Skeletal System (Exam II) Flashcards
Primary function of bone
Support
Locomotion/movement
Secondary function of bone
Protection
Mineral storage
Hemopoiesis
Bone is ______ while cartilage is _____
Rigid; semi-rigid
Both bone, and cartilage are derived from:
Primitive mesenchymal cells
Relative strength of bone and cartilage is due to:
Properties of ground substance and extracellular fibers
Bone precursor
Cartilage
Cartilage formation begins with _____ cells which differentiate into _____
Stellate mesenchymal cells; rounded chondroblasts
The rounded chondroblasts of cartilage grown and synthesize:
Ground substance and fibrous ECM
What happens when the chondroblasts grow and synthesize ground substance and fibrous ECM
The chondroblasts get trapped in the lacunae
In cartilage, further mitotic divisions produce clusters of mature ____ referred to as ____
Chondrocytes; isogenous groups
Isogenous groups of chondrocytes are separated by
Extracellular matrix
ECM surrounding the isogenous groups of chondrocytes
Territorial
Pink ECM between the isogenous groups of chondrocytes
Interterritorial ECM
Surrounds cartilage
Perichondrium
Peripheral zone of dense connective tissue, containing fibroblasts, collagen & immature chondroblasts
Perichondrium
Type of growth in which new cartilage forms within a mass
Interstitial growth
Type of growth that allows chondrocytes to retain the ability to divide
Interstitial growth
Type of growth in which new cartilage forms at surface of pre-existing cartilage
Appositional growth
Type of cartilage growth that is most common
Appositional growth
In Appositional growth, new chondrocytes are derive from mesenchymal cells of the:
Inner periochondrium
In Appositional growth, the new chondrocytes derived from mesenchymal cells of inner perichondrium differentiate first into:
Chondroblasts
In appositional growth, more mature chondrocytes present at _______ while the younger cells present at the _______
Center of cartilage mass
Periphery
Bone growth can be directly ______ cells —-> _____ OR _____ cells —> ______ to _____
Mesenchymal cells —> bone
Mesenchymal cells —> cartilage —-> bone
What is found in the perichondrium (peripheral zone of dense connective tissue)
- Fibroblasts
- Collagen
- Immature chondroblasts
Type of connective tissue cartilage is classified as
Avascular connective tissue
Cartilage lacks:
Blood vessels
Due to the lack of blood vessels, exchange of metabolites occurs through:
Diffusion through ground substance
Due to cartilage relying on diffusion of metabolites through the ground substance this limits the:
Thickness
If cartilage is thick it will have blood vessels in:
Secondary cartilage canals
Cartilage contains an ECM of ________ containing _____
Amorphous ground substance containing collagen
The ECM of cartilage is hydrated and contains ~60-80% h2o bound to:
Proteoglycans
The hydration status of the matrix account for its (2):
Flexibility
Incompressibility
The GAGs found in cartilage (3):
- Hyaluronic acid (non-sulfated)
- Chondroitin sulfate
- Heparin sulfate
Most common glycoproteins in cartilage
Chondronectin
Potentially chondronectin could have:
Anti-cancer properties
Determines the variable types of cartilage:
Amounts of fibers embedded in matrix
Type of cartilage found in articular surfaces, growth plates, nasal septum, costal cartilage (ribs), tracheal & bronchial rings
Hyaline cartilage
The precursor for bone in most skeleton
Hyaline cartilage
Collagen type that is characterized by small aggregates of chondrocytes in amorphous matrix of ground substance, reinforced with type II collagen fibers
Hyaline cartilage
Type of collagen fibers present in hyaline cartilage
Type II Collagen
Most prevalent type of cartilage
Hyaline
Greek term hylos means:
Glass-look
Type of cartilage found in:
End of long bones
Growth plate
Nasal septum
Articular surfaces
Octal cartilages
Tracheal/bronchial rings
Hyaline cartilage
common precursor for bone in the skeleton
Hyaline cartilage
Consists of alternating layers of hyaline cartilage & dense connective tissue
Fibrocartilage
Type of collagen fibers present in fibrocartilage
Type I & II collagen
Fibrocartilage is less ____ than the other types of cartilage
Cellular
Fibrocartilage lacks ____
Perichondrium
Type of cartilage found in intervertebral discs
Fibrocartilage
Type of cartilage found in these articular areas: knee, mandible (TMJ), shoulder, sternum, ligaments, tendons, joint capsules, pubic symphysis
Fibrocartilage
Cartilage that is histologically similar to hyaline cartilage with addition of large numbers of elastic fibers in ECM
Elastic cartilage
Type of collagen fibers present in elastic cartilage
Type II
Type of cartilage found in the external ear, auditory & eustacian canals, epiglottis & larynx
