1. CHAPTER 15 MUSCULAR SYSTEM
Antagonist
Atrophy
Contraction
Contracture
Dystrophy
Myalgia
Paralysis
Posture
Prime mover
Range of motion
Sarcomere
Skeletal
Stimulus
Tonus
Visceral
Journal question: What are the six functions of the muscular system?

2. Chapter 15 Learning Objectives
Define at least 10 terms relating to the muscular system.
Describe the six functions of the muscular system.
Identify at least 10 structures of the muscular system, and explain the function of each.

3. Chapter 15 Learning Objectives
Describe at least three methods of assessment of the muscular system.
Describe at least five disorders of the muscular system.

4. Structure and Function
Functions of the muscular system
Aid in movement
Provide and maintain posture
Protect internal organs
Provide movement of blood, food, and waste products through the body
Open and close body openings
Produce heat
The human body has more than 600 muscles.

5. Common Muscle Groups
The human body has fewer muscles in it than a caterpillar.
FIGURE 15-2 Common muscle groups. A, Front view. (From Sorrentino S: Mosby’s textbook for nursing assistants, ed 7, St. Louis, 2008, Mosby.)

6. Common Muscle Groups
FIGURE 15-2 Common muscle groups. B, Back view. (From Sorrentino S: Mosby’s textbook for nursing assistants, ed 7, St. Louis, 2008, Mosby.)

7. Types of Muscle Tissue
Discuss the three types of muscle tissue and where they are located in the body.

8. Unique Characteristics of Muscle Tissue
Irritability or excitability
Muscle’s ability to respond to a stimulus
Contractility
Ability to shorten forcefully when stimulated
Extensibility
Ability to stretch and lengthen
Elasticity
Ability to recoil to its resting length when relaxed
Discuss the difference between the irritability and excitability characteristics of muscle tissue.

9. Skeletal Muscle Makes up more than 40% of a person’s body weight
Looks striated, or banded, under the microscope
Skeletal muscles have three parts:
Origin is one end of the muscle, attached to the less movable part of the bone.
Insertion is the other end of the muscle, attached to the more movable part of the bone.
The action, or body, is the thick middle part of the muscle.
Skeletal muscles are also called voluntary or striated muscles.
Discuss locations of skeletal muscles in the human body.

10. Parts Of A Muscle
Review the origin, action, and insertion parts of a muscle.
FIGURE 15-4 Parts of a muscle.

11. Skeletal Muscle Movement
Working in pairs, have students mimic skeletal muscle movement, as in the Figure 15-5, and feel a contracted and relaxed muscle movement.
FIGURE 15-5 Skeletal muscle movement.

12. Types of Muscle Movement
Call on several students to demonstrate the four types of muscle movement in Figure 15-6, one at a time.
Have the class identify what muscle movement the student is demonstrating, using the correct term for each.
FIGURE 15-6 Types of muscle movement. A, Flexion and extension. B, Rotation. C, Abduction and adduction. D, Pronation and supination.

13. Visceral Muscle Lines various hollow organs
Makes up the walls of blood vessels
Found in the tubes of the digestive system
Smooth and has no striations
Controlled by the autonomic nervous system
Visceral muscles are also called involuntary muscles or smooth muscles.

14. Cardiac Muscle Found only in the heart Striated muscle
Under involuntary control
Has specialized cells that provide a stimulus for contraction
The cardiac muscle makes up most of the heart.

15. Muscle Contraction
Isotonic contraction is muscle shortening that produces movement.
Muscle tone, or tonus, is a state of partial contraction that maintains a person’s posture.
Isometric contraction does not cause muscle shortening or movement.
A twitch is a quick, jerky contraction of a whole muscle from one stimulus.
Not all muscle contractions are the same.
The eye has the fasting reacting muscle in the whole body. It contracts in 1/100th of a second.

16. Muscle Contraction
Tetanic contraction is more sustained than a twitch.
Fibrillation is uncoordinated contraction of muscle fibers.
Convulsions are contractions of groups of muscles in an abnormal manner.
Spasms are involuntary, sudden, and prolonged contractions.
Tetanic contraction is caused by many stimuli in rapid succession.

