Lesson 2 Flashcards
What is the ECM made up of?
Water, collagen fibers (organic), and crystallized mineral salts (inorganic)
What makes up the ECM the least and most?
15% water, 55% crystallized mineral salts
What secretes collagen fibers?
Osteoblasts
What do osetoblasts secrete?
Collagen fibers
What purpose do collagen fibers serve?
Prevent bone shattering
What would happen if bone was only made up of crystallized mineral salts?
Bones could shatter upon harsh impact
What cells are in osseous tissue?
Osteogenic cells
Osteoblast cells
Osteocyte cells
Osteoclast cells
Where are osteogenic cells found in higher densities?
Outer bone surfaces and in the medullary cavity
Where are osteoblast cells found in higher densities?
Outer bone surfaces and in the medullary cavity
What cells develop into osteoblasts?
Osteogenic cells
What do osteogenic cells develop into?
Osteoblasts
What cells build bone?
Osteoblasts
What do osteoblasts do?
Build bone
What cells are mature bone cells?
Osteocytes
What do osteocytes do?
Communicate with other osteocytes to upkeep with daily metabolism of bone tissue
What do osteoclasts do?
Breakdown bones via lysosomal enzymes
Which of the cells in the osseous tissue are the biggest?
Osteoclasts
What cells breakdown bone tissue?
Osteoclasts
What cells communicate with osteocytes to upkeep with the daily metabolism of bone tissue?
Osteocytes
What is the life cycle of osseous tissue?
Osteogenic cells→ osteoblasts→ osteocytes
What cells are not part of the life cycle of osseous tissue?
Osteoclasts
What are the 2 types of bone?
Spongy and compact
What is compact bone also known as?
Dense or cortical bone
What type of bone has strength in bending?
Compact bone
What do compact bone have strength in?
Bending
What type of bone forms the bulk of diaphysis of long bones?
Compact bones
What bone is the longest of long bones?
Femur
What does compact bone consist of?
Neighbouring osteons/Harvesian systems
How are osteons aligned in compact bone?
In the same direction along stress lines
What are concentric lamellae in osetons?
Mineralized ECM with osteocytes
What are lacunae in osteons?
Spaces between lamellae
What are canliculi in osteons?
Lacunae extensions
What are interstitial lamellae in osteons?
Old osteon fragments to be removed from the bone
What is the central canal in osteons?
A passageway for neurovasculature and lymphatics
What cells do cicumferential lamellae have lots of?
Osteogenic and osteoblast cells
What are circumferential lamellae important for?
Bone width growth or appositional growth
What is the end part of a long bone called?
Epiphysis
What is the epiphysis?
The end of a long bone
What is the diaphysis?
The middle of a long bone
What is the middle of a long bone called?
Diaphysis
What is the metaphysis?
The part of the long bone between the epiphysis and diaphysis
What is the part of the long bone between the epiphysis and diaphysis called?
Metaphysis
What is the epiphyseal plate of a long bone made up of?
Hyaline cartilage
When do bones stop growing in length for males and females?
21 in males and 18 in females
What is the hyaline cartilage replaced by?
Bone at 21 in males and 18 in females resulting in the bones stop growing in length
Where is articular cartilage located?
On the ephiphysis
What does the articular cartilage do?
Helps with shock absorption
Why does articular cartilage not heal well?
B/c it does not have high blood supply
What is the periosteum?
An outer connective tissue layer that surrounds all bones (except where there is articular cartilage)
What surrounds all bones except where there is articular cartilage?
Periosteum
What is the periosteum adhered to?
Circumferential lamellae
What are the periosteum layers like?
Outer fibrous layer
Inner osteogenic layer
What lies within the periosteum and is lined by endosteum?
Medullary cavity
What fibers allow close adherence between the periosteum and the compact bone?
Perforating/Sharpey’s fibers
What canals perforate the periosteum and compact bone to allow neurovasculature to enter?
Perforating/Volkmann’s canals
What is spongy bone also known as?
Trabecular or cancellous bone
What type of bone has strength in compression?
Spongy bone
What does spongy bone have strength in?
Compression
What type of bone forms the bulk of epiphysis of long bones and short, flat, irregular bones?
Spongy bone
What does spongy bone do?
Protects the marrows and reduces bone weight