Elastic cartilage
Type of cartilage that has a very limited distribution throughout the body
Elastic cartilage
______ of cartilage is limited because it requires blood flow
Repair
Repair in cartilage is limited, because repair requires blood flow; this results in:
Production of dense connective tissue (fibrosis)
Invasion of cartilagenous site by blood vessels frequently results in (2):
- Death of chondrocytes
- Formation of bone
There is a tendency for all hyaline cartilage to:
Calcify with age
The calcification of hyaline cartilage is due to the deposition of ______ within the matrix
Calcium phosphate crystals
The deposition of calcium phosphate crystals within the matrix of hyaline cartilage eventually results in:
Bone
Most common repair of cartilage is done via:
Fibrosis
In the healing process of cartilage, the chondrocytes get replaced with:
Osteocytes
Old people are often stiff because they do not have the same amount of ______ in their cartilage as younger people do
Turgor pressure
Specialized support tissue in which the extracellular components are mineralized
Bone
Two characteristics of bone
Strength
Rigidity
Two main forms of bone:
Woven
Lamellar
Immature form of bone characterized by random orientation of collagen fibers
Woven
Describe the orientation of collagen fibers in woven bone
Random (disorganized)
Immature woven bone is later remodeled into:
Lamellar bone
Lamellar bone contains concentric layers called:
Circumferential lamellae
In lamellar bone, the collagen fibers of the circumferential lamellae are oriented:
Parallel
The extracellular component of bone are:
Mineralized
Lamellar bone can be either:
Dense & compact
Cancellous & spongy
Location we may find dense & compact lamellar bone
Cortex of long bones
Location we may find cancellous & spongy lamellar bone
Ends of bones
Cancellous bone contains a network of thin, bony _____ and ____
Trabeculae & open spaces
Trabeculae of cancellous bone may also be called:
Spicules
The open spaces in cancellous bone
Marrow cavity
Type of bone found in the limbs
Long bones
Shaft of long bones
Dipahysis
Diaphysis of long bones is composed of compact bone in the ______ and spongy cancellous bone in the ____
Cortex
Medullary cavity (marrow)
Type of marrow contained within long bones
Red & yellow
Red bone marrow is:
Hematopoietic
Yellow bone marrow is:
Fatty
Ends of long bones
Epiphysis
The epiphysis of long bones is composed of _____ bone covered with _____
Spongy/cancellous; hyaline articular cartilgae
Flared regions between epiphysis and diaphysis
Metaphysis
Metaphysics contains _____ if the long bone
Epiphyseal plate
The swollen ends of longs bones
Epiphysis
External surface of bone is covered by
Periosteum
A layer of fibrous connective tissue that covers the external surface of bone
Periosteum
Type of cells contained within periosteum
Fibroblasts
Osteoprogenitor cells
Internal marrow cavity is lined by
Endosteum
Parallel bundles of collagen fibers that extend from the periosteum or muscle tendon & insert into superficial layer of bone
Sharpey’s fibers
Sharpey’s fibers provide:
Anchorage and support
Resting mesenchymal cells that reside in the periosteum and endosteum
Osteoprogenitor cells
Location osteoprogenitor cells reside
Periosteum & endosteum
Osteoprogenitor cells can differentiate into:
Osteoblasts and osteocytes
Roughly polygonal, mesenchymal cells derived from osteoprogenitor cells
Osteoblasts
Osteoblasts are very _____ due to the synthesis of large amounts of protein and proteoglycans
Basophilic
Osteoblasts synthesize large amounts of:
Protein & proteoglycans
Osteoblasts are responsible for synthesis of ECM and collagen, collectively referred to as:
Osteoid
Osteoid is similar to _______ and later mineralized to form _____
Collagen; bone
Osteoblasts are responsible for calcification of matrix via secretion of:
Matrix vesicles
Matrix vesicles secreted by osteoblasts contains:
Alkaline phosphatase
The matrix vesicles bud off the osteoblasts into the matrix causing:
Precipitation of mineral salts
Mineral salts that precipitate due to matrix vesicles budding off the osteoblast (2):
Calcium
PO4
After the osteoid matrix mineralizes, osteoblasts mature into osteocytes in the:
Lacunae
Mature bone cells
Osteocytes
Large multinucleate bone cells
Osteoclasts
Osteoclasts are likely derived from ______ and have _____ properties
Monocyte-macrophage lineage; phagocytic
Osteoclasts are actively involved in:
Resorption & remodeling of bone
Location osteoclasts are usually found
Howship’s lacunae or resporption bays
What are howships lacunae/resorption bays
Endosteal/periosteal surface depressions
Type of cell that functions in calcium homeostasis
Osteoclasts
Osteoclasts function in calcium homeostasis by producing:
Organic acids
Lysozymes
