Bones, joints, cartilages, and ligaments
When we were born we had over 300 bones. As we grew up,
some of the bones fused together. As an adult we only have
206 bones!
____
97% of all the creatures do not have a backbone or spine.
The human hand has 27 bones and our face has 14!
The smallest bone in our body is the stirrup bone in our ear it
measures 1/10 of an inch.
Video
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Support
Protection
Movement
Storage
Blood cell formation
Homeostatic balance
• Our bones are an internal framework
• Without bones to hold us up, we’d all be gooey
piles of mush flopping around on the floor
• Bones are the ‘reinforced concrete’ of the body
• Bones protect soft body organs
• For example, what would happen to our brain
if we didn’t have a skull??
• Our vertebrae protect our spinal cord
• Can you think of any other examples?
• Skeletal muscles are attached to bones by
tendons
• These muscles use our bones as levers to move
the body and its parts
• Fat is stored in the internal cavities of bones
• Bones are a ‘storehouse’ for minerals, including
calcium and phosphorous
• IMPORTANT: Ca2+ (calcium ion) must be
present in the blood at all times for
1. the nervous system to transmit messages
2. for muscles to contract
3. for blood to clot
• “Hematopoiesis” is blood cell formation
• Hematopoiesis occurs within the marrow cavities
of certain bones
• Longer than they are wide
• They typically have a long
centerpiece with a head at
both ends
• All the bones of the limbs (legs,
arms) except the carpals and
tarsals
•
•
•
•
Generally cube shaped
Contain mostly spongy bone
Best known example is a patella
Carpals, tarsals
• Thin, flattened
• Usually curved
• Have two thin layers of
compact bone sandwiching a
layer of spongy bone
• Most bones of the skull, the ribs,
and the sternum
• Any bone that doesn’t fit into a previous category
• Vertebrae of the spinal column, hip bones
HINT: Humans have 7.
7!! Both Humans and giraffes have the same
amount of bones on their necks, just that the
giraffes have a much longer vertebra.
Compact and spongy
• Compact
• Spongy
• COMPACT
• Dense
• Looks smooth and homogenous
• SPONGY
• Composed of small needlelike pieces of
bone and lots of open space
Yucky!
General anatomy of our bones
Pg 133
Proximal epiphysis
• Diaphysis: the
shaft of a long
bone, filled with
compact bone
• Epiphysis:
Rounded end of
a long bone
Distal epiphysis
• Periosteum: Fibrous
connective tissue that
covers and protects the
diaphysis
• The periosteum contains
the blood vessels and
nerves that provide
nourishment and
sensation to the bone.
• Instead of periosteum, articular cartilage covers both
epiphyses
• Glassy hyaline
cartilage which
makes it smooth
and slippery
• Why do you think
our bones are
covered with
glassy hyaline
cartilage?
• The epiphyseal line is a remnant of the epiphyseal plate
(a flat line of hyaline cartilage) seen in young, growing
bone
• When the bones are done
growing, the epiphyseal plate is
completely replaced by bone
• In adults, the cavity of the diaphysis is primarily a
storage area for FAT (or ‘adipose’ tissue)
• This is called yellow marrow.
• The cavity
where the
yellow marrow
is found is
called the
medullary
cavity.
Short
bones!
206!
1. What are the different functions of bones? Name as many of
the six as you can.
2. What are the four types of bones?
3. What are the ends of a long bone called? The proximal and
distal ____________?
4. What is the inner cavity of the diaphysis called?
5. Watch this video and reflect: “What properties of the skeletal
system make this man’s talent possible?”
•
A Man With No Bones
More details, baby!
• Axial (80 bones)
• Skull (cranium and face
bones)
• Vertebral Column
• Thoracic Cage
• Miscellaneous (hyoid and
inner ear ossicles)
126 bones)
• Appendicular (___
• Pectoral Girdle
• Arm
• Pelvic Girdle
• Leg
• Fibrous bands of
CT
• Ligaments connect
bone to bone.
• Tendons connect
muscles to bone.
• Ligaments and
tendons play a
significant role in
musculoskeletal
biomechanics.
1. Fibrous (synarthroses)
• Sutures (skull)
2. Cartilaginous (amphiarthroses)
• Pubic symphysis
• Intervertebral joints
3. Synovial (diarthroses)
• Most joints in appendages
• Joint cavity with synovial fluid
• What does it mean to be double jointed?
• What happens when we crack our knuckles?
Does this lead to arthritis?
1. Malleus (“hammer”
2. Incus (“anvil”)
3. Stapes (“stirrup”)