Muscular System 1
Name: ________________________________________________________________________Lab________
Standard 5: Muscular System
Indiana Content Standards
AP 2.2 Compare and contrast the structure, function and location of cells that make up various types of muscle tissue…
AP 5.1 Name the components of a skeletal muscle fiber and describe their functions. Describe how the thin and thick filaments are
organized in the sarcomere.
AP 5.2 Explain the molecular processes and biochemical mechanisms that provide energy for muscle contraction and relaxation.
AP 5.3 Describe a motor unit and its importance in controlling the force and velocity of muscle contraction. Describe the
neuromuscular junction and the neurotransmitter released at the neuromuscular junction.
AP 5.4 Distinguish between isotonic and isometric contractions of skeletal muscle; cite examples of each and discuss how the forces
generated in muscle contraction are amplified by the use of levers.
AP 5.5 Identify the major muscles on a diagram of the body’s musculature, through dissection or both. Describe the movements
associated with each muscle.
AP 5.6 Explain what is meant by muscular hypertrophy and atrophy and discuss causes of these processes.
Objectives
Know the functions of the muscular system
2.2 Compare and contrast skeletal, cardiac and smooth muscle.
5.1 Name the components of the skeletal muscle fiber and describe their functions
5.2 Explain the sliding filament theory
5.3 Explain what occurs at the neuromuscular junction
5.3 Explain the difference between slow twitch and fact twitch muscle fibers
5.4 Give examples of isotonic and isometric muscle contractions.
5.4 Explain the effect the use of a lever has on muscle contractions.
5.5 Label diagram with the major muscles and functions of the muscular system
5.5 Describe the point of insertion and the point of origin
5.6 Give examples of the causes of muscular hypertrophy and atrophy and what is happening to the muscle in each
Lecture Notes:
Important Notes for the Test:
The Muscular System
Functions of the Muscular System
1. _________________________________________
2. _________________________________________
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3. _________________________________________
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There are ___________ muscles in our body!
Know the functions of the muscular system.
Muscular System 2
Three Types of Muscle
1. ___________________________________________
Label the three types of muscle:
2. ___________________________________________
3. ___________________________________________
Smooth Muscle
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Examples of what smooth muscle does in our bodies:
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Cardiac Muscle
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Explain intercalated discs: _______________________
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Skeletal Muscle
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Skeletal muscles attach to joints at points of:
_____________________________________________
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Made up of _______________ & __________________
muscle fibers.
Know which are voluntary and involuntary.
Know which are striated and which is not.
Muscular System 3
Points of Origin and Insertion
Label the point of origin and the point of insertion:
Point of Origin: ________________________________
Point of Insertion: ______________________________
Fast Twitch Muscle Fibers
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Slow Twitch Muscle Fibers
Distinguish between the characteristics of slow twitch
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and fast twitch muscle fibers.
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Structure of a Skeletal Muscle Fiber
Muscle Fiber
A muscle fiber is the muscle ___________.
Myofibrils
Located in the _______________________________.
They are long strands of _______________________.
Contain ________________ and ________________
filaments.
Sarcomere
A section of a myofibril that contains the actin and
myosin needed to make a muscle _____________.
Name the components of the skeletal muscle fiber.
Actin
Actin filaments are __________ protein fibers. They are
Know the characteristics of the myofibril, sarcomere,
attached to the ends of the sarcomere, called the
actin and myosin.
________________. Pulling actin filaments causes the
sarcomere to ___________________.
Muscular System 4
Myosin
Myosin filaments are ______________ protein fibers.
They are attached to the center of a sarcomere which is
called the _______________. Myosin fibers are
responsible for the _________________ action that
causes the sarcomere to __________________.
Sarcomere Diagram
Sarcomere Diagram
Instructions: Sketch a relaxed and contracted
You will have to recognize the difference between a
sarcomere. Label the actin, myosin, z line and m line
relaxed and contracted sarcomere diagram and label
in each.
each part.
Sliding Filament Theory
Complete the Sliding Filament Theory Exercise on the
next page.
Put steps 1 - 5 of the sliding filament theory in the
correct order.
Muscular System 5
Sliding Filament Theory Exercise
The sliding filament theory explains muscle contraction based on how muscle fibers (actin and myosin) slide against each
other to generate tension in the overall muscle.
Step 1: A muscle contraction starts in the brain, where signals are sent along the motor neuron (a). Color the motor
neuron yellow . Within the motor neuron are vesicles that contain the neurotransmitter, acetylcholine. Color vesicles
gray and the triangles that represent the acetylcholine orange . Acetylcholine reaches the receptors (b) on the
muscle sarcolemma which causes an impulse.
Step 2: The impulse travels down the membrane and into the transverse tubules (c) where it causes calcium to be
released from the sarcoplasmic reticulum. Color the t-tubule green and the circles that represent calcium dark blue
. The sarcoplasmic reticulum is only partially pictured, shade this structure pink.
Step 3: Calcium binds to a structure on the actin that causes it to change shape. Color the actin myofilament (e) red.
Step 4: The change in shape allows myosin heads to form cross-bridges between the actin and the myosin. Color the
myosin (g) blue. Color the cross bridges (f) purple.
Step 5: Energy from ATP is used to create a "power stroke" between the two filaments. Color the ATP bright orange
The actin filament then slides inward and shortens, or contracts, the whole muscle.
.
Muscular System 6
Increase or Loss of Muscle Tissue:
Hypertrophy
Muscles grow when they are exposed to ____________
__________ causing microscopic damage. When this
happens the body releases __________________that
activate the immune system telling the body to repair
the damage. The repetitive process of damage and
repair eventually makes muscles _____________ &
_______________. This increase in mass due to
exposure to increased resistance is called
__________________.
The body’s ability to repair muscle is also affected by
__________________________________________
__________________________________________
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Atrophy
When muscles are not exposed to resistance they
_________. This process is known as ______________.
Isotonic Contractions
There _______ movement with isotonic exercise.
Isotonic contractions __________muscle tissue.
Isometric Contractions
Isometric contractions are ______________ exercises.
There ___________movement with isometric exercise.
Isometric contractions ____________muscle tissue.
Muscular System 7
Major Muscles and Functions Reference Sheet
Muscular System 8
Major Muscles and Functions Work Sheet