Psychology Chapter 10 Homework Name the common patterns of muscle fascicle arrangement

CHAPTER

10

The Muscular System

Objectives

Actions and Interactions of Skeletal Muscles

Naming Skeletal Muscles

3. List the criteria used in naming muscles. Provide an example to illustrate the use of each

criterion.

Muscle Mechanics: Importance of Fascicle Arrangement and Leverage

4. Name the common patterns of muscle fascicle arrangement and relate them to power

generation.

Major Skeletal Muscles of the Body

7. Name and identify the muscles described in Tables 10.1 to 10.17. State the origin,

insertion, and action of each.

Suggested Lecture Outline

I. Actions and Interactions of Skeletal Muscles (pp. 319–320; Fig. 10.1)

A. Muscles only pull; they never push, and as a muscle shortens, the insertion is pulled

toward the origin (p. 319).

II. Naming Skeletal Muscles (pp. 320–322)

A. Criteria used to name skeletal muscles include location, shape, size, direction of muscle

fibers, number of origins, location of attachments, or action. A muscle name often incor-

porates more than one of these criteria. (p. 320)

1. An example of a muscle named for its location is the temporalis, which covers the

temporal bone.

2. An example of a muscle named for its shape is the deltoid, which has a triangular shape.

3. Terms such as maximus, minimus, longus, and brevis indicate relative muscle size.

III. Muscle Mechanics: Importance of Fascicle Arrangement and Leverage

(pp. 322–324; Figs. 10.2–10.4)

A. In skeletal muscles, the common arrangement of the fascicles varies, resulting in muscles

with different shapes and functional capabilities (pp. 322–323; Fig. 10.2).

1. The fascicular pattern is circular when the fascicles are arranged in concentric rings.

2. A convergent muscle has a broad origin and its fascicles converge toward a single

tendon of insertion.

B. The operation of most skeletal muscles involves the use of leverage and lever systems—

partnerships between the muscular and skeletal systems (pp. 323–324; Figs. 10.3–10.4).

1. A lever is a rigid bar that moves on a fixed point, or fulcrum, when a force is applied to it.

2. The applied force, or effort, is used to move a resistance, or load.

6. There are three types of levers: first-class, second-class, and third-class.

a. First-class levers have the effort applied at one end and the load at the other end,

with the fulcrum in between.

IV. Major Skeletal Muscles of the Body (pp. 324–382; Figs. 10.5–10.26; Tables

10.1–10.17)

The muscles listed in the following sections are outlined in tables that differ

from the tables in the textbook. Textbook tables are designed to be more ency-

clopedic, but not necessarily practical for a lecture outline. The following tables

condense the information found in tables in the main text in order to provide a

more concise, teachable outline of the more commonly taught muscles, along

with their actions, origins, and insertions.

A. Muscles of the Head, Part I: Facial Expression (pp. 329–331; Fig. 10.7; Table 10.1)

1. Muscles of facial expression located in the scalp and face insert into skin or other

muscles, rather than bones, and are innervated by cranial nerve VII, the facial nerve.

Muscle Action Origin Insertion

Muscles of the Scalp

Epicranial

Skin of eyebrows

Epicranius

Muscles of the Face

Orbicularis oculi Closes eye Frontal and

maxillary bones

Eyelid

Zygomaticus Raises lateral

corners of the mouth

Zygomatic bone Skin and muscle at

corner of mouth

B. Muscles of the Head, Part II: Mastication and Tongue Movement (pp. 332–333;

Fig. 10.8; Table 10.2)

1. Muscles involved in mastication (chewing) move the mandible and anchor the tongue,

and are innervated by the mandibular branch of cranial nerve V, the trigeminal nerve.

Muscle Action Origin Insertion

Muscles of Mastication

2. Additional muscles controlling the mandible and tongue, as well as more detailed

descriptions of the actions, origins, and insertions listed above are found on pp. 332–

333, Table 10.2.

C. Muscles of the Anterior Neck and Throat: Swallowing (pp. 334–335; Fig. 10.9;

Table 10.3)

1. Muscles involved in swallowing are part of the anterior triangle next to the sternoclei-

2. For a detailed listing of the names, actions, origins, and insertions of muscles involved

1. Head movements are produced by muscles originating from the axial skeleton.

a. Movements of the head from side to side are accomplished by contraction of

muscles on only one side of the neck.

2. Extension of the back, and maintenance of normal spinal curvatures are produced by

deep back muscles originating from the sacrum to the skull.

