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HISTOLOGY > MIDTERM LEC 2: BONE AND CARTILAGE > Flashcards

MIDTERM LEC 2: BONE AND CARTILAGE Flashcards

1
Q

● Part of/surrounded by connective tissue
● Tough, durable form of supporting
connective tissue, characterized by its
extracellular matrix (ECM)
● Lacks nerves

A

CARTILAGE

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2
Q

CARTILAGE ORIGNATED FROM?

A

EMBRYONIC MESENCHYME

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3
Q

ECM of cartilage:
➢ Has high concentrations of ___and __________, interacting with collagen and elastic fibers

A

GAGs, proteoglycans

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4
Q
  • is a SHEATH OF DENSE CONNECTIVE TISSUES that surrounds cartilage in most places
  • forming an interface between the cartilage and the tissues supported by the cartilage
  • HARBORS THE BLOOD SUPPLY serving the cartilage and a small neural component
A

PERICHONDRIUM

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5
Q

THE PHYSICAL PROPERTIES OF CARTILAGE DEPEND ON ELECTROSTATIC BONDS BETWEEN:

A

● ECM TYPE II COLLAGEN
● HYALURONAN/ HYALURONATE/ HYALURONIC ACID

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6
Q
  • COVERS THE ENDS OF BONE in
    movable joints
  • erodes in the course of arthritic
    degeneration,
  • LACKS PERICHONDRIUM and is
    sustained by the diffusion of
    oxygen and nutrients from the
    synovial fluid
A

ARTICULAR CARTILAGE

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7
Q

● (Gr. chondros, cartilage + kytos, cell)
● Cartilage cells
● Cells of the cartilage embedded in the
ECM which unlike connective tissue
proper contains no other cell types
SYNTHESIZE ANDMANTAIN ALL ECM COMPONENTS
● Exhibit LOW METABOLIC ACTIVITY
● Location: cavities (LACUNAE)

A

CHONDROCYTE

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8
Q
  • HYALOS: glass; glassy appearance,
    bluish
  • MOST COMMON TYPE OF CARTILAGE
    ● Fresh state: HOMOGENOUS and
    SEMI TRANSPARENT
    ● Location in adult:
    1. Articular surfaces of movable joints
    2. Walls of larger respiratory
    passages - (nose, larynx, trachea,
    bronchi)
    3. Ventral ends of ribs - where they articulate with the sternum, and
    4. Epiphyseal plates of long
    bones - where it makes possible longitudinal bone growth
A

HYALINE CARTILAGE

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9
Q

hyaline cartilage that forms the temporary skeleton and later on replaced by bones

A

EMBRYO

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10
Q

● Nearly 40% collagen (mostly type II)
● Embedded in a firm, hydrated gel of
proteoglycans and structural
glycoproteins

A

ECM OF HYALINE CARTILAGE

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11
Q

make the matrix generally BASOPHILIC (negative) and the thin collagen fibrils are barely discernible.

A

PROTEOGLYCANS

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12
Q
  • MOST ABUNDANT PROTEOGLYCAN OF HYALINE CARTILAGE
  • bound noncovalently by link proteins to long polymers of hyaluronan
A

AGGRECAN

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13
Q
  • a form of structural MULTIADHESIVE GLYCOPROTEIN
  • Binds specifically to GAGs, collagen, and integrins, mediating the adherence of chondrocytes to the ECM.
A

CHONDRONECTIN

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14
Q

CHONDROCYTES OF HYALINE CARTILAGE
● Chondrocytes respire under________
tension because cartilage matrix is
AVASCULAR

A

LOW - OXYGEN

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15
Q

Cell metabolism: Glucose metabolized
mainly by

A

ANAEROBIC GLYCOLYSIS

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16
Q

young chondrocytes that has an elliptic
shape, with the long axes parallel to the
surface; may appear in groups of up to
eight cells that originate from mitotic
divisions of a single chondroblast and
are called ISOGENOUS AGGREGATES

