Skeletal System (Exam II) Flashcards
What is the primary function of bone?
Support & locomotion/movement
What is the secondary function of bone?
Protection, mineral storage, hemopoeisis
Bone is ____, while cartilage is _____.
Rigid; semi-ridid
Both bone and cartilage are derived from:
Primitive mesenchymal cells
What is the relative strength of bone and cartilage due to?
Properties of ground substance and extracellular fibers
_____ is a bone precurser
Cartilage
Cartilage formation begins with ____ cells which differentiated into ______.
Stellate mesenchymal cells; rounded chondroblasts
The rounded chondroblasts of cartilage grow and synthesize:
Ground substance and fibrous extracellular matrix
When the chondroblasts grow and synthesize ground substance & fibrous extracellular matrix, what happens?
The chondroblasts get trapped inside lacunae
In cartilage, further mitotic divisions produces clusters of mature _____ referred to as _____.
Chondrocytes; isogenous groups
The isogenous groups of chondrocytes are separated by:
Extracellular matrix
The ECM surrounding the isogenous groups
Territorial matrix
The pink ECM between the isogenous groups of chondrocytes:
Interteritorial matrix
Cartilage is surrounded by:
Perichondrium
The peripheral zone of dense connective tissues, containing fibroblasts, collagen & immature chondroblasts
Perichondrium
In what type of growth, does cartilage form within the mass?
Interstitial growth
What type of growth allows chondrocytes to retain the ability to divide
Interstitial growth
Type cartilage growth where new cartilage forms at surface of pre-existing cartilage
Appositional growht
What type of cartilage growth is more common?
Appositional
In appositional growth, new chondrocytes are derived from mesenchymal cells of the:
Inner perichondrium
In appositional growth, the new chondrocytes derived form mesenchymal cells of inner perichondrium differentiate first into:
Chondroblasts
In appositional growth, more mature chondrocytes present at _______, while the younger cells present at ________.
Center of cartilage mass; periphery
Bone growth can be directly ______ cells to ______ OR ____ cells to _______ to ________
Mesenchymal cells —-> bone
Mesenchymal cells ——> cartilage ——> bone
What is found in the perichondrium? (Peripheral zone of dense connective tissue)
- Fibroblasts
- Collagen
- Immature chondroblasts
What type of connective tissue is cartilage?
Avascular
Cartilage lacks:
Blood vessels
Since cartilage is a vascular, exchange of metabolites occurs via:
Diffusion through ground substance
Since cartilage relies on diffusion of metabolites through the ground substance, this limits the:
Thickness of cartilage
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 hydrates and contains ~60-80% H20 bound to:
Proteoglycans
The hydration status of the matrix accounts for its: (2)
Flexibility & incompressibility
The GAGs found in cartilage (3):
- Hyaluronic acid (non-sulfated)
- Chondroitin sulfate
- Heparin sulfate
The most common glycoprotein in cartilage is:
Chondronectin
Potentially, chondronectin can have:
Anti-cancer properties
What determines the different types of cartilage:
Amounts of fibers embedded within matrix
Type of cartilage found within articular surfaces, growth plates, nasal septum, coastal cartilage (ribs), tracheal and bronchial rings:
Hyaline cartilage
Precursor of bone in most skeleton:
Hyaline cartilage
Collagen type that is characterized by aggregates of chondrocytes in amorphous matrix of ground substance & reinforced with type II collagen fibers:
Hyaline cartilage
What type of collagen fibers are present in hyaline cartilage:
Hyaline cartilage
What is the most common type of cartilage:
Hyaline cartilage
The Greek term hylos means:
Glass look
Specific locations for what type of cartilage:
- End of long bones
- Growth plates
- Nasal septum
- Articular surfaces
- Octal cartilage
- Tracheal & bronchial rings
Hyaline cartilage
What is a common precursor for bone in the skeleton?
