Bone Tissue Flashcards
Attributes of Bone
Makes up the hard parts of the skeleton with hard ECM to provide structure to the body, anchor skeletal muscles,
protect the CNS, heart, + lungs.
This connective tissue also devevlops blood, stores calcium in the ECM + triglycerides in adipose.
Primary components of the ECM in bone
Collagen
Calcium Phosphate
Osteoprogenitor cells
Stem cells that produce new osteoblasts
They live between periosteum and bone.
osteoblasts: Cells that make bone’s ECM
Osteoblasts
Cells that make bone’s ECM - type of fibroblast
Osteocytes
Mature osteoblast cells that have moved to the mature part of the bone to maintain the ECM.
Osteoclasts
Specialized cell that breaks down bone ECM. Unrelated to the other types of bone cells because they’re white blood cells (macrophage)
Compact bone
Solid bone
What, where, components
Located on the outside of bones without any visible holes.
Components:
* Osteons
* Lamellae → Lacunae → Osteocytes + Canaliculi
* Central Canal
* Perforating canals
Osteons
Circles of tissue in compact bone with a large channel running up the middle and along the axis of long bones.
They act as pillars for baring the weight of the bone.
Lamellae, lacunae, osteocytes, + canaliculi are found in these circles.
Lamellae
Visible concentric circles of ECM around the central canal.
Lacunae
Small holes in the spaces between the lamellae
Osteocytes live here to maintain the bone and touch little extensions though the canaliculi.
Canaliculi
Tiny canals touching eachother in bone ECM that connects lucanae to each other + to the central canal.
Gasses and nutrients are exchanged through these extensions.
Central Canal
Hole running through the middle of osteon containing blood vessels, lymph vessels + nerves.
Perforating canals
Channels that run perpendicular to osteon and carry blood between the central canals and blood outside the compact bone.
Spongy bone
What, where, components
Recognized by large visible holes giving it the appearance of a sponge. Located inside of bone.
Components:
* Bone marrow
* Trabeculae
* Lacuna
* Canaliculi + osteocytes
No central canal or osteons
Trabeculae
The hard web-looking part of spongy bone.
The different angles + multiple directions provide support to the bone.
Lacuna, canaliculi + osteocytes also live here.
Yellow marrow
Composed of adipose tissue storing triglycerides.
Red marrow
Blood cells (red + white) development site.
Long bone structure
- 2 Epiphysis
- Articular cartilage
- Diaphyis
Epiphysis
Long bone head with a proximal + distal end
Made of thin compact bone around the outside + has spongy bone with red bone marrow inside.
Articular cartilage
Located on either end of long bones.
It’s composed of hyaline cartilage that forms the base of joints with other bones.
Diaphyis
Also known as the long shaft of long bone
Composed of compact bone around the outside, Spongy bone only at the ends, and a medullary cavity filled with yellow bone marrow.
Medullary cavity
The empty space in diaphyis filled with yellow bone marrow.
Flat, irregular, + short bones structure similarities
Compact bone is around the outside
Mostly filled with spongy bone on the inside
Hyaline cartilage where joints will be connected.
Periosteum
Membrane of dense irregular connective tissue that lines the outer surface of all bones. Blood vessels + sensory neurons cen be found in this membrane.
Endostium
Membrane of dense irregular connective tissue that line the inside of bone, trabeculae in spongy bone + inside of the medullar cavity.
What is cartilage’s relavance?
The other connective tissue found in the skeleton that’s strong but more flexible than bone with no calcium in the ECM. Cartilage has no blood vessels or neurons.