1. Muscular System

2. Introduction Over 600 muscles make up the muscular system
MUSCLES ARE =
Bundles of muscle fibers that are held together by connective tissue

3. Characteristics of Muscles
Excitability/Irritability =
ability to respond to a stimulus such as a nerve impulse
Contractibility =
When muscle fibers are stimulated by nerves they contract = become short and thick
This causes movement

4. Characteristics of Muscles
Extensibility =
Ability to be stretched
Elasticity =
Allows the muscle to return to its original shape after it has contracted or stretched

5. Kinds of Muscles CARDIAC Form the walls of the heart
Contract to circulate blood
Involuntary = function without conscious thought or control

6. Kinds of Muscles VISERAL/SMOOTH
Found in the internal organs of the body (digestive system, respiratory system, blood vessels, and eyes)
Contract to cause movement in these systems
Involuntary

7. Kinds of Muscles SKELETAL Attached to bones
Voluntary = person has control over their action
Will focus on SKELETAL muscles in the following sections

9. Function of Skeletal Muscles
Attach to bones to provide voluntary movement
Produce heat and energy
Help maintain posture
Protect internal organs

11. DID YOU KNOW?
You need 17 muscles to smile, but you need 43 muscles to frown
Every 2000 frowns create one wrinkle

12. Major Muscles of the Body
Masseter
Located = cheek to lower jaw
Biting and chewing
Sternocleidomastoid
Located = Side of the neck
Turns and flexes the head

13. Major Muscles of the Body
Trapezius
Located = Upper back and neck
Extends head, moves shoulders
Deltoid
Located = Shoulder
Abducts arm, is an injection site

14. Major Muscles of the Body
Biceps brachii
Located = Upper arm
Flexes lower arm
Triceps brachii
Extends lower arm
Pectoralis major
Located = Upper chest
Adducts and flexes upper arm

15. Major Muscles of the Body
Intercostals
Located between ribs
Moves ribs for breathing
Rectus abdominus
Located = anterior ribs to pubis (pelvis)
Compresses abdomen
Latissimus dorsi
Located = posterior spine around to chest
Extends and adducts upper arms

17. Major Muscles of the Body
Gluteus maximus
Located = buttocks
Extends thigh, is an injection site
Sartorius
Located = front of thigh, runs diagonal
Abducts thigh, flexes leg
Tibialis anterior
Located = front of lower leg (tibia side)
Flexes and inverts the foot

19. Quadriceps Muscles
Group of four muscles located in the anterior thigh.
Rectus Femoris
Vastus Medialis
Vastus Lateralis
Vastus Intermedialis.

20. Major Muscles of the Body
Soleus
Located = posterior lower leg
Gastrocnemius
Flexes the foot

21. Methods of Attachment Tendon Strong, tough connective tissue cord
Examples: Achilles tendon, which attaches the gastrocnemius muscle on the calf of the leg to the heel bone

22. Images of tendons

23. Methods of Attachment Fascia Tough, sheet like membrane
Covers and protects the tissue
Example: lumbodorsal fascia, which surrounds the deep muscles of the trunk and back

24. Images of Fascia

25. Methods of Attachment ORIGIN and INSERTION
When muscle attach to bones, one end becomes the origin and one end becomes the insertion
ORIGIN = end that does not move
INSERTION = end that moves when muscle contracts

26. Movements of Muscles ADDUCTION Moving a body part toward the midline
ADD to the body

27. Movements of Muscles ABDUCTION
Moving a body part away from the midline
Opposite of ADD

28. Movements of Muscles FLEXION
Decrease the angle between two bones or the bending of a body part

29. Movements of Muscles EXTENSION
Increasing the angle between two bones or straightening a body part

30. Movements of Muscles ROTATION CIRCUMDUCTION
Turning a body part around its own axis
Example
Turning head side to side
Turning (rotating) wrist
CIRCUMDUCTION
Moving in a circle at a joint
Example = swinging the arm in a circle

31. Muscle Tone MUSCLE TONE =
Muscles are partially contracted at all times even though they may not be in use
This is also called a “state of readiness to act”

32. Loss of Muscle Tone This is called ATROPHY or WASTING AWAY
This can occur in severe illnesses such as paralysis
Occurs when muscles are not used for a long period of time
This is called ATROPHY or WASTING AWAY

33. Contractures Lack of use can also result in a CONTRACTURE
This is a severe tightening of a flexor muscle
Results in bending of a joint
FOOT DROP is a common contracture
Also fingers, wrists, and knees, as well as other joints, can be affected

34. Contractures

35. Muscle spasms usually occur in the legs or feet
sudden painful, involuntary muscle contractions
usually occur in the legs or feet
causes are overexertion, low electrolyte levels, or poor circulation
gentle pressure and stretching of muscle are used to relieve the spasm

36. Strain Frequent sites include the back, arms, legs
is an overstretching of or injury to a muscle and/or tendon
Frequent sites include the back, arms, legs
prolonged or sudden muscle exertion is usually the cause.
symptoms are muscle pain, swelling and limited movement
Tx- rest, muscle relaxants, or pain medications, elevating the extremity and alternating hot & cold applications

37. Diseases of the Muscles
Fibromyalgia
Chronic, widespread pain experienced in specific muscle sites (tender points)
Etiology (cause) is unknown but stress, weather, and poor physical fitness seems to affect this condition
80% - 90% diagnosed are women

38. Diseases of the Muscles
Fibromyalgia - Symptoms
Muscle stiffness
Numbness or tingling in the arms or legs
Fatigue
Sleep disturbances,
Headaches
Depression

39. Diseases of the Muscles
Fibromyalgia
Treatment is directed toward pain relief
Physical therapy
Massage therapy
Exercise
Stress reduction techniques
Medication to relax muscles
Medication for pain
Medication for sleep and depression

40. Diseases of the Muscles
Muscular Dystrophy
Group of inherited diseases
Leads to chronic progressive muscle atrophy
Muscles shrink in size and lose strength
Usually appears in early childhood
Most types result in total disability and early death

41. Muscular Dystrophy
Treatment = physical therapy to slow progression of the disease, prevent contractures
No known cure or drug treatment

42. Tetanus
Infectious disease caused by contamination of wounds from the bacteria Clostridium tetani
Spores produced by the bacteria live in the soil and animal feces
The usual locations for the bacteria to enter the body are puncture wounds, such as those caused by rusty nails, splinters or insect bites, burns or IV drug sites.
Tetanus is acquired through contact with the environment; it is not transmitted from person to person

43. Tetanus Tetanus results in severe, uncontrollable muscle spasms.
Lockjaw – severe spasms cause the jaw to “lock”
Muscles used to breathe can spasm possibly leading to death

44. Treatment / Prevention:
Tetanus
Treatment / Prevention:
Vaccinations: series of 5 shots starting at 2 months old – DTaP. Tetanus booster every 10 years
Wound care
Antibiotics

45. REVIEW
What is the difference between voluntary and involuntary muscles?
What is the action of cardiac, visceral/smooth, and skeletal muscles?
How does a tendon differ from a fascia?
What is the origin and insertion of a muscle?

46. REVIEW
What happens to muscle tone in a severe illness such as paralysis?
What is a contracture?
What is fibromyalgia?
What is muscular dystrophy?