1. The Muscular System

2. Muscle Facts 45% body weight Over 600 muscles
Muscles are bundles of muscle fibers held together by connective tissue
Takes 17 muscles to smile, 43 to frown, every 2000 frowns creates a wrinkle

3. 3 Types of Muscle Skeletal Smooth Cardiac
Application: Make a trifold and in each column draw and describe the 3 types of muscle. Include where located and how controlled (voluntary vs. involuntary)

4. Skeletal Muscle Attach to bones of skeleton Striped or striated
Also called voluntary
Bundles of muscle cells
Each cell is multinucleate
Fleshy body parts, provide movement
Most attach to bones: facial to skin

5. 4 Functions of Skeletal Muscles
Attach to bones to provide voluntary movement and involuntary movement
Produce heat and energy for the body
Help maintain posture
Protect internal organs

6. Smooth (Visceral) Muscle
Small, short, spindle shaped
1 nucleus located in center of cell
Do not have any striations – appear smooth
Unattached to bones, act slowly, do not tire easily, can remain contracted for a long time
INVOLUNTARY
Walls of internal organs (except heart)

7. Cardiac Muscle Found only in heart
Branched, striated, interconnected chains
1 nucleus
Involuntary
No independent cell contraction
Requires constant oxygen supply
> 30 seconds w/o oxygen – cells die

8. 3 types of muscle cell video

9. 4 Characteristics of Muscle
Excitability: ability to respond to a stimulus such as a nerve impulse
Contractibility: muscle fibers stimulated by nerves contract or become short and thick causing movement
Extensibility: ability to be stretched
Elasticity: allows muscle to return to its original shape after it has contracted or stretched

10. Muscle attachments: Muscles are attached at both ends
Can be attached to bones, ligaments, cartilage, tendons, skin, to other muscles
Fascia: touch, sheetlike membrane that covers and protects

11. Origin vs. Insertion
When muscle attaches to bone, end that does not move is called the origin
End that moves when muscle contracts is insertion
Belly – central body of muscle

12. Muscle Action/Movement
Using DHO, define the following:
Adduction
Abduction
Flexion
Extension
Rotation
Circumduction

13. Adduction: moving a body part toward the midline
Abduction: moving a body part away from the midline
Flexion: decreasing the angle between 2 bones, bending a body part
Extension: increasing the angle between 2 bones, straightening a body part
Rotation: turning a body part around its own axis (head)
Circumduction: moving in a circle at a joint (swinging arm)

14. What is muscle tone: State of partial contraction
State of readiness to act
Muscles are partially contracted at all times
Loss of muscle tone occurs in paralysis
Lack of use causes atrophy (shrink)
Contracture – severe tightening of flexor muscle

15. Contractures

16. Application:
Using Body Structures and Functions, explain how the muscles are a source of heat and energy. Be sure to include how ATP is involved in this process.

17. Muscle need energy to function Adenosine Triphosphate - ATP – major source of energy Cells bring in oxygen, glucose, etc Muscle stimulated ATP released producing heat for our body and energy for muscle contracting

18. During process of ATP release creating energy/heat: lactic acid (byproduct of cellular metabolism) builds up
Increased lactic acid levels in muscles cause muscle fatigue
WHY? Vigorous exercise – blood can’t transport enough oxygen to complete oxidation of glucose in muscles – muscles contract anaerobically
So why does resting help a cramp?

19. Fibromyalgia Chronic, widespread muscular pain
S&S: muscle stiffness, numbness, tingling in arms or legs, fatigue, sleep disturbances, memory and mood issues, headaches and depression
Causes:unknown
Tx: pain relief, PT, massage, exercise, stress reduction, pain meds, muscle relaxers

20. Muscular Dystrophy
A group of inherited diseases that lead to chronic,progressive muscle atrophy. Usually begins in childhood
S&S: muscle atrophy including heart and respiratory system muscles leading to total disability and early death.
Causes: inherited- genetic defect
Tx: PT

21. Living with Muscular Dystrophy

22. Myasthenia Gravis
Chronic condition where nerve impulses are not properly transmitted to the muscles leading to progressive muscle weakness and paralysis.
S&S: eye weakness, drooping eyelids, altered speech, difficulty swallowing or chewing
Causes: unknown but may be autoimmune
Tx: no cure but cholinesterase inhibitors seems to increase communication bw muscles and nerves, corticosteroids limit antibody production, immunosuppressants, plasmapharesis

23. Muscle Spasms
also known as cramps. Sudden, painful, involuntary muscle contractions
S&S: cramps
Causes: overexertion, dehydration, low electrolyte levels, poor circulation
TX: gentle pressure and massage, stretching of muscle to relieve spasm

24. Muscle Strain Overstretching of or an injury to a muscle or tendon
S&S: myalgia, swelling, limited movement
Causes: prolonged or sudden exertion
Tx: rest, muscle relaxers, pain meds, ibuprofen, elevation, compression, hot/cold applications

25. Tennis Elbow
Inflammation of the tendon that connects the arm to the elbow
S&S: pain at elbow
Causes: repetitive use of arm
Tx: pain relief, ice packs

26. Shin Splints Injury to muscle tendon in front of shin
S&S: pain in shin
Causes: running/jogging
Tx: proper fitting shoes with arch support

27. Rotator Cuff Disease
Inflammation of group of tendons that surround shoulder joint
S&S: repetitive swinging action of joint
Causes: pain at shoulder
Tx: rest, PT, surgery

28. Rotator Cuff Surgery
3 Signs of Rotator Cuff injury by PT