TOPIC 4 - OSSEOUS TISSUE/BONE Flashcards
Major and structural and supportive connective tissue of the body that forms the rigid part of the bone organs that make up the skeletal system.
Osseous tissue
Give the 7 characteristics of bone.
- Most dynamic structure in the body and is greatly affected by nutritional and metabolic changes
- Reservoir for calcium and phosphorus that undergo a constant flux in and out (absorption and release) of the bone matrix
- Respond to injury by rapid healing
- Undergoes internal modeling (modified, reshaped and overhauled) throughout life without changing its gross appearance
- Bone cells are in contact with each other thru cellular processes embedded in tiny channels in the hard bone matrix called canaliculi
- Highly vascular
- Grows thru appositional method only
Bone forms when ___ salts are deposited around protein fibers which provides ___ to bones.
calcium, rigidity
Fibers in bone provides ?
Elasticity and strength
Give the 5 functions of osseous tissue.
- Support for muscles, organs and soft tissues
- Leverage and movement
- Protection of vital organs
- Storage of calcium phosphate
- Hematopoiesis - formation of blood cells in the bone marrow within the spongy bone
This forms a system of channels thru which processes from one osteocyte can contact adjacent cells allowing osteocytes to communicate with one another for passage of information, nutrients and wastes from cells near blood vessels to those trapped in lacunae.
Canaliculi
Bones are formed by what cell?
Osteoblasts
Osteoblasts deposit Type __ collagen and also release ___, ___ and ___ within that ultimately combine chemically within the collagenous matrix into a crystalline mineral known as ___.
I, calcium, magnesium, phosphate, hydroxyapatite
Type of osseous tissue that forms an extremely hard exterior
Compact/Cortical Bone
Type of osseous tissue that fills the hollow interior.
Spongy bone
Other terms for spongy bone
Trabecular/Cancellous bone
Functional unit of compact bone
Haversian System
Other term for haversian system
Osteon
Concentric layers of haversian system is called?
Lamellae
Lamella surrounds a canal called ?
Central canal/Haversian Canal
Haversian canal contains bone’s ___ and ___ ___
nerve, blood supplies
Boundary of an osteon is called ?
Cement line
Remnants of osteons that have been destroyed.
Interstitial Lamellae
Lamellae that are arranged parallel to the surface
Circumferential Lamellae
An oblique channel connecting osteon to the periosteum.
Volkmann’s or Perforating Canals
These fibers rub parallel to each other in lamellae and oblique in others.
Collagen fibers
This type of bone develops directly from pre-existing mesenchymal connective tissue.
Intramembranous bone/membrane bone
This type of bone develops indirectly from a pre-existing cartilage that is gradually destroyed and replaced by cancellous bone.
Endochondral bone
Give a classification of bone that is intramembranous bone.
Flat bones
Give a classification of bone that is endochondral bone.
Tubular bones ( femur, radius)
Give the five shapes of bone.
- Long bones
- Short bones
- Flat bones
- Irregular bones
It refers to the long shaft of bone.
Diaphysis
It refers to the ends of bone.
Epiphysis
It is the growth plate.
Epiphyseal plate
It refers to the part between epiphysis and diaphysis.
Metaphysis
It covers epiphysis.
Articular cartilage
It is the external covering of the bone.
Periosteum
Bundles of collagen fibers that attaches periosteum to the underlying bone.
Sharpey’s fibers
Hollow chamber in bone
Medullary cavity
Thin layer lining the medullary cavity
Endosteum
Blood vessels and nerves penetrate periosteum through horizontal openings called ___ canals.
Volkmann’s/Perforating
Bone is supplied with blood by ___ and ___.
- Periosteal arteries
- Epiphyseal veins
It carries blood away from long bones.
Epiphyseal veins
The periosteum is rich in ___ nerves sensitive to tearing or tension.
Sensory
Cancellous bone is in what arrangement?
Haphazard arrangement
These shape of bones are made up of mostly spongy bone.
- Short bones
- Flat bones
- Irregular bone
Composition of bone matrix
25% water
25% protein
50% mineral salts
4 cell types making up osseous tissue
- Osteoprogenitor cell
- Osteoblasts
- Osteocytes
- Osteoclasts
These are bone cells derived from mesenchyme; unspecialized stem cell; found on inner surface of periosteum and endosteum
Osteoprogenitor cell
This bone cell develop into osteoblasts.
