Unit 3

Lecture #1

1. Types of Muscle Tissue: (location, nucleus, striations, control and function)

    1) Skeletal (pg.282)

    2) Smooth (297-298)

    3) Cardiac (298-299)

2. Skeletal Muscle Function (complete in class):

    1) Mobility-

    2) Posture-

    3) Heat Production-

3. Structure of a Skeletal Muscle (pg.282)

  List Tissues-

  A. Connective Tissue Coverings (define each)




  B. Skeletal Muscle Fibers (define each))pg. 284-285)

    skeletal muscle fiber-






    sarcomeres (wait till lecture)(pg.285 + handout)

Lecture #2

4. Neuromuscular Junction (pg.286)

  A. Skeletal muscles contract only if stimulated

    1) Neuromuscular Junction (draw&label the lower right diagram in the bow)pg.286

  B. Define the following (pg.286)

    1) motor neuron-

    2) neuromuscular junction-

    3) motor end plate-

    4) synaptic cleft-

    5) neurotransmitter-

    6) synaptic vesicles-

    7) acetylcholine-

  C. Motor Units (summarize the 2 paragraphs) pg. 286-287

5. Skeletal Muscle Contraction (pg.287-288)

    Discuss myosin-

    Discuss actin-

    Cross Bridge-

    What is the function of tropomyosin and troponin?

Lecture #3

  A. Discuss the Sliding Filament Theory (pg. 288)

  B. Stimulus for Contraction (pg. 289)

    Discuss the importance of Acetycholinesterase (enzyme)-

    Duplicate table 9.1

Muscle fiber Contraction Muscle fiber relaxation

Lecture #4

Energy Sources for Muscle Contraction (pg.291-293)

  Muscle Contraction- sliding actin over myosin requires energy. This energy comes from ATP molecules.

I. Energy Source- discuss the importance of ATP-

    What does ATP stand for- (glossary)

II. The energy required to produce ATP comes from 3 sources: (list them)




III. Discuss Creatine Phosphate (pg. 291)

IV. Discuss Anaerobic Respiration (pg. 292)

V. Discuss Aerobic Respiration (pg. 292)

    Formula (wait till lecture)-

    Sources of Oxygen (wait till lecture)-

VI. Breakdown of ATP yields energy (class lecture)

VII. ATP Made in Mitochondria Utilizing Glucose (class lecture)

    Glucose -

    Glycogen -

VIII. What is Oxygen Debt (pg. 292)

Lecture #5

Muscle Responses (pg.294-297)

I. Important Terms for Muscle Response: (Discuss each)

    1. Threshold -

    2. All or Nothing Response -

II. Recording of muscle contraction

  There are different types of skeletal muscle contractions.

    1. Twitch- A jerky contraction in response to 1 stimulaton.

      Ex. Myogram (draw Figure 9.15 n pg. 295)

    a) Parts of a contraction

    stimulus- (single action potential)

    latent phase-

    contraction phase-

    relaxation phase-

    refractory period-

III. Sustained Contractions

    1) Muscle tone-

    2) Tetanic: sustained contraction due to repeated rapid stimulations(multiple wave summation.) Most useful contraction. Allows us to walk, lift, etc.

      a) Isometric: muscle tightens but does not shorten or produce movement
      b) muscle contracts and produces movement
      c) isokinetic: the force a muscle generates is less than that required to move or lift an object

Lecture #6

Muscle Tissue (Describe how muscles lengthen passively)

IV. Interaction of skeletal muscle actions: Skeletal muscles usually work in groups rather than singularly. They produce movement by pulling bones never pushing.

    prime movers-



V. Abnormal Contractions:

    spasm- sudden involuntary contraction of a skeletal muscle contraction. (cramp)

    rigor mortis- locking of muscle after death due to the inability to produce ATP to remove Ca++. lasts 2-72 hours

    Atrophy- when a muscle decreases in size due to lack of use
    Hypertrophy- when a muscle increases in size due to forceful exercize. (filaments increase not # of fibers)

VI. Other interesting facts:

  Strength of muscle Contraction Depends On:




Muscles that move a part dont usually lie over that part.


VI. Sequence in walking.

    - flex thigh and knee

    - plantar flex foot (opposite foot)

    - extend lower leg

    - dorsi flex foot

    - hyperextend leg

How does a Muscle Contract and Relax (Must know for test)

1) Brain initiates impulse
2) Motor neutron transmits to muscle fiber through action potential(depolarization)
3) Acetylcholine is released from end plate
4) Acetylcholine attaches to sarcolemma releasing Ca++ ions
5) Ca++bind to troponin to expose cross bridges
6) Actin slides over myosin using ATP
7) Cholinesterase destroys Acetylcholine
8) ATP is used to remove Ca++. If Ca++ remains attached to triponin movement can occur many times
9) Filaments separate and muscle relaxes
10) ATP reassembles using creatine phosphate, aerobic and anaerobic responses
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