1. MUSCLES

4. THREE TYPES OF MUSCLES
Cardiac
Smooth
Skeletal

5. PROPERTIES OF MUSCLES Ability to contract
Extensibility – ability to be stretched
Elasticity – ability to return it its original length
Irritability – ability to receive and repord to stimuli

6. TERMS
Myo – muscle
Sacro - flesh
Muscle fiber – individual muscle cell

7. SKELETAL MUSCLE
Bundles of muscle fibers that are package to form the organ

8. CONNECTIVE TISSUE OF SKELETAL MUSCLE
Warps or bundles up muscle fibers
Provides support and strength to muscle
Keeps muscles form being ripped apart under tremendous forces

9. PARTS OF MUSCLE FIBER
Endomysium – connective tissue sheath that wraps each individual muscle fiber
Perimysium – coarser fibrous membrane that surrounds several muscle fibers
Fascicle – bundle of fibers
Epimysium – tougher layer of connective tissue that covers many fascicles – covers entire muscle –

11. Epimysium

12. EPIMYSIUM Ends of it will blend into Tendons
Aponeurosis – attaches muscles indirectly to bones, cartilage or connective tissue

13. TERMS Origin – muscle attaches to stationary bone
Insertion – muscle attaches to bone that moves
When muscle contracts, one bone moves and the other is stationary

14. MOVEMENT OF BODY PARTS Body part is moved by a group of muscles:
Prime mover
Synergists
fixators
Antagonists - pairs that work opposite

16. Tendon- connective tissue that attaches muscle to bone
Very tough – thus is gives muscles durability
Does not wear out next to rough projections of bone
Usually tendon that passes over bony joint and not muscle

17. Muscles are arrange differently depending on where they are located

18. FUNCTIONS OF MUSCLES PRODUCE MOVEMENT MAINTAIN POSTURE
STABALIZE JOINTS
GENERATE BODY HEAT

19. COMPONENTS OF SKELETAL MUSCLE
Saroclemma
Sarcoplasmic reticulum
Sarcoplasm
sarcomere

20. Parts of Sarcomere
Myofibril (fibril) 0 complex organelle composed of bundles of myofilaments. Fill the cytoplasm of muscles.
Myofilaments – threadlike filaments – has alternating light and dark bonds - composed of 2 key proteins
Actin
myosin

21. PROTEINS OF MYOFILAMENTS

22. myosin Thick protein filament
Contains ATPase – splits ATP to generate the energy needed for muscle contraction
Extends the entire length of the dark A boand
Midpart is smooth
End are studded with projections called myosin heads or cross bridges

23. actin Thin filament Made up of contractile protein
Actin is anchored to the Z line
I band – 2 adjacent sarcomeres and contains only actin
Actin does not extend into the middle of the A band which makes the H zone appear lighter

24. When contraction occurs – actin filament slide toward each other into the center of the sarcomeres
Light zone disappears because actin and myosin totally overlap

25. SLIDING FILAMENT THEORY

28. Relaxed muscle has regulatory proteins on the actin to prevent myosin from bending

29. AP stimulates the sarcolemma of the muscle
Ca ions are released from the sarcoplasmic reticulum
Ca ions bind to the regulatory proteins on the actin
This changes the shape and location of the regulatory proteins on the actin

30. Binding sites on the actin become exposes
Myosin heads attach to the binding sites on the actin (called cross bridge formation)
When heads attach, they snap toward center of sarcomere (power stroke)
This pulls actin toward center of sarcomere
ATP provides Energy to release and recock myosin heads

32. Cross bridge is broken
Myosin head reattaches to another site further along the actin (another cross bridge and power stroke)
This is called walking of the myosin
AP ends
Ca ions reabsorbed by sarcoplasmic reticulum

33. Regulatory proteins return to their original shape and position
Myosin can’t attach
Muscle relaxes

34. MACROSCOPIC CONTRACTION
Muscle cell - all or none response
Thousands of muscle cells form the organ
Skeletal muscle’s response is graded – different degrees of contraction

35. 2 WAYS TO PRODUCE GRADED REPONSE
1 - Changing the speed of muscle stimulation
2 - Changing the number of muscle cells stimulated

36. Pat vs. slap
If few cells (motor units) are stimulated, then the contraction of the muscle is slight.
As more cells are stimulated, the grater the contraction

37. THE 5 GOLDEN RULES OF SKELETAL MUSCLE ACTIVITY

38. All muscles cross at least 1 joint
The bulk of the muscle lies proximal to the joint crossed.
All muscles have at least 2 attachments
Muscles can only pull, they never push
During contraction muscle moves toward the origion

39. DISEASES Tetanus Muscular dystrophy Duchenne muscular dystrophy
Problems associated with steroid use.
What is the proper way to lift a heavy object?

40. Muscle twitch
Bell’s palsy
Inguinal hernia
Muscle cramp

41. Pictures to label