10/20/2008
Chapter 7 – The Muscular System
What are the three types of muscle?
What is Smooth Muscle?
What is a striation?
What is Cardiac Muscle?
What is Skeletal Muscle?
What are the three primary functions of the
skeletal muscle?
What is Muscle Tone and what does it do?
What are the three layers of connective tissue in
skeletal muscle and what is their location?
What is a motor unit?
What is a neuromuscular junction?
1.
2.
3.

Smooth
Cardiac
Skeletal
Makes up the walls of hollow body organs,
blood vessels, and respiratory passageways
 Moves involuntarily
 Produces wavelike motions that move
substances through a system
 Controls diameter of openings like blood
vessels, causes contractions
 Smooth because of lack of striations
 React because of nerve impulse, hormonal
stimulation, stretching, etc
Visible bands on muscles
 Makes up the wall of the heart
 Moves involuntarily
 Striated
 Creates a pulsing action One nucleus per cell,
branching interconnections
 Intercalated discs – special membranes for
electrical impulses that are inserted between
cells
 Heavily striated
 Muscles are attached to bones to produce
movement in joints
o Exceptions: abdominal, facial
 40% of body weight
1. Movement
2. Posture (muscle tone)
3. Heat generation
A steady partial contraction of muscle, known as
muscle tone, keeps the body in position.
 Endomysium – Around each individual muscle
fiber
 Perimysium – Around fascicles (bundles) of
muscle fibers
 Epimysium – Around entire muscle; forms the
innermost layer of the deep fascia
A single neuron and all the muscle fibers it
stimulates comprise a motor unit.
The point at which a nerve fiber contacts a muscle
cell is the neuromuscular junction. It is here that a
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What is a synapse?
What is a motor end plate?
What is the property of excitability, and what is
action potential?
What are actin and myosin?
What is contractility?
Name three compounds that store oxygen, energy,
or nutrients in muscle cells.
What is lactic acid?
What’s the difference between isotonic
contractions and isometric contractions?
What is a tendon?
Most skeletal muscles function in pairs. What is
the name of the two parts of a pair?
neurotransmitter is released from the neuron to
stimulate the muscle fiber.
A point of communication between cells.
The receiving membrane of a muscle cell.
Muscle fibers show the property of excitability,
that is, they are able to transmit electrical signals
along the plasma membrane.
Actin and myosin are filaments, or threads, that
make up skeletal muscle fibers.
The capacity of a muscle fiber to undergo
shortening and to change its shape, becoming
thicker.
 Myoglobin – stores oxygen
 Glycogen – stores glucose
 Creatine phosphate – stores energy
This is an organic acid that accumulates in the cells
when the alternate pathway of metabolism is
used. Anaerobic metabolism can continue only
until the buildup of lactic acid causes the muscles
to fatigue.
 Isotonic – the tone or tension of a muscle
remains the same but the muscle as a
whole shortens
 Isometric – those in which there is no
change in muscle length but an increase in
tension (pushing against an immovable
force)
The cordlike extension that the muscle is attached
to a bone by.
The prime mover and the antagonist.
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