Bone Tissue
Spaces within spongy bone
Red marrow is found within: the large cavities contained within the shafts of long bone. compact bone canals. spaces within spongy bone. all osseous tissue of the appendicular skeleton.
Metaphysis
Region between shaft and end; this is where growth occurs in immature bone
tensile strength
Resistance to tearing and stretching
Example of a flat bone
Scapula
Membrane covering surface of bone
periosteum
hydroxypatite
primary mineral in bone, makes up major portion of bone; gives bone matrix compression strength for weight bearing; tricalcium phosphate
Function of compact bone
protection and support
Spongy bone aka
Cancellous bone, medullary bone
Example of a short bone
Carpals
What must be present before calcification?
Collagen fiber network
What is responsible for tensile strength in bone?
Collagen fibers
Osteocyte processes and ECF inside canaliculi provide network of
Communication & Exchange (oxygen, nutrients, waste products)
Shaft is what type of bone?
Compact
Two types of bone
Compact and spongy
Always covers spongy bone
Compact bone
What does osteoblast do?
Participates in bone formation; secretes matrix: collagen and uncalcified ground substance (osteoid)
Osteoblast becomes
Osteocyte
Principle bone cell
Osteocyte
Types of cells in trabeculae
Osteocytes within lacunae and canaliculi
Inner Periosteum
Osteogenic layer
Lines marrow cavity
endosteum
Osteogenic Cells aka
osteoprogenitor cells
Characteristics of collagenous fibers in bone
Arranged in parallel bundles; layers fit together like plywood, fibers aren't normally naturally visible
What is type of bone tissue based on?
Based on number of spaces in matrix
Mesenchyme
- Embryonic Connective Tissue - Gives rise to all other connective tissues
Parts of a long bone
1) Diaphysis 2) Epiphysis 3) Metaphysis 4) Hyaline 5) Periosteum 6) Marrow cavity 7) Endosteum
Characteristics of bone
1) Forms most of the skeleton 2) Relatively lightweight, considering its strength. 3) Bone is a very dynamic tissue. 4) Continually being remodeled
Five Principle Types of Bones
1) Long 2) Short 3) Flat 4) Irregular 5) Sutural 6) Sesamoid
Composition of Bone
30% collagenous fibers; 50-60% Mineralized salts, <20% Water
Matrix of osseous tissue
50% mineral salts, 35% fibers
When does osteoblast become an osteocyte?
After it is surrounded by matrix
What is Haversian canal surrounded by?
Concentric layers of bone matrix calle lamallae
Compact bone aka
Dense bone; cortical bone
Calcification
Deposition of mineral salts into a framework of collagen fibers
Why isn't a central canal needed in spongy bone?
Diffusion distance isn't very long
Epiphysis
End of a long bone
Example of a long bone
Femur
Outer Periosteum
Fibrous layer
Example of sutural bone
Found in skull (individual variations)
Insterstitial lamellae
Fragments of older, degenerating osteons
What are at ends of branches in compact bone?
Gap junctions
Canaliculi
Hairlike canals that connect lacunae to each other and the central canal; radiate from lacunae; filled with ECF
Funtion of Osseous Tissue
Homeostasis of Important Minerals, Hemopoiesis, Energy storage
Interstitial means
In between
Spongy bone is made up of
Lamellae arranged in an irregular network (lattice)
Components of mineralized salts
Makes bone largely inorganic (50-60%); Hydroxypatite, Calcium carbonate, Magnesium Salts
Periosteum
Membrane that covers bone surface
Endosteum
Membrane that lines the marrow cavity
What are osteoprogenitor cells derived from:
Mesenchyme
What is responsible for compressive strength in bone?
Mineral Salts
Can osteoblasts divide?
No
Does an osteocyte secrete matrix?
No
What do osteocytes direct?
Ongoing activities in mature bone such as protein synthesis and exhange.
Function of spongy bone
Only site of red marrow storage (blood cell formation); arranged to maximize transmission of force)
What does osteoprogenitor cells differentiate into
Osteoblast
Bone cell that Arises from monocytes
Osteoclast
Hyaline
Sometimes called hyaline-like; cartilage, covers bone surfaces where joints form.
What type of bone are the ends in long bone?
Spongy Bone covered with a thin layer of compact
Characteristics of osteogenic cells
Stem cell with mitotic potential
Function of Skeletal System
Support, protection, movement
Why does Osteoprogenitor cells divide?
To maintain stem cell line
Osteoid
Uncalcified ground substance
Example of an Irregular bone
Vertebrae
Cavity of shaft in long bone filled with
Yellow marrow
Marrow Cavity
aka Medulllary Cavity; space within the diaphysis, contains yellow marrow.
Hemopoiesis
blood cell formation
Osteoclast
bone cell that absorbs and removes unwanted bony tissue
osteocyte processes
branches of cell found within canaliculi
Volkmann's canals
channels lying at right angles to the central canal, connecting blood and nerve supply of the periosteum to that of the Haversian canal; also called Perforating ; passageways for vessels and nerves
Lamellae
concentric circles of bone
Osteocyte
mature bone cell
Haversian canal
one of a network of tubes running through compact bone that contains blood vessels and nerves
4 types of cells in bone tissue
osteogenic, osteoblasts, osteocytes, osteoclasts
Diaphysis
shaft of a long bone
Lacunae
small cavities in bone (lamella) that contain osteocytes
Haversian system
structural unit of compact bone; osteons
trabeculae
the irregular latticework of thin bony plates in spongy bone tissue
Spongy bone is composed of
thin plates: trabeculae