Endochondral Ossification, Bone Growth & Remodeling Flashcards
- _______ ossification involves the direct differentiation of _______ cells into Osteoblasts and is how ____ bones of the skull and the ____ develop
- ______ ossification requires a ______ ______ template that eventually gets substituted for bone
- Intramembranous; mesenchymal; flat; clavicle
- Endochondral; Hyaline Cartilage
Endochondral Ossification
-Occurs in _____ bones: ____ and _______ skeleton
-Replacement of Type II/______ cartilage by bone
Stains:
-______ red stain of ______
-______ blue stain of _______
-Long; axial; appendicular
-Hyaline
-Alizarin; bone
Alcian; cartilage
- ______ condensation at day ____ leads to the formation of condensed _______ by day ____. Due to the TF ____ & _____ signaling
- Differentiation of condensed ________ to early ______ by day ____. Due to ____ signaling mediated by Wnt/β-Catenin signaling, & ___/___ mediated by Bmp signaling
- Mesenchymal; E10.5; prechondrocytes; E12.5; Tgfβ; Wnt
- Prechondrocytes; Chondrocytes; E14.5; Sox9; Sox5/6
Primary Ossification Center Steps
1) _____ ______ is the template of long bones
2) Proliferation of _____ followed by their _____ at the ____ of the shaft initiates the formation of the _____ ____ ____. ______ ____ secrete a ____ ____ ____ ____ ___ (___) to induce sprouting of blood vessels from the ______, and are larger than regular chondrocytes due to taking up liquid and appear _____. Calcification of the ____ and ____ of the ______ _____ than occurs.
3) _____ ____ of the perichondrium form the ____ ____
4) Blood vessels form the ______ _____ and branch in opposite directions, bringing _____ & ______ to the Primary Ossification Center.
5) The skeletal element grows in _____ as the _____ _____ template is converted to ____
- ______ cartilage is the only type of cartilage remaining after the conversion to _____
1) Hyaline cartilage
2) Chondrocytes; hypertrophy; midpoint; Primary Ossification Center; Hypertrophic Chondrocytes; Vascular Endothelial cell Growth Factor (VEGF); Perichondrium; white; matrix; apoptosis; Hypertrophic Chondrocytes
3) Osteoprogenitor cells; Periosteal Collar
4) Periosteal Bud; Osteoblasts; Osteoclasts
5) Length; Hyaline Cartilage; bone
- Articular; bone
Growth Plate
- Region where the _____ between cartilage and bone is occurring
- Migrate towards the _______ of the bone
- _____ ____: Cartilage located furthest away from the growth plate, consisting of ____ cartilage growing in size due to the presence of ______. Allows for the formation of more _____ _____ to be converted to _____.
- ______ ____: Proliferative _____ that align in _____ & _____ columns.
- ______ _____: Location of the hypertrophic ______ that undergo _____, and the point where _____ of the territorial _____ begins. ______: Individual calcified zones within lacunae.
