Cartilage, Bone and Bone Development. Flashcards
Cartilage
One of the supporting connective tissues.
____ support in adult. Pinna of ear, epiglottis
Minimizes ____
____ surfaces in joints.
____ support
- During ____ development.
- During ____ of bony tissue e.g. fractures.
One of the supporting connective tissues. Flexible support in adult. Pinna of ear, epiglottis Minimizes abrasion. Articular surfaces in joints. Temporary support During embryonic development. During healing of bony tissue e.g. fractures.
Cartilage Composition.
Cells in cartilage are ____s
. Chondroblasts are on the ____
Extracellular matrix
- ____
- ___ ___
____ and receives nutrition by diffusion Nutrients diffuse from the capillaries in ___ or from the ___ ___. No ___ ___ or ___
Cells in cartilage are chondrocytes. Chondroblasts are on the surface. Extracellular matrix fibers “ground substance”. Avascular and receives nutrition by diffusion Nutrients diffuse from the capillaries in perichondrium or from the synovial fluid No lymphatic vessels or nerves!
Cartilage Cells.
Chondrocytes. Lie within the ____ they have synthesized.
Chondroblasts. Located in _____
Perichondrium. A __ ____ connective tissue divided into the__ ___ ___ and the ___ __ ___
Chondrocytes. Lie within the matrix they have synthesized. Chondroblasts. Located in perichondrium Perichondrium. A dense irregular connective tissue divided into the outer fibrous layer and the inner chondrogenic layer.
Chondrocytes.
Lie within spaces known as ____ in the ECM.
May continue to synthesize material around them by ___ ___.
Capable of cell division: Clusters of 2, 4 or 8 cells___ __ ___
Lie within spaces known as lacunae in the ECM. May continue to synthesize material around them by interstitial growth. Capable of cell division: Clusters of 2, 4 or 8 cells Isogenic cell nests.
Chondroblasts.
Located in the ____ on surface of the cartilage.
___ to ___ cells that may resemble ____.
Easily differentiate into ____
Located in the perichondrium on surface of the cartilage. Flattened to oval cells that may resemble fibroblasts. Easily differentiate into chondrocytes.
The Three Types of Cartilage Hyaline Elastic Fibrocartilage
Hyaline Elastic Fibrocartilage
Hyaline Cartilage.
____ plus____ flexibility.
Where: ___ , ___ ___
Fibers:. Type ___ collagen only.
Perichondrium?
Strength plus limited flexibility. Ribs, articular surfaces. Type II collagen only. Perichondrium.
Elastic Cartilage.
___ strength but___ flexibility.
Collagen type ___ plus ____ fibers.
Where: ___ of ___ , ____
Perichondrium?
Elastic fibers stained with Weigert’s stain.
Some strength but great flexibility. Collagen type II plus elastic fibers. Pinna of ear, epiglottis. Perichondrium. Elastic fibers stained with Weigert’s stain.
Fibrocartilage.
Resistance to __ ___
Where: ____ ___ of ___, ___ ___.
Thick bundles of type ___ collagen plus fine fibers of type ___ collagen.
____ chondrocytes or____ c groups arranged in long or short ___.
Perichondrium?
Resistance to mechanical stress Intervertebral disc of vertebrae. Pubic symphysis. Thick bundles of type I collagen plus fine fibers of type II collagen. Single chondrocytes or isogenic groups arranged in long or short rows. No perichondrium.
Extracellular Matrix Fibers All cartilage types contain Collagen type II. Collagen type II fibers are generally __ ___to see at the light microscope level. Elastic cartilage also contains elastic fibers. Fibrocartilage also contains numerous large bundles of type I collagen.
Fibers All cartilage types contain Collagen type II. Collagen type II fibers are generally too small to see at the light microscope level. Elastic cartilage also contains elastic fibers. Fibrocartilage also contains numerous large bundles of type I collagen.
Extracellular Matrix Ground substance components include:
_____: Chondroitin – 4 sulfate. Chondroitin – 6 sulfate. Keratan sulfate. Core proteins. ____
___ and ___
Ground substance components include: Proteoglycans. Chondroitin – 4 sulfate. Chondroitin – 6 sulfate. Keratan sulfate. Core proteins. Chondronectin. Water and ions.
Extracellular Matrix.
