1. Muscular System
Chapter 16
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2. Muscular System Muscles responsible for all types of body movement
3 basic muscle types found in body:
Cardiac muscle
Smooth muscle
Skeletal muscle

3. Muscle Types

4. Cardiac Muscle Only found in heart Striated and branched Involuntary
Membranes of adjacent cells fused at intercalated discs

5. Cardiac Muscle

6. Smooth Muscle Small and spindle shaped
Unmarked by an distinctive striations
aka Visceral
Involuntary
Unattached to bones
Act slowly
Do not tire easily
Can remain contracted for long time
Actions controlled by autonomic nervous system
Found in wall of internal organs
Stomach
Intestines
Uterus
Blood vessels

7. Smooth Muscle

8. Sphincter Muscle aka Dilator Special circular muscles
Open/close to control passages of substances
Found:
Esophagus-stomach
Stomach-small intestine
Walls of anus, urethra, mouth

9. Sphincter Muscle
Explain acid reflux

10. Skeletal Muscle Attached to bone of skeleton Striped or striated
Have cross-bandings of alternating light/dark bands running perpendicular to length of muscle
aka Voluntary muscle
Movement to limbs
Contract quickly
Fatigue easily
Lack ability to remain contracted for prolong periods

11. Skeletal Muscle

12. Muscle Types

13. Properties of Muscle Contractility Excitability Extensibility
Ability to shorten, reducing distance between two parts
Excitability
Ability to respond to stimuli
Extensibility
Ability to lengthen; increase distance between two parts
Elasticity
Ability to return to normal shape

14. Structure of a Skeletal Muscle

15. Sarcomere
Sliding filament theory:

16. Skeletal Muscle Function Produce movement Maintain posture
Stabilize joints
Generate heat
Site of muscle attachments
Bones
Cartilage
Connective tissue coverings
More than 650 diff muscles in body; for these muscle to produce movement it must be able to exert force upon moveable object
Muscle attach to bone, bones connected by joints, skeletal muscle bridge these joints, R. skeletal muscle contracts bone to which it attached will move

17. Naming Skeletal Muscles
Direction of muscle fibers
Location of muscle
Size
Number of origins
Shape
Location of muscle origin and/or insertion
Action

18. Direction of Muscle Fibers
Relative to midline
RECTUS = parallel to midline
Rectus Abdominus
TRANSVERSE = perpendicular to midline
Transverse Abdominus
OBLIQUE = diagonal to midline
External Oblique

19. Location Structure near which muscle is found
FRONTALIS = near frontal bone
OCCIPITALIS = near occipital bone

20. Size Relative size of muscle MAXIMUS = largest MEDIUS = middle
Gluteus Maximus
MEDIUS = middle
Gluteus Medius
MINIMUS = smallest
Gluteus Minimus
LONGUS = longest
Fibrularis Longus
BREVIS = short
Fibrularis Brevis
TERTIUS = shortest
Fibularis Tertius

21. Number of Origins Number of tendons of origin BICEPS = two
Biceps Brachii
Biceps Femoris
TRICEPS = three
Triceps Brachii
QUADRICEPS = four
Quadriceps Femoris

22. Shape Relative shape of the muscle DELTOID = triangular shape
TRAPEZIUS = trapezoid shape
SERRATUS = saw-toothed
RHOMBOIDEUS = rhomboid shape
TERES = round

23. Origin & Insertion Origin—attachment to an immoveable bone
Insertion—attachment to a moveable bone
ILIO COSTALIS = attaches to the ilium & ribs (costal = ribs)
Belly—the central part of a muscle
Belly: central body of muscle

24. Origin & Insertion Biceps Brachii Triceps
O: coracoid process, supraglenoid tubercle
I: radial tuberosity
Triceps
O: infraglenoid tubercle of scapula, posterior humerus
I: olecranon process of ulna
O both of scapula

25. ORIGIN Upper half of lateral shaft of tibia and interosseous membrane
BICEPS BRACHII
TIBIALIS ANTERIOR
ORIGIN Upper half of lateral shaft of tibia and interosseous membrane
INSERTION Inferomedial aspect of medial cuneiform and base of 1st metatarsal
ACTION Extends and inverts foot at ankle. Holds up medial longitudinal arch of foot
NERVE Deep peroneal nerve (L4, 5)
ORIGIN Long head:supraglenoid tubercle of scapula. Short head: coracoid process of scapula with coracobrachialis
INSERTION posterior border of bicipital tuberosity of radius (over bursa) and bicipital aponeurosis to deep fascia and subcutaneous ulna
ACTION Supinates forearm, flexes elbow, weakly flexes shoulder
NERVE Musculocutaneous nerve (C5, 6) (from lateral cord)

26. Action Name Action Example FLEXOR Decrease angle at a joint
Flexor Carpi Radialis
EXTENSOR
Increase angle at a joint
Extensor Carpi Ulnaris
ABDUCTOR
Move bone away from midline
Abductor Pollicis Longus
ADDUCTOR
Move bone toward midline
Adductor Longus
LEVATOR
Produce upward movement
Levator Scapulae
DEPRESSOR
Produce downward movement
Depressor Labii Inferioris
SUPINATOR
Turn palm upward/anterior
Supinator
PRONATOR
Turn palm downward/posterior
Pronator Teres