- ____ ____ ____: Blood vessels penetrate transverse ____ bringing ____ _____ & _____ that attach to the calcified areas and begin to deposit bone
- Transition
- Epiphyses
- Reserved Zone; hyaline; chondroblasts; hyaline cartilage; bone
- Proliferating Zone; Chondrocytes; Vertical; Parallel
- Hypertrophic Zone; chondrocytes; apoptosis; calcification; matrix; Septa
- Vascular Invasion Zone; septae; Osteoprogenitor Cells; Osteoblasts
Proliferative Zone
- Flattened ______ in columns
- ______ _____: Chondrocytes sharing the same ______
- Chondrocytes
- Isogenous Groups; lacuna
Hypertrophic Zone
- Located ______ the Proliferative Zone
- Chondrocytes take in _____, mainly _____, causing them to increase in size
- Hypertrophy squeezes the _______ matrices separating chondrocytes into ______
- _______ begins at the ____ end of the zone in the _____, preventing the diffusion of nutrients leading to _____ of the cells
- As ____ _____ begins below the hypertrophic zone, invading osteoblasts deposit _____ on the calcified septa, and ______ remove residual chondrocytes and the matrix
- Below
- Fluid; water
- Interterritorial; septa
- Calcification; lower; septa; apoptosis
- Vascular invasion; osteoid; Osteoclasts
Zone of Vascular Invasion
- In close proximity to the lowest part of the ____ ____
- _______ tissue will identify as blue in developing bone marrow
- ______ can be identified as long dark blue/purple structures
- ______ line the septa depositing _____ onto the calcified _______ matrix
- Hypertrophic Zone
- Hematopoietic
- Septa
- Osteoblasts; osteoid; cartilaginous
Osteoclastic “Chase” & Chondrocytic “Run”
-______ enlarge the bone marrow cavity and are derived from monocytes
Chondrocytic Run:
1) The _____ _____ invades and destroys the ______, passing through the _____ they initially inhabited
2) Calcification of the cartilaginous matrix surrounding the _______ ________
3) Proliferating ________ located away from the Ossification Front in the __________ Zone increase the length of the cartilage
- Surrounding _______ provides more cells to the growing cartilage
- An equilibrium between cartilage production in the ______ Zone and the rate of the advancement of the ______ of _______ _______ is needed for proper growth. Bone won’t grow in length resulting in _____ bones if the rate of the advancement of the ______ _____ Zone is too great. If the proliferation of cartilage in the _______ ________ is too great you get longer bones;
- Osteoclasts
1) Ossification Front; chondrocytes; septae
2) Hypertrophic Chondrocytes
3) Chondrocytes; Reserved - Perichondrium
- Reserved; Zone of Vascular Invasion; short; Vascular Invasion; Reserved Zone
Secondary Ossification Centers
- The _____ _______ _____ attracts blood vessels to the midpoint of the bone and begins as an _______
- ______ ______ ______ form in each of the 2 epiphyses. Bone will grow in length after they form and stops at the conclusion of ______. Capillaries can be seen that bring in ______ & ______.
- _______: Portion of the diaphysis nearest to the epiphyses
- ______ _______ _____ ______: Located between the metaphysis and the epiphysis, and eventually gets replaced by bone
- _____ _____: Bone is particularly dense at this point and is the location of the last growth plate, and indicates no more ________ ossification can occur so you no longer grow
- ______ ____(___): TF of the hedgehog family that stimulates chondrocyte _______ in the Epiphyseal Cartilaginous Growth Plate while preventing chondrocyte ________
- Endochondral ossification begins in the ______ and ends at the conclusion of ______
- Primary Ossification Center; embryo
- Secondary Ossification Centers; puberty; Osteoblasts; Osteoclasts
- Metaphysis
- Epiphyseal Cartilaginous Growth Plate
- Epiphyseal Line; endochondral
- Indian Hedgehog (Ihh); proliferation; hypertrophy
- Embryo; puberty
Secondary Ossification Center Formation Steps
1) ______ ______ and _______ infiltrate the Epiphysis establishing a Secondary Ossification Center
2) A similar Secondary Ossification Center appears in the opposite ________
3) The ______ _______ will be replaced by the ______ ______, this occurs gradually from puberty to maturity as both ______ ______ form at the same time preventing further bone growth.
