Download Skeletal and Muscular Systems

To be used with Skeletal and Muscular Systems Guided Notes
Adapted from: M. Baroody

Movement is a Life Function for all living
things
◦ Locomotion: change in position of an
organism
Tropism
Walking/Sliding
Why do we need to move?
 Survival Value of Locomotion
1. Get food and shelter
2. Escape from predators
3. Move to regions better suited to survival
4. Find mates
5. Move away from toxic wastes

What allows us to move?
◦ Skeleton and Muscles
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Functions of the skeleton:
1. Supporting framework for internal
organs and tissues.
2. Anchorage sites for muscle action.
3. Protects the internal organs.
4. Provides leverage for body movement.
5. Blood cells are produced in the bone
marrow.
The bones also store minerals.
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Cartilage: tough, fibrous, elastic connective
tissue
Cartilage Functions
1. Pliable (stretchable) support
2. Flexibility of joints
3. Cushioning of joints
Cartilage makes up most of the embryo's
skeleton.
Most of this cartilage changes to bone by
adulthood.

Ligaments:
connect
bones to
bones (joints)
tough and
elastic

Tendons:
tough
inelastic
fibrous cords
which attach
muscles to
bones
•A is a tendon (it connects the bone at D
to the muscle at B) C is a ligament
(connects bones)

Muscles
◦ only body tissue able to contract
◦ create movement by flexing and extending
joints
◦ body energy converters (many muscle
cells contain many mitochondria)

Smooth Muscle:
◦ Smooth in appearance
◦ Involuntary in action
◦ Slowly contracting
 but contractions are
long in duration
◦ Lines blood vessels, alimentary canal, and
body openings

Skeletal Muscle
◦ Voluntary in action
◦ Contain many striped
long fibers called striations
◦ Found in association
with skeletal bones
 the nervous system interacts with
skeletal muscles to produce motion

Cardiac Muscle:
◦ Resembles skeletal
muscle with lined
appearance
◦ Involuntary in action
◦ Composes the hardest working muscle-the heart

Myosin, Actin, Cross-bridges

Muscles can only pull, cannot push

Voluntary – Can control
◦ Such as:

Involuntary – Cannot control
◦ Such as:

Force increases with the number of fibers that
are stimulated
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Violent muscle contractions require a lot of
oxygen.
◦ If oxygen is not available muscle fatigue
will set in.
Muscle fatigue: results from oxygen debt
◦ lactic acid accumulates in skeletal
muscles
◦ rest restores the oxygen balance

Arthritis: joint inflammation

Tendonitis: tendon inflammation at bone
junctures
◦ a common condition in athletes

Types of bone breaks (fractures):
◦ Range from a simple fracture to a
compound fracture

Cranial Cavity
◦ Holds the Brain and is bounded by
the skull

Thoracic Cavity
◦ Holds the
lungs and
heart and is
bounded by
the ribs,
sternum,
diaphragm,
and spine

Abdominal Cavity
◦ Holds the stomach, pancreas, liver, small
intestine, large intestine, kidneys, spleen,
bladder, and reproductive organs.
Bounded by the diaphragm, ribs,
abdominal muscle, and pelvis