27. Types of Muscle—Actions
Prime mover (agonist)—muscle with the major responsibility for certain movement
Antagonist—muscle that opposes or reverses a prime mover
Synergist—muscle that aids a prime mover in a movement and helps prevent rotation
Fixator—stabilizes the origin of a prime mover
Arranged in pairs

28. Muscle Injuries

29. Acute Muscle Injuries Contusions Strains Tendon Injuries Cramps/spasms
Overexertional problems

30. Contusion
Bruise
Sudden traumatic blow to body (severe compression force)
Not penetrate skin
Usually injury to blood vessels
Superficial, deep, or hemorrhage
Hematoma (blood tumor): formation caused by pooling of blood and fluid w/in a tissue space
Speed of healing depends on tissue damage and internal bleeding
Bone bruise: contusion penetrates to skeletal structures

31. Contusion Symptoms: Treatment: PRICE, stretch
Swelling
Point tenderness
Redness
Ecchymosis
Treatment: PRICE, stretch
Complication: myositis ossificans—calcification of the muscle to bone

32. Strains
Stretch, tear, or rip in the muscle or adjacent tissue (fascia or muscle tendon)
Severe tension force
Common sites:
Hamstring
Quadriceps
Hip flexor
Biceps
Latissimus dorsi

33. Strains Grade 1 Grade 2 Grade 3 Some muscle fibers stretched or torn
Some tenderness/pain with AROM
Grade 2
Number of muscle fibers torn
Active contraction of muscle extremely painful
Grade 3
Complete rupture of muscle (MTJ)
Significant impairment or total loss of movement
Grade 1: movement painful but full range possible
Grade 2: usually depression or divot can be felt; some swelling my occur b/c of capillary bleeding; discoloration possible
Grade 3: initial intense pain but quickly diminishes b/c complete nerve fiber separation

34. Strains Prevention Signs & Symptoms Proper warm-up Localized swelling
Stretch
Proper mechanics
Proper cool-down/ stretch
Proper nutrition & hydration
Signs & Symptoms
Localized swelling
Cramping
Inflammation
Loss of function
Pain
General weakness
Discoloration

35. Strains Treatment Severe— Reduce swelling & pain NSAIDs Hard cast
Surgery

36. Tendon Injuries— Anatomy of a Tendon
Extension of muscle
Musculotendinous junction
Contains wavy parallel collagenous fibers organized in bundles surrounded by gelatinous material that decreases friction
Connects muscle to bone
Concentrates pulling forces in limited area
Not as elastic
May run through sheath
Tendons can produce and maintain a pull from 8700 to pounds per square inch; when tendon is loaded by tension, wavy collagenous fibers straighten in direction of load; when tension is released, collagen returns to original shape; collagen fibers will break if physiological limits have been reached

37. Tendon Injuries
Tears commonly at muscle belly, musculotendinous junction, or bony attachment
Tendon double strength muscle it serves
Tendonitis: inflammation of tendon-muscle attachments, tendons, or both
Tenosynovitis: inflammation of synovial sheath surrounding tendon

38. Tendonitis Signs & Symptoms Treatment Prevention Pain & inflammation
Worse with movement
Worse at night
Treatment
PRICE
NSAIDs
Ultrasound therapy
Rehabilitation
Prevention
Slowly increase intensity & type of exercise
Don’t try to do more than ready for
Proper warm-up & stretch

39. Cramps/Spasms
Cramp: painful involuntary contraction of a skeletal muscle or muscle group
Spasm: reflex reaction caused by trauma of musculoskeletal system
Cramps attributed to lack of water or other electrolyte imbalance in relation to muscle fatigue
→ Can lead to muscle and tendon injuries

40. Overexertion Muscle Injuries
Soreness
Muscular pain from strenuous muscular exercise
DOMS
Preventative
Treatment
Stiffness
Occurs when muscles worked hard for long period of time
Fluids that collect in muscle during/after activity absorbed in bloodstream slowly
Result in swollen, shorter, thicker muscle that resist stretching
AOMS: acute-onset muscle soreness; occurs immediately after exercise
DOMS: delayed-onset muscle soreness; most intense hours after activity then gradually subsides so that muscle symptom-free after 3-4 days; small tears in muscle tissue; disruption of connective tissue that holds muscle tendon fibers together; prevented: beginning exercise at moderate level and gradually increasing intensity over time; tx: static or PNF stretching, ice applied w/in first hrs

41. Chronic Musculotendinous Injuries
Myositis: inflammation of muscle tissue
Fasciitis: inflammation of muscle fascia
Fascia supports and separates muscle
Tendinitis
Tenosynovitis

42. Chronic Musculotendinous Injuries
Ectopic Calcification
Myositis ossificans
Occur in muscle directly overlies bone
Atrophy
Wasting away of muscle tissue
Immobilization of body part; loss of nerve simulation
Contracture
Abnormal shortening of muscle tissue
Resistance to passive stretch
Associated with joint developed resisting scar tissue
Ectopic: located in place diff than normal

43. Critical Thinking
Football player who plays wide receiver sustains repeated blows his to left quadriceps muscle.
What should he be most concerned about?
What type of injury could be sustained from repeated compressive forces to the quad muscle?