Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Chapter 6 The Muscular System © 2015 Pearson Education, Inc.

Muscles and Body Movements  Movement is attained as a result of a muscle moving an attached bone  Muscles are attached to at least two points 1.Origin: attachment to a moveable bone 2.Insertion: attachment to an immovable bone © 2015 Pearson Education, Inc.

Figure 6.12 Muscle attachments (origin and insertion). Muscle contracting Origin Brachialis Tendon Insertion

Types of Body Movements  Flexion  Decreases the angle of the joint  Brings two bones closer together  Typical of bending hinge joints (e.g., knee and elbow) or ball-and-socket joints (e.g., the hip)  Extension  Opposite of flexion  Increases angle between two bones  Typical of straightening the elbow or knee  Extension beyond 180° is hyperextension © 2015 Pearson Education, Inc.

Figure 6.13a Body movements. Flexion Extension Hyperextension (a) Flexion, extension, and hyperextension of the shoulder and knee

© 2015 Pearson Education, Inc. Figure 6.13b Body movements. (b) Flexion, extension, and hyperextension Extension Flexion Hyperextension

Types of Body Movements  Rotation  Movement of a bone around its longitudinal axis  Common in ball-and-socket joints  Example: moving the atlas around the dens of axis (i.e., shaking your head “no”) © 2015 Pearson Education, Inc.

Figure 6.13c Body movements. (c) Rotation Rotation Lateral rotation Medial rotation

Types of Body Movements  Abduction  Movement of a limb away from the midline  Adduction  Opposite of abduction  Movement of a limb toward the midline © 2015 Pearson Education, Inc.

Figure 6.13d Body movements. Abduction Adduction Circumduction (d) Abduction, adduction, and circumduction

Types of Body Movements  Circumduction  Combination of flexion, extension, abduction, and adduction  Common in ball-and-socket joints  Proximal end of bone is stationary, and distal end moves in a circle © 2015 Pearson Education, Inc.

Figure 6.13d Body movements. Abduction Adduction Circumduction (d) Abduction, adduction, and circumduction

Special Movements  Dorsiflexion  Lifting the foot so that the superior surface approaches the shin (toward the dorsum)  Plantar flexion  Depressing the foot (pointing the toes)  “Planting” the foot toward the sole © 2015 Pearson Education, Inc.

Figure 6.13e Body movements. (e) Dorsiflexion and plantar flexion Dorsiflexion Plantar flexion

Special Movements  Inversion  Turning sole of foot medially  Eversion  Turning sole of foot laterally © 2015 Pearson Education, Inc.

Figure 6.13f Body movements. (f) Inversion and eversion Inversion Eversion

Special Movements  Supination  Forearm rotates laterally so palm faces anteriorly  Radius and ulna are parallel  Pronation  Forearm rotates medially so palm faces posteriorly  Radius and ulna cross each other like an X © 2015 Pearson Education, Inc.

Figure 6.13g Body movements. S (g) Supination (S) and pronation (P) Supination (radius and ulna are parallel) Pronation (radius rotates over ulna) S P P

Special Movements  Opposition  Moving the thumb to touch the tips of other fingers on the same hand © 2015 Pearson Education, Inc.

Figure 6.13h Body movements. (h) Opposition Opposition

Types of Muscles  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 © 2015 Pearson Education, Inc.

Naming Skeletal Muscles  By direction of muscle fibers  Example: rectus (straight)  By relative size of the muscle  Example: maximus (largest) © 2015 Pearson Education, Inc.

Naming Skeletal Muscles  By location of the muscle  Example: temporalis (temporal bone)  By number of origins  Example: triceps (three heads) © 2015 Pearson Education, Inc.

Naming Skeletal Muscles  By location of the muscle’s origin and insertion  Example: sterno (on the sternum)  By shape of the muscle  Example: deltoid (triangular)  By action of the muscle  Example: flexor and extensor (flexes or extends a bone) © 2015 Pearson Education, Inc.

Figure 6.15 Relationship of fascicle arrangement to muscle structure. (a) (b) (c) (e) (f) (g) (a) Circular (orbicularis oris) (b) Converent (pectoralis major) (c) Fusiform (biceps brachii) (d) Parallel (sartorius) (e) Multipennate (deltoid) (g) Unipennate (extensor digitorum longus) (f) Bipennate (rectus femoris) (d)

© 2015 Pearson Education, Inc. Table 6.3 Superficial Anterior Muscles of the Body (See Figure 6.22) (1 of 3).

