Skeletal
System
Let’s ask the experts
• What is the skeletal system?
• http://www.brainpop.com/health/skeletals
ystem/skeleton/
X-Rays
• Roentgen took the Fist X-Ray
picture
Functions of the Skeletal
System:
1. Movement
– Strong framework on which muscles can act
2. Supports & protects organs
3. Regulates and stores body
minerals and fats
– calcium, phosphorus
4. Produces red and white blood
cells in bone marrow
Bone
•One of the hard parts
forming the skeleton
in vertebrate animals.
• Bones are composed of
tissue that may take one
of two forms. Most
bones contain both
types.
• Compact- dense bone
• Spongy- cancellous
bone
• Compact bone- is dense ,
hard, and forms the
protective exterior portion
of all bones.
• Spongy bone- is inside the
compact bone and is very
porous (full of tiny holes)
occurs in most bones.
Structure of bones
Red marrow
Yellow marrow
• http://www.brainpop.com/health/sk
eletalsystem/bonestructure/
Bone tissue
• The bone tissue is composed
of several types of bone cells
embedded in a web of
inorganic salts (mostly
calcium and phosphorus) to
give the bone strength and
collagenous fibers and
ground substance to give the
bone flexibility.
• Bone marrowthe soft reddish substance
inside the center of many
bones that is involved in the
production of blood cells and
storage of fat.
Types of bone marrow
• Yellow marrow- yellow fatty tissue
that fills the central cavities of long
and stores fat in bones.
In children, more red marrow fills
the center of long bones.
• Red marrow- is the site of red and
white blood cell production.
It is found inside of long bones.
This red marrow is replaced with
yellow marrow as children become
adults.
Food for thought
•Why do children
have more red
marrow in the
center of their
bones than adults?
• Adult skeleton– 206 bones
• Newborn have
more cartilage
a. Bones start as
cartilage
b. Human babies
contains more bones
which begin to fuse
together as the child
grows.
No bones about it!
• The bones of the body fall into four
general categories:
1. Long bones
2. Short bones
3. Flat bones
4. Irregular bones
Four types of bones
Long Bones
• Are longer than
they are wide
• Work as levers
• Upper and lower
extremities
(exampleshumerus, tibia,
femur, ulna,
metacarpals, etc.)
Short Bones
–minimal or no shaft
–Often square or
cube shaped and
found in the wrist
and ankles.
Flat Bone
• Skull
• Two sheets of
compact bone
• Spongy bone
• They have broad
surfaces for
protection of
organs and
attachment of
muscles.
Irregular bones
• Bones of the face
and vertebrae
• They have varied
shapes, sizes and
surface features.
• All other bones
that do not fall into
the previous
categories.
(aka cranium)
scapula
carpals
metacarpals
phalanges
tarsals
metatarsals
phalanges
Cartilage
• Lines the surface of
joints so they move
smoothly
• Cushions vertebrae
• Supports nose and ears
Movement
• Ligaments
– Connects Bone to bone at a joint
• Prevents excessive movement
• Tendons
– Connects muscle to muscle
– Connects muscle to bone
Play the air piano!!…what you see in your
hands are your tendons working
Joints-
•A part of the
body where
bones are
connected.
Types of joints
• Ball and socket
• Hinge
• Pivot
• Gliding
• Cartlaginous
• http://www.brainpop.com/health/sk
eletalsystem/joints/
Care
• Nutrition: minerals
– Calcium builds strong bones
99% of body
calcium is in
your bones!!!
• Found in dairy products
• During teen years, body builds most of its bone mass
– Phosphorus
• Combines with calcium
• Milk, peas, beans, liver, cottage cheese, broccoli
• Exercise
– Weight-bearing exercises increase bone mass
– Promotes blood circulation which increases bone
nourishment
Fractures
• Fracture: any type of break
• 2 types
–Closed (aka simple)
• Nothing protrudes/sticks out
–Open ( aka compound)
• One or both bone ends
project through skin