Download The Muscular System

The Muscular System
Do Now:
 Happy New Year!!
 Get your Clicker
 Name as many muscles as you can (anterior & posterior)
Facial Muscles
Shoulder
Abdominal Muscles
Back Muscles
Leg Muscles
Id the Masseter
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
0%
0%
0%
0%
0%
0%
0%
1
2
3
4
5
6
7
Id the orbicularis oculi
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
0%
0%
0%
0%
0%
0%
0%
1
2
3
4
5
6
7
Id the deltoid
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
0%
0%
0%
0%
0%
0%
0%
1
2
3
4
5
6
7
Id the rectus abdominis
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
0%
0%
0%
0%
0%
0%
0%
0%
0%
1
2
3
4
5
6
7
8
9
Id the sternocleidomastoid
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
8. 8
9. 9
0%
0%
0%
0%
0%
0%
0%
0%
0%
1
2
3
4
5
6
7
8
9
Id the gastrocnemius
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
0%
0%
0%
0%
0%
0%
0%
1
2
3
4
5
6
7
Id the biceps femoris
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
0%
0%
0%
0%
0%
0%
0%
1
2
3
4
5
6
7
Id the sartorius muscle
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
7. 7
0%
0%
0%
0%
0%
0%
0%
1
2
3
4
5
6
7
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
Do Now:
 Grab your Clicker
 Take out your HW – athlete pic w/labeled muscles
 Review names of muscles from hotlist & diagram
Id the orbicularis oris
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
63%
7. 7
37%
0%
0%
1
2
3
0%
0%
4
5
0%
6
7
Id the temporalis muscle
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
78%
7. 7
22%
1
2
0%
0%
0%
0%
0%
3
4
5
6
7
Id the serratus anterior
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
53%
7. 7
26%
8. 8
9. 9
11%
5%
0%
1
5%
0%
2
3
0%
4
5
6
0%
7
8
9
Id the trapezius
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
82%
7. 7
8. 8
12%
9. 9
6%
0%
1
2
3
4
0%
0%
0%
0%
0%
5
6
7
8
9
Id the exterior obliques
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
78%
7. 7
8. 8
11%
9. 9
0%
0%
0%
0%
0%
1
2
3
4
5
6%
6%
6
7
8
9
Id the soleus
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
67%
7. 7
11%
11%
6%
0%
1
2
6%
0%
3
4
5
6
7
Id the semimembranosis
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
32%
32%
7. 7
21%
5%
5%
5%
0%
1
2
3
4
5
6
7
Id the semitendonosis
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
67%
7. 7
11%
6%
6%
2
3
6%
6%
6
7
0%
1
4
5
Id the vastus medialis muscle
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
65%
7. 7
12%
1
12%
2
3
12%
4
0%
0%
0%
5
6
7
Id the rectus femoris muscle
1. 1
2. 2
3. 3
4. 4
5. 5
6. 6
100%
7. 7
0%
1
2
0%
0%
0%
0%
0%
3
4
5
6
7
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?
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
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
Gross Anatomy of Skeletal Muscle
 Each cell is called a “muscle
fiber”
 Contains several tissues:
 Connective
 Blood vessels
 Nerves – control
contractions
 Skeletal muscle
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
Muscle Fiber Contraction
http://www.youtube.com/watch?v=CepeYFvqmk4
Classwork:
 Draw a flowchart or diagram showing how
muscle contraction and relaxation occurs at
a cellular level
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)

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
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
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
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?