Muscular System Notes
3 Types of Muscle Tissue
 _____________
o Involuntary
o Striated
o Contains ________________ ___________ (allow for faster
impulse transmission)
o Found in _____________
 _____________
o
o
o
o
Involuntary
Non-striated
Another name is _______________
Location: _____________________
 _____________
o
o
o
o
Voluntary
Striated
Attached to bones by _____________
Primary muscle of system
4 Characteristics of all muscles
 ___________________
 ___________________
 ___________________
 ___________________
Muscular System Notes
Functions
 __________________
o Prime movers—
o Antagonists—
o Synergists—
 _________________
o __________ Contraction—partial contraction; counteracts the force
of ______________
 ___________ _________________
o _____% of body heat comes from muscle activity
Gross Anatomy of Skeletal Muscle



Composed of ____________ muscle cells and ________________ tissue
Involves ______ bones with an ______________ between them
Origin—

Insertion—
**Insertion always moves toward origin**

Tendons—

Bursa—

Synovial Memb./Fluid—

Tendon sheaths—
Muscular System Notes
Microscopic Structure


Muscle cells are called _____________ _____________.
Bundles of muscle fibers are called _______________.
 Connective Tissue Components:
o ___________________-o ___________________-o ___________________--
 Parts of Muscle Fibers (cells)

Sarcolemma—

Sarcoplasm—

Sarcoplasmic Reticulum—

Many mitochondria

Several nuclei

Myofibrils/myofilaments
1)
2)
3)
4)

_______________
_______________
_______________
_______________
________________—part of ______________;
________________ ____________; area between two
_____________; Parts of sarcomere:

A-bands—

I-bands—

H-zone—
Muscular System Notes
Muscle Contraction
 In a relaxed state, actin & myosin partially overlap.
 During contraction, myosin attaches to actin causing them to
move toward each other. This is called the sliding filament
theory.
 This shortens the sarcomere, which shortens the muscle fiber.
 When enough muscle fibers contract, the entire muscle will
contract.
 3 requirements:
 Nerve impulse
 Calcium
 ATP
Process of Contraction
 Nerve impulse (__________________) is received.
 _____________ ions are released from SR into sarcoplasm. Ca++
combine with _______________. This allows ____________
__________ to attach to ___________.
 Filaments pull to center and sarcomere _______________.
**If majority of muscle fibers shorten, then contraction occurs.
Relaxation
**Opposite of contraction
 Nerve impulse (____________________) is received.
 Ca++/troponin complex breaks up.
 This prevents myosin from binding to actin
 Filaments slide apart
Muscular System Notes
All-or-None Principle
 A muscle _______________ will contract fully or not at all.
There is _____ partial __________________.
 Entire muscles CAN partially contract.
 Threshold stimulus—
 Subthreshold stimulus—
Motor Unit…Nervous Tissue Component
 Motor Neuron
o Dendrites—pick up _____________ thru receptors;
carries impulse _______________ cell body
o Cell body-–main part of cell that contains ______________
o Axon—carries impulse __________ from cell body toward
the muscle fiber
 Muscle Fibers
 Neuromuscular Junction—space b/t ____________ &
__________ fiber
**KNOW DRAWING!!!!
Muscular System Notes
Fatigue
 Strength of contraction _________________ (no longer
respond to _______)
 Uses up __________ & ______________
 Creates ______________ ______________ & ___________
_____________ build-up (sore muscles)
Types of Contractions
 Twitch—
 Tetanic—
 Isotonic—
 Isometric—
**Flaccid—loss of muscle tone
Effects of Exercise
 Negative:
 ______________
 Positive:
 ________________—increase in muscle size; helped by
____________ _______________ (isometrics & weights)
 Endurance training —has a __________ _________
benefit; increases ___________ _________ & # of
mitochondria in cell (more _________)