Bone Cells and Tissue
Bone Cells
1. Osteoprogenitor cells- stem cells of bone
Osteo = Bone, Geni = beginning.
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Spindle shaped
Oval nucleus
Pale cytoplasm
Found in the
covering of the
bone, and lining of
inner cavity of
bone.
• Osteoprogenitor cells differentiate into osteoblasts.
2. Osteoblasts- make the extracellular matrix .
Blast = sprout
• Cells are more
columnar
• have well
developed
Golgi bodies
– Osteoblasts differentiate into osteocytes.
3. Osteocytes-maintain the matrix.
Cytes = Cell
• Note how
osteocytes are
connected to
each other.
• They live in
small spaces in
the matrix called
lacunae.
4.
Osteoclasts- secrete acid that breaks down
mineralized matrix
• Multinucleated
• Large
After bone is
broken down, what
cell will invade the
area and deposit
new bone matrix?
Osteoblast
Bone Tissue
Compact bone
• Found in the shafts of our long bones and on the inner and
outer surface of our flat bones.
• Provide strength.
1
Canaliculi- small tubes in the
matirx that connect bone cells
2
3
Central/Haversion canalcontains blood vessels
Lacuna- Cavity that holds an
osteocyte
Lamellae- layers of matrix
4
Osteon- cylinder shaped unit
What is the bone matrix made of?
-25% water
-25% collagen fibers (provide strength, resilience)
-50% inorganic salts- calcium and phosphorus
(hard, resistant to crushing)
Spongy (cancellous) bone.
The Structure of
Bone
• Found within flat bones and in the ends of long bones.
• Stores red bone marrow
How do you think
compact and spongy
bone got their name?
Bone marrow aspiration and biopsy.
Cartilage
• Hyaline cartilage
-found at ends of long
bones between joints
-important in bone growth,
protects ends of bones
• Fibrocartilage
-found between vertebrae
-cushions
Dense Regular Connective tissue
• Covering of a bone
• Allows for attachment of tendons and ligaments
Blood
• Found throughout the bone
• Brings nutrients, removes wastes
-Nervous tissue
• Found in the covering of the bone
• Sends and receives messages
Together these tissues function in...
1. Support and Movement (Explain)
– Our bones provide support for sitting and standing.
– Our bones act as levers for our muscles to pull
against.
2. Protection (Explain)
– Our skulls protect our brain.
– Our vertebrae protects our spinal cord.
– Our ribcage acts as a shield to protect our important
thoracic organs (heart and lungs).
3. Storage
(What is bone storing?)
– Our skeletal tissue stores minerals that can be
released as needed- calcium and phosphorous
– Adult long bones store yellow marrow, an energy
reserve
4. Hematopoiesis
-formation of blood cells
Homework
• Complete Bone Cells and Tissue homework
• Color Bone Matrix