Hyaline cartilage
Consists of alternating layers of hyaline cartilage and dense connective tissue:
Fibrocartilage
What type of collagen fibers are present in fibrocartilage:
Type I & Type II collagen
Fibrocartilage is less ____ than the other types of cartilage
Cellular
Fibrocartilage lacks:
Perichondrium
What type of cartilage is present in intervertebral discs?
Fibrocartilage
What type of cartilage is 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
What type of collagen fibers are present in elastic cartilage?
Type II
Type of cartilage found in the external ear, auditory eustachian canals, epiglottis, and larynx?
Elastic cartilage
Type of cartilage that has a very limited distribution throughout the body?
Elastic cartilage
____ in cartilage is limited because it requires blood flow
Repair
Because repair in cartilage is limited, because it requires blood flow, this results in production of:
Dense connective tissue (fibrosis)
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
The most common repair of cartilage is done via:
Fibrosis
In the healing process of cartilage, the chondrocytes get replaced with:
Osteocytes
Old people are stiff because they do not have the same amount of ____ in there cartilage as younger people do:
Turgor pressure
Specialized support tissue in which the extracellular components are mineralized
Bone
What are two characteristics of bone
Strength & rigidity
What are the two main forms of bone?
Woven & lamellar
Immature form of bone characterized by random orientation of collagen fibers
Woven bone
describe the orientation of collagen fibers of 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 fibers of the circumferential lamellae are oriented:
Parallel
The extracellular components of bone are:
Mineralized
Lamellar bone can be either:
Dense & compact or cancellous & spongy
Where might we find dense and compact lamellar bone?
Cortex of long bones
Where might we find cancellous & spongy lamellar bone?
Ends of bones
Cancellous bone contains a network of thing, bony: (2)
Trabeculae and open spaces
Trabeculae of cancellous bone can also be called:
Spicules
The open spaces of cancellous bone:
Marrow cavity
What types of bones are found in the limbs?
Long bones
Shaft of long bones:
Diaphysis
The diaphysis of long bones contains compact bone in the _____, & spongy cancellous bone in the ____
Cortex
Medullary cavity (marrow)
What type of marrow is contained within long bones?
Red marrow or yellow marrow
Red bone marrow is:
Hematopoietic
Yellow bone marrow is:
Fatty bone marrow
Ends of long bones:
Epiphysis
The epiphysis of long bones is composed of ____ bone covered with _____.
Spongy/cancellous bone covered with hyaline articular cartilage
Flared regions between epiphysis & diaphysis:
Metaphysis
The metaphysis contains the ____ of long bones:
Epiphyseal plate
The swollen ends of long bones:
Epihysis
The external surface of bone is covered by:
Periosteum
A layer of fibrous connective tissue that covers the external surface of bone
Periosteum
What type of cells are found within periosteum?
Fibroblasts & osteoprogenitor cells
The internal marrow cavity is lined by:
Endosteum
Parallel bundles of collagen fibers, that extend from the periosteum or muscle tendon and insert into the superficial layer of bone:
Sharpeys fibers
Sharpeys fibers provide:
Anchorage & support
Resting mesenchymal cells that reside in the periosteum and endosteum
Osteoprogenitor cells
Where do osteoprogenitor cells reside?
Periosteum & endosteum
Osteoprogenitor cells can differentiate into:
Osteoblasts & osteocytes
Roughly polygonal, mesenchymal cells derived from osteoprogenitor cells
Osteoblasts
Osteoblasts are very ____ due to the synthesis of large amount of protein and proteoglycans
Basophilic
Osteoblasts synthesize large amounts of:
Proteins & proteglycans
Osteoblasts are responsible for synthesis of ECM & collagen, collectively referred to as:
Osteoid
Osteoid is similar to _____ and later mineralizes to form ___.