Muscle Action Origin Insertion

Anterolateral Neck Muscles

Intrinsic Muscles of the Back

Splenius capitis,

cervicis

Extends head Cervical and

thoracic vertebrae

Mastoid process of

temporal bone, occipital

bone, transverse

processes of C2–C4

3. Additional muscles of the neck and vertebral column, as well as more detailed descrip-

tions of the actions, origins, and insertions listed above are found on pp. 336–339,

Table 10.4.

E. Deep Muscles of the Thorax: Breathing (pp. 340–341; Fig. 10.11; Table 10.5)

1. Deep muscles of the thorax form the anterolateral wall of the thorax and partition the

thoracic from the abdominal cavity.

Muscle Action Origin Insertion

Muscles of the Thorax

External intercostals Elevates ribs Inferior border of

upper rib

Superior border of

rib below

3. More detailed descriptions of the actions, origins, and insertions listed above are found

on pp. 340–341, Table 10.5.

F. Muscles of the Abdominal Wall: Trunk Movements and Compression of Abdominal

Viscera (pp. 342–343; Fig. 10.12; Table 10.6)

Muscle Action Origin Insertion

Muscles of the Anterolateral Abdominal Wall

Rectus abdominis Flexes and rotates

vertebral column

Pubic crest and

symphysis

Xiphoid process,

lower costal

cartilages

3. More detailed descriptions of the actions, origins, and insertions of the abdominal

muscles listed above are found on pp. 342–343, Table 10.6.

G. Muscles of the Pelvic Floor and Perineum: Support of Abdominopelvic Organs

(pp. 344–345; Fig. 10.13; Table 10.7)

1. The muscles of the pelvic floor and perineum close the inferior opening of the pelvis,

H. Superficial Muscles of the Anterior and Posterior Thorax: Movements of the Scapula and

Arm (pp. 346–349; Fig. 10.14; Table 10.8)

1. The superficial thorax muscles run from the ribs and vertebral column to the shoulder

girdle, and both fix the scapula and create greater range of motion of arm movements.

Muscle Action Origin Insertion

Muscles of the Anterior Thorax

Muscles of the Posterior Thorax

Trapezius Fixes, elevates,

retracts, and rotates

scapula

Occipital condyle,

vertebral column

Acromion, spine of

scapula, lateral third

of clavicle

2. Additional muscles moving the scapula and arm, as well as more detailed descriptions

of the actions, origins, and insertions listed above are found on pp. 346–349, Table

10.8.

I. Muscles Crossing the Shoulder Joint: Movements of the Arm (Humerus) (pp. 350–352;

Fig. 10.15; Table 10.9)

2. Muscles originating anterior to the shoulder flex the arm, while those originating pos-

terior to the shoulder extend the arm.

Muscle Action Origin Insertion

Muscles Moving the Arm

Pectoralis major Flexes, adducts,

medially rotates arm

Clavicle, sternum,

costal cartilages

Greater tubercle

3. More detailed descriptions of the actions, origins, and insertions of the muscles

moving the shoulder listed above are found on pp. 350–352, Table 10.9.

J. Muscles Crossing the Elbow Joint: Flexion and Extension of the Forearm (p. 353;

Fig. 10.15; Table 10.10)

1. There are two compartments in the arm: anterior flexors and posterior extensors, both

acting on the forearm.

Muscle Action Origin Insertion

Posterior Muscles

Triceps brachii Extends forearm Scapula, humerus Olecranon

2. Additional muscles crossing the elbow joint, as well as more detailed descriptions of

the actions, origins, and insertions listed above are found on p. 353, Table 10.10.

K. Muscles of the Forearm: Movements of the Wrist, Hand, and Fingers (pp. 354–357;

Figs. 10.16–10.17; Table 10.11)

1. Muscles of the forearm are divided by fascia into two compartments: anterior flexors

and posterior extensors.

Muscle Action Origin Insertion

Anterior Superficial Muscles

Pronator teres Pronates forearm Medial epicondyle

of humerus,

Radius

Anterior Deep Muscles

Flexor pollicis

longus

Flexes distal

phalanx of thumb

Radius, interosseous

membrane

Distal phalanx of

thumb

2. More detailed descriptions of the actions, origins, and insertions listed above are found

on pp. 354–355, Table 10.11.