A

CHONDROBLAST

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17
Q

most collagen in hyaline cartilage

A

TYPE II COLLAGEN

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18
Q

metabolize glucose

A

ANAEROBIC GLYCOLYSIS

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19
Q

DRY WEIGHT OF HYALINE CARTILAGE (40% collagen embedded in firm, hydrated gel of proteoglycans and structural glycoproteins)

A

MATRIX

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20
Q
  • elliptic shape, with long axes parallel to the surface
  • Round and may appear in groups of up to 8 cells (Isogenous aggrefates)
  • Secretes collagen and other ECM
    components
A

CHONDROBLAST

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21
Q
  • a PITUITARY -DERIVED protein
  • major regulator of hyaline cartilage growth
  • acts INDIRECTLY, promoting the
    endocrine release from the liver
    of insulin-like growth factors,
    or somatomedins, which directly
    stimulate the cells of hyaline
    cartilage
A

SOMATOTROPHIN

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22
Q
  • Source of nutrients
  • Dense connective tissue
  • Essential for growth and maintenance of cartilage
A

PERICHONDRIUM

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23
Q

OUTER REGION OF PERICHONDRIUM is consists largely of collagen ______ fibers and ____

A

TYPE I, FIBROBLASTS

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24
Q

OUTER REGION OF PERICHONDRIUM contains ________ which provide a SOURCE FOR A NEW CHONDROBLASTS hat divide and differentiate into chondrocytes

A

MESENCHYMAL STEM CELLS

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25
Q
  • Flexible due to abundant network of
    elastic fibers
  • Contains an abundant network of ELASTIC FIBERS and COLLAGEN TYPE II FIBRILS which gives fresh elastic cartilage a YELLOW COLOR
  • MORE FLEXIBLE than hyaline
  • Found in the auricle of the ear, walls of the external auditory canals, auditory
    (Eustachian) tube, epiglottis, and upper respiratory tract
  • Has perichondrium
  • Cells are the same with hyaline cartilage
A

ELASTIC CARTILAGE

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26
Q
  • MINGLING OF HYALINE CARTILAGE and dense connective tissue
  • Hyaline cartilage + dense CT
  • Found in intervertebral discs,
    attachment of certain ligaments, and in pubic symphysis
  • All place where it serves as VERY TOUGH, YET CUSHIONING SUPPORT tissue for bone
A

FIBROCARTILAGE

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27
Q

occur single and often in aligned isogenous aggregates producing
type II collagen and other ECM components

A

CHONDROCYTES

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28
Q
  • Areas with chondrocytes and hyaline
    matrix are SEPARATED by other regions
    with FIBROBLASTS and dense BUNDLES OF TYPE I COLLAGEN which confer extra tensile strength to this tissue
    ● Proteoglycans: Its scarcity makes
    fibrocartilage matrix more ACIDOPHILIC
    ● Relatively lacks proteoglycans
  • perichondrium: ABSENT
A

ECM SPARSE

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29
Q
  • scarcity of proteoglycans
  • NO DISCTINCT PERICHONDRIUM
A

ACIDOPHILIC

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30
Q
  • FIBROCARTILAGE ACT AS LUBRICATED CUSHIONS and shock absorbers preventing damage to adjacent vertebrae from abrasive forces of impacts
A

INTERVERTEBRAL DISCS OF SPINAL
COLUMN

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31
Q
  • FORMATION OF CARTILAGE
  • Embryonic cartilage formation
    (mesenchyme)
  • Rounding up mesenchymal cell: first indication of cell differentiation
  • Mesenchymal cell → chondroblasts → chondrocyte → ECM → cartilage
  • Superficial mesenchyme develops as the perichondrium
A

CHONDROGENESIS

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32
Q

CARTILAGE GROWTH
- divide by chondrocytes; mitosis of chondrocytes
- Involving mitotic division of pre-existing chondrocyte
- WITHIN LONG BONES: it is important in increasing the length of these structures

A

INTERSTITIAL GROWTH

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33
Q

CARTILAGE GROWTH
- Involves chondroblast differentiation from progenitor cells in the
perichondrium
- More important during POSTNATAL DEVELOPMENT

A

APPOSITIONAL GROWTH

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34
Q

CARTILAGE REPAIR/REGENERATION IS?