Cartilage; bone
Osteoblasts are responsible for calcification of matrix via:
Secretion of matrix vesicles
The matrix vesicles secreted by osteoblasts contain:
Alkaline phophatase
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 osteoblasts:
Calcium and 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 _____ & have _____ properties
Monocyte-macrophage lineage; phagocytic
Osteoclasts are actively involved in:
Resorption & remodeling of bone
Where are osteoclasts usually found:
Howships lacunae or resorption bays
What are howships lacunae or resorption bays?
Endosteal/periosteal surface depressions
Type of cell that function in calcium homeostasis:
Osteoclasts
osteoclasts function in calcium homeostasis by producing:
Organic acids & lysozymes
Modified folded plasma membrane, containing microvilli-like structure, (where the lysozymes & organic acids secreted into ECS chew away the bone)
Ruffled border
Bone serves as a reservoir for ____ & function in homeostasis of _____
Calcium ; calcium
What are the two antagonistic hormones that regulate calcium homeostasis:
Parathormone & calcitonin
Parathormone =
Parathyroid hormone
Parathyroid hormone is secreted by:
Parathyroid gland
Parathyroid hormones stimulates ______ activity leading to ______.
Osteoclast activity; bone resorption
Parathyroid hormones ____ blood calcium levels & _____ renal exertion by kidneys
Increase; decrease
Calcitonin is secreted by:
Thyroid gland
Calcitonin stimulates _____ activity and inhibits ____ activity
Osteoblasts; osteoclasts
Calcitonin functions in bone _____.
Deposition
Calcitonin _____ blood calcium levels
Decreases
Pituitary growth hormone:
Somatotropin
Hormone responsible for stimulating growth especially epiphyseal cartilage and bone
Somatotropin
Somatotropin _____ blood calcium levels
Decreaes
Oversecretion of somatotropin can lead to _____ or ______. Under secretion of somatotropin can lead to ____.
Gigantism or acromegaly
Pituitary dwarfism
The majority of the organic component of compact bone is comprised of ______, synthesized by _____.
Type I collagen synthesized by osteoblasts
GAGs of ground substance consist mostly of: (3)
Hyaluronic acid, Chondroitin sulfate, keratin sulfate
Non-collagenous organic molecules include:
Osteocalcin, osteonectin, & sialoproteins
Non-collagenous organic molecule that binds intracellular calcium during mineralization
Osteocalcin
Non-collagenous organic molecule that bridges/binds collagen & minerals
Osteonectin
Non-collagenous organic molecule that is rich is Salic acid and is concentrated from plasma
Sialoproteins
Mineralized component of bone is formed by:
inorganic salts
Inorganic salts that form the mineralized component of bone:
Calcium & phosphate
Calcium & phosphate form the mineralized component of bone in the form of:
Hydroxyapatite crystals
Ca10(PO4)6(OH)2
Hydroxyapatite crystals
Bone also has the affinity for:
Heavy metals and radioactive isotopes
2 examples of heavy metals that bone has affinity for:
Lead and mercury
Type 1 collagen is the primary _____ in mature bone.
Structural protein
Compact bone contains ___ systems also called ____.
Haversian systems; osteons
How are osteons produced?
Bony remodeling
Removal of existing bone by osteoclasts and redeposition of new bone by osteoblasts
Remodelng
The size of the average haversian system is equivalent to:
Size of osteoclast
The outer margin of osteon is delimited by:
Cement line
What invades the empty tunnels created by osteoclasts:
Osteoblasts
Osteoblasts become trapped in _____ in osteoid matrix & mature into _____.
Lacunae ; osteocytes
Minute canals connecting osteocytes:
Canaliculi
The canaliculi contain:
Cytoplasmic extensions
Osteocytes communicate with eachother when they’re trapped through:
Gap junctions
Within center of each osteon:
Haversian canal
The Haversian canal contains:
Blood vessels and nerves
Longitudinal Haversian canals are connected by transverse:
Volkman’s canals
What is exchanged through Haversian canals?
