Upgrade to remove ads
MSK Lecture 20: Bone II
Terms in this set (57)
What are the 2 ways in which bone can develop? What type of growth model do they undergo respectively?
1- Intramembraenous bone formation
- Connective tissue (mesenchymal) model
2- Endochondral bone formation
- Cartilage model that is replaced by bone
In Bone histogenesis what type of bone forms first and what is it later replaced by?
•Remodeling continues throughout life, although it is slower in mature bone
In Intramembranous bone formation what cells condense to allow the formation of the primary ossification center? What is the Primary ossification center composed of?
Bony spicules (islets)
Bony spicules (blue) stained with Mallory-Azan stain.
In the Intramembranous ossification model what gets differentiated from the primary ossification center? What does it begin to secrete?
Osteoblasts become trapped in their own matrix
As Bony spicules continue to grow (during Intramembranous ossification) they fuse with adjacent spicules to form what?
As growth occurs the Trabeculae become interconnected and what is formed as a result?
Intramembranous ossification is involved in the formation of what bones?
Flat bones of the skull
Where does Endochondral ossification occur? In what type of Cartilage?
Outline of the bone
What 2 things gets formed during the first stage of Endochondral bone formation?
2- Subperiosteal bone
intramembranous ossification process
What acts as the Primary ossification center in Endochondral bone formation?
Subperiosteal bony collar
What acts as the Secondary ossification center in Endochondral bone formation?
Which bones get formed via Endochondral bone formation?
The epiphyseal plate continues to grow by adding what at the epiphyseal end of the plate? This occurs while the plate is being replaced by what at the diaphyseal end?
Diaphyseal bone become continuous with epiphyseal bone (connecting the two marrow cavities) at around what age?
20 years old
What are the 5 zones of the epiphyseal plate?
1- Zone of reserve cartilage
2- Zone of proliferating cartilage
3- Zone of hypertrophic cartilage
4- Zone of calcified cartilage
5- Zone of resorption
The Zone of Reserve cartilage contains small, randomly arranged?
The Zone of Reserve Cartilage serves as a ?
Stem Cell line
Cells in the Zone of Cell proliferation undergo what? This gives rise to? Characteristic appearance?
Rapid mitotic divisions
Rows of Cartilage cells
Stacks of coins appearance
In the Zone of Hypertrophy the chondrocytes are ? What happens to the cartilage matrix between the neighboring chondrocytes?
In the Zone of Calcified Cartilage what happens to the Lacunae Coalesce and the Interlacunar matrices? What does result in? What is the Z of CC appearance?
Apoptosis of Chondrocytes
In Zone of resorption the bone is beginning to be .... upon the ? What activity begins to resorb the calcified bone-cartilage complex?
In Endochondral bone formation the newly formed bone is surrounded by what?
•Some osteoblasts that were captured by the osseous matrix become osteocytes
What are the steps involved in the formation of Osteons?
1- Longitudinal ridges form along the bone
2- Osteogenic cells in the periosteum transform into Osteoblasts
3- Osteoblast start producing bone matrix which form ridges that close off periosteal capillaries as they meet
4- Periosteum lining the newly formed canal becomes the endosteum
5- Endosteum starts forming concentric lamellae to form the osteon
Bone fractures result in the damage of what 3 things?
1- Bone matrix
2- Bone cells in that region
3- Blood vessels supplying the area
Damage to the blood vessels by bone fractures can result in what? Which is followed by?
•macrophages remove much of the debris via phagocytosis
In damaged bones what proliferates in the Periosteum and Endosteum ? This results in surrounding it Internally, Externally or both?
Internally and Externally
During bone repair what gets formed both internally and externally?
Bone is elaborated in the fracture zone via ........ bone formation by ........ derived from osteogenic layer of the periosteum and endosteum in the vicinity of the fracture?
Intramembranous bone formation
Chondrocytes also differentiate from this connective tissue and elaborate cartilage, which will be replaced by bone via ............., thus forming a ........ composed of primary bone?
Endochondral bone formation
The Bony callus formed will be eventually resorbed and replaced with what as the repair process continues?
What are the Main functions of bone?