A

slow or doesn’t heal; low metabolic rate

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35
Q

Cartilage repair primarily dependent on
cells in the __________ which invade the injured area and produce new cartilage

A

perichondrium

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36
Q

● GRADUAL LOSS/CHANGED physical properties of the HYALINE CARTILAGE that lines the articular ends of bones in joints (prone to cartilage degeneration)
● Bone tends to crash (friction)
- Cartilage loss (hyaline)
- Joint space narrowing
- Bone spurs
- Case friction between 2 bones

A

OSTEOARTHRITIS (OA

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37
Q

TUMORS:
- (capsulated to prevent spread) arising from cells of cartilage (BENIGN TUMOR)

A

CHONDROMA

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38
Q

slow growing; seldom metastasize and
are generally removed surgically
(MALIGNANT TUMOR)

A

CHONDROSARCOMA

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39
Q

Due to MUTATION IN FBN1 GENE, which encodes fibrillin-1
- protein that plays a crucial role in the
formation of elastic fibers within the connective tissue

● Abnormalities include skeletal, cardiovascular, ocular, pulmonary,
dural ectasia (covering of the spinal cord)

A

MARFAN SYNDROME

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40
Q

● Specialized CT composed of calcified ECM (bone matrix)
● MAIN CONSTITUENT OF THE ADULT SKELETON
- Provides solid support for the body
- Protects vital organs such as those in the cranial and thoracic cavities, and encloses internal (medullary) cavities containing bone marrow where blood cells are formed
- Reservoir for calcium, phosphate, and other ions
3 MAJOR CELL TYPES: OSTEOCYTE, OSTEOBLASTS, OSTEOCLASTS

A

BONE (OSSEOUS) TISSUE

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41
Q
  • formation of blood cell
A

HEMATOPOIESIS

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42
Q

2 SPECIALIZED BONE TISSUE
(connective tissue covering)

● Layer of dense connective tissue on the outer (external) surface of the bone
● bound to bone matrix by bundles
of type I collagen called Perforating (Sharpey’s) fibers, that secures the periosteum
● Rich in osteoprogenitor cells & osteoblast that mediate much bone growth and remodeling

A

PERIOSTEUM (OUTER)

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43
Q

● Thin layer of active/inactive osteoblast, which LINES ALL THE INTERNAL SURFACES WITHIN BONE
● Osteoblast here also required for
bone growth

A

ENDOSTEUM (INNER)

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44
Q

origin of OSTEOBLASTS

A

OSTEOPROGENITOR CELL

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45
Q

BONE TISSUE SECTIONING
● Bone matrix is usually softened by immersion in a ___________before paraffin embedding/embedded in plastic after fixation & sectioned within specialized microtome

A

decalcifying solution

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46
Q

UNIT OF BONE (MATRIX RINGS)

A

OSTEON (HAVERSIAN SYSTEM)

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47
Q

● OPENING in the CENTER OF AN OSTEON, carrying blood vessels and nerves to all areas of the bone.
● run lengthwise through the bony
matrix

A

CENTRAL (HAVERSIAN) CANALS

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48
Q

● Canal perpendicular (90*) to the central canal

A

PERFORATING (VOLKMANN’S) CANAL

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49
Q

● TINY CAVITY, containing osteocyte
(mature bone cells) , arranged in
concentric rings

A

LACUNAE

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50
Q

● containing arranged lacunae
● Rings around central (Haversian)
canals of lacunae