Waste & nutrients
Haversian systems are oriented:
Parallel to the long axis of bone
Inactive haversian systems:
Interstitial systems
____ bone lacks haversian systems
Spongy & woven bone
Haversian systems are only present in _____ bone.
Compact lamellar
Outer periphery of cortisol bone is arranged in:
Circumferential lamellae
Cortical bone is also called:
Compact lamellar bone
Volkman’s canals run _____ to the long axis of bone.
Perpendicular
The osteons run through the major lines of _____ of the bone.
Tension
Bone growth is controlled by (3)
Growth hormone, thyroid hormone, sex hormones
Replacement of cartilage precursor by bone:
Endochondral ossification
In endochondral ossification, the resulting woven bone is extensively remodel by ______ & ______ to form lamellar bone.
Resorption & appositional growth
Long bones, vertebra, pelvis and base of skull all undergo what type of bone process:
Endochondral ossification
Direct replacement of mesenchyme by bone; NO cartilage precursor
Intramembranous ossification
Mesenchymal cells differentiate into osteoblasts, produce osteoid, later mineralizes into bone
Intramembranous ossificaton
The vault of the skull undergoes what type of bone growth
Intramembranous ossification
In endochrondral ossification, the precursor of long bone is formed of:
Hyaline cartilage
The primary center of ossification occurs in:
Mid-diaphysis
Osteoprogenitor cells and osteoblasts secrete osteoid which mineralizes forming:
Periosteal cuff
Calcification of cartilage matrix inhibits:
Diffusion of nutrients
Diffusion of nutrients is inhibited by the calcification of cartilage matrix this results in death of _____ & spread of _____
Chondrocytes and spread of osteoblasts
In endochondral ossification, the osteoprogenitor cells from the ____ migrate to the _____ along with growing blood vessels
Periosteum —-> medulla
In endochondral ossification two _____ occur in the epiphysis
Centers of ossification
In endochondral ossification, the 1’ center of ossification occurs in the _____ while the 2’ centers of ossification occurs in the _____.
Mid-diaphysis
Epiphysis
_____ is a region of metaphysis that remains open (unmineralized) in endochondral ossification:
Epiphyseal plate
The epiphyseal plate allows for continuous:
Longitudinal growth
At maturity, hormonal changes decrease _____ & cartilage plate is replaced by bone.
Cartilage proliferation
Closure of epiphysis means complete:
Ossification
Last long bone to close in humans:
Femur
After closure, the growth plate persists as ______ in metaphysis, visible on X-rays
Epiphyseal line
Type of growth humans and mammals have:
Determinate growth
The epiphyseal growth plate consist of several distinct zones in transition from:
Cartilage to bone
Hyaline cartilage with clusters of chondrocytes, no cell proliferation (zone)
Zone of reserve cartilage
Successive mitotic divisions of chondrocytes leading to columns of chondrocytes (zone)
Zone of proliferation
Division ceases and chondrocytes increase in size: (zone)
Zone of maturation
The zone closest to the epiphysis:
Zone of reserve cartilage
Chondrocytes greatly enlarge, contain large amounts of glycogen, and come vacuolated & calcify (zone)
Zone of hypertrophy (& calcification)
Capillaries of marrow cavity grow from diaphysis into growth plate: (zone)
Zone of (cartilage) degeneration
In the zone of degernation, chondrocytes ______ and the lacunae are invaded by _____.
Degenerate ; invaded by osteoprogenitor cells
Blood vessels from marrow cavity grow into cartilage mass: (zone)
Zone of ossification
Osteogenic cells differentiate into osteoblasts, congregate on spicules of calcified cartilage matrix to form bony trabeculae: (zone)
Zone of ossification
In Intramembranous ossification, mesenchymal cells differentiate directly into:
Osteoblasts
During Intramembranous ossification the osteoblasts begin synthesizing ____ at multiple sites within the _____.
