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Resorption canal progression
This series of images shows stages in the life span of a bone remodeling unit (BRU), a two-stage process whereby cortical bone is remodeled from within. The first stage of a BRU begins with osteoclastic erosion of bone in a “resorption canal” that advances lengthwise within the bone, forming a tunnel. In the second stage, osteoblasts deposit bone, beginning at the origin of the resorption canal, which creates the “closing end” of the BRU. The continued centripetal deposition of lamellae creates a new osteon.
![Resorption canals <p>This series of images shows stages in the life span of a bone remodeling unit (BRU), a two-stage process whereby cortical bone is remodeled from within. The first stage of a BRU begins with osteoclastic erosion of bone in a “resorption canal” that advances lengthwise within the bone, forming a tunnel. In the second stage, osteoblasts deposit bone, beginning at the origin of the resorption canal, which creates the “closing end” of the BRU. The continued centripal deposition of lamellae creates a new osteon.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.RR_.07-1-ping.png)
Resorption canals
This series of images shows stages in the life span of a bone remodeling unit (BRU), a two-stage process whereby cortical bone is remodeled from within. The first stage of a BRU begins with osteoclastic erosion of bone in a “resorption canal” that advances lengthwise within the bone, forming a tunnel. In the second stage, osteoblasts deposit bone, beginning at the origin of the resorption canal, which creates the “closing end” of the BRU. The continued centripal deposition of lamellae creates a new osteon.
![- Osteoclasts <p>This series of images shows stages in the life span of a bone remodeling unit (BRU), a two-stage process whereby cortical bone is remodeled from within. The first stage of a BRU begins with osteoclastic erosion of bone in a “resorption canal” that advances lengthwise within the bone, forming a tunnel. In the second stage, osteoblasts deposit bone, beginning at the origin of the resorption canal, which creates the “closing end” of the BRU. The continued centripal deposition of lamellae creates a new osteon.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.RR_.07-2-ping.png)
- Osteoclasts
This series of images shows stages in the life span of a bone remodeling unit (BRU), a two-stage process whereby cortical bone is remodeled from within. The first stage of a BRU begins with osteoclastic erosion of bone in a “resorption canal” that advances lengthwise within the bone, forming a tunnel. In the second stage, osteoblasts deposit bone, beginning at the origin of the resorption canal, which creates the “closing end” of the BRU. The continued centripal deposition of lamellae creates a new osteon.
![- Blood vessels <p>This series of images shows stages in the life span of a bone remodeling unit (BRU), a two-stage process whereby cortical bone is remodeled from within. The first stage of a BRU begins with osteoclastic erosion of bone in a “resorption canal” that advances lengthwise within the bone, forming a tunnel. In the second stage, osteoblasts deposit bone, beginning at the origin of the resorption canal, which creates the “closing end” of the BRU. The continued centripal deposition of lamellae creates a new osteon.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.RR_.07-3-ping.png)
- Blood vessels
This series of images shows stages in the life span of a bone remodeling unit (BRU), a two-stage process whereby cortical bone is remodeled from within. The first stage of a BRU begins with osteoclastic erosion of bone in a “resorption canal” that advances lengthwise within the bone, forming a tunnel. In the second stage, osteoblasts deposit bone, beginning at the origin of the resorption canal, which creates the “closing end” of the BRU. The continued centripal deposition of lamellae creates a new osteon.
![Closing end > <p>As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.DR_.17-4A-ping.png)
Closing end >
As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.
![- Osteoblasts <p>As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.DR_.17-5A-ping.png)
- Osteoblasts
As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.
![- Osteoid <p>As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.DR_.17-6A-ping.png)
- Osteoid
As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.
![- New Haversian system <p>As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.DR_.17-7A-ping.png)
- New Haversian system
As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.
![- Oldest lamella <p>As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.DR_.17-8A-ping.png)
- Oldest lamella
As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.
![- Youngest lamella <p>As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.DR_.17-9A-ping.png)
- Youngest lamella
As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.
![- Haversian canal with blood vessel <p>As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.DR_.17-10A-ping.png)
- Haversian canal with blood vessel
As resorption advances, osteoblasts in the endosteum at the original site of resorption become active and begin to secrete osteoid onto the eroded surface. The deposited osteoid eventually mineralizes, forming the outermost lamella of a newly forming osteon. The process continues, lamella by lamella until an osteon is established. This centripetal growth establishes the oldest lamella of an osteon at the periphery, with the youngest located immediately surrounding the Haversian canal.
![- Cement line > <p>The outer boundary of the newly formed osteon is marked by a cement line that appears as a basophilic ring around the osteon due to its higher concentration of ground substance.</p>](https://digitalhistology.org/wp-content/uploads/2019/04/T.C.B.DR_.17-11A-ping.png)
- Cement line >
The outer boundary of the newly formed osteon is marked by a cement line that appears as a basophilic ring around the osteon due to its higher concentration of ground substance.