A

LAMELLAE

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51
Q

● Tiny canals that radiate outward from
the central canals to all lacunae
● GIVES OSTEON A TINY CRACK APPEARANCE

A

CANALICULI

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52
Q

3 TYPES OF BONE CELLS
● BONE - FORMING CELLS
● Origin: mesenchymal stem cell
● SYNTHESIZE AND SECRETE THE ORGANIC COMPONENTS OF BONE MATRIX: type I collagen fibers, proteoglycans, and matricellular glycoproteins (osteonectin).
● Location: surfaces of the bone matrix, bound by integrins, typically forming a single layer of cuboidal cells joined by adherent and gap junctions
● Secretes non-collagen protein
(osteocalcin)
OSTEOCALCIN: for bone
metabolism

A

OSTEOBLASTS (build)

53
Q
  • LAYER OF UNIQUE COLLAGEN rich material between the osteoblast layer and the preexisting bone surface
  • Involves in the MINERALIZATION OF MATRIX
A

OSTEOID

54
Q

(osteon: bone + kytos: cell)
● mature bone cell
● MOST ABUNDANT CELL in the bone
- Found in cavities (lacunae) between bone matrix layers (lamellae) with cytoplasmic processes in small canaliculi (L.canalis, canal) that extend into the matrix
● Express many different proteins, including factors with PARACRINE and ENDOCRINE effects that HELP REGULATE BONE REMODELLING
● Communicate with one another
and ultimately with nearby
osteoblasts and bone lining cells
via GAP JUNCTIONS

A

OSTEOCYTES

55
Q

-(blastos: germ)
- Growing cells which synthesize and
secrete the organic components of the matrix

A

OSTEOBLAST

56
Q

● giant among the 3 types;
development rely on osteoblasts (klastos: broken)
● (osteon + Gr. klastos, broken), which are giant, motile, multinucleated cells involved in REMOVING CALCIFIED BONE MATRIX and REMODELLING bone tissue
● SECRETES ENZYMES AND ACIDS that dissolved the mineralized matrix, releasing calcium & phosphate ions
● Location: lie within the enzymatically etched depressions or cavities in the matrix known as resorption lacunae (or Howship lacunae)
● Development: requires 2 polypeptides produced by osteoblasts
1. Macrophage-Colony-Stimulating Factor (M-CSF)
2. Receptor Activator of Nuclear factor-κB Ligand (RANKL)

A

OSTEOCLAST

57
Q

a layer of unique collagen-rich material between osteoblast layer and the pre-existing bone surface

A

OSTEOID

58
Q

a vitamin K-dependnet polypeptide, prominent among the noncollagen proteins secreted by osteoblasts

A

OSTEOCALCIN

59
Q
  • release membrane-enclosed by osteoblast rich in alkaline phosphatase and other enzymes which raises the local concentration of PO4 3− ions
  • SERVE AS FOCI for the formation of
    hydroxyapatite crystals, the first visible step in calcification
A

MATRIX VESICLES

60
Q
  • Most abundant in bone
  • Enclosed singly within the lacunae spaced throughout the mineralized matrix
A

OSTEOCYTES

61
Q
  • where diffusion of metabolites between osteocytes and blood vessels occurs
  • Communicates via GAP JUNCTIONS which allows osteocytes to serve s
    mechnosensors
A

CANNALICULI

62
Q
  • DETECTS MECHANICAL LOAD on the bone as well as
    stress-or fatigue-induced micro-
    damage and trigger remedial activity
    in osteoblasts and osteoclasts
  • Has less RER, smaller Golgi complexes, and more condensed nuclear chromatin than osteoblast
  • Maintain the calcified matrix and their death is followed by rapid matrix resorption
A

MECHANOSENSORS

63
Q

paracrine and endocrine
that helps regulate bone remodeling

A

PROTEINS

64
Q
  • BINDS THE CELL TIGHTLY TO THE BONE MATRIX and surrounds an area with
    many surface projection called
    “ruffled border”
  • allows the formation of a
    specialized microenvironment
    between the osteoclast and matrix
    in which bone resorption occurs
A