Osteoid within the membrane
How many centers of ossification occur in Intramembranous ossification
Multiple centers of ossification
During Intramembranous ossification, osteoblasts get trapped in lacunae of osteoid and become:
Osteocytes
_____ cells at the _____ continue to divide, providing replacements
Osteoprogenitor cells @ the periphery
During Intramembranous ossification the bone produced is:
Woven bone
During Intramembranous ossification, the woven bone is later remodeled by _____ & _____ to form compact bone.
Osteoclasts & Osteoblasts
Embryonic undifferentiated cells:
Mesenchymal cells
During Intramembranous ossification what type of cells are located at the periphery?
Osteoprogenitor cells
A break where there is no break of skin:
Simple/ closed fracture
A break that causes damage to the skin exposing bone:
Compound/open fracture
Type of break in which bone is broken in several pieces
Comminuted fracture
Following a break, what fills the fracture site? What is this also called?
Blood fills fracture site; aka hematoma
Immediately after fracture, inflammatory response develops leading to:
Pain, swelling, redness & heat
The acute phase of a bone break occurs:
First few days after break
In the acute phase, _____ are first to arrive.
Neutrophils
In the acute phase, the neutrophils are first to arrive and:
Infiltrate the hematoma
In the acute phase, after the neutrophils infiltrate the hematoma, _____ then come to clean up the site of injury
Macrophages
After about 1 week in the acute phase of a bone break, _____ & _____ proliferate and grow into the site
Fibroblasts & capillaries
After about 1 week post break, the fibroblasts & capillaries grow into the site to form:
Granulation tissue
The granulation tissue formed by the fibroblasts & capillaries is ______ tissue.
Vascular collagenous tissue
Post break, the granulation tissue becomes progressively more fibrous in the _____ phase.
Chronic phase
In the chronic phase post break, the granulation tissue becomes progressively more fibrous forming:
Fibrous granulation tissue
Following the formation of fibrous granulation tissue, ______ cells differentiate into _____ and secrete matrix.
Mesenchymal cells; chondroblasts
Post break, when the mesenchymal cells differentiate into chondroblasts & secrete matrix, this causes progressive replacement of granulation tissue by ______ forming _______.
Hyaline cartilage; provisional callous
After the provisional callous is formed in bone repair, _____ & _____ cells from the endosteum & periosteum at the edge of the wound grow ____.
Osteoprogenitor cells & osteoblasts
After the osteoprogenitor cells and osteoblasts grow inward, they produces a mesh work of ______ within the provisional callous.
Woven bone
The osteoprogenitor cells and osteoblasts produce a mesh work of woven bone within the provisional callous and deposit _____ in the collagen matrix
Calcium salts
The deposition of the calcium salts in the collagen matrix of the woven bone within the provisional callous transforms the provisional callous into a:
Bony callous
The bony callous helps to:
Stabilize and bind fracture together
When the fracture site is completely bridged by woven bone, this is called:
Bony union
The bony callous is progressively remodeled to form:
Mature lamellar bone
The process of bone repair takes around 6-12 weeks dependent upon:
Severity and location
Joint allowing for extensive movement
Synovial
Synovial joints are also known as:
Diarhtroses
Synovial joints (diarthroses) are surrounded by a:
Connective tissue capsule
The connective tissue capsule that surrounds the synovial joints:
Joint capsule
The synovial joint is lined by a thin, discontinuous layer of cells called the:
Synovium
The synovium secretes ____ which functions to _____.
Synovial fluid which bathes the articular surface
Synovial joints have no basement membrane so they do not have a true:
Epithelium
Synovial joints are made of up to 4 cell layers of ______ of _____ origin.
Synovial cells of mesenchymal origin
Two types of cells in synovial joints:
A & B
Type A synoviocytes resemble:
Macrophages
Type B synoviocytes resemble:
Fibroblasts
Joint characterized by limited movement, joined by dense connective tissue, lacking an articular surface:
Nonsynovial
Dense fibrous tissue between bones:
Syndesmosis
In the skull, syndesmosis is progressively replaced by bone to become _______.