____ matrix: ECM immediately surrounding the____. ___in glycosaminoglycans- ___ in collagen. ___ basophilic.
____ matrix. Remaining ECM
Territorial matrix: ECM immediately surrounding the lacunae. Rich in glycosaminoglycans- poor in collagen More basophilic. Interterritorial matrix. Remaining ECM
Bone. A supporting connective tissue in which the extracellular matrix is __ ___
A supporting connective tissue in which the extracellular matrix is highly mineralized.
Osteo- , ossi from the Greek osteon meaning ___: Osteoblasts, Osteocytes. Osteoarthritis. Osteoporosis etc.
Osteo- , ossi from the Greek osteon meaning bone: Osteoblasts, Osteocytes. Osteoarthritis. Osteoporosis etc.
Bone. Major Functions:
___ and ___ internal organs.
____ site for muscle leverage.
Site for homeostatis of various___s
. Site for ____s (bone marrow).
Major Functions: Supports and protects internal organs. Attachment site for muscle leverage. Site for homeostatis of various ions. Site for hematopoiesis (bone marrow).
Bone - General Structure.
Cells: Osteo___. Osteo___. Osteo___
Extracellular matrix: ___, __ ___, ____
Cells: Osteocytes. Osteoblasts. Osteoclasts. Extracellular matrix: Fibers. Ground substance. Mineral.
General Structure.
Cells in ___, surrounded by ____.
Matrix is infiltrated with ____ salts for a rigid, inflexible mass.
Periosteum or endosteum –cells on____
____ vascular.
Constant ___ in response to physical stresses of body and mineral needs.
Cells in lacunae, surrounded by matrix. Matrix is infiltrated with inorganic salts for a rigid, inflexible mass. Periosteum or endosteum –cells on surface. Highly vascular. Constant remodeling in response to physical stresses of body and mineral needs.
General structure of bone
Bone Marrow Cavity: Red: Hematopoietic Yellow: Fat
Spongy (Cancellous) Bone: Trabeculae with ___
Compact Bone Almost exclusively __ ___
Bone Marrow Cavity: Red: Hematopoietic Yellow: Fat Spongy (Cancellous) Bone: Trabeculae with spaces Compact Bone Almost exclusively bone substance.
Components. By volume: Water ~ 10% Organic components ~ 35- 45% Inorganic ~ 50% By weight: Water ~ 10% Organic components ~ 33% Inorganic ~ 60 -65%
By volume: Water ~ 10% Organic components ~ 35- 45% Inorganic ~ 50% By weight: Water ~ 10% Organic components ~ 33% Inorganic ~ 60 -65%
Inorganic. A mixture of calcium phosphate, carbonate, potassium, magnesium, sulfate, fluoride and traces of other metals.____is the most common: Ca10(PO4)6OH2
A mixture of calcium phosphate, carbonate, potassium, magnesium, sulfate, fluoride and traces of other metals. Hydroxyapatite is the most common: Ca10(PO4)6OH2
Organic Collagen type ___ major organic ~ 90%.
Proteoglycan aggregates, specific structural glycoproteins, non-collagenous proteins ~ 10%.
Collagen type I major organic ~ 90%. Proteoglycan aggregates, specific structural glycoproteins, non-collagenous proteins ~ 10%.
Non Collagenous Proteins.
Include:
Osteocalcin – involved in ___ ___
Osteonectin - important in ___ ___
Osteopontin - ____ ____
Bone sialoprotein - ___ ___
Bone morphogenic protein - may be a ____ factor.
Note that many of these are found in various tissues.
Include: Osteocalcin – involved in bone mineralization. Osteonectin - important in bone formation. Osteopontin - osteoblast attachment. Bone sialoprotein - osteoblast adhesion. Bone morphogenic protein - may be a differentiation factor. Note that many of these are found in various tissues.
Other Components. Chondroitin -_–sulfate. Chondroitin -_ – sulfate. ____ sulfate.
Chondroitin -6 –sulfate. Chondroitin -4 – sulfate. Keratan sulfate.
Bone Cells and Functions. There is always a __ ___r of cells on bone surface. Osteocytes - cells ___ in bone ECM. ____ bone.
Osteoblasts - on the ___e of bone. ____bone. Bone lining cells - ___ ___
Osteoclasts - on the ____of bone. ____ bone.
There is always a continuous layer of cells on bone surface. Osteocytes - cells embedded in bone ECM. Maintain bone. Osteoblasts - on the surface of bone. Form bone. Bone lining cells - resting osteoblasts. Osteoclasts - on the surface of bone. Resorb bone.