SEALING ZONE

65
Q

BONE MATRIX
- ____ INORGANIC MATERIALS

A

50%

66
Q

Flat bones that form the calvaria
(skullcap) have two layers of compact
bone

A

PLATES

67
Q

a thicker layer of cancellous bone that
separates the plates

A

DIPLOE

68
Q

organized most bone in adults compact or
cancellous bones
- characterized by multiple layers or
lamellae calcified matrix (3-7 um thick)

A

LAMELLAR BONE

69
Q
  • Occurs continuously thoughout life
  • In compact bone, remodeling resorbs
    parts of old osteons and produce new
    ones
  • In healthy adults, 5%-10% of the bone
    turns over annually
A

BONE REMODELING

70
Q
  • Where most flat bones begin to form
  • osteoblasts differentiate directly from mesenchyme and begin secreting osteoid
  • Most bones of the skull and jaws, as well as the scapula and clavicle, are formed embryonically by intramembranous ossification
A

INTRAMEMBRANOUS OSSIFICATION

71
Q

2 TYPES OF BONE
● Dense bone immediately beneath, periosteum
● Represents 80% of the total bone mass

A

COMPACT (CORTICAL BONE)

72
Q

2 TYPES OF BONE
● A.K.A: Spongy bone/Diploe
(makapal) - has porous
● Inner region/deeper areas with
numerous interconnecting cavities
● Constitutes 20% of the total bone
mass

A

CANCELLOUS (TRABECULAR) BONE

73
Q
  • Body of long bone
  • medullary cavity; bone marrow located
A

DIAPHYSIS

74
Q
  • Ends of the long bone
  • cancellous covered by compact bone
A

EPIPHYSIS

75
Q

2 types of organization that both compact and cancellous bones typically show:
● A.K.A: IMMATURE BONE primary bone; bundle bone
● Non Lamellar, random disposition of type I collagen fibers & 1st bone tissue to appear in an embryonic development & in fracture repair
● Usually temporary & replaced in adults by lamellar bone lower mineral content and a higher proportion of osteocytes than mature lamellar bone
● Location: Developing and growing bones; hard callus of bone fractures

A

WOVEN BONE

76
Q

● A.KA: MATURE BONE; secondary bone
● Has matrix existing as DISCRETE SHEETS
● Multiple layers (lamellae) of calcified matrix
● Alternating organization of collagen fibers in lamellae add greatly to strength
● Remodeled from woven bone
● Location: adults bone
● Canals communicate with one another through transverse perforating (Volkmann) canal

A

LAMELLAR BONE

77
Q

outer boundary of each osteon

A

CEMENT LINE

78
Q

numerous irregularly shaped of parallel
lamellae; scattered among intact osteons

A

Interstitial lamellae

79
Q

● Have cores of cancellous bone
surrounded by compact bone.
● Example: wrist and ankle

A

SHORT BONES

80
Q

● EPIPHYSIS
- Bulbous ends
- Composed of cancellous bone
(spongy) covered by a thin layer
of compact bone
● DIAPHYSIS
- Cylindrical part
- Body of long bone
- Almost totally dense compact
bone, with a thin region of
cancellous bone on the inner
surface around the central
marrow cavity
- Start of first bone formation
● MEDULLARY CAVITY: contains bone
marrow

A

LONG BONE

81
Q

● Have 2 layers of compact bones (plates),
separated by a thick layer of cancellous
bone (diploe)
● Example: calvaria (skullcap)

A

FLAT BONES

82
Q

BONE DEVELOPMENT/OSTEOGENESIS
● Osteoblast differentiate DIRECTLY
from mesenchyme & begin secreting osteoid
● Forms most flat bone (skull, jaws, scapula