Synotosis
Synotosis of the skull is also called:
Sutures
Primary cartilage joint that contains a single layer of hyaline cartilage:
Synchondrosis
What type of joint unites the first rib with the sternum (only one in adult human)
Synchondrosis (primary cartilage joint)
What type of cartilage is found in Synchondrosis?
Hyaline cartilage
Secondary cartilage joint
Symphysis
cartilage joint that contains two hyaline cartilage surfaces connected by fibrocartilage plate
Symphysis
Intervertebral discs are a specialized type of:
Symphysis
Intervertebral joints contain intervertebral discs that are evolutionarily derived from _____ in _____.
Notochord in chordates
Intervertebral discs are formed of concentric layers of:
Fibrocartilage
Central cord of viscous ground substance of the intervertebral disc
Nucleolus pulposis
Dense layer that forms around the nucleolus pulposus
Annulus fibrosus
Damage to the annulus fibrosus causes nucleus pulposus to _____ resulting in _____
Herniate ; herniated disc
Inflammation of joints:
Arthritis
Progressive degeneration and loss of articular cartilage
Osteoarthritis
Osteoarthritis leads to:
Eburnation, pitting, erosion
The eburnation, pitting, and erosion caused by osteoarthritis leads to:
Pain, swelling, and thickening of joint capsule
Production of irregular new bone at edges of articular surfaces
Osteophytes
Osteophytes may also be called:
Bone spurs
Osteophytes (bone spurs) limit the:
Range of motion
Progressive build up of osteophytes, osteoarthritis, or trauma can lead to:
Ankylosis
Bone fusion of joint with loss of mobility:
Ankylosis
Polishing of articular surface:
Eburnation
Most common pathology we see of bones:
Arthiritis
Local autoimmune reaction in joints
Rheumatoid arthritis
Rheumatoid arthritis is when the body produces _____ that attacks the joints:
Antibodies
In RA, the antibodies that attack the joints, leads to pain and damage of the articular cartilage & thickening and inflammation of the:
Synovial membrane
Replacement of articulate cartilage with fibrovascular tissue:
Pannus
Deposited of urates and uric acid crystals in joints (especially fingers and toes)
Gout
Gout is extremely painful and associated with of consumption of large quantities of:
Red wine & meat
Causative vegetables of gout:
Asparagus, broccoli, cauliflower & brussel sprouts
The certain veggies associated with gout all represent ____ & are high in _____ & _____
New growth & protein & nitrogen
Bone matrix that doesn’t calcify normally in children during growth resulting in soft, deformed bones & can be permanent
Rickets
Rickets is due to insufficiency in dietary _____ or ____
Calcium or vitamin D
In adults, insufficient calcium and vitamin D can lead to:
osteomalacia
Failure of mineralization resulting in softening of bone in adults: (pretty much adult form of rickets)
Osteomalacia
Loss of bone mass
Osteoporosis
In osteoporosis the ____ by osteoclasts exceeds the _____ by osteoblasts
Resorption ; deposition
Osteoporosis is a common problem in ______ due to decreased _____
Menopausal women due to decreased estrogen levels
Osteoporosis can be treated by: (5) ORAL
Oral calcium
Oral vitamin D
Chondroitin
Glucosamine
Gelatin
Fosamax, a newer osteoporosis medication functions by binding _____ in the GI tract to minimize ____
Possible side effect includes:
Function by binding phosphates in GI tract to minimize absorption
Mandibular necrosis
VItamin C is necessary for the synthesis of:
Collagen
Vitamin C deficiency causes:
Scurvy
When the bone matrix is not calcified due to lack of vitamin C
Scurvy
Vitamin D deficiency can also lead to weakening of collagen in: (in addition to scurvy_
Ligands (periodontal ligament)
