Download Skeletal and Muscular System

Skeletal and Muscular System
By:
Kim Beach, Melody Bernhardt,
Priscilla Lee, and Shannon Vickers
Skeletal System
• Determines shape or
body
• Protects organs
• Works with muscles to
create movement
• Over 200 bones in
body
• Made of bones,
ligaments, and tendons
Bone Composition
• Consists of calcium,
phosphorus, carbonate crystals,
and collagen fibers.
• Layer of compact bone
surrounds layer of spongy bone,
except at the marrow cavity
• At joints, a layer of cartilage
covers the end of the bone to
prevent friction.
• Bone marrow fills bone cavities
• Red marrow produces red blood
cells
• Yellow bone marrow stores fats
and produces white blood cells
• Tendons attach a muscle to a
bone and transmit a mechanical
force of muscle contraction to
the other part
• They are much like ligaments,
and are composed of dense
fibrous connective tissue with
high collagen content
Bone Growth
• Endochondral ossificationprocess of converting cartilage in
embryonic skeletons to bone
• Cells begin depositing minerals
and spongy bone forms
• Osteoclasts remove the material
from the center of the bone
• Perichondrium forms around
cartilage and begins forming
compact bone
• Blood vessels form and grow into
the perchondrium transporting
stem cells into the interior
Muscular System
• Allows movement
• Over 600 individual
muscles
• 3 types: skeletal,
cardiac, and smooth
• Voluntary and
involuntary muscles
Cardiac Muscle
• Involuntary (non-controllable)
• Makes up brain, wall of the
heart, mydocardium
• This muscle is striated and
contracts through the sliding
filament method
• Contains branching fibers
• Attached together instead of
bone
Skeletal Muscle
• Makes up 40% of an
adult’s body weight
• Striated
• Composed of long
muscle fibers; each fiber
is a cell with several
nuclei
• Nervous system controls
the contraction of the
muscle
• Voluntary muscle
• Tendons attach muscle to
bone
Smooth Muscle
• Makes up most of our internal
organs
• Controlled by the nervous
system and hormones
• Involuntary muscles
• Muscles fibers tightly
intertwined
Extensor and Flexor
To see the flexor and
extensor at work click on:
http://www.innerbody.com/a
nim/arm.html
• Extensor muscles increase the
angle of a joint (straightening
the elbow, or the triceps).
• It is usually bent backwards,
except at the knee.
• Flexor muscles decreases the
angle of the joint (bends the
elbow, or biceps).
• It is usually directed forwards,
except at the knee.
Muscle Contraction
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To See Muscle Contraction
•
Go to :
http://bio.winona.msus.edu/ber
g/ANIMTNS/muscle.htm
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Neuromuscular junctions are the point
where a motor neuron attaches to a
muscle.
When the nerve impulse reaches the
junction the acetycholine is release
from the axon of the nerve cell.
Electrical changes are produced in the
muscle cell when the Ach binds to the
receptors of the surface of the cell and
changes to Na ions. This is called
depolarization.
During repolarization the muscle
cannot be stimulated. This is the
refractory period and once started the
action spreads throughout the entire
muscle cell.
This is the all or none response.
Joints
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Gliding Joint
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Immovable joints have tightly
interlocked edges like sutures in the
skull
Partly movable joints allow some
movement have cartilage between
bones
Synovial joints allow greatest
amount of movement and ends of
bones covered with a connective
tissue filled with synovial fluid
Synovial joints have an outer
surface that strengthens joints and
hold bones in place
Some joints also have tendonswhich link muscle to bone
Moveable Joints
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Ball and Socket Joint: a ball shaped
end of one bone fits inside the cup
shaped end of another. (shoulder
or hip)
Pivot Joint: the end of one bone
rotates inside ring formed by
another. (forearm)
Saddle Joint: enables a bone to
move backwards to forwards and
side to side.
Hinge Joint: hinge can only move
in one direction like a door hinge.
(elbow or knee)
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Health
Osteoporosis, or porous bone, is characterized by low bone mass and
structural deterioration of bone tissue. This leads to bone fragility and
an increased susceptibility to fractures of the hip, spine, and wrist.
There is no known cure at this time, but there are many options of
medications that you can take.
Paget’s disease results in enlarged and deformed bones; it is a chronic
disorder. The excessive breakdown and formation of bone tissue that
occurs can cause bone weakening and pain, arthritis, deformities, and
fractures. Treatments can lessen symptoms but not cure the disease.
Duchenne Muscular Dystrophy (DMD) is characterized by muscular
enlargement and by a rapid progression of muscle degeneration.
Treatments on mice are promising, and may lead to effective therapies.
Myotonic Dystrophy is when the muscles contract but have decreasing
power to relax. Due to this, the muscle become weak, and waste away,
and it can cause mental deficiency, hair loss and cataracts.
Artificial limbs help to restore a normal way of life to people who have
had their limbs amputated. Joints, like the knee and hip, can be
replaced also so that the person can return to an active life. In the
future, technology may be able to recover senses in the artificial limbs.
Bibliography
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http://library.thinkquest.org/11965/html/cyber-anatomy_musboth.html
http://www.osteo.org/
http://library.thinkquest.org/10348/find/content/muscular.html
http://www.enchantedlearning.com/subjects/anatomy/skeleton/skelprin
tout.shtml
• http://www.ecsu.ctstateu.edu/depts/edu/textbooks/skeleton/html
• The Ultimate Visual Science Dictionary. Dorian Kindersly (company)
• The Random House Book of 1001 Questions and Answers About the
Human Body. Trevor Day