Bone & Bone Development Flashcards
What Bone Does Provides: -\_\_\_\_\_ -Gives \_\_\_\_ & \_\_\_\_\_ to the body -Provides \_\_\_\_\_\_ -Stored source for \_\_\_\_\_\_ and \_\_\_\_\_\_ -Provides \_\_\_\_\_\_\_ when muscles acts as joints formed between bones -\_\_\_\_\_\_\_\_\_ in the bone marrow
- Support
- Strength; support
- Protection
- Calcium; phosphate
- Movement
- Hematopoiesis
2 Ways of Visualizing Bone:
1) _____ _____: Unpreserved bone is _______ down so thin light can pass through. _____ and ______ matrix do not survive but the general architecture does. Good detail of the _____ matrix, and ____ _____ is used as a stain.
2) _____ _____: Cells are fixed and ________ matrix is removed by _______. Good detail of the _______ matrix, and _____ is used as a stain.
1) Ground bone; ground; Cells; organic; inorganic; India Ink
2) Decalcified bone; inorganic; decalcification; organic; H & E
Bone as Specialized CT
ECM
-________: Proteins (______) made of long peptide chains produced by _______
-____ _____: Gel-like matrix where cells and fibers are embedded
Cells
-______ _____ cells give rise to: __________ cells, _______, ______, _______, ________, & _______ cells
-Immune cells are present in the ______ ______: _______, _____ cells & _______
-Immune cells are present in the blood: _____, ______ cells, ________, ________, & ________
- Fibers; Collagen; Fibroblasts
- Ground Substance
- Mesenchymal Stem; Osteoprogenitor; Osteoblasts; Chondroblasts; Myofibroblasts; Fibroblasts; & Adipose cells
- Bone marrow; Macrophages; Mast cells; Basophils
- Monocytes; plasma cells; neutrophils; eosinophils; lymphocytes
Classification of Bone
- ____/____/____: Forms outside
- ____/____/____: Forms inside of the bone and consists of ______: Spaces within that have marrow and blood vessels
- ____/_____: Immature bone that is first formed and cells are randomly arranged. There are ______ cells per unit of area and more _____ ______ than _______/______ bone. The ______ bone formed.
- _____/______: Regular arrangement of collagen fibers that contains less ____ ____ & _____ than _____/_____ bone. The _____ bone formed.
- Dense/Cortical/Compact
- Spongy/Trabecular/Cancellous; Trabeculae
- Woven/Non-lamallar; more; ground substance; Lamellar/Mature; Primary
- Lamellar/Mature; ground substance; cells; woven/non-lamellar; secondary
Bone Development
- ______ _______: From modifying a hyaline cartilage precursor
- ______ ______: Directly from mesenchymal stem cells and their progeny
- _______ bone from either process looks exactly the same
- Most bones of the skull form via ____ _____
- Skull base forms via ______ _______
- Endochondral Ossification
- Intramembranous Ossification
- Immature
- Intramembranous Ossification
- Endochondral Ossification
- ______: Form the bone matrix
- Derived from ________ ______ cells that arose from _________ stem cell, which are _________
- ___________ ____ are found on the external (______) and internal surface (_______) of bones, and will appear ______ and squamous with elongated/______ nuclei
- Osteoblasts
- Osteoprogenitor stem; mesenchymal; multipotent
- Osteoprogenitor cells; periosteum; endosteum; flattened; oval
- _______: Flattened, simple squamous, bone-lining cell that secrete _______. Difficult to differentiate from ______ ______ histologically, and their formation is controlled by members of the ____ _____ _____ Family.
- ___ _____: Quiescent osteoblasts on the outside of bone
- _____ _____: Quiescent osteoblasts on the inside of the bone
- ______: Osteoblasts trapped within the lacuna of the osteoid they secreted
- Osteoblasts; osteoid; Osteoprogenitor cells; Bone Morphogenetic Protein
- Periosteal Cells
- Endosteal Cells
- Osteocytes
Bone Formation by Osteoblasts
1) _______ Deposition
- Forms a majority _______ ________ fibril matrix, _______ collagen is the _________ prevalent in the human body.