1- Supports the body and provides sites of attachment for muscles
2- Protects the CNS and vital organs
3- Dynamic tissue that constantly undergoes changes in
shape and form due to the stresses placed upon it
4- Growth is directed toward to applied stresses
The bone contains 99% of the body's .....? Thus it acts as a ? What processes is this element essential for?
muscle contraction, enzymatic activities, transmission of nerve impulses, cell adhesion, and blood coagulation
What does Decalcification of bone occur as a result of? During the remodeling of spongy bone, Calcium is transferred from .... to the ....?
Diet inadequate in Calcium
Bone to Blood stream
What greatly affects bone development? Diets low in ..... can result in deficiency of ..... essential for collagen synthesis by Osteoblasts?
Lack of ...... from either from low intake or inadequate absorption by the small intestine (due to a lack of vitamin D) results in what? Which condition can it lead to in children? Adults?
Poorly calcified bone
Histologically Rickets and Osteomalacia appear as what? With a delay in?
delayed Mineralization rate
What becomes irregular and widened with Rickets? Also get delayed ..... of Hypertrophic chondrocytes?
Which Vitamin is essential for proper Ossification? Excess of that vitamin can cause?
What does Vitamin A deficiency result in? Excess can result in?
Improper Bone formation and growth
Increased Osteoclast activity and makes bones fragile
What Vitamin is necessary for Collagen formation? Deficiency of this vitamin results in?
- characterized by poor wound healing and bone repair after fractures
What are the 3 main hormones that exert influence on bone formation?
1- Parathyroid hormone (PTH)
3- Growth Hormone (GH)
Parathyroid hormone indirectly stimulate what cells? What does that result in?
-since osteoclasts lack PTH receptors PTH binds to osteoblasts which then activates osteoclast stimulating factor
Release of Calcium and Increased blood Calcium levels
Parathyroid hormone may also activate what cells to initiate what process? What does this result in?
Liberation of Calcium from the walls of their lacunae, thus elevating blood calcium levels
What negative effects does excess Parathyroid hormone have on bones?
1- Bones become more susceptible to fractures
2- Subsequent deposition of calcium in arterial walls and certain organs such as the kidney
What is Calcitonin produced by? It inhibits the activity of what cells? What result does that thus have?
Parafollicular cells of the Thyroid glands
Lowered blood calcium levels
What does Pituitary Growth hormone (GH) simulate the growth of? Excess of it results in? Lack of it results in?
In adulthood excess Growth hormone results in what condition?
enlarged face and hands
What occurs in Osteoporosis? What can it lead to an increased risk of ? 3 types of Osteoporosis?
Progressive loss of bone density
1- Primary Type I Osteoporosis
2- Primary Type 2 Osteoporosis
3- Secondary Osteoporosis
osteoclastic activity > osteoblastic activity
Primary Type I Osteoporosis typically occurs in? Occurs as a result of? Treatment?
Decreased Estrogen levels --> Increased activity of Osteoclasts (normally estrogen limits the activity of osteoclasts)
Hormone therapy, selective estrogen receptor modulators therapy available
1/3 postmenopausal women affected
Primary type II osteoporosis in what age group?
Elderly: 70-80 years of age
Secondary Osteoporosis can develop as a consequence of what?
Drug therapy (corticosteroids) or other disease processes (malnutrition, weightlessness, metastatic cancer, radiation)
Summary table 2
THIS SET IS OFTEN IN FOLDERS WITH...
MSK Lecture 22: Genetics Cases 1
MSK Lecture 18/DLA46: Cartilage
MSK Lecture 19: Bone I
MSK DLA 47: Vitamin D
YOU MIGHT ALSO LIKE...
Anatomy Ch. 6
A & P ch. 6
Anatomy Chapter 7
Anatomy Skeletal System Exam (Bone Tissu…
OTHER SETS BY THIS CREATOR
NB DLA 57: Regulation of Controlled Subs…
NB DLA 56: Drug Rehabilitation
NB DLA 55: Drug and Alcohol Screening
NB DLA 54: Addiction Medicine Terminology
OTHER QUIZLET SETS
Chapter 42: Circulation and Gas Exchange…
Patho retake quiz
R4 Corporate Taxation - M7 Entity/Owner Transactio…