2. The Muscular System 5
Lesson 5.1: Muscle Tissue Categories and Functions Lesson 5.2: Skeletal Muscle Actions Lesson 5.3: The Major Skeletal Muscles Lesson 5.4: Common Injuries and Disorders of Muscles

3. Muscle Tissue Categories and Functions
Chapter 5: The Muscular System
Lesson 5.1
Muscle Tissue Categories and Functions

4. Do Now Work on the “Learning the Key Terms” Worksheet.
Chapter 5 Lesson 1 begins on page 155.
You have 10 minutes to complete the worksheet.
Turn the worksheet in to Mr. B when you are finished.

5. Today’s Objectives
Discuss the structural and functional characteristics of each of the three categories of muscle.
Describe the four behavioral characteristics of all muscle tissue.
Explain the roles of agonist and antagonist muscles.

6. Muscle Tissue
Muscle is the only tissue capable of shortening, or contracting.
Muscles control movements of our body, move our eyes, move our food through our digestive system and beats our heart.

7. Muscle Tissue categories functions skeletal smooth cardiac
behavioral properties
tension and types of skeletal muscle contractions

8. Muscle Tissue Categories
Skeletal
Skeletal muscles attach to bones and are largely responsible for body movements.
Skeletal muscles are also known as striated muscles because of their cross-stripes.
Skeletal muscle is also known as voluntary muscle because these muscles are stimulated consciously through nerve activity.

9. Skeletal Muscle Organization
The cell membrane of the muscle fiber is called the sarcolemma.

10. perimysium bundles groups of muscle fibers to make up a fascicle
epimysium encloses several fascicles to make up a muscle
aponeurosis connects muscle to other tissues

11. Skeletal Muscle Organization

12. Smooth Muscle
Smooth muscle fibers are small, spindle shaped, and non-striated.
Involuntary – not under conscious control.
Found on the walls of many internal organs like the stomach, intestines, bladder, and respiratory passages.

13. Cardiac Located solely in the walls of the heart.
Cardiac cells are, involuntary and striated.
Arranged in an interconnected network of figure-eight or spiral-shaped bundles that join at the intercalated disks.

14. Review and Assessment
True or False? 1. Smooth muscle is voluntary. 2. Cardiac muscle has branching fibers. 3. Smooth muscle is multinucleate. 4. Perimysium wraps fascicles to make a muscle. 5. Endomysium surrounds the muscle fibers.

15. Behavioral Properties of Muscle
All muscles have four behavioral characteristics in common:
extensibility– the ability to be stretched.
elasticity– the ability to return to normal length after a stretch.
irritability– the ability to respond to a stimulus.
contractility– the ability to contract or shorten.

16. Muscle Tissue Functions
tension and types of skeletal muscle contraction
agonist– the prime mover, moves bone
antagonist–opposes the movement of the agonist
Example: Bicep Curls. The bicep acts as the agonist and triceps acts as the antagonist.

17. Concentric Contraction
agonist contracts, antagonist relaxes

18. Eccentric Contraction
agonist contracts while lengthening, antagonist relaxes

19. Isometric Contraction
both agonist and antagonist contract

20. Review and Assessment
Match these words with 1–5 below: extensibility, elasticity, irritability, contractility, agonist, antagonist. 1. respond 2. opposes movement 3. stretch 4. shorten 5. causes movement

21. END

22. Exit Ticket Which is not a category of muscle? a. skeletal b. smooth
d. rough
e. cardiac

23. 2) What is the only type of muscle found in the heart. a
2) What is the only type of muscle found in the heart? a. smooth muscle b. eccentric c. cardiac d. sarcolemma

24. 3) When you perform a bicep curl, there are two muscles involved, the bicep and the tricep. Which of muscle is the agonist and which is the antagonist? Agonist = ________________ Antagonist = ________________

25. Skeletal Muscle Actions
Chapter 5: The Muscular System
Lesson 5.2
Skeletal Muscle Actions

26. Do Now Work on the “Learning the Key Terms” Worksheet.
Chapter 5 Lesson 2 begins on page 162.
You have 10 minutes to complete the worksheet.
Turn the worksheet in to Mr. B when you are finished.

27. Today’s Objectives
Describe a motor unit and explain the functional differences between motor units that contain large and small numbers of muscle fibers.
Explain how a nerve impulse generates an action potential in a muscle fiber.
Explain how muscle contraction occurs at the level of the sarcomere.
Describe the differences between slow-twitch and fast-twitch skeletal muscle fibers.
Discuss the concepts of muscular strength, power, and endurance.

28. Skeletal Muscle
Development of tension in a skeletal muscle is influenced by a number of variables.
Signals from the nervous system
The properties of the muscle fibers
The arrangement of fibers within the muscle
the motor unit
skeletal fiber types
muscular strength, power, and endurance

29. The Motor Unit
group of muscle fibers under the control of one motor neuron

30. The Motor Unit
Muscle tissue is not able to develop tension unless stimulated by one or more nerves.
A nerve that stimulates skeletal muscle, which is under voluntary control is called a motor neuron.
A single motor neuron and all of the muscle cells that it stimulates is known as a motor unit.
One motor neuron supplying impulses to a muscle may connect anywhere between 100 to nearly 2000 skeletal muscle fibers.