4) Blood vessels from the _______ & _______ intercommunicate
5) All the _______ Cartilage is replaced by bone, except for the _______ cartilage
1) Blood vessels; mesenchyme
2) Epiphysis
3) Epiphyseal Plate; Epiphyseal line
4) Diaphysis; Epiphysis
5) Epiphyseal; Articular
Regulators of Chondrocyte Differentiation in the Growth Plate
- _____ ______(___): Secreted by Proliferative Zone Chondrocytes, regulating the formation of the bone _____ and stimulates the synthesis of ______
- ______ ________ _______ (___): Stimulates the proliferation of Chondrocytes in the Reserved Zone, while inhibiting differentiation of ______ Zone chondrocytes into Hypertrophic Chondrocytes
- ________ ______ secrete VEGF which attract ______ ______ , and they secrete ______ __ Collagen which provides structural support to cells
- High [___] & [___] stimulates cartilage proliferation while inhibiting the differentiation to _______ Chondrocytes effectively lowering [___] slowing the rate of the advancement of the Vascular Invasion Zone. This is an example of a _______ mechanism that allows the continued growth of _______ cartilage
- Indian Hedhehog (Ihh); collar; PTHrP
- Parathyroid Hormone-related Protein (PTHrP); Proliferative
- Hypertrophic Chondrocytes; blood vessels; Type X
- [Ihh] & [PTHrP]; Hypertrophic; [VEGF]; feedback; hyaline
Bone Modeling
- Alteration in the size & shape of bones only during _____ by the process of bone _______ & _______.
- Growth in width of the _______ long bone cylinder and expansion of the _______ _______ cavity.
- Shaping of the ____ of the long bones to convert the broad _______ ______ into a narrow _____ ______.
- Enlargement of the _____ _____ curvature.
- Bone growth is an ______ mechanism, where new bone is added to an existing bone ______.
- ______ growth is ______ in a rigid calcified ECM
- Growth; formation & resorption
- Diaphyseal; inferior marrow
- Ends; Metaphyseal Funnel; Diaphyseal Cylinder
- Cranial Vault
- Appositional; surfaces
- Interstitial; Impossible
Bone Growth in Width
1) A new _____ ______ forms under the Periosteum. Longitudinal ridges form along the ______, and Periosteal Cells differentiate into _____. A ______ capillary is found in the groove, and new bone begins to extend ______ ridges towards each other.
2) The ridges ______ and the groove becomes a bony tunnel enclosing the ______ ______.
3) Additional bone_____ are deposited around the tunnel, causing the diameter of the tunnel to _____ in size. This tunnel gets converted into the ______ _____ containing the blood vessel.
4) The _____ _____ continues to receive blood through the Volkmann’s Canals extending obliquely across the _______ and are perpendicular to the _____ _____. The _____ _____ is surrounded by _______ lamellae, and multiple form resulting in _______ growth widening the bone shaft.
- Similar widening of the ______ cavity occurs
1) Haversian System; diaphysis; Osteoblasts; Periosteal; Adjacent
2) Fuse; blood vessel
3) Lamellae; reduce; Haversian Canal
4) Haversian Vessel; Diaphysis; Haversian Vessels; Haversian Vessel; concentric; Appositional
- Medullary
Factors Affecting Bone Growth
- 20 or more ______, ______, and ______ _____ control bone growth. ______ are more life secondary factors since they serve as _______ for reactions.
- Epiphyseal ______ activity is stimulated by ______ ______ released by the anterior pituitary during ______ & _________
- During puberty ___ ______ mainly regulate bone growth. Both ______ & _______ initially promote adolescent growth spurts by stimulating proliferation of ______ cells and _______ in the growth plate. This results in masculinization and feminization of specific parts of the _______. Once the _____ ______ closes longitudinal bone growth ends.
- Adolescent _______ grow faster and reach their full _____ earlier at roughly ____ years of age, since _____ has a strong effect on bone growth.
- Adolescent _____ grow for a longer time due to sustained high levels of ________ resulting in larger than average stature until roughly ____ years of age.
- Growth ceases when the _____ & ____ fuse
- _______ _______ can cause premature closure of growth plates resulting in a shorter stature
- Hormones; Vitamins; growth factors; Vitamins; Cofactors
- Plate; growth hormones; infancy & childhood
- Sex Hormones; estrogen & testosterone; Osteogenic; Chondrocytes; skeleton; Epiphyseal Plate
- Women; height; 18; Estrogen
- Men; Testosterone; 21
- Epiphysis & Diaphysis
- Anabolic Steroids