© 2015 Pearson Education, Inc. Figure 6.16 Superficial muscles of the face and neck. Frontalis Orbicularis oculi Zygomaticus Buccinator Orbicularis oris Platysma Trapezius Masseter Sternocleidomastoid Occipitalis Temporalis Cranial aponeurosis

© 2015 Pearson Education, Inc. Table 6.3 Superficial Anterior Muscles of the Body (See Figure 6.22) (2 of 3).

© 2015 Pearson Education, Inc. Figure 6.17a Muscles of the anterior trunk, shoulder, and arm. Clavicle Deltoid Sternum Pectoralis major Biceps brachii Brachialis Brachio- radialis (a)

© 2015 Pearson Education, Inc. Figure 6.17b Muscles of the anterior trunk, shoulder, and arm. Pectoralis major Rectus abdominis Transversus abdominis Internal oblique External oblique Aponeurosis (b)

© 2015 Pearson Education, Inc. Table 6.3 Superficial Anterior Muscles of the Body (See Figure 6.22) (3 of 3).

© 2015 Pearson Education, Inc. Figure 6.20c Pelvic, hip, and thigh muscles of the right side of the body. 12th thoracic vertebra Iliac crest Iliopsoas Psoas major Iliacus Anterior superior iliac spine Sartorius Rectus femoris Vastus lateralis Vastus medialis Quadriceps 5th lumbar vertebra Adductor group Patella Patellar ligament 12th rib (c)

© 2015 Pearson Education, Inc. Figure 6.21a Superficial muscles of the right leg. Fibularis longus Fibularis brevis Tibialis anterior Extensor digitorum longus Fibularis tertius Tibia Soleus (a)

© 2015 Pearson Education, Inc. Figure 6.20d Pelvic, hip, and thigh muscles of the right side of the body. Vastus lateralis Sartorius (d) Adductor muscles Inguinal ligament

© 2015 Pearson Education, Inc. Table 6.4 Superior Posterior Muscles of the Body (Some Forearm Muscles Also Shown) (See Figure 6.23) (1 of 3).

© 2015 Pearson Education, Inc. Figure 6.18a Muscles of the posterior neck, trunk, and arm. Occipital bone Spine of scapula Deltoid (cut) Triceps brachii Latissimus dorsi Humerus Olecranon process of ulna (deep to tendon) (a) Deltoid Trapezius Sternocleidomastoid

© 2015 Pearson Education, Inc. Figure 6.18b Muscles of the posterior neck, trunk, and arm. (b) C7C7 T1T1 Erector spinae Iliocostalis Longissimus Spinalis Quadratus lumborum

© 2015 Pearson Education, Inc. Figure 6.19 The fleshy deltoid muscle is a favored site for administering intramuscular injections. Humerus Deltoid muscle

© 2015 Pearson Education, Inc. Table 6.4 Superior Posterior Muscles of the Body (Some Forearm Muscles Also Shown) (See Figure 6.23) (2 of 3).

© 2015 Pearson Education, Inc. Figure 6.18a Muscles of the posterior neck, trunk, and arm. Occipital bone Spine of scapula Deltoid (cut) Triceps brachii Latissimus dorsi Humerus Olecranon process of ulna (deep to tendon) (a) Deltoid Trapezius Sternocleidomastoid

© 2015 Pearson Education, Inc. Figure 6.22 Major superficial muscles of the anterior surface of the body. Temporalis Masseter Trapezius Deltoid Triceps brachii Biceps brachii Brachialis Brachioradialis Flexor carpi radialis Iliopsoas Facial Shoulder Arm Forearm Pelvis/thigh Thigh (Quadriceps) Rectus femoris Vastus medialis Vastus lateralis Leg Fibularis longus Extensor digitorum longus Tibialis anterior Leg Thigh Soleus Gastrocnemius Gracilis Adductor muscle Sartorius Abdomen Thorax Neck Rectus abdominis External oblique Internal oblique Transversus abdominis Intercostals Serratus anterior Pectoralis major Pectoralis minor Platysma Sternocleidomastoid Frontalis Orbicularis oculi Orbicularis oris Zygomaticus

© 2015 Pearson Education, Inc. Figure 6.23 Major superficial muscles of the posterior surface of the body. Triceps brachii Arm Brachialis Brachioradialis Forearm Extensor carpi radialis longus Flexor carpi ulnaris Extensor carpi ulnaris Extensor digitorum Iliotibial tract Leg Gastrocnemius Soleus Fibularis longus Calcaneal (Achilles) tendon Hamstrings: Semimembranosus Semitendinosus Biceps femoris Adductor muscle Thigh Hip Gluteus medius Gluteus maximus Latissimus dorsi Deltoid Shoulder/Back Neck Occipitalis Sternocleidomastoid Trapezius