Bone and Cartilage Flashcards
What are the 3 types of bone?
- woven bone - occurs during bone development and repair
- compact bone- aka lamellar bone
- spongy bone- aka trabecular or cancellous bone
A non-functional osteoclasts becomes functional after it does what?
uncouples from the osteoblast
What are the 2 major components of the matrix of the bone?
Osteoid = organic component
hydroxyapatite = inorganic component (makes up 35 to 65 percent of matrix)
What is G?
Volkmann canal
These cells are stems which are described as bone lining cells in the adult?
Osteoprogenitor cells
When does the differentiation of a monocyte into a macrophage take place?
When the M-CSF released by the osteblast binds to the M-CSF receptor on the monocyte.
- Macrophage expresses RANK at this point
What is C?
Lacuna
What is appositional growth?
It is the growth of something through the process of adding mass to the outside layers (wider).
How are the major types of cartilage Classified?
They are classified based on the composition of their matrix. More specifically, the predominant types of fibers within the matrix.
Identify this tissue
Compact bone
Pockets within the matrix where the chondroblasts and chondrocytes are found.
Lacunae (aka “Little lake”)
These cells are dervied from the monocyte lineage, which, in turn, are derived from monocyte precursors in bone marrow?
Osteoclast
PTH has 2 main functions, what are they?
- stimulate the differentiation of monocyte precursors to form osteoclasts
- stimulates the formation of the ruffled borders on osteoclasts
These cells give rise to osteoblasts and bone lining cells?
Osteoprogenitor cells
What process couples together the osteoblast and the macrophage?
The binding of RANK to RANKL
True or False, hyaline cartilage is surrounded by perichondrium.
True
List the components of hyaline cartilage
matrix
chondrocytes
lacuna
chondrogenic perichondrium
fibrous perichondrium
Bone tissue is based on what type of system?
A canalicular system
This matrix surrounds each chondrocyte.
Territorial matrix
The inter-territorial matrix is _____ in glycosoaminoglycan content and ____ in collagen content?
Low, High
There are 6 listed functions of cartilage, name 4 of them.
- compressible
- resists distortion
- absorbs shocks in joints
- reduces friction in movable joints
- necessary for endochondral bone growth
- involved in bone fracture repair
In regards to cartilage formation, chondrocytes ______ cartilage matrix?
Maintain
Are chondrocytes in hyaline cartilage usually found in groups or by themselves?
In groups, this is the result from cell division
True or False: Bone is not highly vascularized?
False; bone is highly vascularized and is found in close proximity to capillaries
List 4 of the 6 locations where hyaline cartilage is found.
external auditory meatus
larynx
tracheal cartilages
bronchial cartilages
fetal long bones
articular ends of bones
What is D?
Chondrocytes
What is A?
Fibrous perichondrium (source of fibroblasts)
Calcitonin acts to _____ bone resorption
Reduce
Define interstitial growth.
growth in length; growth by chondrocytes which are later replaced by bone
Identify this tissue
Hyaline cartilage
This type of bone is present during bone development and repair.
Woven bone
List 4 of the 6 characteristics of fibrocartilage
- increased collagen in the matrix
- reduced cellularity compared to hyaline cartilage
- not surrounded be perichondrium
- opaque appearance from fibrous texture
- Type I collagen
- Single sparse chondrocytes
How are osteocytes connected to each other and to the Haversian canal?
Canaliculi
Identify this tissue
Hyaline cartilage
Identify this tissue
Elastic cartilage
Lamellar bone is another word for which type of bone?
Compact bone
Identify this tissue
Developing mebrane bone (fetus)
In regards to cartilage formation, chondroblasts lay down cartilage _____ and become ______?
matrix, chondrocytes
Identify this tissue
Compact bone
What are the growth patterns of hyaline cartilage?
Appositional and interstitial
What is characteristic of trabecular bone?
It has a 3-D lattice of branching, bony spicules intertwined to form trabeculae surrounding the bone marrow spaces in the long bones and flat bones.
Which layer of the perichondrium contains fibroblasts?
Outer fibrous layer.
In the absence of PTH osteoblasts will secrete what?
Osteoprotegerin
In an adult, where would you find osteoprogenitor cells?
- inner portion of the periosteum
- the endosteum
- lining the vascular canals of compact bone
What is B?
Chondrogenic Perichondrium ( source of chondroblasts and osteoprogenitor cells)
These cells are derived from osteoblasts and are trapped by the matrix they secrete?
Osteocytes
What is F?
Haversian canal
This matrix surrounds the territorial matrix?
Inter-territorial matrix
Identify this tissue
Cancellous bone
What do osteoblasts release in the presence of high PTH?
Osteoclast diffentiation factors
This region of the matrix is somewhat “older: when compared to the other matrix that has been laid down
Inter-territorial matrix
Identify this tissue
Fibrocartilage
Increase in bone length occurs through ______ grotwh of a ________ model
Appositional, hyaline cartilage
This type of bone lacks visible cavities and forms a dense plate on the outside of long bones or flat bones?
Compact bone
What is C?
