1. Muscular System
Chapter 9

2. Orthopedics
The medical specialty that studies the anatomy and physiology of the muscular and skeletal systems and uses laboratory and diagnostic tests, medical and surgical procedures, and drugs to treat muscular and skeletal diseases.

3. Figure 9-1 Muscular system.

4. Anatomy and Physiology
The muscular system moves the bony framework of the body.
There are approximately 700 skeletal muscles in the body, as well as tendons and other structures of the muscular system.

5. Figure 9-2 Types of muscle.

6. Anatomy of the Muscular System
Types of Muscles: Skeletal muscles
Provide the means by which the body can move
Are voluntary muscles that contract and relax in response to conscious thought
Are striated
Of the three types of muscles, only skeletal muscle belongs to the muscular system.

7. Anatomy of the Muscular System
Types of Muscles: Cardiac Muscle
Cardiac muscle of the heart pumps blood through the circulatory system.
An involuntary muscle that is not under conscious control

8. Anatomy of the Muscular System
Types of Muscles: Smooth Muscles
Involuntary, nonstriated muscles
Form a continuous, thin layer around many organs and structures (blood vessels, intestines, etc.)

9. Muscle Origins, Insertions, and Related Structures
A muscle is attached to a bone by a tendon, a cordlike, non-elastic, white fibrous band of connective tissue.
The origin or beginning of a muscle is where its tendon is attached to a stationary or nearly stationary bone.
The insertion or ending of a muscle is where its tendon is attached to the bone that moves when the muscle contracts and relaxes.

10. Figure Tendon.

11. Figure 9-4 Origin and insertion of a muscle.

12. Muscle Names 9-1 Muscle names are in Latin.
They describe where the muscle is located, its shape, its size, or what action it performs.

13. Types of Muscle Movement
Muscles function in antagonistic pairs to produce movement.
These are opposite movements controlled by muscle pairs:
Flexion and extension
Abduction and adduction
Rotation to the right and to the left
Supination and pronation
Eversion and inversion

14. Table 9-2 Types of Muscle Movement
Description
Muscle Type
Pronunciation/Word Parts
flexion
Bending a joint to decrease the
angle between two bones or two
body parts. (Note: Plantar flexion
of the foot causes the toes to point downward. Dorsiflexion of the foot causes the toes to point upward.)
flexor
flexion (FLEK-shun)
flex/o- bending
-ion action; condition
flexor (FLEK-sor)
-or person who does; person who produces; thing that does; thing that produces
extension
Straightening and extending a joint
to increase the angle between two
bones or two body parts
extensor
extension (eks-TEN-shun)
extens/o- straightening
extensor (eks-TEN-sor)

15. Table 9-2 Types of Muscle Movement
Description
Muscle Type
Pronunciation/Word Parts
abduction
Moving a body part away from the midline of the body
abductor
abduction (ab-DUK-shun)
ab- away from
duct/o- bring; duct; move
-ion action; condition
abductor (ab-DUK-tor)
-or person who does; person who produces; thing that does; thing that produces
adduction
Moving a body part toward the
midline of the body
adductor
adduction (ad-DUK-shun)
ad- toward
adductor (ad-DUK-tor)

16. Pronunciation/Word Parts
Movement
Description
Muscle Type
Pronunciation/Word Parts
rotation
Moving a body part around its axis
rotator
rotation (roh-TAY-shun)
rotat/o- rotate
-ion action; condition
rotator (ROH-tay-tor)
-or person who does; person who produces; thing that does; thing that produces
supination
Turning the palm of the hand
anteriorly or upward. (Note: Here,
lying on the back refers to the back of the hand.)
supinator
supination (soo-pih-NAY-shun)
supinat/o- lying on the back
supinator (SOO-pih-nay-tor)
pronation
posteriorly or downward. (Note:
Here, face down refers to the face
of the palm.)
pronator
pronation (proh-NAY-shun)
pronat/o- face down
pronator (proh-NAY-tor)
9-1

17. Pronunciation/Word Parts
Movement
Description
Muscle Type
Pronunciation/Word Parts
eversion
Turning a body part outward and
toward the side
evertor
eversion (ee-VER-zhun)
e- out; without
vers/o- travel; turn
-ion action; condition
evertor (ee-VER-tor)
vert/o- travel; turn
-or person who does; person who produces; thing that does; thing that produces
inversion
Turning a body part inward
invertor
inversion (in-VER-zhun)
in- in; not; within
invertor (in-VER-tor)

18. Figure 9-5 Extension, abduction, and dorsiflexion.

19. Figure 9-6 Extension, adduction, pronation, abduction, flexion, and plantar flexion.

20. Figure Rotation.

21. Figure 9-8 Extension, supination, abduction, flexion, and inversion.

22. Figure 9-9 Muscles of the head and neck.

23. Figure 9-10 Muscles of the shoulder and chest.

24. Figure 9-11 Muscles of the shoulder and back.

25. Muscles of the Upper Extremity
Biceps brachii
Triceps brachii
Brachioradialis
Thenar muscles

26. Muscles of the Abdomen External abdominal oblique
Internal abdominal oblique
Rectus abdominis

27. Muscles of the Lower Extremity
Quadriceps femoris is a collective name for the group of four muscles on the anterior aspect of the thigh:
Rectus femoris
Vastus lateralis
Vastus intermedius (beneath the vastus lateralis)
Vastus medialis

28. Muscles of the Lower Extremity
Hamstrings is a collective name for the group of three muscles on the posterior aspect of the thigh:
Biceps femoris
Semitendinosus
Semimembranosus

29. Figure 9-15 Muscles of the lower extremity.

30. Figure 9-17 Parts of a muscle.
9-2

31. Diseases 9-3 Diseases of the Muscles
Atrophy- no muscle development- AKA muscle wasting
Avulsion- muscle tears away from tendon
Contracture- muscle becomes progressively flexed. ROM exercises are needed

32. Figure 9-19 Muscle contracture.
9-3

33. Diseases 9-3 Diseases of the Muscles Muscle contusion- bruise
Muscle spasm- muscle cramp- sudden involuntary contraction of muscle
Muscle strain- pulled muscle- overstretching a muscle

34. Diseases 9-3 Movement Disorders
Ataxia-incoordination of muscles during movement
Bradykinesia- slow muscle movement
Dyskinesia- difficulty controlling the voluntary muscle movement- see in Parkinson’s & cerebal palsy
Tetany- constant muscle contraction

35. Medical and Surgical Procedures
9-3
Medical and Surgical Procedures
Medical Procedures
Braces and adaptive devices
Deep tendon reflexes (DTR)

36. Figure Braces.
9-3

37. Figure 9-23 Deep tendon reflex.
9-3

38. Figure 9-24 Active exercise.
9-3