Transcript Skeletal and Muscular System

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Make sure to write down anything in this
color!!!
Function: to protect, hold up body and
move it from place to place
Definitions:
 Locomotion- being able to move one's
self from place to place
 Sessile- stationary, staying in one
place
Easier to get food
Easier to find a suitable place to live
and away from harmful conditions.
3. Allows organism to escape from
enemies or seek shelter
4. Allows organism to find mates and
reproduce
1.
2.
Pseudopods- “false
feet”, cytoplasm
moves by flowing and
extending the
pseudopods [e.g. amoeba]
 Cilia and Flagellashort hair like
structures
(paramecium) or long
whip like (euglena)
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Endoskeleton internal structure such as human skeleton made of bone
or cartilage.
 Skeleton can grow with organism as it gets larger.
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Exoskeleton external hard outer structure such as a grasshopper
 Skeleton must be shed (molting) in order for the
organism to grow.
***Both skeleton types use muscles to move their
skeletons***
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Bones & Cartilage
 Types of connective
tissue
▪ Bone – hard and
inflexible
▪ Cartilage- soft and
flexible
1.
Serve as site for muscles to attach to move
body parts
2.
Give body its shape and support
3.
Protects delicate organs.
4.
Stores calcium and phosphorus
5.
Produces red and white blood cells in marrow.
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Compact bone- very dense & strong
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Spongy Bone- very porous (full of holes)marrow fills holes
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connective tissue that bends easily
gives support and cushions joints against
impact and pressure
Found in:
 Embryos- most of skeleton begins as cartilage then becomes bone
▪ Ossification- change of cartilage into bone
 Children- more cartilage than adults therefore
their bones are more elastic and not as easily
broken
 Adults- Ear, nose, ribs, around joints
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Red marrow Found: in spongy bones of vertebrae, ribs,
cranium and tips of long bones or arms and legs
 Function: makes red blood cells, platelets and
some white blood cells
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Yellow Marrow found in hollow center of long bones
 made of fat cells
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Total number of bones: 206
2 main parts:
 Axial skeleton
Skull and spine
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Appendicular Skeleton –
▪ Arms and Legs, Pectoral girdle, Pelvic girdle
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point where bones meet
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Held together by LIGAMENTS (tough fibrous
bands of connective tissue)
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Immovable- cranium (tightly fitted)
Movable Hinge- Back & Forth motion (knee & elbow)
 Ball & Socket- move in all directions, ball shaped
fit into a cuplike space (shoulder & hip)
 Pivot- side to side & up and down motion (base of
skull)
 Gliding- some bending and twisting movement
(wrist & vertebrae)
Types:
1. Skeletal Muscle- used in locomotion and
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in all voluntary movement
Cells fuse together to form fibers
 bundles of fibers bind together to form muscles
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Striated appearance- striped with light &
dark bands, shows overlapping fibers
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Fibers made up of thin filaments called
Actin & Myosin
 Filaments slide over each other to contract
(shorten) and relax (lengthen)
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Connected by tendons to bones
Muscles pull bones when they contract
(shorten)** cannot push**
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Work antagonistic to each other:
 As one muscle contracts (shortens) the opposite
muscle relaxes (lengthens)
 Example- Biceps (flexor bends a joint) and triceps
(extensor extends or straightens a joint) in the
arm
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Unique to Skeletal Muscle:
 Fast, strong contractions unlike smooth muscles
Skeletal muscle is a system of pairs that relax and contract to move a joint.
For example, when front leg muscles contract, the knee extends
(straightens) while back leg muscles relax. Conversely, to flex (bend)
the knee, back leg muscles contract while front leg muscles relax.
2. Smooth Muscle- involuntary muscle
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Found: in digestive tract, blood vessels,
diaphragm and some other internal organs
Appearance:
 Long, overlapping sheets of cells
 Non-striated (no bands)
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Unique to Smooth Muscle: Long, less
intense contractions
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Cardiac muscle- found in heart only
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Appearance:
▪ Interlocking network of muscle cells with a single
nucleus in each
▪ Striated muscle
 Unique to Cardiac Muscle:
▪ Built-in ability to contract on their own
▪ Muscles can contract together (heartbeat)- different
than skeletal
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Osteoporosis- brittle bones due to lack of
calcium
Treatment- medication and increased
calcium intake in diet
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Scurvy- caused by a lack of vitamin C
(Absorbic Acid) causing wounds to heal
poorly, bruising easily, gums bleed, teeth
loosen, loss of appetite
Treatment- Vitamin C
Caption: Close of the mouth of a person
suffering from scurvy, a disease caused by
a deficiency of vitamin C (ascorbic acid), showing
swollen and bleeding gums. Scurvy results from
a diet that is devoid of fresh fruit & vegetables.
Swollen and bleeding gums are initial symptoms
and may be followed by bruising of the skin
(subcutaneous bleeding) and the opening of
previously healed wounds. A prolonged
deficiency may cause death. Scurvy responds to
treatment with vitamin C.
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Arthritis- inflammation of the joints can be
immune system related
Treatment- anti-inflammatory drugs
 Scoliosis- curvature of the spine caused by
unknown (idiopathic); it can eventually lead to
decreased lung capacity and congestive heart
failure
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Treatment- wearing a spine straightening
brace or surgery
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Muscular Dystrophy- muscles break down
and waste away to nothing eventually
affects all voluntary muscles, heart and
breathing muscles Duchenne’s MD usually
only affects boys
Treatment- none currently, physical therapy
to help with symptoms
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ALS or Lou Gehrig’s disease- muscle
weakness and wasting, some twitching then
paralysis of arms and legs and then all
voluntary muscles from motor neuron
malfunction
Treatment- none currently, some medication
to slow it but physical therapy is needed
Ex. Steve Gleason -Saints