L2 - Bone Histology - Articulate H Flashcards
Connective tissues are composed of two general things, what are they?
- Cells
2. Extracellular matrix (ECM)
Extracellular matrix has two major components, what are they?
- Proteins
2. Ground substance
The proteins in ECM are composed of what three things?
- Collagen fibers
- Reticular fibers
- Elastic fibers
The ground substance in ECM are composed of what three things?
- Glycosaminoglycans (GAGs)
- Proteoglycans
- Multiadhesive glycoproteins
What cells give rise to osteoblasts?
Mesenchymal stem cells
What cells give rise to Hematopoietic stem cells?
Mesenchymal stem cells
What cells give rise to osteoclasts?
Hematopoietic stem cells
What are the 5 listed major functions of bones?
- Support
- Protection
- Mechanical basis for movement
- Storage
- Blood cell formation
What are the 5 different shapes of bones?
- Long
- Short
- Flat
- Irregular
- Sesamoid
____ bones are found in all extremities except the patella, carpels, and tarsals.
Long bones
____ bones are found in the carpals and tarsals.
Short bones
____ bones are found in the sternum, scapulae, ribs, and most of the skull
Flat bones
____ bones are found in the vertebrae and os coxae?
Irregular bones
____ bones are found in the hands, knee, and feet as a bone that forms in a tendon.
Sesamoid bones
What are the two gross observations of bone tissues?
- They can be compact (cortical) bone
2. They can be spongy (cancellous)(trabecular) bone
Under a microscope do the histological structures of compact or spongy bone differ?
NO
What is the formal name for the shaft of a long bone?
Diaphysis
The diaphysis has what kind of outer shell and inner core?
Outer - compact
Inner - medullary (red or yellow bone marrow)
As humans age what happens to the red bone marrow found in long bones?
It is converted over to yellow bone marrow
What is the formal name for the bones ends?
Epiphysis
The epiphysis has what type of shell and what type of core?
Outer - compact
Inner - spongy
What can be found between the spicules of the spongy bone at the epiphysis?
red or yellow bone marrow
What is the formal name of the flared portion of bone found between diaphysis and epiphysis?
Metaphysis
The metaphysis extends from what to what?
Extends from diaphysis to the epiphyseal line.
What is found between the metaphysis and the epiphysis?
The epiphyseal line (plate)
When will you find an epiphyseal plate
In individuals that are still growing
What happens to the epiphyseal plate as we get older?
It is filled with bone as we stop growing and becomes the epiphyseal line
What is the name of the external double membrane covering of bones?
Periosteum
The periosteum has two layers what are they and what do they contain?
- The outer fibrous layer has dense irregular connective tissue.
- The inner osteogenic layer consisting of osteoblasts, osteoclasts, and osteogenic cells.
How does the periosteum anchor to the underlying bone?
Through collagen fibers termed perforating (Sharpey’s) fibers.
What is the name of the membrane that covers the internal surfaces of the bone?
Endosteum
What covers the articulating surfaces or joint surfaces of the bone?
Articular cartilage
What type of cartilage is articular cartilage?
Hyaline cartilage
What fibers create a strong anchor for the periosteum to attach to the bone?
Perforating (Sharpey’s) fibers
What do the long bones have that the short, irregular, and sesamoid bones not have?
Diaphyses, meaphyses, epiphyses, marrow cavities.
What are the layers of the short, irregular, and sesamoid bones? Is there marrow?
Inner - Spongy bone Inner covering - Endosteum Outer - Compact bone Outer shell - Periosteum - Yes there can be red or yellow marrow
Bone tissues have two major components, what are they?
- Cells
2. Extracellular matrix
What are the 4 components of bone cells?
- Osteogenic cells
- Osteoblasts
- Osteocytes
- Osteoclasts
What are the two components of bone ECM? what are they composed of?
- Organic (Osteoids) - Type I collagen and bone matrix proteins
- Inorganic - Hydroxyapatite
Order from osteogenic cell –> osteocyte in production?
Osteogenic cell –> Osteoblast –> Osteocyte
Osteogenic cells divide by ____ to give rise to osteoblasts?
Mitosis
_____ are responsible for synthesis and secretion of the organic component in bone matrix (osteoid). They also signal for the calcification of bone
Osteoblasts
_____ are located on the surface of bone matrix, they look basophilic and cuboidal.
Osteoblasts
_____ secrete so much matrix they get stuck there and turn into _____
osteocytes
_____ sit in lacuna, they live many years, and extend long cytoplasmic extensions in tunnels called canaliculi
Osteocytes
____ have reduced rough ER and Golgi complexes
Osteocytes
____ sit in pits called resorption bays and have a ruffled boarder
Osteoclasts
____ are formed from many monocytes and thus they are multi-nucleated
Osteoclasts
____ dissolve bone matrix by secreting enzymes and hydrogen ions creating an acidic environment.
Osteoclasts
Which of the 4 bone cells has a different pathway than arising from mesenchymal stem cells?
Osteoclasts - they arise from hematopoietic stem cells
Which cells are cuboidal looking with a basophilic cytoplasm? They actively secrete matrix
Osteoblasts
Large multi-nucleated motile cells removing newly deposited bone are called?
osteoclasts
Which cell has a halo surrounding the cell? This cell is responsible for maintaining the matrix.
Osteocyte
A stripe of material coming off of an osteoblast in an H&E staining would be considered what?
Osteoid
What does osteoblast secrete that secrete a small amount of vitamin K dependent polypeptide?
Osteoclasin
What are the small tunnels called that project off of an osteocyte?
Canaliculi
What is the important role of canaliculi?
This is the passageway for osteocytes, nutrients and waste products are sent through the cytoplasmic processes.
What are the two types of bone found under a microscope?
- Primary bone (woven or immature bone)
2. Secondary bone (lamellar or mature bone)
Which type of bone develops in fracture repair and in embryonic development by collagen fibers laid down in random arrangement?
Primary bone
Which bone type has lower mineral content and high amounts of osteocytes and is only temporary?
Primary bone
Which type of bone is very organized with collagen fibers laid parallel around a canal?
Secondary bone
Which bone type has concentric circles?
Secondary bone
When looking at a slide of a fractured bone what portions will be secondary and which portions will be primary?
The organized lamellar bone is secondary, the sporadic bone is primary
What type of tissue are both spongy (cancellous) bone and compact bone made from? primary or secondary?
Secondary
What gives structural organization to compact bone? Looking for one name.
Osteons (Haversian system)
What is at the center of an osteon and how is the osteon built out from there?
Central or Haversian canals surrounded by repeating concentric lamellar rings, each ring has opposing collagen fibers for strength.
How many concentric lamella generally make up 1 osteon?
4-10
What part of the osteon communicates with the marrow cavity and the periosteum through transverse (oblique) canals?
Central canals
The portion of the bone not associated with osteons but connecting to the periosteum is called what?
Outer circumferential lamella
The portion of bone between concentric rings that is not associated with the osteon is called?
Interstitial lamella
The portion of the bone not associated with osteons but connecting to the endosteum is called what?
Inner circumferential lamella
Is decalcified bone basophilic or acidophilic (eosinophilic)?
Acidophilic or eosinophilic
Perforating canals (volksman canals) allow the central canal to do what?
Communicate with the marrow cavity
Can you state the steps of developing new osteons?
- Osteoclasts tunnel
- Osteoprogenitor cells and blood capillaries
- Osteoblasts line the tunnel
- Osteoblasts –> Osteocytes
fill in everything around the central blood vessel
Spongy bone DOES NOT contain what?
Osteons
Trabeculae surround what space?
Red marrow space