Presentation is loading. Please wait.

Presentation is loading. Please wait.

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.

Similar presentations


Presentation on theme: "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."— Presentation transcript:

1

2 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 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 Connective tissue surrounding muscles tissue

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

7 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 Spiral Fibers that twist Between their points of attachments

11 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 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? 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. 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 2 nd 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 In the body: all movement is made by 3 rd class levers. The muscle insertion is very close to the joint being moved. The movement is strong but it is also fast

20 So……

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

24 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 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

28

29

30

31


Download ppt "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."

Similar presentations


Ads by Google