2) Secretion of _______ ________
- Amorphous matrix of ______, _______, _______, _____, & ______
- _______: Bone matrix that is a combination of _____ & ______ ______
3) ______ Seeding
- Osteoblasts saturate ground substance with ______ and ______ which precipitate as _____ ______ crystals
4) _______ & _______
- _________ _______ crystals are modified to form _______ crystals tethered to collagen by ________
1) Collagen
- Type I Collagen; Type I; most
2) Ground Substance
- Proteoglycans; glycosaminoglycans; glycoproteins; salt; water
- Osteoid; collagen; ground substance
3) Crystal
- Calcium; Phosphate; Calcium Phosphate
4) Mineralization & Maturation
- Calcium Phosphate; Hydroxapatite; Proteoglycans
Components of Osteoid -\_\_\_\_% organic and \_\_\_\_\_% inorganic Organic: -Fibers: \_\_\_\_\_\_\_\_ -\_\_\_\_\_\_\_\_ \_\_\_\_\_\_\_\_\_\_ -\_\_\_\_\_\_\_\_\_\_\_ proteins: \_\_\_\_\_\_\_\_, a ligand to induce formation of Osteoclasts; \_\_\_\_\_\_\_\_\_\_\_\_\_ (\_\_\_\_), Induces the formation of bone-specific macrophages; \_\_\_\_\_\_; & \_\_\_\_\_\_ Inorganic: -\_\_\_\_\_\_ \_\_\_\_\_\_ deposits with crystalline characteristics of \_\_\_\_\_\_\_
- 35%; 65%
- Type I Collagen
- Ground Substance
- Non-Collagenous; RANKL; Macrophage Colony Stimulating Factor (M-CSF); Osteoprotegerin; Osteopontin
- Calcium Phosphate; Hydroxyapatite
-______: Osteoblasts that became trapped in the matrix they secreted. Maintain bone ____, transmit _______ signals, and are linked by ____ _______ to each other and to _____ _____ cells and is how they ______ and obtain ________. Not very active and are mainly ______.
-Osteocytes; quality; mechanical; gap junctions; bone lining; communicate; nutrients; quiescent
-Flat cells are _______ ________ or ______/_____ cells, but those that are cuboidal are _______
-Osteoprogenitor cells, endosteal/periosteal; Osteoblasts
-_______: Completely surrounded by bone matrix, & maintain _______ homeostasis.
-_______: Space the cell inhabits
-_________ processes in ________ are linked by _____ junctions
-_______ than their Osteoblast precursors and are usually highly distorted by _____ in routine preps
States:
-_______
-_______: Deposits matrix
-______: Has active lysosomes
- Osteocytes; Calcium
- Lacuna
- Cytoplasmic; Canaliculi; gap
- Smaller; shrinkage
- Quiescent
- Formative
- Resorptive
- _________ & ______ are bone-lining cells derived from ________ that cover bone that is not remodeling
- Flat cells with few _________, still have ______ _____ that join processes of adjacent cells
- Function: Maintenance & _________ support of ______ in underlying bone
- Endosteal; Periosteal; Osteoblasts
- Organelle; gap junctions
- Nutritional; Osteocytes
-______ _______: Forms lamellar bone and continues throughout life. Controlled mainly by _________.
Steps:
1) ________ are activated and recruited to the bone surface; this process takes _______
2) Osteoclasts _______ bone; this process takes _____
3) _________ undergo apoptosis, reversing the process
4) __________ deposit new______ and mineralize it; this process takes _______
- Bone remodeling; Osteoblasts
1) Osteoclasts; weeks
2) Resorb; weeks
3) Osteoclasts
4) Osteoblasts; osteoid; months
Origin and Activation of Osteoclasts
- Osteoclasts are derived from bone marrow _______
- ________: Triggered by macrophage colony-stimulating factor (M-CSF) and by RANKL produced by osteoblasts to form osteoclasts . ______ binds to a monocyte and induces it to form a macrophage. The macrophage now expresses ________. _______ on the osteoblast, ______, or _____ _______ _____ binds to RANK and this commits the macrophage to ___________ to become an osteoclast
- Monocytes
- Osteoclastogenesis; M-CSF; RANK; RANKL; T-Lymphocyte; Stromal Stem Cell; Osteoclastogenesis
Resorption of Bone
- Osteoclasts become active when ______ bind to _________ on the bone and seals the area for absorption. This isolates the cavity, ______ ______, from the rest of the bone.