A

INTRAMEMBRANOUS OSSIFICATION

83
Q

● Pre-existing matrix of hyaline cartilage is eroded & invaded by osteoblasts, which then begin osteoid production
● Forms most bones of the body

A

ENDOCHONDRAL OSSIFICATION

84
Q

GROWTH
- Increase the circumference of a
bone by osteoblast activity at the
periosteum & is accompanied by
enlargement of the medullary
marrow cavity

A

APPOSITIONAL BONE GROWTH

84
Q

A region of cartilage located at the epiphyses of long bones & is responsible for the increase in the bone length unit skeletal maturity

A

EPIPHYSEAL PLATE

85
Q
  • composed of typical hyaline cartilage
A

ZONE OF REVERSE (resting) cartilage

86
Q
  • Cartilage cells divide repeatedly,
    enlarge, & secrete more type II
    collagen & proteoglycans &
    become ORGANIZED INTO COLUMNS
A

PROLIFERATIVE ZONE: (cell division
of chondrocytes)

87
Q
  • most MATURE CHONDROCYTES in these lacunae SWELL UP, compress the matrix & undergo apoptosis
A

ZONE OF HYPERTROPHY: (increase in size of chondrocytes)

88
Q
  • Bone tissue first appears
  • osteoprogenitor cells differentiate into osteoblasts leading to bone tissue formation (ossification)
A

ZONE OF OSSIFICATION: (bone formalin takes place; cartilage replaced by bone)

89
Q

● Growth of bones occurs throughout life, with cells & matrix turning over
continuously through activities of
osteoblasts & osteoclast
- Very active in young children
(200x faster than that of adults)

A

BONE REMODELING AND REPAIR

90
Q

➢ By degrading bone, calcium will go back to blood
➢ Continuous process involving the
removal of old/damaged bone tissue &
formation of new bone tissue
➢ Bones change size & shape according to changes in mechanical stress
➢ Key cells: osteoclasts & osteoblasts
➢ OSTEOCLASTS - remove damage bone tissue
➢ OSTEOBLASTS - form/relapse new bone tissue

A

BONE REMODELING

91
Q

_________-disrupt blood vessels, causing
bone cells near the break to die

A

BONE FRACTURES

92
Q

The damaged blood vessels produce a localized hemorrhage or __________

A

hematoma

93
Q

bubble bone for repair

A

FIBROCARTILAGE

94
Q

bone removes tissue

A

RESORPTION

95
Q

_________required for the activity of many enzymes and many proteins mediating cell adhesion, cytoskeletal movements, exocytosis, membrane
permeability, and other cellular functions.

A

Calcium ions

96
Q

Skeleton serves as the ____________, containing 99% of the body’s total calcium in hydroxyapatite crystals

A

calcium reservoir

97
Q

The concentration of calcium in the blood ? and tissues is generally quite stable because of a continuous interchange between blood calcium and bone calcium

A

(9-10 mg/dL)

98
Q

The principal mechanism for raising blood calcium levels is the mobilization of ions from _____________ TO ____________, primarily in the cancellous bone.

A

hydroxyapatite to interstitial fluid

99
Q

Ca2+ mobilization is regulated mainly by
____________ among bone cells

A

paracrine interactions

100
Q

2 polypeptide hormones that target bone cells
to influence calcium homeostasis:

A

PTH & CALCITONIN

101
Q
  • From the parathyroid glands
  • RAISES LOW BLOOD CALCIUM LEVELS by stimulating/ activating osteoclasts and osteocytes to resorb/ regrade bone matrix and release Ca2+ in the blood
A

PARATHYROID HORMONE (PTH)

102
Q
  • Produced within the thyroid gland
  • REDUCE/DECREASE BLOOD CALCIUM LEVELS by opposing the effects of PTH in bone.
  • This hormone directly targets osteoclasts to slow matrix resorption and bone turnover
A

