicular Muscles • Axial muscles arise on the axial skeleton (60% of skeletal muscles) ; position the head and spinal column and move the rib cage • Appendicular muscles stabilize and move the appendicular skeleton (40% of skeletal muscles) © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

22-63 Major Skeletal Muscles • The muscle name • As you study indicates muscles, you will find it easier to remember – Location them if you think – Size about what the name – Action describes. – Shape OR – Number of attachments of the muscle © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Superficial Muscles: Anterior Figure 6.20 Slide 6.43 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Superficial Muscles: Posterior Figure 6.21 Slide 6.44 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Head and Neck Muscles Figure 6.14 Slide 6.38 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

22-67 Muscles of the Head • Sternocleidomastoid • Splenius capitis – Pulls the head to one – Rotates the head side – Allows it to bend to the – Pulls the head to the side chest • Orbicularis oris • Frontalis – Allows the lips to pucker – Raises the eyebrows © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Frontalis • Forehead • Raises eyebrows and pulls scalp anteriorly © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Temporalis • Lateral muscles of the skull • Closes mandible © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Occipitalis • Posterior and inferior part of the skull • Pulls scalp posteriorly © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Orbicularis oculi • Encircles the eye • Closes the eye; for example when you blink © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Zygomaticus • Located at the cheek • Facial expression muscle • Elevates corners of mouth (in a smile or laugh) © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Buccinator • Located at the cheek • Tightens cheek; compresses cheeks inward (as when blowing air); assists with chewing © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Orbicularis Oris • Encircles the mouth • Closes mouth; protrudes lip (kissing) © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Masseter • Located at the jaw • Closes mandible; major muscle of chewing © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Platysma • Located in the inferior face and the neck • Facial expression muscle • Depresses lower lip; draws angle of mouth downward © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Sternocleidomastoid • Located in the neck • Rotates and extends head • Flexes neck © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Deltoid • Located at the shoulder, clavicle area • Abducts, extends, and flexes arm © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Trapezius • Connects the upper extremity to the vertebral column • Extends across the neck and back • Abducts and extends head; rotates and adducts scapula; shrugs your shoulders © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Trunk Muscles Figure 6.15 Slide 6.39 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Pectoralis Major • Located in the thoracic region (clavicle, sternum, ribs area) • Adducts, flexes, and rotates are medially © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

External Intercostals • 11 muscles found between the ribs • Assist with breathing © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Rectus Abdominus • Also known as the “abs” • Runs from the sternum to the pubic bone • Flexes lumbar vertebrae; compresses abdomen © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

External Oblique • Lateral part of the abdomen region along the ribs (5-12) • Compresses abdomen, laterally rotates the trunk © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Internal Oblique • Located beneath (deep to) the external oblique in the abdominal region at the ribs • Compresses abdomen; laterally rotates the trunk © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Transverse Abdominus • Located in the lower abdomen region • Compresses abdomen; laterally rotates the trunk; tenses abdominal wall © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Deep Trunk and Arm Muscles Figure 6.16 Slide 6.40 Copyright © 2003 Pearson Education, Inc. publishing as Benjamin Cummings © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Latissimus Dorsi • Located in the back (thoracic and lumbar vertebrae, sacrum) • Adducts, extends, and medially rotates arm, pulls shoulder inferiorly © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Erector Spinae • Group of three muscles that run along the spinal column • Extends vertebral column (keeps it erect) © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Biceps Brachii • Anterior upper arm muscle • Flexes forearm © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Brachialis • Located anterior, distal portion of humerus • Flexes forearm © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Brachioradialis • Located at the distal lateral end of the humerus • Flexes the forearm © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Flexor Carpi Ulnaris • Located in the forearm (along the ulna) • Flexes and adducts hand © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Arm Muscles (cont.) 22-94 • Biceps brachii © 2011 The McGraw-Hill Companies, Inc. All rights reserved. – Flexes the arm at the elbow – Rotates the hand laterally • Brachialis – Flexes the arm at the elbow • Brachioradialis – Flexes the forearm at the elbow

Flexor Carpi Radialis • Located in the forearm (along the radius) • Flexes and abducts the hand © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Arm Muscles (cont.) 22-96 • Triceps brachii © 2011 The McGraw-Hill Companies, Inc. All rights reserved. – Extends the arm at the elbow • Supinator – Rotates the forearm laterally (supination) • Pronator teres – Rotates the forearm medially (pronation)

Triceps Brachii • Located on the posterior side of the humerus • Adducts the arm, extends the arm and forearm © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Extensor Carpi Radialis Longus • Located in the forearm • Extends wrist and abducts hand © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Extensor Carpi Ulnaris • Located in the forearm • Extends wrist and adducts hand © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

Extensor Digitorum • Located in the forearm • Extends the fingers © 2011 The McGraw-Hill Companies, Inc. All rights reserved.

22-101 Wrist, Hand, and Finger Muscles • Flexor carpi radialis and flexor carpi ulnaris – Flex and abduct the wrist • Palmaris longus – Flexes the wrist • Flexor digitorum profundus – Flexes the distal joints of the fingers, but not the thumb © 2011 The McGraw-Hill Companies, Inc. All rights reserved.