31. Generating Action Potentials
How does the motor neuron communicate with the muscle cells in the motor unit to stimulate them?
acetylcholine crosses the synaptic cleft at the neuromuscular junction
Acetylcholine causes an influx of sodium ions into the cell and potassium ions out of the cell.
depolarization takes place on muscle fiber
action potential begins as a result of positive sodium ions.

32. Contraction of the Sarcomeres
sarcomeres shorten by actin filaments sliding along myosin filaments

33. Maximum Tension and Return to Relaxation
All-or-None Law
An action potential always causes entire motor unit muscle fibers to contract.
Skeletal motor units develop tension in a twitch-like manner.
The muscles will generate maximum tension very briefly, then immediately go into a resting state.

34. Review and Assessment True or False?
1. An action potential causes one half of the fibers in the motor unit to contract.
2. Acetylcholine crosses the synaptic cleft at the neuromuscular junction.
3. The sarcomeres lengthen by myosin filaments sliding over actin filaments.

35. Skeletal Muscle Fiber Types
Why are some athletes especially good at events or tasks like running marathons or dunking a basketball.
Skeletal muscles are divided into two categories:
slow-twitch
fast-twitch
type IIa
type IIb

36. Slow-Twitch Fibers Fast-Twitch Fibers
Muscle fibers that are found in people that are better suited for endurance type activities.
Fast-Twitch Fibers
Contract much faster compared to slow-twitch.
Type IIa
Intermediate speed
Type Iib
Contract very rapidly
About 1/7 the time required for slow-twitch fibers to contract.
Fatigue rapidly

37. Skeletal Muscle Fiber Architecture
Fiber architecture refers to the ways in which muscle fibers are arranged.
2 Major Categories
parallel fiber arrangements
fusiform
bundled
triangular
pennate fiber arrangements
Unipennate – fibers aligned in one direction to a central tendon
Bipennate – fibers that are attached to a central tendon.
Multipennate – fibers that attach to a central tendon in more than two directions.

38. Muscular Strength Muscular strength can be difficult to assess.
More precise assessment of muscular strength is torque.
Torque is a rotary force that muscles can produce at a joint
the maximum weight you can lift is a measurement of muscular strength
The more toque a muscle generates at a joint, the greater the tendency for movement of the bones.

39. Muscle Power
Muscular power is defined as muscle force multiplied by muscle shortening velocity.
Muscular power generated by several different muscles working collectively.
force x velocity
how fast you can sprint is a measurement of muscle power

40. Muscle Endurance
The ability of a muscle to produce tension over a period of time.
The longer the physical activity is maintained, the greater the required muscular endurance.
muscle tension/time
how far you can run is a measurement of muscle endurance

41. END

42. Exit Ticket A nerve that stimulates muscle is call a(n) ____.
a. Motor Unit
b. Motor Neuron
c. Motor Home
d. Motor Muscle

43. 2) A(n) ___ is an electrical charge that creates tension within a muscle fiber. a. action mark b. action speed c. action potential d. action spark

44. 3)

45. Review and Assessment
Match these words with 1–5 below: muscle endurance, muscular strength, muscle power, Type I, Type IIb. 1. force x velocity 2. muscle tension/time 3. rotary force that muscles can produce at a joint 4. slow twitch, slow fatigue 5. fast twitch, fast fatigue

46. The Major Skeletal Muscles
Chapter 5: The Muscular System
Lesson 5.3
The Major Skeletal Muscles

47. The Major Skeletal Muscles
directional motions
head and neck muscles
trunk muscles
upper limb muscles
lower limb muscles

48. Skeletal Muscle Attachments
origin
fixed end of a muscle
insertion
movable end of a muscle

49. Sagittal Plane Movements
flexion
extension
hyperextension
dorsiflexion
plantar flexion

50. Frontal Plane Movements
abduction
adduction
inversion
eversion
radial deviation
ulnar deviation

51. Transverse Plane Movements
medial rotation
lateral rotation
pronation
supination

52. Multiplanar Movements
circumduction
opposition

53. Review and Assessment
True or False? 1. Circumduction is a multiple plane movement. 2. Supination is a multiple plane movement. 3. The insertion is the fixed end of a muscle. 4. Extension is a sagittal plane movement. 5. Adduction is a frontal plane movement.

54. Head and Neck Muscles

55. Trunk Muscles

56. Upper Limb Muscles

57. Lower Limb Muscles

58. Review and Assessment
Match these words with 1–4 below: head, trunk, upper limb, lower limb. 1. temporalis 2. brachioradialis 3. external oblique 4. biceps femoris

59. Common Injuries and Disorders of Muscles
Chapter 5: The Muscular System
Lesson 5.4
Common Injuries and Disorders of Muscles

60. Muscle Injuries strain–overstretched muscle contusion–bruised muscle
grade I, II, III
contusion–bruised muscle
myositis ossificans
cramps–spasming muscle
delayed onset muscle soreness–tear

61. Tendon Injuries tendinitis–inflamed tendon
tendinosis–degeneration of a tendon
Val Thoermer/Shutterstock.com

62. Joint Injuries rotational injury at shoulder overuse of elbow
shin splints
whiplash

63. Muscle Disorders
muscular dystrophy
hernia

64. Review and Assessment
True or False? 1. Tendinitis is muscle strain. 2. A contusion is a bruise. 3. Whiplash is a joint injury. 4. A hernia is a tendon injury. 5. A strain is an over stretch of a tendon.