1. MUSCLE TISSUE

2. Movement of the body is important for survival.
A few short facts:
Movement of the body is important for survival.
There are more than 600 muscles in the human body
40% - 50% of body weight
Muscles pulling on bones is responsible for movement
The way muscle is grouped and their relationship to joints determines the type of movement they create

3. Connective tissue surrounding muscles tissue
Endomysium – around muscle cells or fibers
Perimysium - hold groups of muscle fibers together
Epimysium – covers the entire muscle group
All these layers attach the muscle to the bone so the muscle pulls as one unit

4. Broad flat sheet of connective tissue that covers muscle groups called
aponeurosis usually merges with fibrous wrappings of another muscle
You will see that clearly on the cat

5. Structure of skeletal muscle
Size, shape and fiber arrangement
The movement and strength of a muscle is determined by its overall shape and type of attachment

6. Vary in length but are strap-like
Parallel
Vary in length but are strap-like
Fibers are running parallel to each other

7. Wide point of attachment to a small point of attachment
Convergent
Wide point of attachment to a small point of attachment

8. Pennate
Feather-like

9. Fusiform
Close to parallel in the middle or belly of muscle but converge to tendon at both ends

10. Between their points of attachments
Spiral
Fibers that twist
Between their points of attachments

11. Circle around a body tube or opening
Circular
Called sphincters
Circle around a body tube or opening

12. Most muscles span at least one joint, some span two joints

13. Names for the attachments of muscles Origin
The point of attachment that does not move when the muscle contracts
Insertion
The point of attachment that moves when the muscle contracts

14. Skeletal Muscles act in groups Some contract while others relax

15. Prime mover Antagonists Agonist
The muscle or group of muscles that directly performs a specific movement
Antagonists
Muscles that directly oppose the prime mover
The antagonists is relaxed when the prime mover is contracting
Provides precision and control during the contraction of the prime mover
the name antagonists is misleading

16. Synergists
Muscles that contract at the same time as the prime mover
Complement the prime mover actions to make a more effective movement
Fixator
Joint stabilizers
Maintain posture or balance
Example would be the muscles in the front and back of the thigh stabilizing the leg when standing

17. Most movements are very complex
Most muscles function as prime mover, antagonists synergists or fixators at some time depending on the movement

18. A prime mover in flexing arm at the elbow is……. The Antagonist is…….
Is it different when the arm is above the head?

19. Do you remember levers, which one is which?
In the body: all movement is made by 3rd class levers. The muscle insertion is very close to the joint being moved.
The movement is strong but it is also fast
In the body: face is the load, the c2 vertebrae is the fulcrum, the muscles of the neck and upper back is the pull
In the body: some anatomists do not agree. Some say raising up on one’s toes is a 2nd class lever.
Fulcrum is the toes point of contact with the ground, load is the ankle, pull is the gastrocnemius muscle in the lower leg
Opening mouth against resistance
Figure 10-4C. Lever classes. A, Class I: fulcrum (F) between the load (L) and force or pull (P); B, Class II: load (L) between the fulcrum (F) and force or pull (P); C, Class III: force or pull (P) between the fulcrum (F) and the load (L). The lever rod is yellow in each.

20. So……

21. Muscle doing the moving
When a body part is moved the muscle moving that part usually does not lie over the part being moved.
The muscle doing the moving is usually proximal to the part being m0ved
Muscle doing the moving
Body part being moved

22. Before we go to the lab to look at the cats we need to understand how muscles are named.
If we understand how they are named the language isn’t as foreign as it appears at first glance

23. Location Function brachialis - arm, upper arm gluteus - buttock
adductor – moving the leg toward the midline of the body
abductor – moving the part away from the midline of the body

24. Number of Heads or Divisions
Shape
deltoid – triangular
Direction of Fibers
rectus – meaning straight
Number of Heads or Divisions
“cep” - means head
triceps, quadriceps
biceps bracahii

25. Point of Attachment Size of Muscle origin and/or insertion points
Sternocleidomastoid
Size of Muscle
Size compared to size of nearby muscles
gluteus maximus, gluteus medius, gluteus minimus

26. When you and your lab partner start looking at the cat keep these things in mind
Use the larger muscles as a guide
Try to figure out to which bones the two ends attach
Determine what is being moved when the muscle shortens – what is being moved, what is staying stationary
insertion and origin

27. Deltoid
Pectoralis major
Latissimus dorsi
Serratus anterior
Linea alba
Rectus abdominis
External oblique
Transverse abdominis
Internal oblique