1. 4
Musculoskeletal System

2. Muscular System at a Glance
Functions of muscular system
Hold body erect and produce movement
Move body fluids through the ducts and tubes of other systems
Move food through digestive system
Produce body heat – 85% of our heat comes from muscle activity

3. Muscular System at a Glance
Organs of muscular system
Muscles – made up of long slender cells bound together by connective tissue – body has >600 muscles
Fascia – is the connective tissue binding or separating muscle or muscle groups
Tendons – narrow band of non-elastic, dense fibrous connective tissue, attaching muscle to a bone by inserting into periosteum

4. Types of Muscles
Skeletal muscle Smooth muscle Cardiac muscle

5. Types of Muscles Voluntary muscles
Consciously choose to contract the muscle
Skeletal muscles are voluntary muscles
Involuntary muscles
Under control of subconscious brain
Smooth, or visceral muscles and cardiac muscles

6. Produce voluntary movement of skeleton
Skeletal Muscles
Attached to bones
Produce voluntary movement of skeleton
Also referred to as striated muscle
Looks striped under microscope

7. Skeletal Muscles

8. Smooth muscle Associated with internal organs
Also called visceral muscle
Stomach
Respiratory airways
Blood vessels
Called smooth because has no microscopic stripes
Produces involuntary movement of these organs

9. Smooth Muscles

10. Also called the myocardium Makes up the walls of the heart Involuntary
Cardiac muscle
Also called the myocardium
Makes up the walls of the heart
Involuntary

11. Cardiac Muscle

12. Characteristics of the three types of muscles.

13. Muscle innervation
The stimulation of a muscle by an impulse transmitted by a motor nerve Neuromuscular- the relationship between a nerve and a muscle (neur/o+muscul+ar)

14. Antagonistic- working in opposition of each other
Antagonistic pairs
Antagonistic- working in opposition of each other
Pair of muscles arranged around a joint
Produce opposite actions
While one contracts the other relaxes
agonist-muscle that is contracting
Antagonist-muscle that is relaxing

15. Contrasting muscle motion
Abduction-movement away from the midline Adduction-movement towards the midline Flexion- decreasing the angle between two bones Extension- increasing the angle between two bones Rotation- circular movement around an axis Supination- rotating the arm in forward or upward position Pronation- rotating the arm in a downward or backward position Dorsiflexion- bending the foot in a upward position Plantar flexion- bending the foot in a downward position Inversion- movement of the foot in a inward position Eversion-movement of the foot in a outward position

16. Figure 4.4, p 104 Abduction and adduction of the shoulder joint.

17. Figure 4.5 Flexion and extension of the elbow joint.

18. Figure 4.8 Dorsiflexion (A) and plantar flexion (B) of the ankle joint.

19. Eversion and inversion of the foot.

20. Pronation and supination of the forearm.

21. Pathology of the muscular system
Fibers, fascia & tendons
Fasciitis – inflammation of the fascia
Fibromyalgia – chronic condition – bone or muscle pain, fatigue, causing progressive weakness
Tenosynovitis - inflammation of the sheath around a tendon
Tendinitis/tendonitis – inflammation of a tendon caused by over-use of a joint
Chronic fatigue syndrome – generalized, debilitating disorder not relieved by bed rest

22. Pathology of the muscular system
Muscle Disorders
Adhesion – fibrous tissue band holding structures together abnormally
Atrophy – muscle wasting
Myalgia – muscle pain

23. Pathology of the muscular system
Muscle movement
Ataxia – shaky unsteady movement due to lack of coordination
Contracture – permanent tightening of the muscle, fascia, tendons, ligaments or skin due to connective tissue changes – ie scarring
Intermittent claudication – pain in leg muscles during exercise, relieved by rest – due to poor circulation (associated with PVD)
Spasm – sudden involuntary contraction of a muscle
Cramp – painful localized spasm

24. Pathology of the muscular system
Muscular dystrophy
Group of more than 30 genetic disorders characterized by progressive weakness and atrophy of muscles controlling movement
Two most common:
Duchenne muscular dystrophy – most common form in kids, boys more than girls, onset 3-5 yrs, rapid progression to 12 yrs
Becker muscular dystrophy – less severe form of duchenne

25. Problems of the muscular system
Carpel tunnel syndrome- repetitive motion disorder; compression of finger tendons and median nerve as they pass through carpal tunnel of the wrist ganglion cyst- cyst on tendon sheath; usually on hand, wrist, or ankle Epicodylitis- inflammation of the tissues surrounding the elbow Plantar fasicitis- inflammation of the plantar fascia Strain- injury to a specific tendon Shin splint- injury to the tibialis anterior.