Osteoid. Bone is formed by first synthesizing a ___ ___d bone matrix know as osteoid and then ____this matrix.
While the osteoid is being mineralized __ ___ is being formed
The surface of bone therefore always contains a ___ of__ ___ ___
Bone is formed by first synthesizing a non mineralized bone matrix know as osteoid and then mineralizing this matrix. While the osteoid is being mineralized new osteoid is being formed The surface of bone therefore always contains a layer of non mineralized osteoid.
Osteocytes. Lie within spaces (____) in the bone ECM
Communicate with other osteocytes and with osteoblasts on the surface by means of ___ ___ in bone known as ____.
Osteocytes are able to aid in homeostasis via metabolism of ions that are then transferred to cells on the surface.
Lie within spaces (lacunae) in the bone ECM Communicate with other osteocytes and with osteoblasts on the surface by means of small channels in bone known as canaliculi. Osteocytes are able to aid in homeostasis via metabolism of ions that are then transferred to cells on the surface.
Osteoblasts.
Cells on the surface of bone that form the bone ECM and then ____e it.
Cuboidal cells with basophilic cytoplasm.
When surrounded by ECM they produce they become ____.
Cells on the surface of bone that form the bone ECM and then mineralize it. Cuboidal cells with basophilic cytoplasm. When surrounded by ECM they produce they become osteocytes.
Bone Lining Cells. In essence “resting osteoblast”.
____cells on surface of bone. Able to again become____ osteoblasts if required.
In essence “resting osteoblast”. Flattened cells on surface of bone. Able to again become active osteoblasts if required.
Periosteum and Endosteum.
Periosteum: A __ ___ connective tissue of ___layers on the___l surfaces of bone. Endosteum A ___ layer of cells on all ____ surfaces of bone.
Periosteum: A dense irregular connective tissue of 3-4 layers on the external surfaces of bone. Endosteum A single layer of cells on all inner surfaces of bone.
Osteoclasts.
Large ____ cells on the surface of bone.
Pink to red in H and E due to large number of ____.
Resorb both the___ and ___ components of bone.
Form hollowed spaces known as ____ ____
Large multinucleate cells on the surface of bone. Pink to red in H and E due to large number of mitochondria. Resorb both the organic and inorganic components of bone. Form hollowed spaces known as Howship’s lacunae.
Bone Cells.
Bone cells are coordinated in their ___ and have various ___.
Osteoclast and osteoblast differentiation and functions are controlled by a variety of ___ and ___ factors.
Bone cells are coordinated in their functions and have various receptors. Osteoclast and osteoblast differentiation and functions are controlled by a variety of transcription and signaling factors.
Classifications of Bone.
Development – time of formation ___, ___
Function:___, ____.
Method of formation: _____, ____
Development – time of formation Mature, immature. Function: Spongy. Compact. Method of formation: Intramembranous. Endochondral.
Immature Bone. Various names. Immature bone. ___, ____
Various names. Immature bone. Primary bone. Woven bone.
Immature Bone. This is laid down ____ without time for the regular ____ seen in adult bones. Cells and fibers ___ oriented. Bone is___ as ____as mature bone.
Immature bone is a ____ bone.
____
____ of fractures
This is laid down rapidly without time for the regular organization seen in adult bones. Cells and fibers randomly oriented. Bone is not as strong as mature bone. Immature bone is a temporary bone. Development Healing of fractures
Mature Bone. Also known as ____ bone or___ bone.
Bone composed of layers or ____.
Alternate lamellae have ____ fibers oriented in ____directions to increase overall ____.
Mature bone is an adult bone that includes both __- and ____ bone
Also known as lamellar bone or secondary bone. Bone composed of layers or lamellae. Alternate lamellae have collagen fibers oriented in different directions to increase overall strength. Mature bone is an adult bone that includes both spongy and compact bone.
Spongy Bone.
Various names:
Spongy bone – ___ like appearance.
____bone – as it is made of plates known as ____
___bone – because of the presence of ____ between bone plates.
This is a type of mature bone and is always formed of lamellae.
Various names: Spongy bone – sponge like appearance. Trabecular bone – as it is made of plates known as trabeculae. Cancellous bone – because of the presence of spaces between bone plates. This is a type of mature bone and is always formed of lamellae.
Spongy Bone. Forms a network from individual ____ of bone known as trabeculae.
____ but supportive.
A very ___ surface area available for metabolism. Is a type of lamellar bone.
