Flashcards

Lab 4: Cartilage and Bone

Sharon Leal English 36 cards

Osteoclasts Fx: Type of bone cell that breaks down bone tissue Maintenance, repair, and remodeling of bones of the…

Cards in this deck (36)

1—Osteoclasts
Fx: Type of bone cell that breaks down bone tissue
Maintenance, repair, and remodeling of bones of the vertebral skeleton
2—Woven Bone/ Immature
AKA Fibrous Bone
Characterized by a haphazard org. of collagen fibers and mechanically weak
Location: Embryonic Skeleton, cortical & cancellous bone in states of rapid bone growth, bone replacement/ high bone turnover
3—Osteon/Haversian sys.
Desc: Haversian canals: tubes in outermost region (cortical bone), allows blood vessels and nerves to travel
Formed by concentric layers= lamellae
Communicate w/ bone cells = canaliculi
4—Demineralized bone
Bone is fixed and calcium hydroxyapatide extracted w/ organic bone components
5—Ground compact bone
Consists of outer and inner sheets of lamellar bone and Haversian systems (run parallel to the long axis of bones
6—Endochondral Ossification
-Transformation of cartilage "bone models"
-Periosteal bud invades cartilage model and allows osteoprogenitor cells to enter cartilage
-Cartilage is in state of hypertrophy and partial calcification
-osteoprogenitor-> osteoblasts (framework. of calcified cartilage to deposit new bone) in lamellar bone
-Initial site of bone depositions is called Primary Ossification centre
-Secondary occurs in epiphyses of bone
7—Intramembranous ossification
-Ossification centre-> osteoprogenitor cells-> osteoblasts
-Osteblasts deposit organic bone matrix in OSTEOID
-Matrix separates osteoblasts at lacunae
-Collagen fibers of osteoid form a woven network = woven bone (lack of orientation)
-Osteoid clarifies-> formation of primitive trabecular bone
8—Fibrocartilage
Mixture of white fibrous tissue & cartilaginous tissue, associated w/ denseCT
Location: Pubic symphysis, annulus fibrosus intervertebral discs, menisci, temporal mandibular joint
Fx: Greater tensile strength and elasticity
9—Elastic Cartilage
AKA Yellow fibrocartilage
Fx: Provides both strength and elasticity, principal protein elastin and type II collagen; withstand repeated
Location: External ear, epiglottis, external auditory canal, corniculate and cuneiform of larynx
10—Hyaline Cartilage
Both Type I and II collagen
LOC: Initial skeleton of fetus, epiphyseal growth plate, articular cartilages of joints, trachea, bronchi, larynx, nose and ends of ribs
Fx: Provides smooth surfaces-> enables tissues to move/slide over each other
11Cellular components of cartilage-Chrondrocytes, deposit in small spaces= lacunae
-Chrondroblasts & chondrogenic cells at Perichondrium (dense irregular collagenous CT; w/ fibrous and inner chondrogenic layer)
12Fibrous LayerComposed of fibroblasts and collagen fibers
13Chrondrogenic LayerAKA inner cellular
-composed of chondroblasts (secrete cartilage matrix) and chondrogenic cells
-growth happens appositionally
14ChondrocytesYoung cartilage
undergoes cell division
-contributes to growth of cartilage from w/in (Interstitial Growth)
Then Lacunae house several chondrocytes= cell nest= isogenous group
SOx9, transcription factor aids to make type II collagen and other components
15Hyaline Cartilage-Surrounded by perichondrium
-Type II collagen fibers+ Glycosaminoglycans= texture smooth, glassy
-Proteoglycan- hyaluronic acid complex= lg. domains for binding w/ cations & water
LOC. in bone articulation, C rings of trachea, costal & nasal cartilages
16Elastic Cartilage-Has Perichondrium
-Matrix= Type II col. + elastic fibers
-LOC. epiglottis, external ear, ear canal & smaller laryngeal cartilage
17Fibrocartilage-NO perichondrium
-Chondrocytes: smaller and parallel orientation
-Matrix: Type I col. fiber bundles bet. rows of chondrocytes
-LOC. symphyses, Eustachian tube, intervertebral discs, areas where tendons insert into bone
18Bone-Fx: permits articulation & movement
-Composed of: 65% MINERALS (calcium hydroxyapatite crystals), 35% org. matter (Type I col., sulfated glycoproteins, & proteoglycans)
19Bone TypesCancellous: (Spongy-like)
Dense: (Compact)
20CancellousSpongy-like) Present inside epiphyses of lg. bones, lg spaces= marrow spaces & plates bones = trabeculae w/ several layers/ lamellae
21Dense(Compact) Covered & lined by soft CT, marrow cavity lined by endosteum (osteoprogenitor cells, osteoblasts, & osteoclasts)
Periosteum: outer fibrous layer (collagen & fibroblasts), inner osteogenic layer (some collagen & many osteoprogenitor cells, osteoclasts)
Affixed to bone via Sharpey's fibers
22Types of Bone Cells-Osteoprogenitor Cells
-Osteoblasts
-Osteocytes
-Osteoclasts
23Osteoprogenitor cells-factor-β and bone morphogenic protein-> Osteoblasts
-Hypoxic conditions-> chondrogenic cells
24Osteoblasts-Fx: elaborate bone matrix, calcify matrix via matrix vesicles; formation, recruitment and maintenance of osteoclasts, initiator for bone resorption
-Quiescent= lose mucho of protein and resemble osteoprogenitor
25OsteocytesTranscription factors: Cbfal/Runx2 & osterix
At lacunae and housed in canaliculi
Cytoplasmic form gap junctions
Respond to Calcitonin & parathormone
26Osteoclasts-Howship's lacuna (shallow cavity)
- 4 regions:
Basal Zone
Ruffled border (resorption of bone)
Vesicular Zone (vesicles that take material in/out of cell)
Clear Zone (form seal w/ bone)
27Cartilage DegenerationResults in decreasing mobility and joint pain
28Vitamin A DeficiencyExcess accelerates ossification of epiphyseal plates producing small stature
29Vitamin D Deficiency-Used for absorption of calcium from intestines
--> Poorly calcified bone
Rickets in children and osteomalacia in adults
-In EXCESS, bone is resorbed
30Vitamin C Deficiency-For collagen formation
--> Scurvy, poor bone growth and repair
31Hormonal Influences-Calcitonin: inhibits bone matrix resorption by altering osteoclast function
-Parathyroid hormone: activates osteoblasts to secrete osteoclast-stimulating factor
--> In EXCESS, bone brittle and susceptible to fracture
32Paget's diseaseAffects older people
--> thickened, softer bones of skull and extremities
Discovered by radiographic examination
Alkaline phosphatase levels
33Osteoporosis-Decrease in bone mass
-Commonly in old age (decreased in growth hormone) and postmenopausal women (decreased of estrogen)
34OsteopetrosisHeritable disorders= denser bones w/ pos. skeletal malformations
Types: Early onset, delayed onset type
35OsteomalaciaIn adults that resembles vitamin D deficiency levels in kids
Can'y absorb enough calcium in gastrointestinal tract
36ChondrosarcomaMalignant tumor in cartilage/ bone
Present commonly in males and most common cancer of bone
3 Types
Central chondrosarcoma: Develops in marrow cavity
Peripheral chondrosarcoma: Initial then invades bone
Juxtacortical chondrosarcomal: at metaphysis