Muscle Action Origin Insertion

Posterior Superficial Muscles

Brachioradialis Flexes forearm Radial styloid process

Humerus

Posterior Deep Muscles

Supinator Supinates forearm Lateral epicondyle

of humerus, ulna

Radius

Abductor pollicis

longus

Abducts and extends

thumb

First metacarpal,

trapezium

Extensor pollicis

(brevis, longus)

Extends thumb

Radius, ulna,

interosseous

membrane Proximal, distal

phalanx of thumb

3. More detailed descriptions of the actions, origins, and insertions of forearm muscles

listed above are found on pp. 356–357, Table 10.11.

Muscle Action Origin Insertion

2. For a detailed listing of the names, actions, origins, and insertions of muscles of the

hand, refer to pp. 360–362, Table 10.13.

N. Muscles Crossing the Hip and Knee Joints: Movements of the Thigh and Leg

(pp. 363–369; Figs. 10.20–10.21; Table 10.14)

1. Fascia divide the thigh into three compartments: anterior, posterior, and medial.

Muscle Action Origin Insertion

Anterior and Medial Muscles: Iliopsoas and Sartorius

Iliacus Iliac fossa, crest, and

Flexes thigh at trunk,

Lesser trochanter

Muscles of the Medial Compartment: Adductor Group, Pectineus,

and Gracilis

Adductor

magnus

Adducts, flexes,

extends, medially

rotates thigh

Ischial and pubic

rami, ischial

tuberosity

Linea aspera

Muscles of the Anterior Compartment: Quadriceps Femoris Group and

Tensor Fasciae Latae

Rectus femoris Extends knee,

flexes thigh

Anterior inferior

iliac spine,

acetabulum

Patella, tibial

tuberosity via

patellar ligament

Muscle Action Origin Insertion

Posterior Muscles

Gluteus maximus Extends thigh Ilium, sacrum,

coccyx

Gluteal tuberosity of

femur, iliotibial tract

Gluteus medius

Gluteus minimus

Abducts, medially

rotates thigh

Ilium Greater trochanter

Posterior Compartment of the Thigh: Hamstrings

2. For a detailed listing of the names, actions, origins, and insertions of muscles acting on

Table 10.15)

1. The leg muscles moving the ankle and toes are divided into three compartments by

deep fascia: anterior, lateral, and posterior.

Muscle Action Origin Insertion

Muscles of the Anterior Compartment

Muscles of the Lateral Compartment

Fibularis (peroneus)

longus

Metatarsal I, medial

cuneiform

Fibularis (peroneus)

brevis

Plantar flexes

and everts foot

Fibula

Metatarsal V

Superficial Muscles of the Posterior Compartment: Triceps Surae

and Plantaris

Deep Muscles of the Posterior Compartment

Flexor digitorum

longus

Plantar flexes

and inverts foot,

flexes toes

Posterior tibia Tendon passes behind

medial malleolus to

distal phalanges of toes

2–5

2. More detailed descriptions of the actions, origins, and insertions of the muscles of the

leg listed above are found on pp. 370–375, Table 10.15.

P. Intrinsic Muscles of the Foot: Toe Movement and Arch Support (pp. 376–379; Fig.

10.25; Table 10.16)

Cross References

Additional information on topics covered in Chapter 10 can be found in the chapters listed below.

1. Chapter 7: Bones of the skull; facial bones; bones of the vertebral column; the bony

thorax; pectoral bones; upper extremity; pelvic girdle; lower extremity

Lecture Hints

1. It is easy for students to treat the muscular (or any other) system as an individual unit,

without relating it to the rest of the body. Emphasize that students should associate any

specific muscle (and its associated synergists, antagonists, etc.) with its fascicle arrange-

ment, origin and insertion sites, and bones involved to “keep sight of the whole picture.”

4. When describing different muscles of the body, try coaxing names from the class by

carefully indicating locations, properties, etc. For example, point to a diagram (or model)

displaying transverse abdominis and ask the class which way the fibers are running. They

should answer: “transversely.” Then ask: “What general area of the body is this muscle

located in?” Answer: “abdominal.” Finally, ask: “What would be a logical name for this

muscle?” Using this approach in class will encourage students to do this type of analysis

when they start learning the information outside of class.

Activities/Demonstrations

1. Audiovisual materials are listed in the Multimedia in the Classroom and Lab section of

this Instructor Guide (p. 387).

3. Obtain a dissected preserved animal, such as a cat or a fetal pig, and exhibit the major

muscle groups.

4. Have students work in pairs as follows: One student should attempt to contract a particu-

lar muscle, while the second student provides resistance to prevent that movement. In this

5. As muscles are being described, project 2×2 slides of cadaver dissection so that students

6. Obtain a 3-D model or chart to illustrate the major human muscle groups.

Critical Thinking/Discussion Topics

1. Why is it necessary for pregnant women to strengthen their “pelvic floor”?

2. What do bones possess that allow them to act as effective levers?

3. What are the most appropriate modes of therapy for a pulled hamstring muscle or pulled

groin muscle?