Lacuna
These structures run perpendicular to the Haversian canals and connect the Haversian canals to each other and to the surface of the bone.
Volkmann’s canals
Name the 3 of the 4 components of the cartilage matrix
- collagen type i (type II in fibrocartilage)
- hyaluronan (hyaluronic acid)
- Chondroitin sulfate (most abundant) , keratin sulfate, heparin sulfate
- Glycosoaminoglycans
What are the layers of the perichondrium?
- Outer fibrous layer
- Inner chondrogenic layer
Chondrocytes are cells of the cartilage that do what?
Chondrocytes are cartilage-maintenance cells; they remove/clear away cartilage
What is A?
Fibrous periosteum
Identify this tissue
Compact bone
What is B?
Osetogenic periosteum
Identify this tissue
Hyaline cartilage
Chondroblasts are cells of the cartilage that do what?
Chondroblasts are cartilage-forming cells; they build cartilage.
Identify this tissue
Compact bone
What is the primary regulator of bone turnover?
PTH
There are ____ types of cartilage, What are they?
There are three types.
- Hyaline
- elastic
- fibrocartilage.
Name the cells of the cartilage that are responsible for forming and destroying cartilage.
Chondroblasts and chondrocytes.
The territorial matrix is ______ in gylcosoaminoglycan content and ______ in collagen content?
High, Low
The skeletal system in all _____ begins as cartilage.
Vertebrates.
When does the macrophage become a multinucleated immature osteoclast?
After it binds to the osteoblast via RANK and RANKL interactions
List 2 of the 3 points characterizing isogenous groups.
- groups of 2-8 chondrocytes occupying the same lacunae
- They are a result of mitotic division
- cells will become separated as the begin to lay down the matrix of their own
Where is the inter-territorial matrix located?
The matrix between the lacunae.
Which type of collagen fibers does hyaline cartilage contain?
type II
Identify this tissue
Elastic cartilage
Name a couple of places where you find fibrocartilage.
- intervertebral discs
- pubic symphysis
- insertion of some tendons and ligaments
- closely associated with dense connective tissue or hyaline cartilage
Osteoprogentior cells are derived from the ______ of the _______ _______ and possess mitotic potential?
Mesenchyme, embyronic somite (sclerotome)
What is E?
Canaliculus
Identify this tissue
Developing membrane bone (fetus)
A macrophage expresses _______ after it is differentiated from a monocyte by the binding of M-CSF to the monocyte M-CSF recptor?
RANK
True or False: bone is formed by osteocytes, which become osteoblasts?
False; bone is formed by osteoblasts, which become osteocytes
Identify this tissue
Hyaline cartilage
This matrix is the “newest” matrix the has been laid down and is much more labile than the other type of matrix.
Territorial matrix
Identify this tissue
Elastic cartilage
What is another name for spongy bone?
Trabecular or cancellous bone
Identify this tissue
Hyaline cartilage
Identiy this tissue
Fibrocartilage
What is D?
Lamellae
True or False: Cartilage can not form all of the skeletal system in vertebrates?
False; Cartilage can form part or all of the skeletal system in vertebrates.
Cartilage is avascular, what does this mean and what 2 characteristics does this attribute to cartilage?
Avascular = no blood vessels within its substance. Because of this cartilage is (1) slow to heal. Also, (2) nutrients and oxygen are derived from the blood vessels that surround the cartilage and must diffuse through the matrix to the cells.
What is the function of Osteoprotegerin and how does it work?
It inhibits the maturation of osteoclasts. It works because it binds to RANKL with greater affinity than RANK (macrophage) and because PTH blocks the synthesis of osteoprotegerin (no M-CSF secretion or RANKL formation from osteoblast)
When PTH binds the receptors on the osteoblast, this stimulates the osteblast to release what?
- M-CSF
- RANKL
Identify this tissue
Cancellous bone
Too much PTH can lead to this
Osteitis fibrosa- eroded bone and fibrosis of the resulting spaces
What are some characteristics of hyaline cartilage?
It is translucent, bluish gray to white in color, and it is solid yet flexible in rigidity.
In a Haversian sytem, where would you find osteocytes?
Osteocytes are found between the lamellae located in lacunae
True or False: Type II collagen is the primary fiber type found in fibrocartilage?
False; type I collagen are the primary fiber type found in fibrocartilage
The chondrocyte is involved in the production of _____ and _____ in the matrix? They also secrete ______?
collagen, proteoglycans. chondronectin
Which layer of the perichondrium gives rise to chondroblasts, which becomes chondrocytes?
Inner chondrogenic layer
What is the most common type of cartilage?
Hyaline cartilage
Collagen fibers in the extracellular matrix of cartilage are predominantly which type?
Type II (type I in fibrocartilage)
What is E?
Matrix
Name the components of the extracellular matrix of cartilage.
Collagen fibers and an amorphous ground substance.
How is bone tissue classified?
Bone tissue is based on the arrangement of the matrix
At _____ PTH levels, bone formation by osteblasts is stimulated.
LOW
What cycle oocurs at adult remodeling sites and during development?
The activation resorption reversal formation (ARF) cycle