CALCITONIN

103
Q

● Cancer of the bone
● Arise in osteoprogenitor cell
● Sunburst appearance

A

OSTEOSARCOMA

104
Q

● Genetic disease characterized by dense heavy bone (“MARBLE BONES”)
● Osteoclast lacks raffled borders & bone resorption is lacking
● Mutation in genes for the osteoclasts’ proton-ATPase pumps/chloride channels
● Overgrowth & thickening of bones

A

OSTEOPETROSIS

105
Q

● Imbalance in skeletal turnover so that bone resorption exceeds bone formation
● Leads to Ca2+ loss from bones & reduce bone mineral density (BMR)
● Common: immobilized patients & in POSTMENOPAUSAL WOMEN

A. OSTEOPOROSIS
B. RICKETS
C. OSTEITIS FIBROSA CYSTICA
D. OSTEOPETROSIS

A

OSTEOPOROSIS

106
Q

● In children: primarily due to a DEFICIENCY OF VITAMIN D or problem with its absorption → mineralization of bone tissue is impaired → soft

A

RICKETS

107
Q

DEFICIENCY OF VITAMIN D in adults

A. OSTEOPOROSIS
B. OSTEOGENESIS IMPERFECTA
C. OSTEITIS FIBROSA CYSTICA
D. OSTEOMALACIA

A

OSTEOMALACIA

108
Q

● INCREASED OSTEOCLAST ACTIVITY results in removal of bone matrix and fibrous degeneration
● Severe & rare manifestation of hyperparathyroidism → increased PTH → increased bone resorption

A. OSTEOPOROSIS
B. OSTEOGENESIS IMPERFECTA
C. OSTEITIS FIBROSA CYSTICA
D. OSTEOMALACIA

A

OSTEITIS FIBROSA CYSTICA

109
Q

● A.K.A: “ Brittle bone disease”
● Group of related congenital disorders
● Osteoblasts produce deficient amount of type I
collagen/defective type I collagen due to genetic
mutations
● Significant fragility of the bones

A. OSTEOPOROSIS
B. OSTEOGENESIS IMPERFECTA
C. OSTEITIS FIBROSA CYSTICA
D. OSTEOMALACIA

A

OSTEOGENESIS IMPERFECTA

110
Q

● Lack of growth hormone during the growing years

A

PITUITARY DWARFISM

111
Q

● excess of growth hormone causes excessive growth of the long bones

A

GIGANTISM

112
Q

A disease in which the bones (long become very thick.

A

ACROMEGALY

113
Q

● chronic inflammation of the synovial membrane
● causes thickening of connective tissue and stimulates macrophages to release collagenases and other hydrolytic enzymes → . Destruction of articular cartilage

A. GOUTY ARTHRITIS
B. RHEUMATOID ARTHRITIS
C. OSTEOARTHRITIS

A
114
Q
  • high concentration of URIC ACID CRYSTAL in blood

A. GOUTY ARTHRITIS
B. RHEUMATOID ARTHRITIS
C. OSTEOARTHRITIS

A

GOUTY ARTHRITIS

115
Q

● Regions where adjacent bones are capped and held together firmly by other connective tissues.
● Places where bones meet, or articulate, allowing at least the potential for bending or movement in that portion of the skeleton.
● Classified as SYNARTHROSES (no movement) & DIARTHROSES (free mobile)

A

JOINTS

116
Q

● Allow very limited or no movement
● Subdivided into fibrous and cartilaginous joints, depending on the type of tissue joining the bones.

A

SYNARTHROSES JOINTS

117
Q

● Involve bones linked to other bones and allow essentially no movement.
● Older adults: unite the skull bones, which in children
● Young adults: held together by SUTURES, or thin layers of dense connective tissue with osteogenic cells.

