The Muscular System

1
The Muscular System
2
Do Now

• Happy New Year!!
• Get your Clicker
• Name as many muscles as you can (anterior
  posterior)

3
Facial Muscles
4
Shoulder
5
Abdominal Muscles
6
Back Muscles
7
Leg Muscles
8
Id the Masseter

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

9
Id the orbicularis oculi

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

10
Id the deltoid

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

11
Id the rectus abdominis

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9

12
Id the sternocleidomastoid

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9

13
Id the gastrocnemius

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

14
Id the biceps femoris

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

15
Id the sartorius muscle

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

16
Homework

• Find and print a picture of your favorite athlete
  (bathing suit preferred to see as many muscles as
  possible)
• Hand label the visible muscles on their body
  using the muscles we discussed in class

17
Do Now

• Grab your Clicker
• Take out your HW athlete pic w/labeled muscles
• Review names of muscles from hotlist diagram

18
Id the orbicularis oris

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

19
Id the temporalis muscle

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

20
Id the serratus anterior

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9

21
Id the trapezius

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9

22
Id the exterior obliques

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9

23
Id the soleus

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

24
Id the semimembranosis

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

25
Id the semitendonosis

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

26
Id the vastus medialis muscle

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

27
Id the rectus femoris muscle

1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7

28
Do Now

• Why do you think that muscle-enhancing
  supplements (steroids, creatine, andro) are so
  popular at all levels of fitness and athletics
  (high school, college, pro, etc.) and do you see
  any problems with this?

29
Muscle Tissues

• Cardiac
• Involuntary striated muscle
• Dinucleated
• Communicate via intercalated disks
• Natural contraction cycle determined by pacemaker
  cells
• Smooth
• Lines blood vessels, digestive organs, urinary
  system, and parts of respiratory system
• Involuntary nonstriated muscle
• Ca triggers contractions differently (lacks
  sarcomeres)
• Skeletal
• Voluntary striated muscle
• Multinucleated cells called muscle fibers
• Controlled by motor nerve cells

30
Functions of Skeletal Muscle

• Produce Movement
• Contractions pull on tendons and move bones
• Maintain posture and body position
• Continuous contractions maintain posture
• Support/protect soft tissues
• Abdominal wall
• Floor of pelvic cavity
• Guard entrances and exits
• Voluntary control of swallowing, defecation, and
  urination
• Maintain body temp
• Some energy from contractions lost as heat

31
Gross Anatomy of Skeletal Muscle

• Each cell is called a muscle fiber
• Contains several tissues
• Connective
• Blood vessels
• Nerves control contractions
• Skeletal muscle

32
Microanatomy of Skeletal Muscle

• Sarcolemma cell membrane
• Sarcoplasm cytoplasm
• Myofibrils bundles of myofilaments
• Thin filaments actin proteins
• Thick filaments myosin proteins
• Sarcoplasmic reticulum smooth ER (stores Ca)
• Sarcomeres repeating units of myofilaments

33
Muscle Fiber Contractionhttp//www.youtube.com/wa
tch?vCepeYFvqmk4
34
Classwork

• Draw a flowchart or diagram showing how muscle
  contraction and relaxation occurs at a cellular
  level

35
Muscle Mechanics

• Muscle cells pull on collagen fibers producing
  tension (can only contract!)
• Amount of tension dependent upon
• Frequency of neural stimulation
• Latent period (2msec) action pot. release of
  Ca
• Contraction phase (15msec) cross bridges form
• Relaxation phase (25msec) tension, cross
  bridges and Ca decrease
• of muscle fibrils activated
• Motor unit - muscle fibrils controlled by singe
  motor neuron
• Fine control of movement determined by size of
  motor unit
• Ex. Eye vs. Leg muscles
• During sustained contraction motor units
  activated on a rotating basis (some rest/some
  contract)

36
Muscle Tone

• Tone resting tension
• Stabilizes the position of your joints
• Any skeletal muscle not stimulated on a regular
  basis will atrophy fibers become smaller and
  weaker
• Initially atrophy is reversible
• Extreme atrophy is permanent

37
Energetics of Muscle Activity

• Active Skeletal Muscle fibril requires 600
  trillion ATP/sec!
• Sources of ATP
• Stored (ADP Creatine-P ? ATP)
• Lasts 15 sec
• Aerobic Metabolism (Krebs ? Oxidative
  Phosphorylation)
• Provides 30 of ATP needed during peak exertion
• Anaerobic Metabolism (glycolysis)
• Main E source
• Lactic acid builds up
• Ineffective
• Muscle Fatigue no contraction despite
  stimulation
• Lack of ATP or lactic acid build up
• Recovery Period returns to pre-exertion levels

38
Muscle Performance

• Force and endurance depends on
• Types of muscle fibers
• Fast Twitch (white)
• Powerful contractions
• Fatigue rapidly (few mitochondria)
• Slow Twitch (red)
• Extended contraction (many mitochondria)
• Extensive capillary network
• Myoglobin binds O2
• Physical conditioning ( increase power and
  endurance)
• Anaerobic
• Frequent, brief intense workouts (hypertrophy of
  muscle fibrils)
• Aerobic
• Sustained low levels of activity
• Carb-load the day before drink glucose rich
  sports drinks

39
Muscle Review

• What muscle do you use to shrug your shoulders?
• What muscle would be well developed in a trumpet
  player?
• What is the most likely cause of a muscle cramp?
• What muscle do you use to stand on your
  tippy-toes?
• What muscle do you use to close your eye-lids
• What muscle do you use when using a butterfly
  machine?
• Compare white muscles to red muscles
• A friend wants to bulk up his arms. What would
  you suggest to him?
• What are the 3 sources of energy for muscles?
  What limits each?