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

5. Muscle Tissue Categories
skeletal
voluntary
striated
smooth
involuntary
no striations
cardiac
intercalated disks

6. Muscle Tissue Categories

7. Skeletal Muscle Organization
endomysium - surround the muscle fiber
fascicle – bundle of muscle fibers
perimysium - bundles groups of muscle fibers to make up a fascicle
epimysium - encloses several fascicles to make up a muscle
aponeurosis and tendons - connect muscle to other tissues

8. Skeletal Muscle Organization

9. 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.

10. Behavioral Properties of Muscle
extensibility–stretch
elasticity–snap back
irritability–respond
contractility–shorten

11. Muscle Tissue Functions
tension and types of skeletal muscle contraction
agonist–moves bone
antagonist–opposes the movement of the agonist

12. Concentric Contraction
agonist contracts, antagonist relaxes

13. Eccentric Contraction
agonist contracts while lengthening, antagonist relaxes
the weight of the barbell causes tension of the bicep muscle causing it to lengthen against gravity

14. Isometric Contraction
both agonist and antagonist contract
no arm movement

15. 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

16. Heat Production
Muscles generate heat when ATP is broken down for energy
Even when not exercising, muscle generate heat which helps maintain our normal body temperature

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

18. Skeletal Muscle
the motor neuron – a nerve that stimulates skeletal muscle
motor unit – a single motor neuron and all the muscles it stimulates

19. Skeletal Muscle Fibers
A muscle fiber is a long, thin cell
Each muscle fiber is composed of myofibrils
2 types of protein filaments that reside in functional units called sarcomeres
Thick filaments = myosin
Thin filaments = actin
Striations are caused by the arrangement of thick and thin filaments within the myofibrils

21. muscle contraction involves the sliding movement of the thin filaments (actin) past the thick filaments (myosin)
sliding continues until the overlapping between the thin & thick filaments is complete.
The myosin heads (cross bridges) interact with active sites on thin filaments making linkages between the thick and thin filament. 
* Remember that in a relaxed muscle cell, overlapping of thick and thin filaments is only slight (i.e. striations).

22. What causes the sliding movement of the actin?
In order for a skeletal muscle to contract, its fibers must first be stimulated by a motor neuron.
The process begins when a motor impulse is initiated by the brain, travels down the spinal cord, into a motor neuron
The axon of the neuron branches into axon terminal which then branch out to individual muscle fibers
Neuromuscular junctions link the axon terminals to the individual muscle fibers.
Synaptic clefts are tiny gaps between the axon terminals and the muscle fibers and are filled with interstitial fluid

23. When the nerve impulse reaches the axon terminal, the neurotransmitter acetylcholine is released
Acetylcholine opens the ion channels, allowing Na+ to enter the muscle fiber and K+ to exit the muscle fiber
Greater amount of sodium ions enter than potassium ions exit, creating action potential
Action potential activates the sarcomeres causing the sliding of the actin over the myosin

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

25. http://www. g-wlearning

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

27. Maximum Tension and Return to Relaxation
action potential always causes entire motor unit muscle fibers to contract

28. Skeletal Muscle Fiber Types
slow-twitch – long distance runners
fast-twitch - sprinters
- type IIa – intermediate in contraction speed
type Iib – contract rapidly and fatigue rapidly

29. Skeletal Muscle Fiber Architecture
parallel fiber arrangements
fusiform – biceps brachii
bundled – rectus abdominis
triangular – pectoralis major
pennate fiber arrangements –
each fiber attaches obliquely to
a central tendon
unipennate – muscles in the hand
bipennate – rectus femoris
multipennate - deltoid

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

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

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

33. Sagittal Plane Movements
flexion
extension
hyperextension
dorsiflexion
plantar flexion

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

35. Transverse Plane Movements
medial rotation
lateral rotation
pronation
supination

36. Multiplanar Movements
circumduction
opposition

37. 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.

38. Head and Neck Muscles

39. Trunk Muscles

40. Upper Limb Muscles

41. Lower Limb Muscles

42. 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

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

44. 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

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

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

47. Muscle Disorders
muscular dystrophy
hernia

48. 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.