17. Assessment Techniques
Reflex tests
Assesses neurologic functioning
Joint motion measured using a protractor
Range of joint motion
Blood tests
Measures enzymes
Electromyography
Tests muscles through needles inserted into the muscle
Muscle biopsy
Used to assess for tissue disorders
The muscular system is assessed for asymmetry, deformity, swelling, or bruising with general inspection.
With systematic movement of the body parts, muscle groups can be assessed for weakness.

18. Disorders of the Muscular System
Back pain
From weakened muscles around the spine in the lower back
Contracture
Condition in which muscles remain contracted as a joint loses flexibility and ligaments and tendons shorten
Viral infection that results in paralysis of muscles
Muscle cramp
Sudden involuntary contraction of a muscle, producing pain
Discuss the causes, symptoms, and treatment of these disorders.

19. Disorders of the Muscular System
Muscular dystrophy
Group of genetic diseases involving painless, gradual atrophy of muscle tissue
Fibromyalgia
Group of muscle disorders affecting the tendons, ligaments, and other fibrous tissues
Gangrene
Caused by Clostridium bacteria that kill muscle tissue
Discuss the causes, symptoms, and treatment of these disorders.

20. Disorders of the Muscular System
Hernia
Abnormal protrusion of a body part into another body area
Myasthenia gravis
Condition in which nerve impulses are not transmitted normally from the brain to the muscles
Poliomyelitis
Discuss the causes, symptoms, and treatment of these disorders.

21. Disorders of the Muscular System
Muscle sprain
Traumatic injury to the tendons, muscles, or ligaments of a joint
Muscle strain
Torn or stretched tendons and muscles, causing pain
Pes planus
Also called flatfoot or fallen arches, may be congenital or result from weakened foot muscles
Discuss the causes, symptoms, and treatment of these disorders. Discuss possible preventions.

22. Disorders of the Muscular System
Tetanus
Commonly called lockjaw, is caused by a bacterial infection
Trichinosis
Parasitic infection caused by eating undercooked pork
Discuss the symptoms, prevention, and treatment of these disorders.

23. Issues and Innovations
Sports medicine
Treats sports injuries
Directs healthful development and training of athletes
Addresses biomechanics
Offers novel treatments
Ultrasound
Electric stimulation
Platelet-rich plasma (PRP) therapy
Ask student to name types of athletic injuries affecting the muscular system, such as strains, sprains, and bruises.
Discuss the term biomechanics.

24. Issues and Innovations
Fitness fads
Importance of regular exercise for good health
Feeling better
Having less stress
Exercise obsession
Increase in number of health clubs and spas
Dependence on “high” of exercise
Endorphins are released while exercising.
Person addicted to exercise feels withdrawal symptoms.
According to the CDC, more than 20% of the population of all states (except Colorado) is obese.

25. Summary Functions of the muscular system Movement Posture
Protection of internal organs
Transport of blood
Producing heat

26. Summary Structures of the muscular system Skeletal muscles
Biceps
Triceps
Quadriceps
Deltoid
Masseter
Gracilis
Visceral muscle
Cardiac muscle

27. Summary Methods of assessment of the muscular system Inspection
Electromyography
Blood and reflex tests

28. Summary Disorders of the muscular system Contractures Cramps Dystrophy
Poliomyelitis
Gangrene

29. Review Fibromyositis, with regard to the muscular system, is:
a. Faulty growth
b. Uncontrolled muscle contraction of the eyelid
c. Inflammation of the muscle tissues
d. A tumor of the muscle
e. Interior organs

30. Review Fibromyositis, with regard to the muscular system, is:
a. Faulty growth
b. Uncontrolled muscle contraction of the eyelid
c. Inflammation of the muscle tissues
d. A tumor of the muscle
e. Interior organs

31. Review
The human body has more than: a. 400 muscles b. 450 muscles c. 500 muscles d. 550 muscles e. 600 muscles

32. Review
The human body has more than: a. 400 muscles b. 450 muscles c. 500 muscles d. 550 muscles e. 600 muscles