Essentials of Human Anatomy & Physiology PDF

Essentials of Human Anatomy & Physiology Thirteenth Edition Global Edition Chapter 6 The Muscular System Lecture Presentation by...

Essentials of Human Anatomy & Physiology Thirteenth Edition Global Edition Chapter 6 The Muscular System Lecture Presentation by Patty Bostwick-Taylor Florence-Darlington Technical College Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Muscle Movements, Roles, and Names Follow the Five Golden Rules for understanding skeletal muscle activity (in Table 6.2, shown next) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Table 6.2 The Five Golden Rules of Skeletal Muscle Activity 1. With a few exceptions, all skeletal muscles cross at least one joint. 2. Typically, the bulk of a skeletal muscle lies proximal to the joint crossed. 3. All skeletal muscles have at least two attachments: the origin and the insertion. 4. Skeletal muscles can only pull; they never push. 5. During contraction, a skeletal muscle insertion moves toward the origin. Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Types of Body Movements (1 of 5) Muscles are attached to no fewer than two points 1. Origin: attachment to an immovable or less movable bone 2. Insertion: attachment to a movable bone When the muscle contracts, the insertion moves toward the origin Body movement occurs when muscles contract across joints Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.12 Muscle Attachments (Origin and Insertion) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Types of Body Movements (2 of 5) 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 the angle between two bones – Typical of straightening the elbow or knee – Extension beyond 180 o is hyperextension Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.13a Body Movements Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.13b Body Movements Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Types of Body Movements (3 of 5) 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”) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.13c Body Movements Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Types of Body Movements (4 of 5) Abduction – Movement of a limb away from the midline Adduction – Opposite of abduction – Movement of a limb toward the midline Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.13d Body Movements (1 of 2) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Types of Body Movements (5 of 5) 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 Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.13d Body Movements (2 of 2) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Special Movements (1 of 4) Dorsiflexion – Lifting the foot so that the superior surface approaches the shin (toward the dorsum) Plantar flexion – Pointing the toes away from the head Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.13e Body Movements Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Special Movements (2 of 4) Inversion – Turning sole of foot medially Eversion – Turning sole of foot laterally Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.13f Body Movements Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Special Movements (3 of 4) 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 Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.13g Body Movements Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Special Movements (4 of 4) Opposition – Moving the thumb to touch the tips of other fingers on the same hand Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.13h Body Movements Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Interactions of Skeletal Muscles in the Body (1 of 2) Muscles can only pull as they contract—not push In general, groups of muscles that produce opposite actions lie on opposite sides of a joint Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Interactions of Skeletal Muscles in the Body (2 of 2) 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 or reduces undesirable movements Fixator—specialized synergists that hold a bone still or stabilize the origin of a prime mover Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.14a Muscle Action *These generalities are reversed for the knee and ankle because the lower limb is rotated during development. The muscles that cross these joints posteriorly produce flexion, and those that cross anteriorly produce extension. Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.14b Muscle Action *These generalities are reversed for the knee and ankle because the lower limb is rotated during development. The muscles that cross these joints posteriorly produce flexion, and those that cross anteriorly produce extension. Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.14c Muscle Action Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.14d Muscle Action Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Naming Skeletal Muscles (1 of 3) Muscles are named on the basis of several criteria – Direction of muscle fibers ▪ Example: rectus (straight) – Relative size of the muscle ▪ Example: maximus (largest) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Naming Skeletal Muscles (2 of 3) Muscles are named on the basis of several criteria – Location of the muscle ▪ Example: temporalis (temporal bone) – Number of origins ▪ Example: triceps (three heads) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Naming Skeletal Muscles (3 of 3) Muscles are named on the basis of several criteria – Location of the muscle’s 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) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Arrangement of Fascicles Common patterns of fascicle arrangement – Circular: fascicles are in concentric rings – Convergent: fascicles converge on a single insertion tendon – Parallel: length of fascicles run parallel to the long axis of the muscle – Fusiform: modified parallel arrangement resulting in a spindle-shaped muscle – Pennate: short fascicles attach obliquely to a central tendon Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.15 Relationship of Fascicle Arrangement to Muscle Structure Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Table 6.3 Superficial Anterior Muscles of the Body (See Figure 6.22) (1 of 3) Head/neck muscles Name Origin Insertion Primary action(s) Frontalis Cranial aponeurosis Skin of eyebrows Raises eyebrows Orbicularis oculi Frontal bone and maxilla Tissue around eyes Blinks and closes eye Orbicularis oris Mandible and maxilla Skin and muscle around Closes and protrudes lips mouth Temporalis Temporal bone Mandible Closes jaw Zygomaticus Zygomatic bone Skin and muscle at corner Raises corner of mouth of lips Masseter Temporal bone Mandible Closes jaw Buccinator Maxilla and mandible near Orbicularis oris Compresses cheek (as in molars sucking); holds food between teeth during chewing Sternocleidomastoid Sternum and clavicle Temporal bone (mastoid Flexes neck; laterally process) rotates head Platysma Connective tissue covering Tissue around mouth Tenses skin of neck (as in of superior chest muscles shaving) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.16 Superficial Muscles of the Head and Neck Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Table 6.3 Superficial Anterior Muscles of the Body (See Figure 6.22) (2 of 3) Trunk muscles Name Origin Insertion Primary action(s) Pectoralis major Sternum, clavicle, and first Proximal humerus Adducts and flexes to sixth ribs humerus Rectus abdominis Pubis Sternum and fifth to Flexes vertebral column seventh ribs External oblique Lower eight ribs Iliac crest Flexes and rotates vertebral column Arm/shoulder muscles Name Origin Insertion Primary action(s) Biceps brachii Scapula of shoulder girdle Proximal radius Flexes elbow and supinates forearm Brachialis Distal humerus Proximal ulna Flexes elbow Blank Deltoid (See Table 4) Abducts arm Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.17a Muscles of the Anterior Trunk, Shoulder, and Arm Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.17b Muscles of the Anterior Trunk, Shoulder, and Arm Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Table 6.3 Superficial Anterior Muscles of the Body (See Figure 6.22) (3 of 3) Hip/Thigh/Leg Muscles Name Origin Insertion Primary action(s) Iliopsoas Ilium and lumbar vertebrae Femur (lesser trochanter) Flexes hip Adductor muscles Pelvis Proximal faemur Adduct and medially rotate thigh Sartorius Ilium Proximal tibia Flexes thigh on hip Quadriceps group (vastus Vasti: femur Tibial tuberosity via patellar All extend knee; rectus medialis, intermedius, and Rectus femoris: pelvis ligament femoris also flexes hip on lateralis; and the rectus thigh Tibial tuberosity via patellar femoris) ligament Tibialis anterior Proximal tibia First cuneiform (tarsal) and Dorsiflexes and inverts foot first metatarsal of foot Extensor digitorum longus Proximal tibia and fibula Distal toes 2–5 Extends toes Fibularis muscles Fibula Metatarsals of foot Plantar flex and evert foot Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.20c Pelvic, Hip, and Thigh Muscles of the Right Side of the Body Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.20d Pelvic, Hip, and Thigh Muscles of the Right Side of the Body Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.21a Superficial Muscles of the Right Leg Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Table 6.4 Superficial Posterior Muscles of the Body (Some Forearm Muscles Also Shown) (See Figure 6.23) (1 of 3) Head/Neck/Trunk/Shoulder Muscles Name Origin Insertion Primary action(s) Occipitalis Occipital and temporal Cranial aponeurosis Fixes aponeurosis and bones pulls scalp posteriorly Trapezius Occipital bone and all Scapular spine and clavicle Raises, retracts, and cervical and thoracic rotates scapula vertebrae Latissimus dorsi Lower spine and iliac crest Proximal humerus Extends and adducts humerus Erector spinae* Iliac crests, ribs 3–12, and Ribs, thoracic and cervical Extends and laterally flexes vertebrae vertebrae spine Quadratus lumborum* Iliac crest, lumbar fascia Transverse processes of Flexes spine laterally; upper lumbar vertebrae extends spine Deltoid Scapular spine and clavicle Humerus (deltoid Abducts humerus tuberosity) *Erector spinae and quadratus lumborum are deep muscles (they are not shown in Figure 6.23; see Figure 6.18b). Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.18a Muscles of the Posterior Neck, Trunk, and Arm (1 of 2) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.18b Muscles of the Posterior Neck, Trunk, and Arm Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.19 The Fleshy Deltoid Muscle Is a Favored Site for Administering Intramuscular Injections Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Muscles of Trunk, Shoulder, Arm Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. A&P Flix : Muscles That Act on the Shoulder Joint and Humerus: An Overview https://mediaplayer.pearsoncmg.com/assets/apf-muscles-that-act-on-the-shoulder-joint- and-humerus-overview-a Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. A&P Flix : Muscles of the Pectoral Girdle (1 of 3) https://mediaplayer.pearsoncmg.com/assets/apf-muscles-of-the-pectoral-girdle-a Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. A&P Flix : Muscles of the Pectoral Girdle (2 of 3) https://mediaplayer.pearsoncmg.com/assets/apf-muscles-of-the-pectoral-girdle-b Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. A&P Flix : Muscles of the Pectoral Girdle (3 of 3) https://mediaplayer.pearsoncmg.com/assets/apf-muscles-of-the-pectoral-girdle-c Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. A&P Flix : Muscles That Cross the Glenohumeral Joint https://mediaplayer.pearsoncmg.com/assets/apf-muscles-that-cross-the- glenohumeral-joint Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. A&P Flix : Movement at the Glenohumeral Joint: An Overview https://mediaplayer.pearsoncmg.com/assets/apf-movement-at-the-glenohumeral- joint-overview Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Table 6.4 Superficial Posterior Muscles of the Body (Some Forearm Muscles Also Shown) (See Figure 6.23) (2 of 3) Arm/forearm muscles Name Origin Insertion Primary action(s) Triceps brachii Shoulder girdle and Olecranon process of ulna Extends elbow proximal humerus Flexor carpi radialis Distal humerus Second and third Flexes wrist and abducts metacarpals hand (see Figure 6.22) Flexor carpi ulnaris Distal humerus and Carpals of wrist and fifth Flexes wrist and adducts posterior ulna metacarpal hand Flexor digitorum Distal humerus, ulna, and Middle phalanges of Flexes wrist and fingers superficialis† radius second to fifth fingers Extensor carpi radialis Humerus Base of second and third Extends wrist and abducts metacarpals hand Extensor digitorum Distal humerus Distal phalanges of second Extends fingers to fifth fingers †Although its name indicates that it is a superficial muscle, the flexor digitorum superficialis lies deep to the flexor carp i radialis and is not visible in a superficial view. Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.18a Muscles of the Posterior Neck, Trunk, and Arm (2 of 2) Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Table 6.4 Superficial Posterior Muscles of the Body (Some Forearm Muscles Also Shown) (See Figure 6.23) (3 of 3) Hip/Thigh/Leg muscles Name Origin Insertion Primary action(s) Gluteus maximus Sacrum and ilium Proximal femur (gluteal Extends hip (when forceful tuberosity) extension is required) Gluteus medius llium Proximal femur Abducts thigh; steadies pelvis during walking Hamstring muscles (biceps Ischial tuberosity Proximal tibia (head of Flex knee and extend hip femoris, semitendinosus, fibula in the case of biceps semimembranosus) femoris) Gastrocnemius Distal femur Calcaneus (heel via Plantar flexes foot and flexes calcaneal tendon) knee Soleus Proximal tibia and Calcaneus Plantar flexes foot fibula Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.20 Pelvic, Hip, and Thigh Muscles of the Right Side of the Body Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.21b Superficial Muscles of the Right Leg Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.22 Major Superficial Muscles of the Anterior Surface of the Body Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Figure 6.23 Major Superficial Muscles of the Posterior Surface of the Body Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Developmental Aspects of the Muscular System (1 of 3) Increasing muscular control reflects the maturation of the nervous system Muscle control is achieved in a superior/inferior and proximal/distal direction Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Developmental Aspects of the Muscular System (2 of 3) To remain healthy, muscles must be exercised regularly Without exercise, muscles atrophy With extremely vigorous exercise, muscles hypertrophy Copyright © 2022 Pearson Education, Ltd. All Rights Reserved. Developmental Aspects of the Muscular System (3 of 3) As we age, muscle mass decreases, and muscles become more sinewy Exercise helps retain muscle mass and strength Copyright © 2022 Pearson Education, Ltd. All Rights Reserved.