A. SYMPHYSES
B. SYNOSTOSES
C. SYNDESMOSIS

A

SYNOSTOSES

118
Q

● Join bones by DENSE CONNECTIVE TISSUE ONLY
● Examples include the interosseous ligament of the
inferior tibiofibular joint and the posterior region of the sacroiliac joints

A. SYMPHYSES
B. SYNOSTOSES
C. SYNDESMOSIS

A

SYNDESMOSIS

119
Q
  • Have a THICK PAD OF FIBROCARTILAGE between the thin articular cartilage covering the ends of the bones.
    ● Such as the intervertebral discs and pubic symphysis, occur in the midline of the body.

A. SYMPHYSES
B. SYNOSTOSES
C. SYNDESMOSIS

A

SYMPHYSES

120
Q

● LARGE SYMPHASES between the articular surfaces of successive bony vertebral bodies.
● Held in place by ligaments
● Discoid components of the intervertebral joints cushion the bones and facilitate limited movements of the vertebral column

A. NUCLEUS PULPOSUS
B. INTERVERTEBRAL DISC
C. ANNULUS FIBROSUS

A

INTERVERTEBRAL DISC

121
Q

● Outer portion of each intervertebral disc
● Consisting of concentric fibrocartilage laminae in which collagen bundles are arranged orthogonally in adjacent layers.
● Multiple lamellae of fibrocartilage produce a disc with unusual toughness able to withstand pressures and torsion generated within the vertebral column.

A. NUCLEUS PULPOSUS
B. INTERVERTEBRAL DISC
C. ANNULUS FIBROSUS

A

ANNULUS FIBROSUS

122
Q

● Gel-like body, found in the center of annulus fibrosus
● In children: large, but these structures gradually become smaller with age and are partially replaced by fibrocartilage.
● Allows each disc to function as a shock absorber
● Consists of a viscous fluid matrix rich in hyaluronan and type II collagen fibers, but also contains scattered, vacuolated cells derived from the embryonic notochord, the only cells of that structure to persist postnatally

A. NUCLEUS PULPOSUS
B. INTERVERTEBRAL DISC
C. ANNULUS FIBROSUS

A

NUCLEUS PULPOSUS

123
Q

● PERMIT FREE BONE MOVEMENT
● Generally unite long bones and allow great mobility such as in the elbow and knee.
● In a diarthrosis ligaments and a capsule of dense connective tissue maintain proper alignment of bones.
- Capsule encloses a sealed joint cavity containing a synovial fluid (clear, viscous liquid)
- joint cavity is lined, not by epithelium, but by a synovial membrane

A

DIARTHROSES JOINTS

124
Q

● Specialized connective tissue
● Extends folds and villi into the joint cavity and produces the lubricant synovial fluid.
● May have prominent regions with dense connective tissue or fat.
● Superficial regions: - well vascularized, with many porous (fenestrated) capillaries.
- characterized by 2 specialized cells with distinctly different functions and origins

A

SYNOVIAL MEMBRANE

125
Q

2 SPECIALIZED CELL IN THE SUPERFICIAL REGION OF SYNOVIAL MEMBRANE
● Type A cells
● Derived from blood monocytes and remove wear-and-tear debris from the synovial fluid.
● Modified macrophages, which represent approximately 25% of the cells lining the synovium,
● Important in regulating inflammatory events within diarthrotic joints.

A

MACROPHAGE-LIKE SYNOVIAL CELLS

126
Q

2 SPECIALIZED CELL IN THE SUPERFICIAL REGION OF SYNOVIAL MEMBRANE
● Type B cells
● PRODUCE ABUNDANT HYALURONAN and smaller amounts of proteoglycans.
● Transported by water from the capillaries into the joint cavity to form the synovial fluid, which lubricates the joint, reducing friction on all internal surfaces, and supplies nutrients and oxygen to the articular cartilage.

A

FIBROBLASTIC SYNOVIAL CELLS

127
Q

● COLLAGEN LOSS or other degenerative changes in the annulus fibrosus are often accompanied by displacement of the nucleus pulposus

A

SLIPPED / HERNIATED DISC

HISTOLOGY (12 decks)

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