- ______ from lysosomes degrades ______, while ______ break down protein. This releases ______ and ______ into the blood.
- The process forms a _____ _____, which helps to increase the _______ area.
- Integrins; Osteopontin; Howship’s Lacuna
- Acid; Hydroxyapatite; Proteases; Calcium; Phosphate
- Ruffled border; surface
Histological Identification of Osteoclasts:
- _______ nuclei in a large cell
- ________ cytoplasm
- ________ to the bone _______
- Multiple
- Pink
- Attached; surface
Reversal Step of Bone Formation
- _______ determine when sufficient bone has been resorbed, and release _________: Acts as a decoy receptor that binds to the ______ ligand with a much higher affinity than _____, preventing the activation of additional osteoclast precursors so they remain as _______ in the ______ ______
- Osteoclasts than undergo _______
- Osteoblasts; Osteoprotegerin; RANKL; RANK; Macrophage; Bone Marrow
- Apoptosis
Components of Mature Bone
1) _____ ______ Bone: Outer layer with ______/_____ that are cylindrical units surrounding a ______/_______ Canal. _______ lamella of bone matrix surround the canal. ________ canals are channels through which _____ _____ and _____ travel from 1 surface to another, and run ______ to Haversian Canals.
2) _______ Bone: Inner bone consisting of _______ or spicules have numerous interconnecting narrow spaces
3) ______ Supply: _______ travels from the marrow, into & through bone to the ________ veins by passing through _________ ________
1) Compact Lamellar; Haversian Systems/Osteons; Haversian/Osteonal; Concentric; Volkmann’s; blood vessels; nerves; perpendicular
2) Spongy; trabeculae
3) Blood; blood; Periosteal; Haversian canals
Formation of Lamellar Bone
1) A new _________ ________ forms under the periosteum
2) Ridges of the_______ fuse around the vasculature and the groove becomes a bony tunnel enclosing the _____ _______
3) Additional bone lamellae is deposited around the tunnel, which gets converted into the ______ ______ with newer lamellar bone on the ______.
4) The Haversian ______ continues to receive blood through _______ _______ that extend obliquely across the _________
- Process is mediated mostly by __________
- _____ _______: Remnants of preexisting Haversian Systems replaced by newer ones during remodeling
- As one ______ ______ is formed by Osteoblasts, another is dismantled by ________and is either replaced or rebuilt
1) Haversian System
2) Periosteum; blood vessel
3) Haversian Canal; inside
4) Vessel; Volkmann’s Canal; Diaphysis
- Osteoblasts
- Interstitial Lamellae
- Haversian System; Osteoclasts
Regulation of Bone Turnover
- Balance between bone resorption and formation is regulated by ________
- _______ ______(___): Binds to receptors on Osteoblasts and increases pool of _____, this means more can bind to ______ on Osteoclast Precursor Macrophages. ____ also stimulates the synthesis of _____ the ligand leading the formation of Macrophages and their increased expression of _____. This results in ______ bone ______ and the release of _______.
- _____ also inhibits the synthesis of __________ by Osteoblasts leading to further bone _______.
- ______ & _______: Decrease the release of Calcium
- ______ & _______: Maintain stable skeletal mass in males & both stimulate ___________ synthesis by Osteoblasts while also reducing _______ availability leading to ______ bone resorption
- Hormones
- Parathyroid Hormone (PTH); RANKL; RANK; PTH; M-CSF; RANK; Increased; Resorption; Calcium
- Parathyroid Hormone; Osteoprotegerin; resorption
- Calcitonin & Vitamin D
- Estrogens & Androgens; Osteoprotegerin; RANKL; decreased