Library Research Topics

1. Because muscle cells do not regenerate, what methods of treatment are available if a

major group of muscles is lost? What is the status of skeletal muscle transplants?

2. What effect does old age have on skeletal muscle? What type of research is under way

concerning this topic?

List of Figures and Tables

All of the figures in the main text are available in JPEG format, PPT, and labeled & unlabeled

format on the Instructor Resource DVD. All of the figures and tables will also be available in

Transparency Acetate format. For more information, go to www.pearsonhighered.com/educator.

Figure 10.1 Muscle Action

Figure 10.2 Patterns of fascicle arrangement in muscles.

Figure 10.3 Lever systems operating at a mechanical advantage and a mechanical

disadvantage.

Figure 10.14 Superficial muscles of the thorax and shoulder acting on the scapula

and arm.

Figure 10.15 Muscles crossing the shoulder and elbow joints, causing movements of

the arm and forearm, respectively.

Figure 10.16 Muscles of the anterior fascial compartment of the forearm acting on the

right wrist and fingers.

Figure 10.17 Muscles of the posterior fascial compartment of the right forearm acting

on the wrist and fingers.

Table 10.1 Muscles of the Head, Part I: Facial Expression (Figure 10.7)

Table 10.2 Muscles of the Head, Part II: Mastication and Tongue Movement

(Figure 10.8)

Table 10.3 Muscles of the Anterior Neck and Throat: Swallowing (Figure 10.9)

Table 10.5 Deep Muscles of the Thorax: Breathing (Figure 10.11)

Table 10.6 Muscles of the Abdominal Wall: Trunk Movements and Compression of

Abdominal Viscera (Figure 10.12)

Table 10.7 Muscles of the Pelvic Floor and Perineum: Support of Abdominopelvic

Organs (Figure 10.13)

Table 10.9 Muscles Crossing the Shoulder Joint: Movements of the Arm (Humerus)

(Figure 10.15)

Table 10.10 Muscles Crossing the Elbow Joint: Flexion and Extension of the Fore

arm (Figure 10.15)

Table 10.11 Muscles of the Forearm: Movements of the Wrist, Hand, and Fingers

(Figures 10.16 and 10.17)

Table 10.13 Intrinsic Muscles of the Hand: Fine Movements of the Fingers

(Figure 10.19)

Table 10.14 Muscles Crossing the Hip and Knee Joints: Movements of the Thigh and

Leg (Figures 10.20 and 10.21)

Answers to End-of-Chapter Questions

Multiple-Choice and Matching Question answers appear in Appendix H of the main text.

Short Answer Essay Questions

17. Student answers will vary. (p. 320)

a. Location of the muscle—frontalis, occipitalis, zygomaticus

d. Direction of muscle fibers—rectus abdominus, external oblique, superficial transverse

perineus

18. First-class lever: fulcrum between effort and load

19. When the load is far from the fulcrum and the effort is applied near the fulcrum, the

effort applied must be greater than the load to be moved. This type of leverage can be

advantageous because it allows the load to be moved rapidly through a large distance,

with only minimal muscle shortening. (p. 324)

22. See p. 342.

a. The rectus abdominus, external oblique, internal oblique, and transversus abdominus

23. Flexion of the humerus: pectoralis major and deltoid

Extension of the humerus: latissimus dorsi and deltoid

24. a. The extensor carpi radialis longus and brevis are strong wrist flexors. (p. 356)

b. The flexor digitorum profundus is used to flex the distal interphalangeal joints. (p. 355)

25. Piriformis, obturator externus and internus, gemellus, and quadratus femoris are grouped

together, and perform lateral rotation at the hip. (pp. 366, 368)

28. a. Opponens pollicis, flexor pollicis brevis (p. 360)

b. Supinator, abductor pollicis longus (p. 356)

c. Flexor pollicis longus, flexor digitorum profundus (p. 355)

d. Biceps brachii, brachialis (p. 353)

e. Hyoglossus, styloglossus (p. 332)

Critical Thinking and Clinical Application Questions

1. Flexion of the forearm is more difficult when the forearm is pronated because the biceps

brachii, a prime mover of forearm flexion, is unable to act. (p. 353)

2. Levator ani, coccygeus, and external urethral sphincter (p. 344)