Osteoprogenitor cell
These are bone forming cells found on surface of bone; no ability to mitotically divide; has collagen secretors.
Osteoblasts
These bone cells are “mature”; do not secrete matrix material; take part in nutrient exchange and blood waste.
Osteocytes
These bone cells are called bone resorbing cells and is responsible for growth, maintenance, and bone repair.
Osteoclasts
Give the 5 abundant inorganic mineral salts in bone.
- Tricalcium phosphate in crystalline form called hydroxyapatite - Ca3 (PO4)2(OH)2
- Calcium carbonate - CACO3
- Magnesium Hydroxide - Mg(OH)2
- Fluoride
- Sulfate
Small cavities where the chondrocytes are encased.
Lacunae
These are cartilage-producing cells.
Chondrocytes
Layer of dense irregular connective tissue that surrounds the cartilage.
Perichondrium
What is the process of bone formation called?
Ossification
This cartilage provides support through its flexibility.
Hyaline cartilage
This cartilage can tolerate repeated bending.
Elastic cartilage
This cartilage can resists strong compression and strong tension.
Fibrocartilage
The process of bone formation is called ?
Ossification
4 situations wherein bone formation occurs
- Formation of bone in an embryo
- Growth of bones until adulthood
- Remodeling of bone
- Repair of structures
Cartilage formation and ossification occurs during the __ week of embryonic development.
6th
Flat bones of the skull and mandible are formed in this type of ossification.
Intramembranous ossification
This is the replacement of cartilage by the bone.
Endochondral ossification
3 steps of intramembranous ossification
- An ossification center appears in the fibrous connective tissue membrane
- Osteoblasts secrete bone matrix within the fibrous membrane
- Osteoblasts mature into osteocytes
It is the growth where cartilage continually grows and is replaced by bone.
Longitudinal growth
The growth in length of long bones involves two major events. These major events are ?
- Growth of cartilage on the epiphyseal plate
- Replacement of cartilage by bone tissue in the epiphyseal plate.
4 zones of resting bone growth under hGh
- Zone of resting cartilage (quiescent)
- Zone of proliferating cartilage (proliferation zone)
- Zone of hypertrophic (maturing cartilage)
- Zone of calcified cartilage
This 2nd zone of bone growth under hGH is marked by chondrocytes stacking like coins which then divides.
Proliferation zone
This 1st zone of bone growth under hGH is marked by scattered chondrocytes and no actual bone growth.
Zone of resting cartilage
This 3rd zone of bone growth under hGH is marked by large chondrocytes arranged in columns and lengthwise expansion of epiphyseal plate.
Zone of hypertrophic (maturing) cartilage
This 4th zone of bone growth under hGH is marked by dead chondrocytes surround by a calcified matrix, occupation of osteoblasts and osteoclasts and capillaries from the diaphysis.
Zone of calcified cartilage
This bone growth is classified as growth of a bone by addition of bone tissue to its surface.
Appositional growth
It adds bone tissue to the external surface of the diaphysis.
Osteoblasts
It removes bone from the internal surface of the diaphysis.
Osteoclasts
Does bone continually renews itself? Yes or No?
Yes
What is the process where bone continually renews itself?
Bone remodelling
Spongy bone is replaced every __ years
3-4 years
Compact bone is replaced every ___ years.
10 years
What are the steps of bone repair?
- Hematoma formation
- Fibrocartilaginous callus formation
- Bony callus formation
- Remodeling of bone
This 3rd stage of bone repair is marked by osteoclasts resorbing the dead bone; osteogenic cells become active, divide, and differentiate into osteoblasts;
The cartilage in the calli is then replaced by trabecular bone via e.c. ossification
Bony callus formation
This 1st stage of bone repair is marked by the formation of fracture hematoma by the clotted blood.
Hematoma formation
In how many hours does hematoma forms after the fracture?
6-8 hours
This 2nd stage of bone repair is marked by internal callus formation of chondrocytes from endosteum.
Then, the periosteal chondrocytes and osteoblasts create an external callus of hyaline cartilage and bone, respectively, around the outside of the break which then stabilizes the fracture.
Fibrocartilaginous callus formation
This 4th stage of bone repair is marked by union of internal and external calli, replacement of compact bone from spongy bone at the outer margins, and healing is complete.
Remodeling of bone
How does chondrocytes from the endosteum create an internal callus?
By secreting a fibrocartilaginous matrix between the two ends of the broken bone