Forms a network from individual spicules of bone known as trabeculae. Lightweight but supportive. A very large surface area available for metabolism. Is a type of lamellar bone.
Compact Bone. Various names:
Compact bone -__ ___ except for lacunae.
___ bone –___and able to withstand ___.
___ bone – composed of units known as___ or ___ ___
Various names: Compact bone - few spaces except for lacunae. Dense bone – tough and able to withstand trauma. Haversian bone – composed of units known as osteons or Haversian Systems.
Compact Bone. A type of lamellar bone in which between 4 and 20 lamellae are arranged around the ____ in a___ ___ ___.
Composed of units known as osteons or Haversian systems.
Compact bone is ___, ___ _flexible, resists abrasion and trauma
____ of long bones. ____ of mandible and maxilla.
A type of lamellar bone in which between 4 and 20 lamellae are arranged around the vasculature in a central Haversian canal. Composed of units known as osteons or Haversian systems. Compact bone is hard, relatively inflexible, resists abrasion and trauma Shafts of long bones. Surfaces of mandible and maxilla.
Bone Formation. Bone is a dynamic tissue that is constantly being remodeled. Provides source of ___ and other ions. Changes with the changing physical demands of muscle etc.
Bone is a dynamic tissue that is constantly being remodeled. Provides source of calcium and other ions. Changes with the changing physical demands of muscle etc.
Methods of Formation. ____(=membranous) de novo formation.____Requires a cartilage template.
Intramembraneous (=membranous) de novo formation. Endochondral Requires a cartilage template.
Intramembranous Bone Formation. This is the __ ____ type of bone formation and can occur ____ in connective tissue with the appropriate ___. The bone that is formed can be remodeled to form either __ or __ bone or both.
This is the most common type of bone formation and can occur anywhere in connective tissue with the appropriate signal. The bone that is formed can be remodeled to form either spongy or compact bone or both.
Intramembranous Bone Formation.
Sequence:
Undifferentiated mesenchymal cells aggregate.
Differentiate into ____
. Osteoblasts lay down bone matrix – ____.
Osteoid becomes ____.
More bone ____ laid down etc.
Osteoblasts become incorporated as ____
Sequence: Undifferentiated mesenchymal cells aggregate. Differentiate into osteoblasts. Osteoblasts lay down bone matrix – osteoid. Osteoid becomes mineralized. More bone ECM laid down etc. Osteoblasts become incorporated as osteocytes.
Endochondral Bone Formation.
This involves the formation of a ___ ___.
This template increases in ___ and ____.
____replaces some of the outer cartilage as a collar of bone (future shaft).
Increase in the size of __ ___ Cavity.
There is growth in ___ of long bone.
Temporary support is bY ____/___ columns.
This involves the formation of a cartilage template. This template increases in diameter and length. Bone replaces some of the outer cartilage as a collar of bone (future shaft). Increase in the size of bone marrow cavity. There is growth in length of long bone. Temporary support is by cartilage/bone columns.
Endochondral Bone Formation
The bone marrow cavity increases due to ____ activity so that the columns of mineralized matrix are _____.
Some bone spicules remain to form _____ bone within the marrow cavity.
The bone marrow cavity increases due to osteoclast activity so that the columns of mineralized matrix are temporary. Some bone spicules remain to form spongy bone within the marrow cavity.
Endochondral Bone Formation.
Cartilage cells formed at the ends (epiphyseal plate) go through different ____s as columns of cells due to influence of __ ___ (somatotrophin).
____
____
____
Cartilage cells formed at the ends (epiphyseal plate) go through different stages as columns of cells due to influence of growth hormone (somatotrophin). Proliferation Hypertrophy Apoptosis
5 zones of endochondral bone formation.
____ zone
Zone of____n
Zone of ___y
Zone of ___ ____.
Zone of ____
Resting zone Zone of proliferation Zone of hypertrophy Zone of cartilage mineralization. Zone of ossification.
Endochondral Bone Formation.
Apoptotic cells break down and their space is occupied by ___ ___cells.
Cartilage between the cells remains as columns
Columns ____ to strengthen them.
____ is then laid down on the ____ of these calcified cartilage columns.
Apoptotic cells break down and their space is occupied by bone marrow cells. Cartilage between the cells remains as columns Columns calcify to strengthen them. Bone is then laid down on the surface of these calcified cartilage columns.
