Muscular System
Muscles for Locomotion
3/15/2016
Engage
Tennis Ball Muscle Activity
March 15, 2016
Explore
Chicken Wing Dissection
The major function of the muscular
system is to support our body in
movement. Through observations
and class discussion, you will make
deduction about certain principles of
muscle function.
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Explore
“Multitalented Muscles”
Web Search
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Explain
What are some functions of the
Muscular System?
Contract and relax to move the body.
Stores energy
Protects internal organs
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Two Muscle Categories
Involuntary
– NOT under conscious control
Voluntary
– Under conscious control
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Think About It!!
Can you think of one body function
that you perform without thinking
about it?
– Breathing, Heart Beating, Digestion,
etc…
How about one that one must think
about?
– Picking up a pencil, walking, running,
etc…
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Three Types of Muscles
Smooth Muscle
Cardiac Muscle
Skeletal Muscle
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Smooth Muscle
Where lining
of Internal
Organs and
Blood Vessels
Involuntary
Non striated
Function
Squeeze, exert
pressure by
slow and
prolonged
contractions
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Cardiac Muscle
Where
Heart
Involuntary
Striated
and
branched
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Skeletal Muscle
Majority of
muscle in the
body
Voluntary
Striated
Found
attached to the
skeleton by
TENDONS.
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Questions
What are the two categories of
muscles?
What are the three types of muscles?
Muscle that contract under conscious
control are _________.
______ attaches muscle to bone.
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Skeletal Muscle Structure
Skeletal Muscle Structure
Muscle - made of bundles
Bundles- many muscle fibers
Muscle Fiber – many myofibrils
Myofibrils- filaments (thick or thin)
Thick filaments –myosin protein
Thin filaments –actin protein
Thick and Thin give striated look
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Skeletal Muscle Structure
Functional Unit of Muscle
Sarcomere
– Section of myofibril
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Muscle Contractions
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Cycle Diagram
1
Myosin forms
cross-bridge
with actin
5
2
Myosin returns
to original
shape
4
Cross-bridge
changes
shape
3
Cross-bridge
releases actin
Actin pulled
Muscle Contractions
March 15, 2016
Cycle Diagram
1
Myosin forms
cross-bridge
with actin
5
2
Myosin returns
to original
shape
4
Cross-bridge
changes
shape
3
Cross-bridge
releases actic
Actin pulled
Muscle Attachment to Bone
Muscles attached to bone by
tendons.
Muscles are attached in opposing
pairs.
One Muscle contracts to raise the
limb, while the second will contract
to lower it.
Bicep / Triceps
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Figure 36-11 Opposing Muscle Pairs
Section 36-2
Movement
Movement
Biceps (relaxed)
Triceps (contracted)
Biceps (contracted)
Triceps (relaxed)
Muscle Strength and Exercise
Strength DOES NOT depend upon
the number of fibers. Why?
Born with all fibers we will have.
Depends on the THICKNESS of fibers
and how many contract at one time
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Muscle Soreness After Exercise
Do muscle cells need O2?
– Yes!!!
Do muscle cells need ATP?
– Yes!!!
Working out moderately provides us enough
oxygen (aerobic) to change glucose into ATP
– Called _________ respiration
Working out rigorously does not allow us to get
enough O2 in our blood. What happens with no
O2 (anaerobic)?
Lactic Acid Fermentation
Lactic Acid builds up in muscle cells passes into
the blood stream, causes the blood to become
acidic, stimulates breathing, and can cause
cramping
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Regular Exercise
Improves functioning of muscles
Aerobic training can affect a muscle’s
ability to share and use energy
Increases endurance and thickness
of muscle filaments (strength)
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Elaboration
The Universe Within
Watch the coordination of several different
body systems and how they make Mike
Powell the world’s greatest long jumper.
Muscle Builders!
Using various materials, you will build a
model that simulates muscle contractions
and relaxations. This model depicts one
muscle working in isolation, but as we
have learned, muscles in the body
cooperate in a group effort, like in the
chicken wing.
March 15, 2016