Summary. Intramembranous:
Converts ____ to bone in ___- and _____ period (____ ossification centers)
Endochondral Bone Formation: Coverts ___ to ___ in pre- and perinatal period (____ ossification centers)
Endochondral bone growth: Occurs after ___, ____ of long bones, requiring cartilaginous ___ ___, ceasing at adulthood
Intramembranous: Converts mesenchyme to bone in pre- and perinatal period (primary ossification centers) Endochondral Bone Formation: Coverts cartilage to bone in pre- and perinatal period (secondary ossification centers) Endochondral bone growth: Occurs after birth, lengthening of long bones, requiring cartilaginous epiphyseal plate, ceasing at adulthood
Bone remodeling
Bone growth is associated with___ ____ of pre-formed tissue.
Shape of the bone is _____while it grows.
Very ___ in children, in adults occurs simultaneously in many areas in the skeleton.
Bone growth is associated with partial resorption of pre-formed tissue. Shape of the bone is maintained while it grows. Very common in children, in adults occurs simultaneously in many areas in the skeleton.
Calcium mobilization Factors
Parathyroid hormone – bone____
Calcitonin – ____ deposition.
Somatotropin – see endochondral bone growth.
Cytokines.
Vitamin D. Vitamin A. Vitamin C.
Rapid
Hydroxyapatite to blood
Spongy bone
Slow
Actions of hormones
Factors Parathyroid hormone – bone resorption. Calcitonin – calcium deposition. Somatotropin – see endochondral bone growth. Cytokines. Vitamin D. Vitamin A. Vitamin C. Rapid Hydroxyapatite to blood Spongy bone Slow Actions of hormones
Bone Repair – Sequence.
A ___ ___ forms in damaged area.
Cells in the Periosteum and endosteum _____.
A ____ s often formed by ___ ___.
Endosteal ____ of these cartilage fragments occurs.
____ bone formation occurs.
Callus and granulation tissue.
A blood clot forms in damaged area. Cells in the Periosteum and endosteum proliferate. A callus is often formed by cartilage fragments. Endosteal ossification of these cartilage fragments occurs. Membranous bone formation occurs. Callus and granulation tissue.
Jaw Fractures The clues to diagnose a broken jaw: facial tenderness, swelling, a change in symmetry of the face, pain on moving the jaw, inability to speak and open or close the jaw. The possibility of other damage, e.g., to the zygomatic arch, the orbit and eye must also be carefully considered (second illustration).
The clues to diagnose a broken jaw: facial tenderness, swelling, a change in symmetry of the face, pain on moving the jaw, inability to speak and open or close the jaw. The possibility of other damage, e.g., to the zygomatic arch, the orbit and eye must also be carefully considered (second illustration).
Bone Healing.
Bony defects often heal slowly.
To allow the bone time to heal and soft tissue to attach and heal, sometimes materials are used in the defect to act as a ____ to allow cell migration .
Materials may be natural biodegradable such as ____, ____ , or ____
. Plastics such as poly propylene fumarate show a ____nflammatory response and allow surrounding tissue to grow into the plastic.
Bony defects often heal slowly. To allow the bone time to heal and soft tissue to attach and heal, sometimes materials are used in the defect to act as a scaffold to allow cell migration . Materials may be natural biodegradable such as collagen, fibrin or plastics. Plastics such as poly propylene fumarate show a low inflammatory response and allow surrounding tissue to grow into the plastic.
Bone Formation and Maintenance
Materials needed for collagen metabolism and mineralization.
Protein 22% of bone mass - 0.5 gms per pound body weight. Potassium. Vitamin C. Vitamin K – protein synthesis Vitamin B12 – controls amount of homocysteine. Magnesium – make up 1% of minerals in bone, aid in preventing crystals from becoming too large.
Materials needed for collagen metabolism and mineralization. Protein 22% of bone mass - 0.5 gms per pound body weight. Potassium. Vitamin C. Vitamin K – protein synthesis Vitamin B12 – controls amount of homocysteine. Magnesium – make up 1% of minerals in bone, aid in preventing crystals from becoming too large.
Some Bone Pathologies.
____
____
____
____
____ disease
Osteoporosis Osteopetrosis Rickets. Osteomalacia. Paget’s Disease.
Osteoporosis. A generic term covering a group of disorders in which there is ___ bone mass and deterioration of the bone mass and bone architecture.
A generic term covering a group of disorders in which there is low bone mass and deterioration of the bone mass and bone architecture.
